EXUBRIS NATURIS CARL &EM1L7 KING o- l! jj CD* D D D m a ! a Marine Biological Laboratory Library Woods Hole, Massachuselts Gift of Bostwiek K. Ketehum - 1976 PLATE I. y-r A MANUAL OF THE STUDY OF INSECTS BY JOHN HENRY COMSTOCK Professor of Entomology in Cornell University AND ANNA BOTSFORD COMSTOCK Member of the Society of American Wood- Engravers urteentb JE&ition ITHACA, N. Y. THE COMSTOCK PUBLISHING COMPANY 1916 Copyright, 1895, BY JOHN HENRY COMSTOCK. PREFACE. FOR many years the most pressing demand of teachers and learners in entomology in this country has been for a handbook by means of which the names and relative affini- ties of insects may be determined in some such way as plants are classified by the aid of the well-known manuals of botany. But, as the science of entomology is still in its infancy, the preparation of such a handbook has been im- possible. Excellent treatises on particular groups of insects have been published ; but no general work including analyt- ical keys to all the orders and families has appeared. It is to meet this need that this work has been prepared. The reader must not expect, however, to find that de- gree of completeness in this work which exists in the man- uals of flowering plants. The number of species of insects is so great that a work including adequate descriptions of all those occurring in our fauna would rival in size one of the larger encyclopaedias. It is obvious that such a work is not what is needed by the teachers and students in our schools, even if it were possible to prepare it. An elementary work on systematic entomology will always of necessity be re- stricted to a discussion of the characteristics of the orders and families, and descriptions of a few species as illustrations. Complete synopses of species will be appropriate only in works treating of limited groups. It is believed, therefore, that it would not be wise to materially change the scope of IV PREFACE. the present work even if it were possible to describe all of our species. Although much pains has been taken to render easy the classification of specimens, an effort has been made to give the mere determination of the names of insects a very sub- ordinate place. The groups of insects have been fully char- acterized, so that their relative affinities maybe learned; and much* space has been given to accounts of the habits and transformations of the forms described. As the needs of agricultural students have been kept constantly in view, those species that are of economic importance have been described as fully as practicable, and particular attention has been given to descriptions of the methods of destroying those that are noxious, or of preventing their ravages. An effort has been made to simplify the study of in- sects as much as possible without sacrificing accuracy in the descriptions. Only such morphological terms have been used as were necessary to accomplish the object of the book in a satisfactory manner. And so far as possible a uniform nomenclature has been used for all orders of insects. The fact that writers on each order of insects have a peculiar nomenclature has been a serious obstacle to the progress of entomology; this is especially true as regards the nomen- clature of the wing-veins. It has been necessary for the student in passing from the study of one order of insects to that of another to learn a new set of terms; and in many cases writers on a single family have a peculiar nomenclature. The present writer has endeavored to remove this obstacle by making a serious study of the homologies of the wing-veins, and by applying the same term throughout the work to homologous veins. The result is that the student is required to learn only one set of terms ; and in applying these terms there will be brought to his attention in a forci- ble manner the peculiar modifications of structure charac- teristic of each order of insects. Heretofore, with a differ- ent nomenclature for the wing-veins of each order such a PREFACE. V comparative study of the various methods of specialization has been beyond the reach of any but the most advanced scholars. The principal features of the method of notation of wing- veins proposed by Josef Redtenbacher has been adopted. But as the writer's views regarding the structure of the wings of primitive insects are very different from those of Redtenbacher, the nomenclature proposed in this book is to a great extent original. The chief point of difference arises from the belief by the present writer that veins IV and VI do not exist in the Lepidoptera, Diptera, and Hymenoptera ; and that, in those orders where they do exist, they are secondary developments. The reasons for this be- lief are set forth at length in my essay on Evolution and Taxonomy. In this essay there was proposed a new classification of the Lepidoptera, which was the result of an effort to work out the phylogeny of the divisions of this order. This classi- fication has been further elaborated in the present work. In the other orders but few changes have been made from the more generally accepted classifications. It is more than probable however, that when the taxonomic principles upon which this classification of the Lepidoptera is based are ap- plied to the classification of the other orders radical changes will be found to be necessary. A serious obstacle to the popularization of Natural His- tory is the technical names that it is necessary to use. In order to reduce this difficulty to a minimum the pronuncia- tion of all of the Latin terms used has been indicated, by dividing each into syllables and marking the accented syllable. In doing this the well-established rules for the division of Latin words into syllables have been followed. It seems necessary to state this fact in order to account for differences which exist between the pronunciations given here and some of those in certain large dictionaries recently published in this country. VI PREFACE. Nearly all of the wood-cuts have been engraved from nature by the Junior Author. As the skill which she has attained in this art has been acquired during the progress of the work on this book, some of the earlier-made illustra- tions do not fairly represent her present standing as an engraver. But it does not seem worth while to delay the appearance of the book in order to re-engrave these figures; especially as it is believed that they will not be found lack- ing in scientific accuracy. The generous appreciation which the best engravers have shown towards the greater part of the work leads us to hope that it will be welcomed as an important addition to entomological illustrations. Although the chief work of the Junior Author has been with the pencil and graver, many parts of the text are from her pen. But in justice to her it should be said that the plan of the book was changed after she had finished her writing. It was intended at first to make the book of a much more elementary nature than it is in its final form. It has seemed best, however, to leave these parts as written in order that the work may be of interest to a wider range of readers than it would be were it restricted to a uniform style of treatment. The figures illustrating the venation of the wings of in- sects have been drawn with great care under the writer's direction by Mr. E. P. Felt and Mr. R. H. Pettit. About one half of those in the chapter on Lepidoptera were drawn by Mr. Felt ; the others in this chapter and those in the chapters on Diptera and Hymenoptera were drawn by Mr. Pettit. I wish also to acknowledge the help of my Assistant Mr. A. D. MacGillivray, to whom I am indebted for much aid in bibliographical researches and in many other ways; also, that of Dr. A. C. White of the Cornell University Library, who has generously given much time to determining the etymologies of many of the more obscure words the pro- nunciations of which are indicated in the text. PREFACE. Vll To the authorities of Cornell University the authors of this book are under deep obligation for aid and encourage- ment. The preparation of the work would not have been possible but for the liberal grants which they have made for the purchase of specimens and books. JOHN HENRY COMSTOCK. ENTOMOLOGICAL LABORATORY, CORNELL UNIVERSITY, December, 1894. CONTENTS. CHAPTER PAGE I. Zoological Classification and Zoological Nomenclature... i II. Insects and their Near Relatives : Branch ARTHROPODA ; Class CRUSTACEA, Crabs, Lobsters, Cra\ fish, and Others; Class ARACHNIDA, Spiders, Scorpions, Mites, and Others; and Class MYRIAPODA, Centipedes and M illipedes 9 III. Class HEXAPODA or Insects: Characteristics of the Class; Metamorphoses of Insects ; External Anatomy of In- sects ; Internal Anatomy of Insects; Table for Deter- mining the Orders of Insects; List of the Orders of Insects 48 IV. Order THYSANURA, Bristle-tails, Spring-tails, Fish- moths, and Others. 82 V. Order EPHEMERIDA, May-flies 86 VI. Order ODONATA, Dragon-flies .... 89 VII. Order PLECOPTERA, Stone-flies 93 VIII. Order ISOPTERA, Termites or White-ants 95 IX. Order CoRRODENTIA, Book-lice and Others 98 X. Order MALLOPHAGA, Bird-lice 100 XI. Order DERMAPTERA Earwigs 102 XII. Order ORTHOPTERA, Cockroaches, Crickets, Grasshop- pers, Locusts, and Others 104 XIII. Order PHYSOPODA, Thrips 119 XIV. Order HEMIPTERA, Bugs, Plant-lice, Bark-lice, and Others 121 XV. Order NEUROPTERA, the Dobson and Others 175 XVI. Order MECAPTERA, Scorpion-flies 184 XVII. Order TRICHOPTERA. Caddice-flies 186 XVIII. Order LEPIDOPTERA, Moths, Skippers, and Butterflies.. 191 XIX. Order DIPTERA, Flies 4'3 XX. Order SIPHONAPTERA, Fleas 490 XXI. Order COLEOPTERA, Beetles 494 XXII. Order HYMENOPTERA Bees, Wasps, Ants, and Others.. 599 INDEX AND GLOSSARY 679 EXPLANATION OF PLATES PLATE I. (FRONTISPIECE.) PAGB FIGURE 1. The Carpet Beetle 539 2. The Twelve-spotted Diabrotica 577 3. The Adalia bipunctata 535 4. The Silver-spotted Skipper 370 5. The American Copper 39 6. The Red Admiral 401 7. The Painted Beauty 401 PLATE II. (PAGE 68 ) THE INTERNAL ANATOMY OF A CATERPILLAR. PLATE III. (PAGE 70.) THE INTERNAL ANATOMY OF A COCKROACH. PLATE IV. (PAGE 343-) PSEUDOHAZIS HERA. PLATE V. (PAGE 353.) FIGURE PAGE 1. The Luna Moth 353 2. The Crinkled Flannel-moth 218 PLATE VI. (PAGE 389.) 1. The Spring Azure 391 2. The Green Comma 44 3. The Hop-merchant. 45 4. The Banded Flfin 393 5. The Mourning-cloak 43 6. The Olive Hair-streak 393 7. The Spring Azure 39 1 8. The Violet Tip 45 xi A MANUAL FOR THE STUDY OF INSECTS. CHAPTER I. * ZOOLOGICAL CLASSIFICATION AND NOMENCLATURE. I. Zoological Classification. (For advanced students. ) IN order that the myriad forms of animals may be studied with facility some system of classification is necessary. And now that we have learned that there exists a blood-relationship between the differ- ent kinds of animals, that system which most clearly expresses this relationship is doubtless the best. This system is termed the Natural Classification. It is now generally believed that long ago, in early geological times, there existed on the earth only very simple animals and plants: and that from these simple beginnings more and more complex forms have been developed. This growth in complexity has taken place in different descendants of these simple primitive beings in very differ- ent ways. Thus while it is probable that the first animals lived in water, and very many still do so, others have become adapted to life on the land, and in still others organs have been developed by which they can fly through the air. And under each of these conditions we find a great diversity of norms, each fitted for some special mode ol Ufe. 3 2 THE STUDY OF INSECTS. The diversity of forms of animal life is much greater than is com monly supposed. A competent authority has estimated that there are now living on the earth more than one million species of animals. And these are merely the surviving descendants of immense series of beings that have existed in past geological times, the remaining tips of a great genealogical tree, of which many twigs and branches have perished. The common figurative use of the word tree in this connection expresses well the convergence of the lines of descent toward the common ancestor from which existing forms have descended. But in one respect it may be misleading. If an ordinary tree be ex- amined, the tip of one branch will closely resemble that of any other branch of the same tree. But in this figurative genealogical tree we must imagine a very different state of affairs. Here the law of growth is constant change; each branch grows in its own individual way: and each twig of each branch bears fruit peculiar to itself. The changes, however, are gradual ; and thus the tips of closely-con- n!-ct(d twigs will be similar though not identical; while the tips of two branches that separated early in the growth of the tree will be very different. It is the effort of the systematist, one who studies the classification of animals and plants, to work out the relations which exist between the various tips of the genealogical tree. This study when carried to its fullest extent includes not only the study of existing forms of life, but also the study of those that have perished, the trunk-forms from which existing forms have descended. This, however, is a very difficult matter; and as yet only the beginnings of the Natural Classification have been made. See pp. 199 to 204. If we accept this theory of descent, now almost universally ac- cepted by naturalists, it is evident that when we take into account ail the forms of life that have existed we cannot classify animals into well-marked groups; for as the modification in form is gradual, series of connecting links have existed between any two forms that might be selected. But practically the student that confines his attention to the study of living forms can classify these forms into more or less well- marked groups, for many of the connecting links have perished; in fact, the groups of living animals and plants are so distinct that it is only in recent years that naturalists have come to understand the blood-relationship referred to above. We find that the Animal and Vegetable Kingdoms ae made up oi a vast assemblage of individuals^ each the offspring cf parents similar ZOOLOGICAL CLASSIFICATION. % to itself, and each in turn producing similar offspring. Although the offspring is never exactly like either parent, the degree of variation in a single generation is slight. And thus we find that there exist large numbers of individuals which very closely resemble ^ach other. Such collection of individuals is termed in popular language a .IVd, in scientific language a species. Thus the kind of pine trees kn wn as pitch-pine is a species; and scrub-pine, still another. In the same way the name sparrow-hawk indicates a kind or species of hav/I*.; and pigeon-hawk, another species. Roughly speaking, a species is a collection of individuals which resemble each other as closely as the offspring of a single parent. For example, if any two pitch-pines be studied, nothing will be found to indicate that they may not have sprung from seeds grown upon the same tree. On the other hand, if a pitch-pine and d. white-pine be carefully compared, they will be found so different that no competent observer would believe that they had a common parent. Unfortunately this mode jf defining the limits of a species cannot be depended upon. Many instances are known where forms of animals or plants living in widely-separated regions differ so greatly that they have been considered distinct species until more extended collections in the intermediate regions have brought to light series of intermediate forms, which connect the two so-called species so closely that it is impossible to say where the one ends and the other begins. The only definite way of determining whether two forms are specifically distinct is to determine whether they naturally interbreed or not. We find among wild animals a sort of race prejudice which keeps the members of different species from pairing, although they may do so when demoralized by domestication. Except in the case of very-closely-allied species, the pairing of individuals of different species results in no. offspring or in the production of sterile offspring. This grouping of individuals into species not only facilitates our study of Natural History, but expresses certain important facts of inheritance and reproduction. A second and somewhat similar step is made by grouping species into genera. We find that there exist groups of closely-allied species, species that resemble each other in all of the more important characters, ana differ among themselves only in what are known as the specific characters. Such a group of species is termed a. genus. Thus all the different species of pine taken together constitute the genus pine, or Finns, as it is termed by botanists. There are many specie* oi oak, 4 THE STUDY OF INSECTS. as red-oak, live-oak, and water-oak. All of the species of oak taken together constitute the genus Quercus of botanists. Several species of hawks and falcons are classed together by zoologists as the genus Falco. The genera in turn are grouped into families. Thus the pines, the spruces, and the larches resemble each other quite closely, and are classed together as the Pine Family (Abietinece) ; the falcons, hawks, kites, and eagles are classed together as the Falcon Family (FalconidcE). Closely-allied families are grouped together to form orders. The Pine Family, the Cypress Family, and the Yew Family comprise the Order Conifera-, or cone-bearing plants, of botanists. The Owl Fam- ily (Strigidtz), the Falcon Family (Falconzdce),a.nA the Vulture Family (Vulturida) constitute the Order Raptorcs, or Birds of Prey. Closely-allied orders are grouped together to form classes. Thus all the orders of birds taken together constiiute the Class Aves or Birds. The classes are grouped into branches, which are the principal divisions of the Animal Kingdom.* In studying the different forms of animals it is found that there are several distinct types of structure. Some animals are built upon one plan or structure, and others on other plans. All animals built on the same plan are said to belong to the same Branch. Thus the back-boned animals comprise the Branch Vertebrata ; the clams, oysters, snails, cuttle fish, and certain other allied forms comprise the Branch Mollusca ; and the insects, spiders, centipedes, lobsters, and their near relatives comprise the Branch Arthropoda. All the branches of animals taken together constitute the Animal Kingdom. It is not possible to lay down rules by which these different groups of animals can be limited. For, as has been shown in our discussion of species, all have been connected in past time by intermediate forms t But notwithstanding this, each of the terms given above (Branch, Class, Order, Family, Genus, and Species) expresses a pretty definite conception, which the student will learn to comprehend by practice in classifying animals. But the sequence in rank of these groups should be learned at the outset. Beginning with the most compre- hensive it is as follows : * The principal divisions of the Vegetable Kingdom are not termed Branches ; hence we will not make further use of botanical illustrations in this connection. ZOOLOGICAL NOMENCLATURE. 5 Animal Kingdom. Branch or Subkingdom. Class. Order. Family. Genus. Species. Individual. It is sometime desirable to indicate other groups than those named above. Thus a family may be divided into subfamilies, or an order into suborders. And occasionally an even more minute division is made. Thus several closely-allied families may be grouped together as a superfamily, a group of lower rank than a suborder. The follow- ing table includes all the grades of groups now commonly employed : Kingdom. Branch or Subkingdom. Class. Subclass. Superorder. Order. Suborder. Superfamily. Family. Subfamily. Genus. Subgenus. Species. Subspecies. Variety. Individual. II. Zoological Nomenclature. (For advanced sfttdents.} At the beginning of his studies of Natural History the student is met with what is to him a new and strange set of names. These names are often long. In form they belong to a dead language, with which, in these days, even many educated people are unfamiliar. It. is not strange that we often hear complaint respecting the difficulty of this nomenclature. O THE STUDY OF INSECTS. A little study of the matter, however, is sufficient to show the necessity for scientific names. The common names of animals will not answer our purpose ; for the same name is often applied to widely different animals in different localities, while a single species of animal is known by totally different names indifferent sections of the country,, In order that information respecting animals may be recorded so that there need not be any doubt regarding the animal to which refer- ence is made, it is necessary that each species or group of species should have a distinct name by which it shall be known by naturalists in all parts of the world. Therefore, to each branch, class, order, family, genus, and species which has been described there has been given a special name, by which it is known, and which pertains to this group alone. As this nomenclature is used by all naturalists of whatever nation- ality, it is necessary that the names should be in a language which can be understood by all. As Latin was the language in which most scientific books were written at the time this nomenclature was estab- lished, that language was chosen as the universal language of science; and the rule has been adopted that all names of animals and plants shall be Latin, or Latin in form. The name of a species consists of two words the name of the genus to which the species belongs, followed by an adjective indicat- ing the particular species ; for in Latin an adjective follows the noun which it qualifies, instead of preceding it as in English. Thus the scientific name of the Pigeon- hawk is Falco columbarius; that of the S|> irrow-hawk is Falco sparvcrius ; and that of the Prairie-falcon is Falco mexicanus. In the case of many species we find well-marked subspecies or geographical races which it is desirable to distinguish by name. Thus the Pigeon-hawk occurs over the whole of North America. But we find that those that live in the northwest coast region extending from California to Sitka, constitute a distinct geographical race known as the Black Merlin. As the Black Merlin and the typical Pigeon-hawk intergrade, they constitute a single species, which is known as Falco columbarius. To the Black Merlin has been applied the subspecific nani.' sitckleyi. When, therefore, it is desired to refer to the Black Merlin as distinguished from the typical Pigeon-hawk the term Falco columbarius suckleyi is used. If reference is to be made to the typical Pigeon-hawk as distinguished from the Black Merlin, it is designated as Falco columbarius columbarius. In writing long names like those given above they are frequently ZOOLOGICAL NOMENCLATURE. / abbreviated if the context is such that the abbreviations will be read- ily understood. Thus the name of the Black Merlin may be written Falco c. sitckleyi or F. c. suckleyi. Subspecitic names are used by entomologists not only to distinguish geographical races, but also to distinguish the different forms of dimorphic and polymorphic species. A good illustration is afforded bv a certain species of Swallow-tail Butterfly common in the Atlantic States. This species exists under two distinct forms ; one of these is yellow marked with black, and has long been known as Jasoniades turnns ; the other is almost entirely black, and has been known as Jasoniades glaucus. At first it was supposed that these were different species ; but in recent years the two forms have been bred from eggs laid by the same female. It is thus evident that the two forms repre- sent a single species. And as the form glaucus was first described its name is given to the species, which is now known as Jasoniades glaucus. This name Jasoniades glaucus is used when reference is made to the species as a whole. But if one wishes to refer to the black form alone.it is distinguished as Jasoniades glaucus glaucus ; while the yellow form is distinguished as Jasoniades glaucus turnus. In the illustrations just given the dimorphism occurs in the same generation. But many instances are known where the dimorphism is seasonal. Thus in the case of certain insects which pass through two or more generations in the course of a year, the different generations, or some of them, differ markedly in form or coloring from the others. These differences in many cases are so great that the different genera- tions of the same species were believed to be distinct species till they were bred from each other. It is therefore often desirable to distin- guish these different forms by subspecific names. Thus iphiclides ajax is a species of Swallow-tail Butterfly which exists under three distinct seasonal forms: an early spring form, /. ajax marcellus ; a late spring form, 7. ajax telamonides ; and a summer form, /. ajax ajax. The name of a genus or of a subgenus is always a single word, and should be a noun in the singular number and nominative case. The names of all groups of genera (i.e., families, orders, classes, and branches) consist each of a single word ; and this word should be a plural noun in the nominative case. The following practices regarding the forms of zoological names are now almost universally followed : The names of all groups in zoology, from kingdom to subgenus inclusive, are written and printed with a capital initial letter. 8 THE STUDY OF INSECTS. Specific and subspecific names are written and printed with a small initial letter. Thus in writing the name of a species the generic name is capitalized, the specific name not ; e.g., Jphiclides ajax. The names of families end in idee ; the names of subfamilies, in ince. It will aid the student greatly in the pronunciation of family and subfamily names to know that the /of -idee in family names is short, and consequently the accent falls on the syllable preceding this letter ; while the / of -z'nce of subfamily names is long, and is conse- quently accented.* Numerous examples are given in the following Pages. * This in accordance with the rule of Latin grammar that in words of more than two syllables the penult if long is accented; but if the penult is short the accent falls on the antepenulu CHAPTER II. INSECTS AND THEIR NEAR RELATIVES. Branch ARTHROPODA (Ar-throp'o-da). The Arthropods (Ar'tJiro-pods). If an insect, a spider, a scorpion, a centipede, or a lobster be examined, the body will W found to be composed of a series of more or less similar riiigs or seg- ments joined together; ai.d some of these segments will be fcund to bear jointed legs (Fig. i). All the animals possessing these characteristics are classed together as the Branch Artliropoda. A similar segmented form of the body is found among \vorms; but these are dis- tinguished from the Arthropods by the absence of legs. It -hould be remembered that many animals commonly called worms, as the tomato-worm, apple-worm, etc., are not true worms, but are the larvae of in- sects (Fig. 2). The angle-worm is the most familiar example of a true worm. The Branch Arthropoda is the largest of the branches of the Animal Kingdom, including many more known species than ail the other branches taken together. Our common representatives are distributed among four classes : these are the Crustacea, the Arachnida, the Myriapoda, and the Hexapoda. The 9 FIG. i. An insect show- ing segmented form of body. IO THE STUDY OF INSECTS. first three classes are briefly discussed in this chapter ; the fourth comprises the Insects, and is the subject of the remaining parts of this book. FIG. 2. A larva of an insect. The following table will enable the student to distin- guish the classes of the Arthropoda.* TABLE OF CLASSES OF THE ARTHROPODA. A. With two pairs of antennae and at least five pairs of legs. Aquatic animals breathing by gills, p. 11 .CRUSTACEA. AA. With one pair of antennae or with none. Air-breathing ani- mals. The number of legs varies from six to many. *The following is the method of using the analytical tables given in this book: Read carefully the statement of characteristics given opposite A and AA respectively, and by examining the animal to be classified determine which is true of this animal. This will indicate in which division of the table the name of the group to which the animal belongs is to be looked for. If this division of the table is subdivided, pass to B and BB (also to BBB if it occurs) in this division and determine in a like manner under which the animal belongs. Continue in this way, passing to the letters C, D, E, etc., in regular order till the name of the group is reached. Then turn to the page indicated and read the description or the group given there, comparing the specimens with the description. It should be borne in mind that an analyt- ical table is merely an aid to the determination of groups. As the groups that we recognize are not always sharply limited in nature, we cannot expect to be able in every case to find characters that will serve to distinctly separate them in a table. Therefore when a student has determined by the aid ot a key to what group a species seems to belong, he should verify this determi- nation by a study of the characters of that group given in the detailed dis- cussion of it. INSECTS AND THEIR NEAR RELATIVES. II B. Without antennae and with four pairs of legs, although the maxillary palpi are often leg-like in form, making the animal appear to have five pairs of legs. p. 12 ARACHNIDA. BB. With antennae. C. With more than three pairs of legs; and without wings, p. 45 MYRIAPODA. CC. With only three pairs of legs, and usually with wings in the adult state, p.48 HEXAPODA, Class CRUSTACEA (Crus-ta'ce-a). The Crustaceans (Crus-ta' ce-ans). The members of this class are aquatic Arthropoda, which breathe by true gills. They have two pairs of ant entice and at least five pairs of legs. The most familiar illustrations of the Crustacea are Cray-fishes, the Lobsters, the Shrimps, and the Crabs. Cray-fishes (Fig. 3) abound in our brooks, and are often improperly called Crabs. The Lobsters, the Shrimps, and the true ^ Crabs live in salt water. The Crustaceans are distinguished from all oth- er Arthropods by their mode of respiration, being the only ones that breathe by true gills. Many in- sects live in water, and are furnished with gill-like FIG. 3 A Cray-fish. organs ; but these are tracheal gills, organs which differ essentially in structure from true gills, as described later, in the chapter on Anat- omy of Insects. The Crustacea also differ from other Arthropoda in having two pairs of antennae; and from all 12 THE STUDY OF INSECTS. except the Myriapoda in having many (more than four) pairs of legs. The illustrations named above are the more conspicuous members of the class ; but many other smaller forms abound both in the sea and in fresh water. Some of the more minute fresh-water forms are almost sure to occur in any fresh- FIG. 4. Crustacea : a. Cypris: t, Cyclops; c, Daphnia. water aquarium. In rigure 4 are represented three of these, greatly enlarged. Among the Crustacea that live in damp places on land the Sow-bugs, Oniscidce (O-nis'ci-dae), are most often- seen. These frequently occur about water-soaked wood; and are often mistaken, by students begin- ning the study of Entomology, for insects or Myria- pods. Figure 5 represents a Sow-bug. On the sea-coast an immense number of forms of Crustacea occur. Class ARACHNIDA (A-rach'ni-da). Scorpions, Harvestmen, Spiders, Mites, and others. The members of this class are air-breathing Arthropods, in which the head and thorax are grown together, forming a cephalothorax, which have four pairs of legs fitted for ivalk- ing, and which have no feeler-like antenna. The Arachnida abound wherever insects occur, and are often mistaken for insects. But they can be easily distin- guished by the characters given above, even in those cases where an exception occurs to some one of them. The more important of the exceptions are the following : In the Sol- pugida the head is distinct from the thorax ; as a rule the young of mites have only six legs, but a fourth pair are added during growth ; and in the gall mites (Phytoptus) there are only four legs. In the Arachnida we find only simple eyes. The cephalothorax (ceph-a-lo-tho'rax) bears six pairs of INSECTS AND THEIR NEAR RELA TIVES. FIG. 6. Lower side of cephalothorax of a spider : md, man- dible; w.r, maxilla; /, palpus ; I, lower lip ; j, sternum. appendages two pairs of jaws, and four pairs of legs. The first pair of jaws are the mandibles (man'di-bles), the second, the maxilla (max-il'lse). The mandibles (Fig. 6, md) lie in front of and above the mouth, and consist each of two or three segments. They serve for seizing prey, and often also for killing it. In many books they are termed the chelicerce (che-lic'e-rae). The maxilla (Fig. 6, nix) lie just behind the mandibles, one on each side of the mouth. Each maxilla bears a large feeler or palpus (Fig. 6, /). These palpi vary greatly in form ; frequently they resemble legs; hence many Arachnida appear to have five pairs of legs. The palpi are often so largely developed that each maxilla ap- pears to be merely the first segment of its leg-like palpus. These appendages are often called the pedipalpi (ped-i-pal'pi). But as the name Pedipalpi is applied to one of the or- ders of the Arachnida, we will call these ap- pendages the palpi. The legs of Arachnida consist typically of seven parts (Fig. 7), which are named, begin- ning with the one next to the body, as fol- lows : i, coxa (cox'a) ; 2, trocJianter (tro-chan'- ter) ; ^ femur (fe'mur); 4, patella (pa-tel'la); 5, tibia (tib'i-a) ; 6, metatarsus (met-a-tar'sus) ; and 7, tarsus (tar'sus). The tarsus may be composed of several segments, and is usually furnished with claws. Two forms of breathing organs are found in this class : one, tracheae, resembling the tracheae of insects, described in the chapter on the anatomy of insects ; and the other, tracheal lungs or lung sacs, which consist of many leaf-like plates enclosed in a sac. Both forms open by paired spira- cles, which are usually situated on the lower side of some of the abdominal segments. FIG. 7. Leg: of a spider. 14 'THR STUDY OF INSECTS. Very great differences exist in the several orders of the Arachnida in respect to the division of the body into seg- ments. In arranging the orders in a series, we place first those in which the segments of the body are most distinctly indicated, while those which seem to depart more widely from the segmented type characteristic of the Arthropoda are placed later. The class Arachnida includes seven orders ; these are designated as follows : The Scorpions, Order SCORPIONIDA (p. 15). The Jointed Spiders, Order SOLPUGIDA (p. 16). The Pseudoscorpions, Order PSEUDOSCORPIONES (p. 17). The Whip-scorpions, Order PEDIPALPI (p. 17). The Harvestmen, Order PHALANGIDEA(p. 19). The Spiders, Order ARANEIDA (p. 20). The Mites, Order ACARINA (p. 42). TABLE OF THE ORDERS OF THE ARACHNIDA. A. Abdomen distinctly segmented. B. Abdomen with a tail-like prolongation. C. Tail stout and armed with a sting at the end ; first pair of legs /iot greatly elongated ; a pair of comb-like appendages on the lower side of the second abdominal segment in the adult. (Scorpions.} p. 15 SCORPIONIDA. CC. Tail slender, whip-lash like, without sting; first pair of legs much longer than the others ; without comb-like appendages on abdomen. (Whip-scorpions^) (Thelyphonidce.) p. 17. PEDIPALPI. BB. Abdomen without a tail-like prolongation. C. Palpi with pincer-like claws. (Pseudoscorpions.') p. 17. PSEUDOSCORPIONES. CC. Palpi without pincer-like claws. D. Abdomen joined to the thorax by a slender stalk; front legs greatly elongated and with whip-lash-like tarsi. (Whip- scorpions.') (P/irym'dce.) p. 17 PEDIPALPI. DD. Abdomen broadly joined to the thorax. E. Legs usually very long and slender; thorax not dis- tinctly divided into three segments. (Harvestmen!) p. 19. PHALANGIDEA. EE. Legs moderately long; head distinct from thorax ; thorax distinctly divided into three segments, p. 16. SoLPUGIPA- INSECTS AND THEIR NEAR RELATIVES. 15 AA. Abdomen unsegmented. B. Abdomen joined to the cephalothorax bya short, narrow stalk. (Spiders.) p. 20 ARANEIDA. EB. Abdomen fused with the cephalothorax. (Mites.) p. 42. ACARINA. Order SCORPIONIDA (Scor-pi-on'i-da). The Scorpions. With the scorpions (Fig. 8), the body is divided into a compact, unsegmented cephalothorax, and a long, segmented abdomen. The abdomen is divided into two portions : a broad pre-abdo- men, consisting of seven segments ; and a slenderer tail-like division, the post-abdomen, consisting of five seg- ments. At the end of the post-abdo- men there is a large poison-sting, which appears like a segment. The mandibles and the palpi are provided with j.incers. As the palpi are very large, with stout pincers, they resem- ble in a striking manner the great claws of lobsters. The cephalothorax bears from three to six pairs of eyes. Scor- pions breathe by means of lung sacs, of which there are four pairs, opening on the lower side of the third to the sixth abdominal segments. Full-grown scorpions possess a pair ot comb-like organs on the lower side of the second abdominal segment. The function of these organs is not yet known. The sexes of scorpions differ in that the male has broader pincers and a longer post-abdomen. Scorpions do not lay eggs, the young being developed within the mother. After the birth of the young, the mother apparently shows great regard for them, carrying them about with her for FIG. 8. A Scorpion. i6 THE STUDY OF INSECTS. some time, attached by their pincers to all portions of her body. Scorpions live in warm countries. They are common in the southern portion of the United States, but are not found in the North. They are nocturnal, remaining concealed dur- ing the day, but leaving their hiding-places at dusk. When they run the post-abdomen is bent upwards over the back. They feed upon spiders and large insects, which they seize with the large pincers of their palpi, and sting to death with their caudal poison sting. The sting of a scorpion rarely if ever proves fatal to man, although the larger species, which occur in the Tropics, pro- duce serious wounds. Nearly twenty species are known from North America. Order SOLPUGIDA (Sol-pu'gi-da). The Jointed Spiders. The members of this order differ from all other Arach- nida in having the head separate from the thorax, and in having the thorax composed of three distinct segments, as with insects. The mandibles are very large, and are furnished with strong pincers. The palpi are shaped like the legs, and are said to be used in locomotion. The first of the four pairs of true legs, like the palpi, are not furnished with claws, and are used as palpi. There are only two eyes. Respi- ration is effected by means of trachese, which open through three FJG. o. A Jointed-spider, Datames ... . , . ,1 diiatata. (After Putnam.) pairs of spiracles, situated in the first thoracic and the second and third abdominal segments. Only a few species of Solpugida occur in the United States, and specimens of these are rarely found. So far INSECTS AND THEIR NEAR KKLATIVES. IJ as is known, our species are nocturnal, remaining con- cealed during the day. They prey upon small insects, and are believed to be harmless. Figure 9 will serve to show the appearance of these curious animals. The popular name, jointed-spiders, is suggested by the segmented con- dition of the abdomen. Order PSEUDOSCORPIONES (Pseu-do-scor-pi'o-nes.) The Pseudoscorpions. The pseudoscorpions (Fig. 10) are small Arachnida, which resemble scorpions in the form of their body, except that the hinder part of the abdomen is not nar- row, as is the post-abdomen of scorpions, and they have no caudal poison-sting. The abdo- men is broad, flat, and composed of eleven segments, or in some cases of only ten. The pseudoscorpions possess only one or two pairs of eyes, and in some, eyes are want- , - . FIG. io. A Pseu- ing. 1 hey breathe by means or tracheae, doscorpion. which open through two pairs of spiracles on the lower side of the second and third abdominal segments. These little scorpion-like creatures live under stones, be- neath the bark of trees, in moss, and in the dwellings of man, between the leaves of books, etc. They run rapidly, side- wise and backwards ; and feed on mites and small insects. They are often found attached to insects, especially to flies; but they probably do not feed on these large insects, but merely use them as means of rapid locomotion. The pseudoscorpions occur in the Northern States as well in the South. Order PEDIPALPI (Ped-i-pal'pi). The Whip-scorpions. These strange creatures are found only in the extreme iouthern part of our country, being tropical animals. In THE STUDY OF INSECTS. their general form they have some resemblance to scor- pions. They can be easily distinguished by the form of the front legs, which are greatly elongated, and have the tarsi broken up into many small segments; this gives these legs a more or less whip-lash-like appearance. In one family the abdomen also bears a whip-lash-like appendage. The mandibles are furnished with claws; the palpi are very large and armed with strong spines, and the abdomen is distinctly separated from the thorax. The order includes two families, both of which are represented in the United States. Family THELYPHONID^E (Thel-y-phon'i-dae). The Tail Whip-scorpions. This family is represented in the United States by only a single species, the Giant Whip- scorpion, Thelyphonus gigantens (The-lyph'o-nus gi-gan te'us). This species measures when full grown from four to five inches in length. Figure 4 1 1 represents one less than natural size. These whip-scorpions are great- ly feared on account of their supposed venomous powers, but it is prob- able that there is no foundation for this fear. Although it has been stated often that their bites are poisonous, we FIG. \\.-Tkeiypkonus giganteus. can find no direct evi- INSECTS AND THEIR NEAR RELATIVES. IQ dence that it is so. They destroy their prey by crushing it with their palpi. Family PHRYNID^; (Phryn'i-dae). The Tailless Whip-scorpions. This family is represented in our fauna by the genus Phrymis (Phry'nus), the members of which are smaller than the Giant Whip-scorpion. In this family the front legs are even more whip-lash-like than in the preceding family ; the whole body is relatively shorter and broader; the abdomen is joined to the thorax by a slender stalk, and the tail-like appendage is lacking. Order PHALANGIDEA (Phal-an-gid'e-a). TJie Harvestmen, or Daddy Long Legs. The Harvestmen are very common in most parts of the United States. They are well known to children in this country under the name Daddy Long Legs, but as this name is also sometimes applied to Crane-flies, Harvestmen is preferable. In some sections of the country the Har- vestmen are known as Grandfather Graybeards. Most Harvestmen can be recognized by their very long and slender legs (Fig. 12), although some species have FIG. 12. The Striped Harvestman. comparatively short ones. The cephalothorax is indistinctly if at all segmented. The abdomen is short, broad, consists 2O THE STUD Y OF INSECTS. of six segments, and is without a tail-like appendage ; it is broadly joined to the cephalothorax. The eyes of the Harvestmen are two in number, and are situated on a prominent tubercle near the middle of the cephalothorax. The mandibles are pincer-like. The maxillae are large, and so opposed as to act as jaws; their palpi are four-jointed, and are small compared with the palpi of the preceding orders; they resemble in form and func- tion the palpi of insects. The members of this order breathe by tracheae, which open by a single pair of spir- acles, on the lower side of the body at the junction of the cephalothorax and abdomen. The Harvestmen feed on small insects, especially Aphids, and are perfectly harmless. They are said to devour their prey, chewing it with their maxillae, and swallowing it, instead of merely sucking out the blood, as do most other Arachnida. Although the Harvestmen have stilt-like legs, they do not raise the body much above the ground when they walk, but carry it quite near their feet, with the middle part of their legs high in the air. They are said to pounce upon their prey as does a cat upon a mouse, and seize it with their palpi as if with hands. It is a common practice with children to catch these creatures and say to them, " Grandfather Graybeard, tell me where the cows are, or I'll kill you." As the poor frightened animal points its legs in all directions in its frantic efforts to escape, it usually earns its freedom ; but too often it is not without the loss of one or more legs. Order ARANEIDA (Ar-a-ne'i-da). The Spiders. The Spiders differ from other Arachnida in having the abdomen unsegmented and joined to the cephalothorax by a short, narrow stalk. The cephalothorax is also un- INSECTS AND THEIR NEAR RELA TIVES. 21 segmented ; and the abdomen bears at its end organs for spinning silk (Fig. 13). FIG. 13. Ftncetia viridans. (From the Author's Report on Cotton Insects.) The mandibles (Fig. 14, md) consist of two segments, a strong basal one and a claw-shaped terminal one, at the tip of which a poison gland opens (Fig. 15). It is by means of these organs that spiders kill their prey. The palpi are leg- like in form, but differ greatly according to sex. In the female the last segment of the palpus resembles a foot of the spider, and is usually armed with a well-developed curved claw. But in the male the corre- sponding segment is more or less enlarged, and very complicated in structure (Fig. 16). FI O G / The greater number of spiders have four pairs of eyes (Fig. 17), but there may be fj p; p ^ sternum.' 01 FIG. 15. Tip of claw of FIG. 16. Maxilla and FIG. 17. Head of spider, mandible of spider. palpus of male house- showing eyes and mandi- spider. bles. 22 THE STUDY OF INSECTS. only one, two, or three pairs ; and certain cave spiders are blind. Spiders breathe by means of lung-sacs, of which there are one or two pairs ; and some have tracheae also. The lung-sacs open on the lower side of the abdomen near its base, and between them is the opening of the reproductive organs. The tracheae open through a single spiracle near the hind end of the body, just in front of the spinning organs. The spinning organs, which are situated near the end of the abdomen, consist of two or three pairs of spinnerets. These appendages (Fig. 18) are more or less finger-like in form, and some- times jointed. Upon the end of each spinneret there are many small tubes, the spinning tubes, from which the silk F,,.. ,8 -End of abdomen of >S spun (Fig. 19). Some spiders have as many as one hundred and fifty or two hundred of these spinning-tubes on each spinneret. The silk is in a fluid state while it is within the body, but it hardens as soon as it comes in contact with the air. In addition to the many small spinning tubes, there are a few larger ones, termed spigots. The ordinary thread is spun from two or four of these. The small spinning tubes are used in making attachment disks for fast- ening threads in place, in making a swathing band for enveloping prey, and, sometimes, in making a broad, wavy band across the center of a web. We have observed a spider seize a large grasshopper which was entangled in its web, and, rolling it over enlar ^ ed - two or three times, completely envelop it in a sheet of silk spun from its spread-apart spinnerets. In the construction of their web some spiders make use of two kinds of silk. One of these is dry and inelastic ; the other, viscid and elastic. This fact can be easily seen by examining an orb-web. If the spiral line which forms INSECTS AND THEIR NEAR RELATIVES. 2$ the greater part of the web be touched, it will adhere to the finger, and will stretch, when the finger is withdrawn, to several times the original length. But if one of the radiat- ing lines or a portion of the outer framework be touched, it will neither adhere to the finger nor be stretched. If the spiral line be examined with a lens, it will be found to bear numerous bead like masses of viscid matter (Fig. 20); this explains its adhesiveness. It is supposed that the two kinds of silk are spun from different spinnerets, and that the viscid silk comes from the front pair. When this silk is first spun the viscid matter forms a continuous layer of liquid on the outside of it. But very soon this layer breaks up into the bead-like masses in a way similar to that in which the moisture on a clothes-line in a foggy day collects into drops. Spiders of the two families Dictynidce and Uloboridce have spinning organs differing from those of all other FIG. 20. Viscid silk FIG. 21. Spinnerets of FIG. 22. Last two segments from an orbweb. a Dictvuid spider. of hind leer of spider, show- The middle pair of ing calanrstrum. spinnerets are con- cealed by the first pair, c, cribellum. spiders. They have i;i front of the usual spinnerets an additional organ, which is named the cribellum (cri-bel'lum) (Fig. 21). This bears spinning-tubes like the other spinner- ets, but these tubes are much finer. These spiders have also on the metatarsus of the hind legs one or two rows of curved spines : this organ is the calamistrum (cal-a-mis'trum) (Fig. 22). By means of the calamistrum these spiders comb from the cribellum a band of loose threads, which forms a part of their webs. THE STUD Y OF INSECTS. Spiders make use of silk in the construction of their webs or snares, in the building of tubes or tents within which they live, in the formation of egg-sacs, and in loco- motion. Fig. 23 represents the large egg-sac of one of the orb- weavers. This is made in the autumn, and contains at that season a large number of eggs five hun- dred or more. These eggs hatch early in the winter; but no spiders emerge from the egg-sac until the following spring. If egg-sacs of this kind be opened at differ- ent times during the winter, as was done by Dr. Wilder, the spiders will be found to increase in size but diminish in num- ber as the season advances. In fact, a strange tragedy goes on within these egg-sacs: the stronger spiders calmly devour their weaker brothers, and in FIG. 23 ._Egg-sac of the spring those which survive emerge (vKm' wiide'ro*'" sufficiently nourished to fight their bat- tles in the outside world. The egg-sacs of the different species of spiders vary FIG. 24. Egg-sac of Nepkila plumfjes (From Wilder.) greatly in form. In some, as in that figured above, the outer covering is very dense, while in others the outer part con- INSECTS AND THEIR NEAR RELATIVES. 25 sists of loose flossy silk (Fig. 24). One of the most common kinds is very flat, silvery in color, and is firmly attached to stones lying upon the ground (Fig 25) Every on" knows that a spider wishing to descend to some place beneath it simply fastens a line to the object which it is upon and then drops boldly off, regulat- FlG 25 ._ EK? . sac o a ing the rate of its descent by spinning the line rapidly or slowly ; when the spider wishes to return, it has only to climb up the same line. Frequently spiders pass from point to point in a hori- zontal direction by means of silken bridges. These are formed in this way : The spider spins out a thread, which is carried off by a current in the air. After a time the thread strikes some object and adheres to it ; then the spider pulls the lin? tight, and fastens it where it is standing. It then has a bridge, along which it can easily run. But more remarkable than either of these uses of silk for locomotion is the fact that many spiders are able to travel long distances, hundreds of miles, through the air by means of these silken threads "sailing mid the golden air In skiffs of yielding gossamere." (Hogg.) The Aeronautic Spiders, or Flying Spiders, as they are more commonly called, are frequently very abundant, espe- cially in warm autumn days. At such times innumerable threads can be seen streaming from fences, from bushes, and the tips of stalks of grass, or floating through the air. The flying spider climbs to some elevated point, which may be merely the tip of a stalk of grass, and then, standing on the tips of its feet, lifts its body as high as it can, and spins out a thread of silk. This thread is carried up and away by a current of air. When the thread is long enough the force of the air current on it is sufficient to buoy the spider up. It 2(3 THE STUDY OF INSECTS. then lets go its hold with its feet and sails away. That these spiders travel long distances in this manner has been shown by the fact that they have been seen floating through the air at sea far from land. Representatives of nearly thirty families of spiders have been found in the United States. But some of these fami- lies include only rare species, and others are represented by so few species that we cannot discuss them here. The greater number of our spiders belong to the eleven families described below. The following table will aid the student in separating these families. TABLE FOR SEPARATING THE PRINCIPAL FAMILIES OF SPIDERS. A. Claw of the mandibles moving vertically ; four lung-slits present. ( Tarantulas) p. 27 THERAPHOSID.E. AA. Claw of the mandibles moving horizontally; only two lung-slits present, but with a single spiracle or a pair of spiracles also. B. Eyes equal or nearly equal in size, and usually arranged in twc rows. C. Feet furnished with two claws (Fig. 28). Spiders which do not spin webs for catching prey. D. Second pair of legs not so long as the fourth pair. E. Maxillae with a concavity or furrow (Fig. 29). Spiders which live on the ground, p. 29 DRASSID/E. EE. Maxillae convex (Fig. 32). Spiders which live chiefly in silken tubes on bushes, p. 30 CLUBIONID^E. DD. Second pair of legs as long as or longer than the fourth pair. ( The crab-spiders.} p. 40 THOMISID^E. CC. Feet furnished with three claws (Fig. 38). Spiders which spin webs for catching prey. D. The caudal pair of spinnerets very long, and two- jointed. Spiders which make irregular webs with a tube or hiding- place at one side, from which they run on the upper surface of the web, to catch their prey. p. 30. ., AGALENID.lus, first stage. (After Emerton.) FIG. 58. Nympli of Melnnof>lus, second stage. (After Emerton.) FIG. 59. Nymph of Melanof>lus^ third stage. (After Emerton.) FiG. 60. Nymph of Hfelatwf>lus, fourth stage. (After Emerton.) FIG. 61 Nymph of Melanoplus^ fifth stage. (After Emerton.) FIG. 62. Melanoplus, adult. in size from time to time till the adult state is reached (Figs. 57 to 62). During this development there is no point at which the insect passes into a quiescent state corresponding to the chrysalis state of a butterfly. Those insects which, like the locust, when they emerge from the egg resemble in form the adult, but still undergo some change, are said to un- dergo an incomplete metamorphosis. In other words, after leaving the egg they do not undergo a complete change of form. Complete Metamorphosis. Still other insects, like the but- THE STUDY OF INSECTS, terf.ies, beetles, bees, and flies, leave the egg in an entirely different form from that which they assume when they reach maturity. A butterfly begins its active life as a caterpillar. It feeds and grows, and when full grown changes to a chrys- salis. In this stage it has very little resemblance to a cater- pillar. After a time there bursts forth from the chrysalis shell the butterfly, which looks very little like the chrysalis, and still less like the caterpillar from which it came. In a similar way, from the egg laid by a fly upon a piece of meat there hatches, not a fly, but a footless, worm-like maggot. This when fully grown changes to a quiescent object corre- sponding to the chrysalis of a butterfly. Later from this ob- ject there escapes a winged fly like that which laid the egg. Those insects, like the butterflies and flesh-flies, which when they emerge from the egg bear almost no resemblance in form to the adult insect, are said to undergo a complete met- amorphosis. In other words, the change of form undergone by the insect is a complete one. How Insects groiv Molting. The skin of an insect is hard- ened more or less by a horny substance known as cliitine (chi'tine). This hardening usually occurs to a much greater extent in adult insects than it does in the young. But in all the skin becomes so firm that it cannot stretch enough to allow for the growth of the insect. The result is, that from time to time an in- sect's skin becomes too small for it, and must be shed. But before this is done a new skin is formed beneath the old one; then the old skin bursts open, and the insect crawls forth, clothed in a soft skin, which stretches to accommodate the increased size of the animal. Very soon, however, this new skin becomes hardened with chitine, and after a time FIG. 62rt. Exuviae of nymph of Dragon-fly, it in turn must be shed. This shedding of the skin is termed molting, and the cast skin is some- HEXAPODA. 53 times referred to as the exuvice (ex-u'vi-ae). Insects differ greatly as to the number of times they molt : many species molt only four or five times, while others are known to molt more than twenty times. Figure 62a represents the cast skin of a Dragon-fly clinging to a reed. The Egg. This is the first stage in the existence of any insect, although in some few instances the egg remains in the body of the mother till it hatches. But almost always the eggs are laid by the mother insect on or near the food which gives nourishment to the young. Many of the most interesting habits of insects are connected with the care of the eggs by the parent. The eggs may have smooth oval shells ; but often the shells are beautifully ribbed FIG. 6 3 . Egg- of Cotton-worm, greatly enlarged. (From the Author's Report and pitted (rig. 03), and some- on Cotton insects.) times they are ornamented with spines, and are frequently exquisitely colored. The Larva. This is the second stage of an insect's life, and is the form that hatches from the egg. Familiar exam- ples of larvae are caterpillars, maggots, and grubs (Fig. 64). FIG. 64. A caterpillar, the larva of a moth. In fact, nearly all the creatures commonly known as worms are larvae of insects. Away from the ocean we find but few worms, except earthworms, leeches, " hair-snakes," and worm parasites in the intestines of men and animals. Nearly all the rest, except millipedes and centipedes, are larvae of insects, and finally change to forme with wings, 54 THE STUDY OF INSECTS. The larval stage is devoted to growth; the sole business of a larva being to eat and grow. All molting, because of in- creased size, is done in the larval stage, later molts are simply for change of shape. The Pupa. This is the third stage in the life of an in- sect, and is ordinarily a period of inaction, except that rapid and wonderful changes go on within the body. Very few pupae, like those of mosquitoes, are active. Usually pupae have no power of moving around, but many of them can squirm when disturbed. When the last skin of the larva is thrown off the pupa is re- vealed ; it is an oblong object, F,G. 6 5 .-A pupa of a large moth. and frequently apparently headless and footless. In many pupae the skin is a shiny covering like porcelain. If a pupa be examined closely the antennae and legs and wings may be seen ; these are folded up closely and soldered to the breast in the case of tne moths and butterflies (Fig. 65), but free in case of the bees, ants, and beetles. The Chrysalis. This term is often applied to the pupa of a butterfly. The word is derived from a Greek word mean- ing gold, and came into use because of the golden dots and markings on many of the butterfly pupae. The Cocoon.- Many larvae, especially those of moths, when full grown, spin about the body a silken case, so that when they change to helpless pupae they may be protected from enemies, and from rain and snow; these silken cases are called cocoons They are frequently made within a rolled leaves (Fig. 66). or beneath grass and rubbish on the ground, or in cells below the ground. Some hairy caterpil- lars make cocoons largely of their own hairs, which they fasten together with a film of silk. The Nyir.phs The terms larva and pupa are only ap. plied to the early stages of those insects that have a com- HEX A POD A. 55 plete metamorphosis; for in the case of other insects there is no distinct pupa stage. When reference is made to the young of an insect that undergoes an incomplete metamor- FIG. 66. A large cocoon within a rolled leaf. phosis it is called a nyjnph. This term is applied to all stages of such an insect from the time they hatch from the egg until they shed their skin for the last time. When a nymph first hatches it has no signs of wings ; but after it molts several times two projections appear on each side of the thorax. These projections become larger and larger, and more wing-like in form with each successive molt. Usually the change in the size of these organs, between the last nymph stage and the adult stage, is much greater than that of any previous molt. With the nymphs of certain families, dragon-flies, crickets, grasshoppers, and locusts, the front pair of developing wings extend back beneath the hind pair instead of covering them ; and by this inverted position of the wings the nymphs may be distinguished from the adults, even in those cases where the adults have only rudimentary wings. The Adult. This is the last stage or the mature form of the insect. Almost all adult insects except Thysanura have wings, although there are numerous exceptions to the rule ; for there are many cases where wings have been lost through disuse. An insect never grows after it reaches the adult stage, and therefore never molts. There is a popular belief that a small fly will grow into a large fly, but this is not true, for after any insect gets its perfect wings it can $6 THE STUDY OF INSECTS. grow no larger, except that in case of females the body may be distended by the growth of eggs within it. While many adults eat mere or less, it is only to sustain life, and not for growth. Indeed, many adult insects take very little food, and some have lost their mouth-parts entirely, through disuse. The adult stage usually lasts for a considerably shorter time than the larval or nymph stages. In fact, it seems planned in the economy of nature that the grown-up insects should live only long enough to lay eggs, and thus secure the perpetuation of the species. THE EXTERNAL ANATOMY OF INSECTS. The subject of insect anatomy is separated into two divi- sions : one, treating of the structure of the body-wall or skeleton ; the other, of the internal organs. The former is termed external anatomy ; the latter, internal anatomy. In our own bodies we find a central framework or skele- ton, about which are arranged the muscles, blood-vessels, nerves, and other organs. But insects are constructed on an entirely different plan: with them the supporting skele- ton is outside, and the muscles, nerves, and other organs are within this skeleton. The difference can be well seen if the figure showing the internal structure of the leg of a May-beetle (Fig. 67) be compared with one of our own limbs, either arm or leg. FIG. 67, Leg of M;iy-beetle. (After Straus Durckheim.) The body of an insect is built on the same plan as are its legs. The outside of the body is more or less firm, being hardened by chitine ; and this firm outer wall supports the muscles and other organs, thus serving as a skeleton. The skeleton is therefore, in general outline, a hollow cylinder. HEXAPODA. 57 This hardening of the body-wall is not continuous, but takes place in a series of more or less regular, ring-like bands, which give the well-known seg- mented appearance characteristic of insects, and the animals closely FIG. es. A Larva, allied to them. Between the hardened ring-like segments the body-wall remains soft and flexible. In this way provi- sion is made fcr the various motions of the body. The ring-like nature of the segments of the body is best seen in larvae (Fig. 68), and in the hinder part of an adult insect (Fig. 69). The movements of the legs, antennae, and certain other appendages are provided for in the same way ; each one is a cylinder made up of several segments, and between these seg- ments the wall of the cylinder remains flexible. When a single segment of the body is examined, the hardened portion is not found to be a continuous ring, but is seen to be made up of several portions more FIG. 6 9 . A Mole Cricket, or less movable upon each other. Such a hardened portion of the body-wall is termed a sclerite (scle'rite). The sclerites constitute the greater part of the body-wall, the soft membranous portions separating them being in most cases narrow. Usually these narrow portions are mere lines; they are then called sutures (sut'urs). Frequently the sutures become entirely effaced. We are therefore often unable to distinguish certain sclerites in one species of insect which we know to exist in another. In such cases the effaced sutures are said to be obsolete. If the central portion or thorax of an adult insect be examined, numerous sclerites and sutures can be observed (Fig. 70). THE STUDY OF INSECTS. The subject of external anatomy of insects consists very largely in a study of the sclerites of which the different segments of the body and of its appendages are composed. This part of the subject is quite difficult, and will not be discussed here. It is treated, however, in the discussion of the characters used in the classification of the Coleoptera given on pages 499 to 504. These pages should be carefully studied before attempting to use the table that follows them. FIG. 70. Side-view of Locust with wings removed FIG. 71. Wasp, with head, thora.x, and abdomen separated. The segments of the body in a fully developed insect are grouped into three regions : head, thorax, and abdomen (Fig. 71). In the larval state this grouping of the segments is not well shown. The Head and its Appendages. The head is the first of the three regions of the body. It is supposed to be formed of several body-segments grown together ; but entomologists differ in their views as to the number of segments that have entered into its composition. The head bears the compound eyes, the simple eyes, the antennae, and the mouth-parts. The Compound Eyes. On each side of the head of an adult insect is an organ, which is recognized at once as an eye. But when one of these eyes is examined with a microscope it is found to present FIG. 72. Part of com- ,.,-, , , f pound eye, greatly en- an appearance very ditlerent trom that of the eye of higher animals ; its surface is divided into a large number of six-sided divisions HEX A POD A. 59 7-P (Fig. 72). A study of the internal structure of this organ has shown that each of these hexagonal divi- sions is the outer end of a distinct eye (Fig. 73). Hence what at first appears to be a single eye is really an organ composed of hundreds of eyes ; it is termed, therefore, a compound eye. Each of the small eyes of which a compound eye is composed is termed an ommatidium. The number of ommatidia of which a compound eye is composed varies greatly : there may be not more than fifty, as in certain ants, or there may be many thousand, as in a butter- fly or a dragon-fly. Compound eyes are not found in larvae, though they may possess a group of simple eyes on each side of the head. The Simple Eyes. In addition to the com- pound eyes, many adult insects possess simple eyes. These are situated between the com- pound eyes. They vary in number from one to four; the most common number is three (see Fig. 71). The simple eyes are usually termed ocelli ; sometimes, stemmata (stem'ma-ta). When the term ocelli is used in descriptive works, if there is nothing in the context to F]G indicate the contrary, it is almost invariably applied to the simple eyes, and not to the ele- ments of the compound eyes. In the same way the term eye usually refers to the com- pound eyes, unless otherwise indicated by the context. The Antenna. The antennae are a pair of jointed appendages inserted in the head in front of the eyes or between them. They vary in form. In some insects they are thread-like, consisting of a series of similar segments; in others certain segments are greatly modified in form. Three ommatidia from the compound eye of a May-beelle. (After Grenach- er.) The pig- ment has been dissolved away from two of them, f, corneal facet; A', crystal- line cone ; /, pig- ment-sheath ; /', chief pigment- cell ; /", pig- ment-cells of the second order ; R, retinulas. 6o THE STUDY OF INSECTS. The various forms of antennae are designated by special terms. The more common of these forms are represented in Figure 74. These are as follows : 1. Setaceous (se-ta'ceous) or bris- tle-like, in which the segments are successively smaller and smaller, the whole organ tapering to a point. 2. Filiform (fiTi-form) or thread- like, in which each segment is of nearly uniform thickness throughout its length; and the antenna as a whole tapers gradually, if at all, to- . /^^ x ^* wards the tip. AJ \/^^^ 3- Moniliform (mo-niri-form) or "7 V5f w^-^ 5 "' necklace-form, in which the segments are more or less globose, suggesting a string of beads. 4. Serrate (ser'rate) or saw-like, in which the segments are triangular, and project like the teeth of a saw. $. Pectinate (pec'ti-nate) or comb-like, in which the seg- ments have long processes on one side, like the teeth of a comb, or on both sides, like a feather. 6. Clavate (cla'vate) or club-shaped, in which the seg- ments become gradually broader, so that the whole organ assumes the form of a club. 7. Capitate (cap'i-tate) or with a head, in which the terminal segment or segments form a large knob. 8. Lamellate (Jam'el-late), in which the segments that compose the knob are extended on one side into broad plates. The Month-parts. No set of organs in the body of an in- sect vary in form to a greater degree than do the mouth-parts. Thus with some the mouth is formed for biting, while with others it is formed for sucking. Among the biting insects some are predaceous, and have jaws fitted for seizing and FIG. 74. Various forms of an- tennae. HEXAPODA, 61 tearing their prey ; others feed upon vegetable matter, and have jaws for chewing this kind of food. Among the suck- ing insects the butterfly merely sips the nectar from flowers j while the mosquito needs a powerful instrument for piercing its victim. In this place the typical form of the mouth- parts as illustrated by the biting insects is described. The various modifications of it presented by the sucking insects are described later, in the discussion of the characters of those insects. In the biting insects, the mouth-parts consist of an upper lip, the /rt/;/7/;//(la'brum) (Fig. 75, 8); an under lip, the labium (la'bi-um) (Fig. 75, 12); and two pairs of jaws between them. These jaws open sidewise, instead of in a vertical direction, as do the jaws of the higher animals. The upper pair of jaws are called the mandibles (man'di-bles) (Fig. 75, 10); the lower pair, the maxilla (max-il'lae) (Fig. 75, u). There may be also within the mouth one or two tongue-like organs, the eflzfl/tarynx(ep-i-pha.r'ynx) and hypopliarynx (hy - po - phar'ynx) (Fig. 75, 13). The epipharynx is attached to the upper wall of the cavity of the mouth, and the hypopharynx to the lower. The position of the hypopharynx is quite analogous, therefore, to that of our tongue. The mandibles vary much in form, but usually each consists of a single sclerite. The maxillae of biting insects, on the other TIG. 7 6.-Maxiiia of a hand, are very complicated organs, each com- posed of several sclerites. Each maxilla bears an appendage consisting of several segments; these FIG. 75. Mouth-parts of the Red- legged Locust. 62 THE STUDY OF INSECTS. appendages are termed the maxillary palpi. In the maxillae of certain biting insects, as the grasshoppers and the ground beetles, there is an appendage usually consisting of two segments : this is the galea (ga'le-a) or outer lobe. In some of these insects, as the ground-beetles and the tiger- beetles, the galea is shaped like a palpus, and thus there appears to be two pairs of maxillary palpi (Fig. 76). The labium is furnished with a pair of jointed appendages ; these are the labial palpi (Fig. 75, 12, d\ The Thorax and its Appendages. The thorax is the second or intermediate region of the body ; it is the region that bears, in the adult insect, the organs of locomotion, the legs, and the wings when they are present. This region is composed of three of the body- segments more or less firmly joined together ; the segments are most readily distinguished by the fact that each bears a pair of legs. In winged insects, the wings are borne by the second and third segments. The first segment of the thorax, the one next to the head, is named the protJiorax ; the second thoracic segment is the mesothorax ; and the third, the metatliorax. The Legs. Each leg consists of the following parts, beginning with the one next to the body (see Fig. 77): coxa, trochanter, femur, tibia, and tarsus. Each of these parts consists of a single seg- ment except that in certain Hymenoptera the trochanter consists of two segments (Fig. 77, /), and in most insects the tarsus consists of several seg- ments. The number of seg. ments of the tarsus varies from one to six ; the most common number is five. Frequently the first segment of the tarsus is much longer than either of a b c FIG. 77. Legs of insects : a. Wasp ; t. Ichneumon-fly; c, Bee ; ^trochanter; ;;z, metatarsus. HEXAPODA. 63 the other segments, and it may also differ greatly in form from them ; under such circumstances it is sometimes desig- nated the metatarsus (met-a-tar'sus) (Fig. 77, /;/). The last segment of the tarsus usually bears one or two claws. On the ventral surface of the segments of the tarsus in many insects are cushion-like structures ; these are called pulvilli (pul-vil-li). The cuticle of the pulvilli is traversed by numerous pores which open either at the surface of the cuticle or through hollow hairs, the tencnt hairs, and from which ex- udes an adhesive fluid that enables the insect to walk on the lower surface of objects. The ivings. The two pairs of wings are borne by the mesothorax and metathorax ; the prothorax never bears wings. In form, an insect's wing is a large membranous append- age, which is thickened along certain lines. These thickened lines are termed the veins or nerves of the wing ; and their arrangement is described as the venation or neuration of the wings. The thin spaces of the wings which are bounded by the veins are called cells. When a cell is completely sur- rounded by veins it is said to be closed ; but when it extends to the margin of the wing it is said to be open. The wings of different insects vary greatly in structure, and thus afford excellent distinctions for the purposes of classification. The various parts of the wing have, there- fore, received special names. There is considerable lack of uniformity among entomologists as to the names applied to these parts ; but we have adopted the set of terms defined below as representing the best usage. An insect's wing is more or less triangular in outline ; it therefore presents three margins : the costal margin, or costa (Fig. 78, a, b] ; the outer margin (Fig. 78, 6, c) ; and the inner margin (Fig. 78, c, d\ The angle at the base of the costal margin (Fig. 78, a] is the humeral angle (hu'me-ral) ; that between the costal mar- gin and the outer margin (Fig. 78, b) is the apex of the wing ; 64 THE STUDY OF INSECTS. and the angle between the outer margin -and the inner mar- gin (Fig. 78, c] is the anal angle (a'nal). There have been many different sets of names applied to the veins of the wings. Not only have the students of each III, Hl2 C FIG. 78. Fore wing of a butterfly with the veins and cells numbered. order of insects had a peculiar nomenclature, but in many cases different students of the same order of insects have used different sets of terms. This condition of affairs was incident to the beginning of the science, the period before the correspondence of the veins in the different orders had been worked out. But now the time has come when it seems practicable to apply a uniform nomenclature to the wing veins of all orders; and the following set of terms is proposed for that purpose. The principal veins of the wing, those that arise at or near the base of the wing, are termed, beginning with the one lying on the costal margin, the costa (cos'ta), the subcosta, the radius (ra'di-us), the media (me'di-a), the cubit its (cu'bi- tus), and the anal veins. The radius, media, and cubitus are usually branched, and there may be several anal veins. In addition to the principal or longitudinal veins, there may be a greater or less number of cross-veins veins extend- ing transversely from one longitudinal vein to another. HEXAPODA. The principal veins may be designated 'by numbers as well as by names ; the following table indicates the correspondence of the names and numbers : Costa = vein I. Subcosta = vein II. Radius = vein III. Media = vein V. Cubitus = vein VII. 1st anal vein = vein VIII. 2d anal vein = vein IX. 3d anal vein = vein XI. It was formerly believed that in certain insects three other longitudinal veins were present ; these were numbered IV, VI, and X respectively ; hence these numbers are omitted in the above table. At the time the first edition of this book was written, it was thought best to designate the veins by numbers; and conse- quently numbers are used in the following pages much more generally than are the names of the veins. But owing to a lack of uniformity in the numbering of the veins by different writers, it is now clear that the names are to be preferred. In 3d A 2d A FIG. 79. Diagram representing- the typical arrangement of the wing-veins, includ- ing the four more important cross-veins : //, humeral cross-vein ; r-m, radio- medial cross-vein ; m, medial cross-vein ; m-cu, medio-cubital cross-vein. the lettering of figures abbreviations of the names can be used as is done in Figure 79. The divisions of a branched vein are numbered, beginning with the one nearest the costal margin of the wing ; and these numbers are indicated by sub-figures. For example, G 66 THE STUDY OF INSECTS. the five branches of the typical radius, or vein III, are designated either thus, R b R 2 , R 3 , R 4 , R 5 ; or thus, IIIi, III 2 , III,, III 4 , III 5 . When two or more branches of a branched vein coalesce, the compound vein is designated by an expression indicating this coalescence, as III 2+3 or R 2+3 . In this way it is possible to indicate some of the changes that have taken place in the de- velopment of the species; and to make use of them in working out the classification of the group to which the species belongs. The cells of the wing are designated by applying to each the number or the abbreviation of the name of the vein that forms its cephalic (front) margin. In Figure 78 the veins are designated by numbers at the margin of the figure ; the cells by numbers within the figure. When a cell is divided by a cross-vein the parts are numbered, as in the case of cell V 2 in Figure 497, page 422. The Abdomen and its Appendages. The abdomen is the third or caudal region of the body. Its segments are more simple, distinct, and ring-like than those of the other regions. The number of segments of which it appears to be composed varies greatly. In the Cuckoo-flies (Chrysididce) there are usually only three or four visible, while in many other insects nine appear. Except in the lowest order of insects (Thysanurct) the abdomen of the adult bears no locomotive appendages. But many larvae have fleshy appendages which aid in locomotion : these are termed prolcgs. In the adult the end of the body in many families is furnished with jointed filaments the cerci, and caudal setce. Frequently also the body is furnished in the male with organs for clasping the claspers ; and in the female with saws, pierces, or borers the ovipositor. In the female of certain insects there is a sting, a modified ovipositor, which is used as an organ of defence ; and the abdomen of plant- lice and certain other insects bears a pair of tubes or tuber- HEX A POD A. 67 cles, through which a waxlike material is excreted : these are commonly called Iwney-tiibcs \ they are also termed cornicles, nectaries, or sip/iunclcs; see page 157. THE INTERNAL ANATOMY OF INSECTS^ (For advanced students.) As has been shown in the preceding pages, the body-wall serves as a skeleton, being hard, and giving support to the other organs of the body. This skeleton may be represented, therefore, as a hollow cylinder. We have now to consider the arrangement and the general form of the organs contained in this cylinder. For the details of the structure of th internal organs the student is referred to more special works. The accompanying diagram (Fig. 80), which represents a vertical, longitudinal section of the body, will enable the student to gain an idea of the relative position of some of the more important organs. The parts shown in the diagram are as follows: The body-wall, or skeleton FIG. 80. Diagram showing the relation of the internal organs. (s) ; this is made up of a series of overlapping segments ; that part of it between the segments is thinner, and is not hardened with chitine, thus remaining flexible and allowing for the movements of the body. Just within the body-wall, and attached to it, are represented a few of the muscles (in) it will be seen that these muscles are so arranged that the contraction of those on the lower side of the body would bend it down, while the contraction of those on the opposite side would act in the opposite direction. The alimentary canal (a) occu- pies the centre of the body, and extends from one end to the other. The heart (k) is a tube open at both ends, and lying between the alimentary canal and the muscles of the back. The central part of the nervous system () is a series of small masses of nervous matter connected by two longitudinal cords: one of these masses, the brain, lies in the head above the alimentary canal ; the others are situated, 68 THE STUDY OF INSECTS. PLATE II. A CATERPILLAR '^Cossus ligniperda). (After Lyonet.) ffV*. T. Caterpillar opened on the ventral middle line. FIG. 2. Caterpillar opened on the dorsal middle line, i, principal longitudinal tracheae ; 2, central nervous syi- tern; 3, aorta ; 4, longitudinal dorsal muscles; 5, longitudinal ventral musclesr 6, wings of the heart; 7, tracheal trunks arising near spiracles; 8, reproductive organs ; 9, vertical muscles : 10, last abdominal ganglion. HEXAPODA, 69 one in each segment, between the alimentary canal and the layer of muscles of the ventral side of the body ; the two cords connecting these masses, or ganglia, pass one on each side of the oesophagus to the brain. The reproductive organs (r) lie in the cavity of the abdo- men and open near the caudal end of the body. The respiratory organs are omitted from this diagram for the sake of simplicity. The Muscular System. We find in insects a wonderfully large number of muscles. Those that move the segments of the body form several layers just wil.iin the body-wall. The two figures on Plate II represent two caterpillars which have been split open lengthwise, one on the middle line of the back and one on the opposite side ; in each case the alimentary canal has been removed, so that only those organs that are attached quite closely to the body-wall are left. From a study of these figures some idea can be obtained of the number and arrange- ment of these muscles. It should be borne in mind, however, that only a single layer of muscles is represented in these figures the layer which would be seen if a caterpillar were opened in the way indicated. When these muscles are cut away many other muscles are found ex- tending obliquely in various directions between these muscles and the body-wall. The muscles of insects appear very differently from those (the lean meat) of higher animals. In insects the muscles are either colorless and transparent, or yellowish white ; and they are soft, almost of a gelatinous consistence. When hardened by alcohol or otherwise, and examined with a microscope, they are seen to be crossed by numerous transverse lines, like the voluntary muscles of Vertebrates. As a rule, the muscles of insects are composed of aii immense number of distinct fibres, which are not enclosed in tendinous sheaths as with Vertebrates. But the muscles that move the appendages oi the body are furnished with a tendon at the end farthest from the body (Fig. 81). FIG. 81. Leg of May-beetle. (After Straus-Durckheim.) Notwithstanding the soft and delicate appearance of the muscles of insects, they are really very strong. One has only to observe the power of leaping possessed by many species to be convinced of this, THE STUDY OF INSECTS. PLATE III. a jtwirT.es A COCKROACH (Periplaneta oriental's). (From Rolleston). a, antennae; ii, 62, 63, tibiae; f, anal cerci ; d, ganglion on recurrent nerve upon the crop ; e, salivary duct ; _/", salivary bladder; g, gizzard ; h, hepatic coeca; t, chylific stomach ; j, Malpighian vessels; k, small intestine; /, large intestine; m, rectum; , first abdominal ganglion ; o, ovary ; /, sebaceous glands. HEX A POD A. 71 And the rapidity of their action is even more wonderful than their strength. This rapidity is best illustrated by the muscles that move the wings. Every one has observed gnats and other flies poising in mid air by a movement of the wings so rapid that the eye cannot follow it. Physicists have been able, however, to count these vibrations by de- termining the pitch of the musical note produced in this way. And they tell us that certain gnats vibrate their wings 15,000 times per second. The Alimentary Canal. The typical position of this is represented in the diagram (Fig. 80); and on Plate III, illustrating the anatomy of a cockroach, its form in that insect is shown. In larvae it is a nearly straight tube, extending from one end of the body to the other. But in adult insects it is usually much longer than the body, and is consequently more or less folded. It is composed of parts differing in form and use. To these parts names have been given similar to those used to designate the corresponding parts in higher animals ; thus we distinguish a pharynx, an oesophagus, sometimes a crop, some- times a gizzard, a stomach, a small intestine, and a large intestine. The Adipose Tissue, or Fat. On opening the body of an insect, especially of a larva, one of the most conspicuous things to be seen is fatty tissue, in large masses. These often completely surround the alimentary canal, and are held in place by numerous branches of the tracheae with which they are supplied. Other and smaller masses of this tissue adhere to the inner surface of the abdominal wall, in the vicinity of the nervous system, and at the sides of the body. In a full- grown larva of Corydalis cornuta I have found the adipose tissue to be greater in bulk than all of the other organs found inside of the muscular walls of the body. In adult insects it usually exists in much less quantity than in larvaa. The Blood-vessels. In insects all parts of the body cavity that are not occupied by the internal organs are filled with blood. Thus the alimentary canal is completely surrounded with blood, and all the spaces between the muscles are filled *"" by this fluid. This is a very different arrangement from what occurs in our own body, where the blood is con- tained in a system of tubes, the arteries and the veins. We find, however, that insects are not entirely deprived of blood-vessels. For there is one which lies above the ali- mentary canal, just within the middle line of the back. See Figure 80, h, and Plate II, i. This extends from near P art of the heart of a the caudal end of the abdomen through the thorax into May-beetle, the head. That part of this system that lies in .the abdomen THE STUDY OF INSECTS. is usually termed the heart. This is a somewhat complicated organ consisting of several chambers arranged in series, and each communicating with the one in front of it by an opening fur- nished with valves. The number and form of these chambers differ in different in- sects. Fig. 82 represents the heart of a May - beetle. These chambers not only communicate with each other, but com- municate with the body-cavity by means of side openings, which are also furnished with valves. These two sets of valves act in such a way that when a chamber of the heart contracts a stream of blood is forced towards the head, and when it expands the blood rushes into it through the side open- ings, and from the chamber behind it. At- tached to the lower surface of the heart and extending out to the side of the body there is on each side a series of triangular muscles : these have been termed the wino-s FIG. 8 3 .-Heart of May-beetle , . (after Straus-Durckheim): a. Of the heart (Plate 11, 6, and Fig. 83, c). lateral aspect of aorta * b T T-" interior of heart showing In Figure c they are represented cut away valves; c, ventral aspect of f rom lhe cau d a l part of the heart. The heart and wing-muscles the muscles are represented as prolongation of the heart, which extends cut away from the caudal part of the heart; ) supplies the mouth- parts with nerves ; and each of the thoracic and abdominal ganglia supplies its segment of the body. How Insects Breathe The Respiratory System. A common mis- take made by beginners in the study of Entomology is to suppose that insects breathe through the mouth as do the higher animals. Many a beginner has carefully poured chloroform on the head of an insect in the expectation of killing it in that way, and has been sur- prised at his poor success. The truth is, insects breathe through their sides. If an insect be carefully examined, there can be found along the sides of the body a series of openings (Fig. 85). These are the openings through which FIG. 84. Nervous system of Corydalis. (After Leidy.) FIG. 85. Side-view of Locust with wings removed. the air passes into the respiratory system and are termed spiracles (spir'a-cles). THE STUDY OF INSECTS. The number of spiracles varies greatly in different insects. There is, however, never more than one pair on a single segment of the body. They do not occur on the head, but are borne by each of the thoracic segments, and by the first eight abdominal segments. Thus there are eleven segments that may bear spiracles, but they are always lacking on some one or more of these. These spiracles are either simple openings into the respiratory system, or are provided with valves, sieves, or fringes of hair for the exclusion of dirt. They lead into a system of air-tubes termed tra- chea- (tra'che-ae). The accompanying figures will indicate the distri- bution of the main trunks of these tracheae in a cockroach (Figs. 86 and FIG. 86. Tracheal system of Cockroach. The dorsal integument removed and the alimentary canal in place. (After Miall and Denny.) FIG. 87. Tracheal system of Cockroach. The alimentary canal removed to show the ventral tracheal communications. (After Miall and Denny,) 87). There is a short trunk arising from each spiracle ; these are all connected together by a large longitudinal trunk on each side of the body, and by numerous transverse trunks. From these large tracheae there arise a great number of smaller ones, not shown in the figures, which branch and subdivide, and extend to all parts of the body. When one dissects an insect the viscera are found to be connected together by the ramifications of these tracheae, so that in order to remove any organ it is necessary to cut some of them. The smaller branches of the tracheae are exceedingly minute, and are intimately associated with the various tissues. By means of these fine tracheal trunks the air is carried to the tissues ; hence the blood plays a much smaller part in respiration than it does in the Vertebrates. Although insects are, strictly speaking, air-breathing animals, many of them, as is well known, live in the water. The study of the ways in which aquatic insects breathe is a very interesting one ; it HEXAPODA; 75 presents to us many wonderful modifications ol structure. Some ot the more common of these are described in subsequent pages of this book ; in this place we can only make a few generalizations. The various modes of respiration of aquatic insects may be classi- fied under two heads: first, those in which the insects obtain air from above the surface of the water; second, those in which the insects breathe the air that is mechanically mixed with the water. With many aquatic insects the spiracles open beneath the wings, which are folded upon the abdomen. The insect, by coming to the surface of the water and lifting the tip of its wings, forms a cavity be- neath them, into which the air rushes. The insect can then swim through the water, carrying this air with it in a position where it can be respired. When the air becomes impure, the insect rises to the surface, forces out the air from beneath its wings, and takes in a new supply. Water-beetles and aquatic bugs afford familiar examples of this mode of respiration. Some insects are provided with long tubes connected with their spiracles, by means of which they can draw their supply of air from above the surface of the water while they crawl upon the bottom of shallow ponds. Our most common illustrations of this are bugs of the family Nepidcc; but the most remarkable development of this kind is exhibited by certain Dipterous larvae of the family Syrphidce, known as Rat-tailed Maggots. Although there are many insects that live in the water and draw their supply of air from above it, the greater number of aquatic insects breathe, as do fishes, the air that is mixed with the water. This is accomplished by organs known as tracheal gills. These are hair-like or more or less plate-like expansions of the body-wall, abundantly supplied with tracheae (Fig. 88). These tracheae divide and subdivide, and their term! nations or fine branches are separated from the water that bathes the organ only by its thin walls. In this way the air contained in the tracheae is separated from the air in the water only by a delicate membrane, which admits of the transfer of gases between them. It w:Jj be observed that the difference between a tracheal gill and a true gill (as of fishes, Crustacea, etc ) is that the true gill is supplied with vessels containing blood, which is purified by being brought in contact with the air in the water, while the tracheal gill is supplied with tracheae F IG . containing air to be purified. Tracheal gills are usually borne by the abdomen, some- times by the thorax, and in case of one genus of Stone-flies by the 88. Tracheal Rill of Agrion. 7 6 THE STUDY OF INSECT^ head. They pertain almost exclusively to the immature stages of insects ; but Stone-flies of the genus Pteronarcys retain them through- out their existence. Tracheal gills vary greatly in form; in Corydalis they are hair-like, and occur in tufts near the lateral margins of the abdominal seg- ments ; in the Cadd ice-worms they are thread-like, more or less branched, and irregularly distributed over the surface of the abdo- men ; and in certain Dragon-flies they are in the form of large plate- like caudal appendages. (Fig. 88.) The Reproductive Organs. The reproductive organs are situated in the abdomen, as represented in Figure 80. There is a set on each side of the body ; but the two sets usually open by a common tube near the caudal end of the body. In the May-flies and in the Ear- wigs, however, the reproductive organs of each side have a distinct opening. Thus May-flies are often found with two bunches of eggs projecting from the caudal end of the body. All insects are developed from eggs ; but there are some appar- ent exceptions. Thus many flies retain their eggs until after they are hatched, if a proper place for laying them is not found earlier; and in some flies (the Pnpipara) the young attain a considerable de- velopment before they are born. In the Plant-lice (Aphididce) there is a remarkable alternation of reproduction by budding with the sexual reproduction. This is described more fully in the account of that family. THE ORDERS OF THE HEXAPODA. (For advanced student?.} The Class Hexapoda, or Insects, is divided in this work into nine- teen orders. This number is somewhat greater than what has been commonly adopted heretofore. But we believe that in the earlier classifications forms were brought together in the same order that are not closely related, and that consequently the present classifica- tion represents better the true relationship of the groups of insects. There has been some hesitation on the part of many entomolo- gists in adopting this division of certain of the old orders, merely for the reason that they felt that the old classification was simpler. But we do not share in this feeling. It seems to us that it is easier for the student to learn the characters of a large number of well-defined groups than it is to learn those of a smaller number of vaguely- defined groups. HEXAPODA. 77 In arranging the orders in a linear series, as must be done in a book, it is impossible to indicate in a satisfactory way either the rela- tion of the orders to each other or the relative rank of the orders. An effort is made to place near together closely allied orders, and to treat first those that are more simple or primitive or generalized in structure, and last those that are more specialized. But this plan could be fully carried out only by having several parallel columns on the pages of the book, each representing a distinct line of descent, an arrangement which, to say the least, is impracticable. What has been done in this work is to place first the Thysanura, which is doubtless the most primitive order. Then follow first the orders that undergo an incomplete metamorphosis, and last, those that undergo a complete metamorphosis. Within these two groups of orders those with biting mouth-parts are placed first, and these are followed by those with sucking mouth-parts, except that in the second group the Coleoptera and Hymenoptera are placed last for want of a better position. We do not intend to indicate by this that these two orders are closely related, or that they are more specialized than the Diptera. In fact, with regard to at least five of the ordersof insects (Hemip- tera, Lepidoptera, Diptera, Coleoptera, and Hymenoptera), it seems idle to us to discuss which is the more highly specialized. Each has been specialized in a direction peculiar to itself ; and to attempt to describe which is the "highest " seems as futile as the discussion by children of the question : " Which is better, sugar or salt ? " We give below a table for use in classifying specimens. This table is merely intended to aid the student in determining to which of the orders a specimen that he is examining belongs. No effort has been made to indicate in the table the relation of the orders to each other. TABLE FOR DETERMINING THE ORDERS OF HEXAPODA.* (This table includes only adult insects.} A. Wingless or with rudimentary wings. B. Mandibles and maxillae retracted within the cavity of the head so that only their apices are visible, p. 82 THYSANURA. BB. Mandibles and maxillse more or less prominent and fitted for biting. (See BBB also.) C. Head with long, trunk-like beak. (Boreus.) p. 184. MECOPTERA. * See note at bottom of p. 10. 78 THE STUDY OF INSECTS. CC. Head not prolonged into a trunk. D. Louse-like insects of small size ; 'oody less than one-sixth inch in length. E. Antennae with not more than five segments. (Bird-lice.) p. 100 MALLOPHAGA. EE. Antennae with many segments. (Book-lice.) p. 98. CORRODENTIA. DD. Insects of various forms, but not louse-like, and, except in the case of some ants, with the body more than one-sixth inch in length. E. Abdomen with short, conical, compressed, many-jointed caudal appendages. {Cockroaches^ p. IO4...ORTHOPTERA. EE. Abdomen without jointed caudal appendages. F. Legs fitted for jumping. {Wingless Locusts, Grasshop- pers, and Crickets.", p. 104 ORTHOPTERA. FF. Legs fitted for running. G. Abdomen broadly joined to thorax. H. Body linear. {Walking-sticks^) p. 104. ORTHOPTERA. HH. Body white and somewhat ant-like in form. ( Termes. ) p. 95 ISOPTERA. HHH. Body neither linear nor ant-like in form, ( Wingless Fire-fly et al.) p. 494 COLEOPTERA. GG. Base of abdomen strongly constricted. (Ants et al.) p. 599 HYMENOPTERA. BBB. Mouth-parts formed for sucking. C. Small abnormal insects in which tne body is either scale-like or gall-like in form, or grub-like and clothed with wax. The waxy covering may be in the form of powder, of large tufts cr plates, of a continuous layer, or of a thin scale, beneath which the insect lives. {Coccida;.} p. 121 HEMIPTERA. CC. Body more or less covered with minute scales, or with thick long hairs. Prothorax not free {i.e., closely united with the mesothorax). Mouth-parts usually consisting of a long "tongue" rolled beneath the head. p. 191 LEPIDOPTERA. CCC. Body naked, or with isolated or bristle like hairs. D. Prothorax not well developed, inconspicuous or invisible from above. Tarsi five-jointed. Mouth-parts developed into an unjointed trunk ; palpi present, p. 413 DIPTERA. DD. Prothorax well developed. E. Body strongly compressed ; tarsi five-jointed. (Fleas.) p. 490 SlPHONAPTERA. HEXAPODA. 79 EE. Body not compressed ; tarsi one-, two , or three-jointed. F. Last joint of tarsi bladder-like or hoof-like in form and without claws , mouth-parts forming a triangular, un- jointed beak; palpi present, p. 119 PHYSOPODA. FF. Last joint of tarsi not bladder-like, and furnished with one or two claws ; mouth-parts forming a slender, usually jointed beak; palpi apparently wanting, p. 121. HEMIPTERA AA. Winged. (The wing-covers, elytra, of beetles and of earwigs are wings.) B. With two wings. C. Wings horny, leathery, or parchment-like. D. Mouth-parts formed for sucking. Wings leathery, short- ened, or membranous at the tip. p. 121 HEMIPTERA. DD. Mouth-parts formed for biting. Jaws distinct. E. Wings horny, without veins. Hind legs not litied tor jumping, p. 494 . . . . . . . . .CoLEOPTERA. EE. Wings parchment-like, with a network of veins. Hind legs fitted for jumping, p. 104 , . . .ORTHOPTERA. CC. Wings membranous. D. Abdomen with caudal filaments. Mouth-parts rudimentary. E. Halteres wanting, p. 86 EPHEMERIDA. EE. Halteres present (males of Coccidce). p. 121. HEMIPTERA. DD. Abdomen without caudal filaments. Halteres in place of second wings. Mouth-parts formed for sucking, p. 413. DIPTERA. BB. With four wings. C. The two pairs of wings unlike in structure. D. Front wings leathery at base, and membranous at tip, often overlapping. Mouth-parts formed for sucking, p. 121. HEMIPTERA. DD. Front wings of same texture throughout. E. Front wings horny or leathery, being veinless wing- covers. (Elytra) F. Abdomen with caudal appendages in form of movable forceps, p. 102 EUPLEXOPTERA. FF. Abdomen without forcep-like appendages, p. 494. COLEOPTERA. EE. Front wings leathery or parchment-like, with a network of veins. F. Under win^s not folded. Mouth-parts formed for suck- ing, p. 121 HEMIPTERA. 8O THE STUDY OF INSECTS. FF. Under wings folded lengthwise. Mouth-parts formed for biting, p. 104 ORTHOPTERA. CC. The two pairs of wings similar, membranous. D. Last joint of tarsi bladder-like or hoof-like in form and without claws, p. 119 , . PHYSOPODA. DD. Last joint of tarsi not bladder-like. E. Wings entirely or for the greater part clothed with scales. Mouth-parts formed for sucking, p. 191.. . LEPIDOPTERA. EE. Wings naked, transparent, or thinly clothed with hairs, F. Mouth-parts arising from the hinder part of the lower surface of the head, and consisting of bristle-like organs inclosed in a jointed sheath. (Homoptera?) p. 121. HEMIPTERA. FF. Mouth-parts in normal position. Mandibles not bristle-like. G. Wings net-veined, with many veins and cross-veins. H. Tarsi consisting of less than five segments. I. Antennae inconspicuous, awl-shaped, short and slender. J. First and second pairs of wings nearly tha same length ; tarsi three-jointed, p. 89. ODONATA. JJ. Second pair of wings either small or wanting; tarsi four-jointed, p. 86 EPHEMERIDA II. Antennae usually conspicuous, setiform, filiform clavate, capitate, or pectinate. J. Tarsi two- or three-jointed. K. Second pair of wings the smaller, p. 98. CORRODENTIA. KK. Second pair of wings broader, or at least of the same size as the first pair. p. 93. PLECOPTERA. JJ. Tarsi four-jointed ; wings equal, p. 95. ISOPTERA. HH. Tarsi consisting of five segments. I. Abdomen with setiform, many-jointed anal fila- ments. (Certain May-flies.} p. 86. EPHEMERIDA. II. Abdomen without many-jointed anal filaments. J. Head prolonged into a trunk-like beak. p. 184 MECOPTERA. J. Head not prolonged into a beak. p. 175. NEUROPTERA. HEX A POD A. 8 1 GG. Wings with branching veins and comparatively few cross-veins, or veinless. H. Tarsi two- or three-jointed. I. Posterior wings smaller than the anterior. p. 98 CORRODENTI A. II. Posterior wings as large as or larger than the anterior ones. (Certain Stone-flies.) p. 93. PLECOPTERA. HH. Tarsi four- or five-jointed. I. Abdomen with setiform, many-jointed anal fila- ments. (Certain May-flies) p. 86. EPHEMERIDA. II. Abdomen without many-jointed anal filaments. J. Prothorax horny. First wings larger than the second, naked or imperceptibly hairy. Second wings without, or with few, unusually simple, veins. Jaws (mandibles) well developed. Palpi small, p. 599 HYMENOPTERA. JJ. Prothorax membranous or, at the most, parchment-like. Second wings as large as or larger than the first, folded lengthwise, with many branching veins. First wings naked or thinly clothed with hair. Jaws (mandibles) in- conspicuous. Palpi long. Moth-like insects. p. 186 TRICHOPTERA. LIST OF ORDERS OF THE HEXAPODA. THYSANURA. HEMIPTERA. EPHEMERIDA. NEUROPTERA. OUONATA. MECOPTERA. PLECOPTERA. TRICHOPTERA. ISOPTERA. LEPIDOPTERA. CORRODENTIA. DlPTERA. MALLOPHAGA. SIPHONAPTERA. EUPLEXOPTERA COLEOPTERA. ORTHOPTERA. HYMENOPTERA. PHYSOPODA. CHAPTER IV. Order THYSANURA (Thys-a-nu'ra). Bristle-tails, Spring-tails, Fish-moths, and others. The members of this order are wingless insects which undergo no metamorphosis, the larval form being retained by the adult. The mandibles and maxilla are retracted witliin the cavity of the head, so that only their tips are visible ; they have, however, some freedom of motion, and can be used for biting and chewing soft substances. True compound eyes are rarely present ; but in some genera there is a group of simple eyes on each side of the head. The abdomen is sometimes furnished zvith rudimentary legs. Under stones and decayed leaves and wood, in the chinks of bark, amongmoss, in damp places, on snow or on pools, ^^^ or sometimes in houses, are / the members of this order to be found. They are for the most part very small insects, but sometimes they are nu- merous and lively enough to make up for their lack in size. They have no wings, but they can either run very FIG. 89. Mouth-parts of a Spring-tail. Ento- /_. , t TM mobryidas. (Drawn by j. it stedman, fast or jump very far. Their under the author's direction.) 8, labrum: 4.1 n r. 10, mandible; n, maxiiia; 12, labium; 12^ mouth-parts are usually fit- ted for biting, but are very difficult to study, because they are retracted within the 82 THYSANURA. 83 cavity of the head, and also on account of the small size of the insects. Figure 89 represents them in place in the head, and also each separately. In certain respects these insects represent a connecting- link between the other six-footed insects (Hexapoda) and the Myriapods ; for many of the Thysanura have rudiments of legs on the abdomen. It is believed, therefore, that they are much like the first insects that appeared on the earth in ancient geological times. The Thysanura undergo no metamorphosis, the young resembling the adult in form. The name of the order is from two Greek words: thysanos, a tassel ; and onra, the tail. The Thysanura include two distinct types of insects ; these are classed as suborders, and can be distinguished by the following table : TABLE OF THE SUBORDERS OF THE THYSANURA. A. With bristle-like and many-jointed appendages at the caudal end of the body (in a single genus these appendages are in the form of forceps, Fig. 91), and without a sucker on the ventral side of the abdomen, p. 83 CINURA. AA. With a forked sucker on the ventral side of the first abdominal segment. Abdomen with a springing apparatus near its caudal end, or without appendages, p. 84 COLLEMBOLA. Suborder ClNURA (Ci-nu'ra). The Bristle-tails. Often the careful housekeeper sees in the ironing-basket, or upon the book-shelf where she is dusting, a flash of light like a tiny thread of quicksilver, that usually vanishes as soon as seen. If she is experienced she knows that this streak of light is a little animal, half an inch long, whose body is clothed in shining scales like those of a fish. Hence she calls it a Fish- moth. Its scientific name is Lepisma saccharina ; (Le-pis'ma sac-cha-ri'na) ; it is especially abundant in warm climates, 8 4 THE STUDY OF INSECTS. and often does damage to starched clothing, book-bindings, and sometimes loosens wall-paper by eating out the paste. Under a microscope the Fish-moth shows beautiful markings FlG. 91. Jaf-yx solifugus. (After Lubbock.) FIG. 90. Lepisma sac- charina. (After Lub- bock.) FIG. 92. Ventral aspect of Afachilis, showing appendages. on the shining scales ; and at the caudal end of the body are three long bristle-like appendages (Fig. 90), which suggest the common name Bristle-tail applied to members of this suborder. Figure 91 represents Japyx (Ja'pyx), a Bristle- tail in which the caudal appendages are in the form of horny forceps; and Figure 92 represents the lower side of MacJiilis (Mach'i-lis), another Bristle-tail, found under stones and loose bark ; this genus has rudimentary abdominal legs as shown in the figure. Suborder CoLLEMBOLA (Col-lem'bo-la). The Spring-tails. In the Spring in the Northern States, on bright sunny days when it is thawing, one often sees upon the snow thou- sands of tiny dark specks. In other places pools of still THYSANURA. 8$ water appear to be covered by a moving mass of minute grains which become more active when disturbed. These masses as well as the dark specks on snow consist of thou- sands of little creatures that are provided with a wonderful means of jumping. There is on the end of the body a tail-like organ that is bent under when the insect is at rest, and that reaches almost to the head ; this when suddenly straightened throws the insect high in the air and several feet away. This action is like a spring-board jump, only these little fellows always carry their spring-boards with them, and have thus won the name of Spring-tails. The species upon snow, called the Snow-flea, AcJwrutes nivicola (Ach-o-ru'tes ni-vic'o-la), sometimes proves a nuisance in maple sugar-bushes by get- ting into the sap. Through a micro- scope a Spring-tail appears very ab- surd, it has long antennae and large, dark eye-spots on the face, which, to- gether with the longhair that sticks forward on the head and thorax, give the creature a look of solemn FIG. ^.Paplrius fitscus. (After fierceness. Different species may Lubbock.) be found at almost any time of the year in damp places. Figure 93 represents one of these. In many forms the body is much more slender than in that figured. CHAPTER V. Order EPHEMERIDA (Eph-e-mer'i-da). The May-flies. The members of this order have delicate membranous wings, with a fine network of veins ; the fore wings are large, and the hind wings are much smaller or wanting. The mouth- parts are rudimentary. The metamorphosis is incomplete. The name of this order is from the Greek word ephemeras, lasting but a day. It was given to these in- sects on account of the shortness of their lives after reaching the adult state.* The May-flies are easily dis- tinguished from other net-winged in- sects by the peculiar shape of the wings and the relative sizes of the two pairs (Fig. 94). The mouth-parts are nearly want- ing, as these insects eat nothing in the adult state ; the antennae are very small ; the abdomen is long, soft, and terminated by two or three many- F.G. 94.-May.fly. jointed, thread-like appendages. In their metamorphoses these insects differ from all others in molting once after they have acquired wings fitted for flight. This order includes only a single family. * We have not adopted the name Plectoptera, which has been proposed for these insects, on account of its similarity to Plecoptera. 86 EPHEMERIDA. 87 Family EPHEMERIDA (Eph-e-mer'i-dae). The May-flies. In river or lake towns, during the warm evenings of late spring or early summer, the electric lights or street lamps are often darkened by myriads of insects that dash against them, and the pavements are made slippery by their dead bodies which have been trampled under foot. They are not ihe ordi- nary night-flying moths: if an individual of the thousands that cling to the posts and buildings in the vicinity of the light be examined, it will prove to be a delicate creature with dainty, trembling wings and two or three long, white, thread-like organs on the end of its body ; the body itself is so transparent that the blood within can be seen pulsating. The front wings are large and finely netted, and the hind wings are small or absent (Figs. 94, 95). FlG a ' So fragile are these pale beings that they seem Mayfly, like phantoms rather than real insects. No wonder that poets have sung of them as the creatures that live only a day. It is true that their winged existence lasts often only a day or even a few hours ; but they have another life, of which the poet knows nothing. Down on the bottom of a stream, feeding on mud, water-plants, or other small insects, lives a little nymph with delicate, fringed gills along its sides and two or three long, many-jointed, -ind often feathery appendages on the end of the body (Fig. 96). It has strong legs and can both walk and swim. After about the ninth molt there may be twenty molts in all there appear on its thorax four little sacs which are the beginnings of wings ; with each molt these grow larger, until finally the last skin of the water-nymph is shed, and gills and mouth-parts are all left behind, and the insect comes forth, a winged May-fly. But there is still Fio.96. Nymph of May-fly, another change to be undergone. .he insect has not yet reached the adult state. After flying a 88 THE STUD Y OF INSECTS. short distance it alights and sheds its skin again, a thin layer coming off from all parts of its body, even from its wings. After this the delicate creature is more fragile than before. It now has but one duty to perform in its brief life in the air, and that is to lay its eggs. These are sometimes laid on the surface of the water, and sometimes the mother wraps her wings about her like a diving-bell and goes down into the water and deposits her eggs on stones. The life of the nymph is from one to three years, according to the species. CHAPTER VI. Order ODONATA (Od-o-na'ta). The Dragon-flics and the Damsel-flics. The members of this order have four membranous wings, which are finely netted wit Ji veins ; the hind wings arc as large or larger than the fore wings ; and each wing has near the middle of the front margin a joint-like structure, the nodus. The moutli-parts are formed for biting. The metamorphosis is incomplete. The name of this order is evidently from the Greek word odous, a tooth ; but the reason for applying it to these insects is obscure. The Odonata are easily recognized by the form of their wings, which are long and narrow ; and possess near the middle of the front margin of each a little notch and a strong cross-vein. This structure resembles in appearance a joint, and is consequently named the nodus. The mouth-parts are fitted for biting, these insects be- ing carnivorous and voracious feeders in the adult state. Both the upper lip and the lower lip are large, and the two nearly enclose the jaws when at rest. The nymphs are all aquatic, and can be easily recog- nized by the form of the labium, which is long and jointed, and when extended reaches far out ; it is armed with pow- erful hooks with which to seize their prey. The terminal portion is broad ; and when the lip is folded back in the position of rest, it presents an appearance which has sug- gested for it the term mask. 89 9O THE STUDY OF INSECTS. Like the adults, the nymphs are strictly carnivorous. They feed on a great variety of insects ; and they also destroy worms, crustaceans, fish-fry, and tadpoles. There are two quite distinct types of insects included in this order; these represent two suborders. Suborder ANISOPTERA (An-is-op'te-ra). The Dragon-flies. The dragon-flies are easily distinguished by the relative size of the two pairs of wings, and by the attitude of the wings when at rest (Fig. 97). The hind wings are larger FlG. 97. A dragon-fly. than the fore wings and are of a somewhat different shape ; the name Anisoptera, from the Greek anisos, unequal, and pteron, wing, refers to this fact. But the most striking characteristic is the fact that the wings are extended horizontally when at rest. Darning-needles, devil's-needles, snake-doctors, spin- dies, and dragon-flies are some of the names given to these insects which dart back and forth over streams and wet places, their rapidly moving wings throwing out gleams of metallic color as they go. Still more beautiful are they when at rest, their wings wide-spread above the abdomen, and as rigid and motionless as if made of iridescent glass; ANISOPTERA. and their great compound eyes shining like gold or pre- cious stones. But for all their terrible names, dragon-flies are entirely innocent of any harm to mankind. They neither sew up people's ears, as northern children think; nor bring dead snakes to life, as colored people in the South believe; but they are very fierce enemies to their insect kindred. Their long, narrow, closely netted wings are strong, carrying them swiftly ; and their jaws are powerful, and their appetites good ; so it is an unfortunate insect that falls in their way. The fact that they destroy mosquitoes has attracted much attention of late ; but they feed upon a great variety of insects ; and the larger species habitu- ally eat the smaller ones. The eggs of dragon-flies are laid in water or fastened to aquatic plants. The nymphs present a striking peculiarity of the respiratory system ; very large tra- chese extend to the rectum, and their branches penetrate its wall and end in a complicated series of tracheal gills in the cavity of the rectum. The insect alternately draws water into this cavity and expels it; and thus the air in these tracheae is purified. This process also helps the insect in swimming, for the water may be expelled with such force that the whole body is sent forward. The full-grown nymph leaves the water to undergo its last molt ; and the exuviae are often found clinging to objects near the water (Fig. 98). Suborder ZYGOPTERA (Zy-gop'te-ra). The Damsel-flies. The damsel-flies differ from the dragon-flies in that the two pairs of wings are similar in form and are either folded FIG. g8. Exuviae of nymph of dragon-fly. 9 2 THE STUDY OF INSECTS. parallel with the abdomen when at rest (Fig. 99) or are up- tilted. The head is transverse, each eye being borne by a lateral prolongation of the head. The females possess an FIG. 99. A damsel-fly. FIG. loo. Nymph of a damsel-fly. FIG. 101. Tracheal gill of nymph of damsel-fly. ovipositor by means of which the eggs are placed in the stems of aquatic plants, sometimes beneath the surface of the water. The name of the suborder is from the Greek zygon, yoke, and pteron, wing ; it probably refers to the fact that the wings are brought together when at rest. Unlike the dragon-flies, the damsel-flies are compara- tively feeble in their flight. They are found near the margins of streams and ponds, in which the nymph stages are passed. The nymphs of damsel-flies (Fig. 100) possess leaflike tracheal gills at the caudal end of the body. One of these is represented greatly enlarged by Fig. 101. CHAPTER VII. Order PLECOPTERA (Ple-cop'te-ra). The Stone-flics. The members of this order have four membranous %vings, ^vitJl comparatively few or with many cross-veins ; the hind wings are much larger than the fore wings, and are folded in plaits and lie upon the abdomen when at rest. The mouth- parts are of the biting type of structure, but are frequently poorly developed. The metamorphosis is incomplete. The name of this order is from two Greek words : plccos, plaited; and ptero n, a wing. It refers to the way in which the hind wings are folded when at rest. Although the mouth-parts are of the biting type of struc- ture, the mandibles are often small, flat, and membranous, and evidently of little use. It is probable that as a rule the adults eat but little. The antennae are long, tapering, and many-jointed ; and in most species the caudal end of the abdomen is furnished with two many-jointed bristles. The nymphs are aquatic. This order includes only a single family. Family PERLID^E (Per'li-dse). 77/i? Stone-flies. Those boys fond of fishing know that a good place to find bait is under stones in streams. And doubtless they have often observed that in the swiftest portion of the stream the turned-over stones have clinging to the lower surface 93 94 THE STUDY OF INSECTS. flat creatures from one-half inch or less to one and one half inches in length. They cling so closely and are so nearly the color of the stone that they look almost like fossils. Their antennas and caudal bristles and three legs on each side extend out like the rays of a star ; the six soft clumps of white hair-like gills, one behind each leg, alone show that they are not engraved upon the stone (Fig. 102). These insects are the nymphs of the stone-flies, and are the favorite- food of fishes, especially of brook trout. If a nymph is fortunate enough to escape the fate of being a luncheon for fish, when it is full-grown it crawls forth from the water and FIG. 102. Nymph of Stone- fly, Acroneura. FIG. 103. Pieronarcys regalis. transforms to a gray or greenish fly, with slender, closely veined fore wings and wide, delicate hind wings (Fig. 103). The cast nymph-skins are common objects on the banks of the streams which these insects inhabit. Several of the smaller species of the stone-flies appear in the winged state upon snow in early spring, and often find their way into houses. CHAPTER VIII. Order IsOPTERA (1-sop'te-ra). The Termites or White-ants. The members of this order are social insects. Each species consists of several distinct castes, of which only the " Kings " and the " Queens " are winged. These have four long, nar- row wings, which are somewhat leathery in structure, and which are furnished with numerous but more or less indistinct veins. The two pairs of wings are similar in form and struc- ture, and are laid flat upon the back when not In use. The mouth-parts are formed for biting. The metamorphosis is in- complete. The name of this order is from two Greek words : isos, equal ; and pteron, a wing. It refers to the fact that the two pairs of wings are similar in form and structure. The wings of the Termites (Ter'mites), although really broad when compared to the size of the body, appear narrow on account of their great length, being in many cases more than twice as long as the entire body. The order includes only a single family. Family TERMITID.E (Ter-mit'i-dse). The Termites or White-ants. These interesting insects are not Ants, nor at all related to them ; but they have been thus called because they have certain social habits that are similar to those of true Ants. They are more abundant in the tropics than here ; and 95 9 6 THE STUDY OF INSECTS. FIG. 104. Termes jlapives, work'er. FIG. 105. Termes flavipes, soldier. there build nests or mounds sometimes twelve feet high, or make roundish nests several feet thick on trees. Our Northern species (Termes flavipes) lives in old logs and stumps, or under stones in the ground. A remarkable thing about the White-ants is the way they are divided into classes, each class fitted to do a certain work for the colony^ First, there is the class of workers (Fig. 104), which is constituted of both sexes : they are wingless, and of a dirty-white color, and while they resemble true ants somewhat, their waists are thicker. Their business is to bring food for everybody, feed and bring up the young termites, and build nests. Second, there is the class called soldiers (Fig. 105) : these too are of both sexes and wingless, and look somewhat like the workers, only their heads are tremendous in size, being often nearly as long as the rest of the body, and their jaws are large and powerful. Third, is the royal class called kings and queens. It would have been better to have called them fathers and mothers, as they are the parents of the colony, and do not rule it. This class when grown have wings which lie flat upon the back when at rest, and may be twice as long as the body. In May or June in our common species this class swarms forth from all the nests of the neighborhood. After a flight of some distance the wings are shed, and a king chooses some queen near him and proposes that they start a king- dom of their own. But like mortal kings and queens they cannot reign unless a kingdom is found for them, and so millions of these royal pairs die because they have no sub- jects. But sometimes a fortunate couple is discovered by some termite workers, who at once take possession of the ISOPTERA. 97 wanderers and provide them with food, and with shelter in the shape of a large circular shallow cell. In this they are really imprisoned, but are well cared for. Soon the queen or mother begins to develop eggs, and her body grows enormously. Finally, it is nothing but a huge sac filled with eggs, looking more like a potato than anything else, and is sometimes six or seven inches long (Fig. 106). Of course the poor queen cannot move herself in the least, and if she were not fed would soon starve ; but her king remains devoted to her, and her ladies and gentlemen in waiting do their best to make her comfortable: they carry away the eggs to other chambers as soon as they are laid, then care for the eggs, and feed the little ones when they are hatched. The young termites are active, and re- semble the adult in form. If a nest becomes queenless, and the workers are unable to procure a queen, there are de- veloped in the nest wingless sexual individuals, which are termed complemental males and females. But as each com- plemental female lays only a few eggs, it requires several to take the place of a real queen. All White-ants are miners, and avoid the light. They build covered-ways wherever they wish to go. In hot countries they are a terrible pest, as they feed upon wood, and actually destroy buildings and furniture and libraries. They leave merely the outside portion of what they feed upon ; and they have been known to enter a table through the bottom of the legs and to eat all the inner portions so that a slight weight crushed it to the floor. In Florida they do damage to orange and other trees by girdling them below the surface of the ground. FIG. 106. Queen white- ant, Terntes gilvus. CHAPTER IX. Order CORRODENTIA (Cor-ro-den'ti-a). The Psocids (Psocids) arid the Book-lice. The vvinged members of this order have four membranous wings, with the veins prominent ', but with comparatively few cress veins; the fore wings are larger than the hind wings; and both pairs when not in use are placed roof -like over the body, being almost vertical, and not folded in plaits. The month-parts are formed for biting. The metamorphosis is in- complete. The name of this order is from the Latin corrodere, to gnaw, and refers to the gnawing habits of these insects. The wings, especially the fore wings, are often smoky in color or F.G. ^j.-fiacus venous. variegated. The arrangement of the veins of the wings (Fig. 107) differs in a striking manner from that of any other biting insect. The order includes two families, but representatives of only one of them occur in the United States. Family PSOCIDS (Psoc'i-dae). The Psocids (Pso'cids) and the Book-lice. Books may be old and out of date from our standpoint, but still be of vital importance to others. Take down from the shelf a time-yellowed book and open its neglected leaves 98 CORRODENTIA. 99 and watch the pale tiny creatures that scurry across its pages; examine one of them with a lens, look veil at his alert, knowing, black eyes, and we are sure you will believe that he is in search of real literature, and not merely a feeder upon paper, as we are taught. Anyway, scientists have con- cluded that these insects look wise enough to bear the name Atropos divinatoria (At'ro-pos di-vin-a-to'ri-a), or the Divining Atropos (Fig. 108). They are, however, more commonly called simply book-lice. f / L --- J \ Some members of the family Psocidae do not live in books, but feed upon lichens that are found on the trunks of trees and on fences, often a great number being grouped together. Many of these have wings, and look like plant-lice. (Fig. 107). The eggs are laid in heaps on leaves and branches, and are covered with a tissue of threads ; for the Psocids have the power of spinning silk similar to that spun by spiders. 108. CHAPTER X. Order MALLOPHAGA (Mal-loph'a-ga). The Bird-lice. The members of this order arc wingless parasitic insects, with biting mouth-parts. Their metamorphosis is incomplete. The name of the order is from two Greek words : mallos, wool ; and phagein, to eat. Although some species infest sheep and goats, feeding upon their wool, by far the greater number live among the feathers of birds. It is due to this fact that the common name Bird-lice is applied to the entire group. The order includes several families; but we will not take the space to define them. The Bird-lice are well known to most people that have pet birds or who keep poultry. They differ from the true Lice in having biting mouth-parts, and in feeding upon either feathers, hair, or the skin ; while the true Lice have sucking mouth-parts and feed upon blood. It is to free themselves from these pests that hens wallow in the dust. When poultry are kept in closed houses they should be provided with a " dust-bath." All poultry-houses should be cleaned at least twice a year, and the old straw burned. Sprinkling powdered sulphur in the nests and oiling th<^ perches with kerosene will tend to keep the pests in check. If a poultry-house becomes badly infested, it should be cleaned thoroughly, and every part whitewashed ; and the poultry should be dusted with Buhach or Persian insect powder (Pyretkruw). 100 MALLOPHAGA 101 Fig. 109 represents Go modes stylifer (Gon-i-o'des styl'i fer), a species which infests the turkey; and Fig. no, FIG. 109. Goniodes stylifer. FIG. no. Trichodectes scalar is. (.From Law.) (From Law.) TricJiodectes scalaris (Trich-o-dec'tes sca-la'ris), a species infesting the ox. CHAPTER XL Order EUPLEXOPTERA (Eu-plex-op'te-ra). The Earwigs. The members of this order have ttsttally four wings ; the first pair of which are leathery, very small, without veins, and when at rest meet in a straight line on the back; the second pair are large, with radiating veins, and when at rest are folded both lengthwise and crosswise. The month-parts are formed for biting. The caudal end of the body is furnished with a pair of appendages which resemble forceps. The meta- morphosis is incomplete. The name of the order is from three Greek words : eu t well ; pleko, to fold ; and pteron, wing. The word is not well formed, but it cannot now be changed. It refers to the unusual folding of the hind wings. This order is termed the Dermaptera by many entomologists, but this name was first applied to certain other insects, and so should not be used for these. The fore wings of these insects resemble the wing-covers of beetles, and like them differ greatly from the usual form. The hind wings are very different from those of any other insects. Figure ill represents one of these; they are furnished with radi- ating veins, which extends from a point some distance from the base of the wings. When the wing is not in use that part over which these FIG. in. wing of Earwig. veins extend is folded in plaits like a fan, after which the wing is folded twice crosswise. Al- 102 EUPLEXOP TERA. 103 though these insects bear some resemblance to beetles, they differ from them markedly in having an incomplete meta- morphosis. The order includes only a single family. Family FoRFlcULlDyE (For-fi cu'li dae). 7 he Eanvigs. These are long and narrow insects, resembling rove- beetles in the form of the body and in the shortness of the wing - covers, but easily distinguished by having a pair of forceps at the end of the body (Fig. 112). The common name, earwig f has reference to a widely spread fancy that these insects creep into the ears of sleeping persons. The earwigs are rare in the North- eastern United States, but are more often found in the South and on the Pacific coast. In Europe they are com- mon, and are often troublesome pests, feeding upon the corollas of flowers, fruits, and other vegetable substances. I FIG. ii2. An Earwig CHAPTER XII. Order ORTHOPTERA (Or-thop'te-rd). Cockroaches, Crickets, Grasshoppers, and of hers. The members of this order have four wings : the first pair are thickened, and overlap when at rest ; the second pair are thinner, and are folded in plaits like a fan. The mouth-parts are formed for biting. The metamorpJiosis is incomplete. The order Orthoptera includes some of the very common and best-known insects. The most familiar representatives are those named above. Although the song of the Katydid and the chirp of crickets are most often associated with recollections of pleas- ant evenings spent in the country, we cannot forget that to members of this order are due some of the most terrible insect scourges man has known. The devastations caused by great swarms of migratory locusts are not only matters of historical record, but are too painfully known to many of our own generation in the Western States. With the exception of a single family {Mantidce), the members of this order are, as a rule, injurious to vegetation ; and many species are quite apt to multiply to such an extent that their destruction of vegetation becomes serious. The name of the order is from two Greek words: orthos, straight; andflteron, a wing. It refers to the longitudinal folding of the hind wings. In the Orthoptera the two pairs of wings differ in struc- ture. The fore wings are parchment-like, forming covers for the more delicate hind wings. These wing-covers have re- 104 ORTHOPTERA. 10$ ceived the special name tegmina (teg'mi-na); they are furnished with a fine network of veins, and overlap at the tip at least. There are many species in which the wings are rudimentary, even in the adult state. Such adults resemble nymphs ; but in the case of the jumping Orthoptera, where this peculiar- ity most often occurs, nymphs can be distinguished by the fact that the rudimentary hind wings are outside of the fore wings, instead of beneath them, as in the adult state. This order includes only six families. We are able, there- fore, to discuss all of them in this work. The following synopsis will aid the student in fixing in his mind the more important characteristics of each family. SYNOPSIS OF THE FAMILIES OF THE ORTHOPTERA. THE RUNNING ORTHOPTERA. The body is oval when seen from above, and is very flat; the three pairs of legs are similar in form ; the insects run rapidly, p. 106 BLATTID^E. THE GRASPING ORTHOPTERA. The prothorax is very long and slender ; the first pair of legs are very different from the others, and are fitted for grasping, p. 106 MANTIDjE. THE WALKING ORTHOPTERA. The body is very long and slender; the three pairs of legs are similar in form, and are also very long and slender ; the insects walk slowly, p. 108. . . . PHASMID^;. THE JUMPING ORTHOPTERA. The hind legs are very much stouter or very much longer, or both stouter and longer, than the middle pair, being fitted for jumping. This group includes three families : The Short-horned Grasshoppers, or Loc^lsts. The antennae are shorter than the body. The ovipositor of the female is short and composed of four separate plates. The tarsi are three-jointed. p. 108 ACRIDIDJE. The Long-horned Grass/toppers. The antennae are very slender and longer than the body. (This is also true of the crickets.) The ovipositor is sword-shaped. The tarsi are four-jointed. p. 112 LOCUSTID.E. The Crickets. The antennae, like those of the long- horned grass- hoppers, are very slender and longer than the body, except in the mole-crickets. The ovipositor is spear-shaped when exerted. The tarsi are three-jointed, p. 115 GRYLLIDJE. io6 THE STUDY OF INSECTS. Family BLATTID.E (Blat'ti-dae). The Cockroaches. After every one is in bed at night and all is quiet in the kitchen where there are water-pipes, often a throng of little creatures come forth from hiding-places and, like brownies., take possession of everything. They race around every where, trying to find something to eat ; they do not care much whether it is raw or cooked, but will devour almost anything that comes in reach of their greedy jaws. They eat book-bindings and bedbugs, if they find them, with equal alacrity ; and sometimes they get bold enough to appear in broad daylight. The little, pale brown rascal called the Croton-bug, which came to us from Europe and infests the vicinity of the pipes of the water systems of many of our cities, is es- pecially bold and impu- dent (Fig. 1 13). In fact, in the North our native cockroaches are mostly FIG. 114. A Wing- less Cockroach. FIG. 115. Ootheca of a Cock- roach. F G. 113. The Croton-bug. respectable, well-behaved insects, living in fields and forests under sticks and stones, the emigrant cockroaches being the offenders. Many cockroaches are wingless (Fig. 114). The eggs of a cockroach are laid, all at once, enclosed in a sort of pod which is more or less bean-shaped (Fig. 115). Thorough and frequent dusting with insect-powder in the cracks about the kitchen will rid a house of these pests. Family MANTID.E (Man'ti-dae). The Praying Mantes, or Mule-killers. Certainly they are pious-looking fellows, with their front legs clasped together in front of their meek, alert faces, and OkTHOPTF.RA. IO7 it is no wonder that they are called Praying Mantes. But the only prayer that could ever enter the mind of a Mantis FIG. 116. Phasmomantis Carolina. would be that some unwary insect might come near enough for him to grab it with his hypo- critical claws, and so get a meal. Devil-horses* rear-horses, and camel-crickets are other names applied to these insects, because of the long, slender prothorax which makes them look like tiny giraffes. They are also called mule-killers* from the absurd superstition that the dark-col- ored saliva they eject from their mouths is fatal to the mule. But they are absolutely harmless to both man and beast. They are mostly tropical insects, and often have wings that resemble the leaves of trees. Our common species, Phasmo- mantis Carolina (Phas- mo-man 'tis) (Fig. 116), is confined to the Southern States. The eggs are _ FIG - "7- Egg-mass of laid in masses and overlaid with a hard covering a Mantis - of silk ; the top of the masses having the appearance of be- ing braided (Fig. 117). THE STUDY OF INSECTS. Family PHASMIDJE (Phas'mi-dae). The Walking-sticks. The rambler in forests is often surprised to discover that a part of the casually-plucked branch in his hand is alive. A certain twig that was stiff and motionless sud- denly, when disturbed, walks off on long slender legs, as awkwardly as if it had never tried to walk before. Strange and uncanny creatures are these walking-sticks with their long pointed bodies and with legs colored and looking exactly like twigs and leaf-peti- oles. In the tropics their resem- blance to foliage is made more perfect by wings which are veined like leaves. In the Northern States we have only one common species, DiapJieromera femorata, (Di-aph-e- rom'e-ra fem-o-ra'ta), and that is wingless (Fig. 118). Walking- sticks feed upon foliage. Their eggs, which are large, are dropped on the ground under the trees by FIG. us. A walking-stick. the mother, who trusts entirely to fate to preserve them. Family ACRIDID^: (A-crid'i-dse). Locusts, or Short-horned Grasshoppers. Every country lad is familiar with the appearance of grasshoppers. But there are many kinds of these insects, representing at least two distinct families. The family Acrididae, or Locusts, includes those grasshoppers in which ORTHOPTERA. tht antennae, are shorter than the body, and in which the ovipositor of the female is short and made up of four sepa- rate plates (Fig. 119). The tarsi are three-jointed; and on FIG. 119. Side view of Locust with wings removed. each side of the first segment of the abdomen there is a cir- cular plate which is believed to be an ear. It is to these insects that the term locust is properly ap- plied. For the locusts of which we read in the Bible, and in other books published in the older countries, are members of this family. Unfortunately in the United States the term locust has been applied to the Periodical Cicada, a member of the order Hemiptera, described later. And, what is more unfortunate, the scientific name Locustidae was given long ago to the next family and cannot now be changed. It should be remembered, therefore, that the locusts do not belong to the Locustida::. Locusts lay their eggs in oval masses and cover them with a tough substance. Some species lay their eggs in the ground. The female makes a hole in the ground with her ovipositor, which is a good digging-tool. Some species even make holes in fence-rails, logs, and stumps ; then, after the eggs are laid, the hole is covered up with a plug of gummy materials. There is but one generation a year, and in most cases the winter is passed in the egg-state. This family is of great economic importance, as the members of it usually appear in great numbers in every region where plants grow, and often do much damage. The males of many locusts are able to produce sounds. This is done in two ways: First, certain species rub the inner surface of the hind femora, upon which there is a row of minute spines, against the outer surface of the wing-covers. HO THE STUDY OF IN 'SECTS. In this case each wing-cover serves as a fiddle, and each hind- leg as a fiddle-bow. Second, other species rub together the upper surface of the front edge of the hind-wings and the under surface of the wing-covers. This is done while the locust is flying, and the result is a crackling sound. There are very many species of locusts in the United States. We have space to refer to only a few here. The most familiar member of the family is the Red- legged Locust, Melanoplus femur-rubrum (Me-lan'o-plus) (Fig. 120). It is more abun- dant than any other species throughout the United States, except in the high dry lands of the central part of the . cont i nen t. Here the Rocky Mountain Locust, Melanoplus sprctus, abounds. This spe- cies closely resembles the red-legged locust, except that it has longer wings. It is this insect that sometimes migrates into the lower and more fertile regions of the Mississippi Valley and does such great damage. It will be remembered that at one time it almost produced a famine in Kansas and the neighboring States. Fortunately the young of this insect hatched in the low regions are not healthy, and die before reaching maturity. Consequently the plagues caused by the emigration of this insect are of short duration. There are several other species of Melanoplus common in this country, but they can be distinguished only by very careful study. The Clouded Locust, Eneoptolophus sordidus (En-cop-tol'- o-phus sor'di-dus) (Fig. 121), is very common in the Eastern United States during the autumn. It abounds in meadows and pastures, and attracts attention by the crackling sound made by the males during flight. Its FlG -Enc ptoi phus color is dirty brown, mottled with darker spots. ORTHOPTERA. Ill The Carolina Locust, Dissosteira Carolina (Dis-sos-tei'ra), is common throughout the United States and Canada, and at the North is our largest species. It lives in roads and on bare places, and its color matches the soil on which it lives. It is usually pale yellowish or reddish-brown or slate color, with small dusky spots. The hind wings are black, with a broad yellow edge. It measures from one inch and a half to nearly two inches in length. The Sprinkled Locust, Chrysochraon conspersuin (Chry- soch'ra-on con-sper'sum) (Fig. Here the wings are a little shorter than the abdomen in the males, and much shorter in the females. In the South and in the 122), is a common species. FiG. ^.- a rar g inicolU. FlG m.Chrysochraon conspersum. West we find several genera in which the body is very long and slender. Lcptysma marginicolle (Lep-tys'ma mar-gin-i- serve as an illustration of the form of these insects. There is a group of small locusts of which Tcttix (Fig. 124) is an example, which is remarkable for the shape of the pronotum. This projects backward like a little roof over the wings, and often extends beyond the end of the abdomen. With these insects the wing-covers are in FlG - 12 -- Tettix - the shape of small rough scales, the wings being protected by the large pronotum. These insects are commonly found in low, wet places, and on the borders of streams. Their colors are usually dark, and are often protective, closely resembling that of the soil upon which they occur. These locusts are very active, jumping great distances. 112 THE STUDY OF INSECTS, Family LOCUSTID^; (Lo-cus'ti-dse). The Long-horned Grasshoppers. Any one that is in the habit of lying in the tall grass of meadows or pastures and watching the insects that can be seen there is sure to be familiar with certain green grass- hoppers, which attract attention by the extreme delicacy and great length of their antennae. These are our most common members of the Locustidae. The antennae are much more slender than with the short-horned grasshoppers or locusts, and much longer, exceeding the body in length. The tarsi are four-jointed. The ear-like organs, when present, are situated near the base of the fore tibiae (Fig. 125), and the ovipositor is sword-shaped. In those species of this family in which the wings are well developed we find the males provided with an elabo- FIG. 126. Wing-cover of Male Meadow Grasshopper. FIG. 127. Wingf-cover of Female Meadow Grasshopper. rate musical apparatus by means of which they call their mates. This consists of a peculiar arrangement of the veins and cells of a portion of each wing-cover near its base. This arrangement differs in the different species ; but in each it is ORTHOPTERA. 113 such that by rubbing the wing-covers together they are made to vibrate, and thus produce the sound. Figure 126 repre- sents a wing-cover of the male of a common meadow grass- hopper, and Figure 127 that of a female of the same species. In order to facilitate the study of this family the more common representatives can be arranged in four groups : The Meadow Grasshoppers, the Katydids, the Cricket-like Grasshoppers, and the Shield-backed Grasshoppers. I. The Meadoiv Grasshoppers. Under this head can be classed our most common members of the family ; they abound upon grass in meadows and in moist places. Figure 1 28 represents one F ' G< *>- of these insects. II. The Katydids. The chances are that he who lies awake of a midsummer night must listen whether he wishes to do so or not, to an oft-repeated, rasping song that says, " Katy did, Katy did ; she did, she didn't," over and over again. There is no use of wondering what Katy did or didn't do, for no mortal will ever know. If, when the dawn comes, the listener has eyes sharp enough to discern one of these singers among the leaves of some neighboring tree, never a note of explanation will he get. The beautiful, finely- veined wings folded close over the body keep the secret hid- den, and the long antennas, looking like threads of living silk, will wave airily above the droll, green eyes as much as to say, " Wouldn't you like to know?" The katydids live only on trees, and sing only during the night. There are several species of katydids common in the United States. The Western and Southern species, called the Angular-winged Katydid, Microcentrum retinervis (Mic-ro-cen'trum ret-i'ner- vis) lays its eggs in neat rows upon leaves and branches ; the eggs are oval, and each overlaps its neighbor slightly 9 114 THE STUDY OF INSECTS. (Fig. 129). In many sections where the katydids do not occur, the song of the Snowy Tree-cricket, described later, is often mistaken for that of a Katydid. FIG. 129. The Angular-winged Katydid and its eggs. III. The Cricket -like Grasshoppers. These are wingless, and resemble crickets in form. The most common members of this group belong to the genus Ceuthophilus (Ceu-thoph/i-lus) (Fig. 130). These insects are found under stones and rub- bish, especially in woods. Very closely allied to them are the colorless and blind Cave-crickets, Hadencecus (Had-e- nce'cus), found in caves. FIG. 130. Ceuthophilus. ORTHOPTERA. 11$ IV. The Shield backed Grasshoppers. These are also wingless, and dull-colored insects, which bear some resem- blance to crickets. They present, however, a queer appearance, due to the pronotum extend- ing backward over the rest of the thorax, like a sun-bonnet worn over the shoulders with the back side forward. This group is repre- sented in the Eastern half of the United States by Thyreo- notus (Thyr-e-o-no'tus) (Fig. 131). In the regions west of the Mississippi River occur the " Western Crickets," belonging to the genus Anabrus (An'a-brus), and on the Pacific coast FIG. \y.Stenopelmatus. there are large, clumsy creatures with big heads, that live under stones and in loose soil, and- are popularly known as Sand-crickets. These belong to the genus Stenopelmatus (Sten-o-pel-ma'tus) (Fig. 132). Family GRYLLID.E (Gryrii-dae). The Crickets. The crickets differ from both families of grasshoppers in having the wing-covers flat above and bent sharply down at the edge of the body like a box-cover, instead of meeting in a ridge above the body like a roof. The antenna:; are long THE STUDY OF INSECTS. and slender, like those of the Locustidae ; but the form of the ovipositor is quite different in this family, being spear- shaped, instead of sword-like. The males of the crickets have musical organs which are even more elaborate than those of the Katydids and meadow grasshoppers. Here all that part of each wing-cover that lies on the back is occupied by them. This gives the males a very different appearance from the females, the wing- covers of that sex being veined simply. During the latter part of summer and in the autumn the air is filled with the chirping of crickets. It is an interest- ing thing to watch one of these fiddlers calling his mate. By moving quietly in the direction from which the sound comes, and stopping whenever the insect stops chirping, but moving on again when he renews his song, one can get near enough to see how he does it. This can be done even in the night with the aid of a lantern, as the crickets do not seem to mind lights. Figure 133 represents the musical apparatus of a cricket. FIG. 133. Tegmina of male GryUus. From this it will be seen that the large veins divide the wing- covers into disk-like membranous spaces. If the principal vein which extends diagonally across the base of the wing- OR THOP TERA. 1 1 7 cover be examined with a microscope, it will be seen to be furnished with ridges like those of a file (Fig. 133, b). On the inner margin of the \ving-cover, a short distance toward the base from the end of the principal vein, there is a hardened portion which may be called the scraper. This is shown enlarged at c in the figure. Each \ving-cover is there- fore provided with a file and a scraper. When the cricket wishes to make his call, he elevates his wing-covers at an angle of about forty-five degrees with the body ; then hold- ing them in such a position that the scraper of one rests upon the file of the other, he moves the wing-covers back and forth sidewise so that the file and the scraper rasp upon each other. This throws the wing-covers into vibration, and produces the call. There are comparatively few species of crickets, but they represent three quite distinct groups. These can be dis- tinguished as the Mole Crickets, the True Crickets, and the Tree Crickets. I. The Mole Crickets. These are , , called Mole Crickets because they burrow in the ground like moles. There are species belonging to the next group, the true crickets, which burrow in the ground ; but the mole-crickets are pre-eminently burrowers. The form of the body is suited to this mode of life. The front tibiae, especially, are fitted for digging; they are greatly broadened, and shaped somewhat like hands, or the feet of a mole. Figure 134 represents one of these insects. The mole-crickets feed upon the tender roots of various plants, and where they are common they are c^rimic r^cfc FIG. 134 SeriOUS peSUS. tarea/is. II. The True Crickets. To this group belong our com- mon, black acquaintances that peep at us from the cracks THE STUDY OF INSECTS. in the paving, or jump across our paths when we walk in the fields. They are com- mon everywhere; some spe- cies even live in our houses. They usually feed upon plants, but are sometimes predaceous. FIG. 135. Gryllus abbreviatus. The eggs are laid in the au- tumn, usually in the ground, and are hatched in the follow, ing summer. The greater number of the old crickets die on the approach of winter ; a few, however, survive the cold season. Figure 135 represents the female of a species com. mon in the East. In this species the wings are shorter than usual. III. The Tree Crickets. The common name of this group was suggested by the fact that these crickets are very apt to inhabit trees ; but they occur also on shrubs, or even on high herbs and tall grass. The most abundant species in the East is the Snowy Tree- cricket, (EcantJius niveus (CE-can'thus niv'e- us). This is a delicate, whitish-green insect, that lives upon shrubs or plants. The female often does serious damage by laying her eggs in raspberry canes, causing them to die above the puncture. Canes thus in- jured should be cut and burned in the early spring before the eggs are hatched. Figure 136 shows the male, his closely folded wings showing beneath his delicate transparent wing-covers. The female has her wing- covers wrapped closely around her body, making her look much narrower than the male. FIG. \-^6.CEcantkus nii'eus, male. CHAPTER XIII. Order PHYSOPODA (Phy-sop'o-da). Tkrips. The members of this order have four ivings ; these are similar in form, long, narrow, membranous, not folded, witli but few or no veins, and only rarely ^vitll cross veins ; tliey are fringed ^vith long hairs, and are laid horizontally along the back when at rest. The metamorphosis is incomplete. The mouth parts are probably used chiefiy for sucking; they are intermediate in form between those of t lie sucking and those of the biting insects (Fig. 138); the mandibles are bristle-like; the maxilla are triangular, fiat, and furnished with palpi ; and tiie labial palpi are also present. The tarsi are two- jointed, bladder-like at tip, and witJiout claws. Pull to pieces a clover-blossom or a daisy, and you will probably find at the base of the florets many wee, black, red, or yellowish insects. These are so small that it would take a dozen or more placed end to end to measure an inch ; and when disturbed they are apt to thrust the end of their bodies up in the air as if they meant to sting, looking as ferocious as such small insects can look. They are extremely lively, leaping or taking flight with great agility. Under a microscope their four narrow wings, delicately fringed all around with long hairs, may be seen ; these wings are laid flat down the back when at rest. The red ones are wingless, and are the young of the black species. Some species eat other insects, but most of them live upon vegetation. There is one species, LimotJirips poapJiagus (Lim'o-thrips po-aph'a- IIQ I2O THE STUD Y OF INSECTS. gus) that damages timothy and June-grass very much by working in the upper joints. In the early summer the dead and yellow heads of grasses thus destroyed may be seen everywhere in grass-growing regions. Some species live under the bark of trees. The accompanying figure repre- sents one of these insects very greatly enlarged (Fig. 137). FlG. 137. Thrift. FIG. 138. Mouth-parts of Thrips. (Drawn by J. M. Stedman, under the author's direction.) 8, labrum; 10, mandible; n, maxilla; 12, labium. The insect infesting grapes, called "The Thrips," is not a Thrips at all, but a leaf-hopper belonging to the Homoptera. The name Physopoda is from two Greek words : physao, to blow up, and potis, a foot. It refers to the curious bladder-like feet of these insects. Figure 138 represents the mouth-parts of Thrips. CHAPTER XIV. Order HEMIPTERA (He-mip'te-ra). Bugs, Lice, Aphids, and otJiers. The winged members of this order have four wings; in cne sub-order t lie first pair of wings are thickened at the base, with thinner extremities which overlap on the back ; in another sub-order the first pair of zvings are of the same thickness throughout, and usually slope at the sides of the body. The month-parts are formed for sucking. The metamorphosis is incomplete. The order Hemiplera includes many well-known pests: here belong the true bugs, the lice, the aphids, the scale insects, and many other forms injurious to plants. On the other hand, some of the species are ranked among beneficial insects on account of their predaceous habits ; while still others, as the cochineal and lac insects, furnish us with useful products. The name Hemiptera is from two Greek words : hemi, half; and pteron, a wing. It was suggested by the form of the first pair of wings in the true bugs. Here the basal half of these organs is thickened somewhat like the wing-covers of beetles, only the terminal half being wing-like. The second pair of wings are membranous, and when at rest are folded beneath the first pair. The mouth-parts are formed for piercing and sucking. Without dissection, they usually appear as a slender jointed beak, Arising at the base of a shorter, pointed upper lip. This beak consists of four bristles, enclosed in a fleshy, 121 122 7WE STUDY OF INSECTS. jointed sheath (Fig. 139). Two of the bristles represent the mandibles, and two the maxillae. The sheath is supposed to consist of the labium and the grown-together labial palpi. In their transformation the Hemiptera pass through an incomplete metamorphosis ; the young nymphs resembling FIG. 13 9. Mouth-parts FIG. 140, a. Head of an heter- FIG. 140, l>. Head of Bug. (Af- opterous insect. of an homopterous ter Muhr.) insert. the adults more or less closely in form, and the wings being gradually developed at successive molts. This order includes three well-marked groups, which are ranked as suborders. The first of these, the Hetcroptera, includes the true bugs. They are placed first, as we believe they resemble the ancient Hemiptera the first to appear on the earth more closely than the members of either of the other suborders. The second suborder, the Parasitica, in- cludes the lice. These insects are much lower in structure than the Heteroptera ; but we believe that this simplicity in structure is a result of degradation due to parasitic habits, and therefore really represents a later development than that shown by the Heteroptera. In other words, the lice are probably descendants of some ancient form resembling some of the existing Heteroptera. Among the Heteroptera the bedbug exhibits a similar downward tendency. The third suborder, the Homoptcra, includes some forms that HEMIPTERA. 12$ are perhaps as primitive as any of the existing Heteroptera, but, on the other hand, we find here forms that represent the widest divergence from the hemipterous type known to MS. These three suborders can be separated by the following table : A. Wingless Hemiptera, parasitic upon man and other Mammals, with a fleshy, unjointed beak p. 147 II. PARASJTICA. AA. Hemiptera with or without wings, but with a jointed beak. B. First pair of wings thickened at the b;ise, with thinner extremi- ties, which overlap on the back; beak arising from the front part of the head (Fig. 140, a), p. 123. .. .1. HETEROPTERA. BB. Wings of the same thickness throughout, and usually sloping at the sides of the body; beak arising from the hinder part of the lower side of the head (Fig. 140, b} p.i48.III. HOMOPTERA. Suborder HETEROPTERA (Het-e-rop'te-ra). The True Bugs. People that know but little regarding entomology are apt to apply the term bug to any kind of insect ; but, strictly speaking, only the Hemiptera are bugs, and many restrict the term to members of this suborder. We therefore des- ignate the Heteroptera as the True Bugs. The bugs are very common insects. They abound on grass and on the foliage of other plants. Certain foul-smell- ing members of this group are well-known pests in gardens, and upon berries in fields. In this suborder the first pair of wings are thickened at the base, while the tips, which overlap each other on the back of the insect, are thin and transparent ; and the beak arises from the front part of the head (Fig. 140, a). Some of the Heteroptera live in water, others on land, while still others live on the surface of the water or in marshy places. Each of these modes of life are characteristic of certain fami- lies. The name Heteroptera is from the Greek heteros, di- verse, and pteron, a wing. The following synopsis will aid 124 THE STUDY OF INSECTS. the student in learning the characters of the families of this suborder : SYNOPSIS OF THE HETEROPTERA. THE SHORT-HORNED BUGS. Bugs with short antennae, which are nearly or quite concealed beneath the head. Bitgs tJiat live within water. The Water-boatmen, Family CORISID^. (p. 129.) The Back-swimmers, Family NOTONECTID^E. (p. 130.) The Water scorpions, Family NEPID^E. (p. 130.) The Giant Water-bugs, Family BELOSTOMID^E. (p. 131.) The Creeping Water-bugs, Family NAUC.ORID^E. (p. 133.) Bugs that live near water. The Toad-shaped Bugs, Family GALGULID^E. (p. 133.) THE LONG-HORNED BUGS. Bugs with antennae at least as long as the head, and prominent except in the Phymatidce, where they are concealed under the sides of the prothorax. The Semi-aquatic Bugs. The Shore-bugs, Family SALDID^. (p. 134.) The Broad-shouldered Water-striders, Family VELIID^E. (p. I34-) The Water-striders, Family HYDROBATID^E. (p. 135.) The Marsh-treaders, Family LIMNOBATID^E. (p. 136.) The Land-bugs. The Land-bugs with four-jointed antenna. The Thread-legged Bugs, Family EMESID^:. (p. 136.) The Assassin-bugs, Family REDUVIID^E. (p. 137.) The Damsel-bugs, Family NABID^E. (p. 138.) The Ambush-bugs, Family PHYMATID.E. (p. 138.) The Flat bugs, Family ARADID^E. (p. 139.) The Lace-bugs, Family TINGITID^E. (p. 139.) The Bed-bug and the Flower-bugs, Family ACANTKIID^E, (p. 140). The Leaf-bugs, Family CAPSID^E. (p. 140.) The Red-bug Family, Family PYRRHOCORID^:. (p. 141.) The Chinch-bug Family, Family LVGMIDJE. (p. 142.) The Stilt-bugs, Family BERYTID^E. (p. 143.) The Squash-bug Family, Family COREIDTE. (p. 143.) The Land-bugs with five-jointed antennce. The Stink-bug Family, Family PENTATOMID^;. (p. 144.) The Burrower-bugs, Family CYDNID.E. (p. 145). The Negro-bugs, Family CORIMEL/ENID.E. (p. 146.) The Shield-backed bugs, Family SCUTELLERID^E. (p. 146 j HEMIPTERA* 125 Classification of the Heteroptera. (For advanced students.} In order to use the following table for determining the families of bugs, the student should become familiar with the names applied to different parts of the fore-wings of these insects. The thickened basal portion is composed of two pieces joined together at their sides : one of these is narrow and is the part next to the scutellum when the wings are closed (Fig. 141, fl); this is distinguished as the clavus (cla'vus). The other broader part is the corium (co'ri-um) p IG ~ , Diagram of (Fig. 141, co). The terminal portion of the wing- wing-cover of a cover is designated as the membrane (Fig. 141, m.) In certain families a triangular portion of the terminal part of the corium is separated as a distinct piece; this is the czmeus (cu'ne-us) (Fig. 141, cii). In certain other cases, a narrow piece on the costal) margin of the corium is separated by a suture; this is the embolhim (em-bo'li-um) (Fig. 141,*?). FIG. 142. Nabidte. FIG. 143. Acanthiidce. FIG 144. Capstdee. FIG. 145. PyrrhocoridcE. FIG. 146. LygieidiB. FIG. 147. Coreidte. TABLE FOR DETERMINING THE FAMILIES OF THE HETEROPTERA. A. Antennae shorter than the head, and nearly or quite concealed in a cavity beneath the eyes. B. Hind-tarsi without claws. C. Fore-tarsi flattened with a fringe of hairs on the edge, and without claws ; head overlapping the prothorax. p. 129. CC. Fore-tarsi of the usual form, and with two claws; head in- serted in the prothorax. p. 130 .............. NOTONECTID^E. 126 THE STUDY OF INSECTS. BB. Hind-tarsi with two claws. C. Caudal end of the abdomen furnished with a respiratory tube composed of a pair of grooved, thread-like organs, p. 130. NEPIDJE. CC. Caudal end of abdomen without respiratory tube. D. Legs flattened, fitted for swimming ; caudal end of the ab- domen furnished with a pair of strap-like appendages (these appendages are retractile and are frequently withdrawn from Sight). p. 131 BELOSTOMIDjE. DD. Legs fitted for walking; abdomen without strap-like caudal appendages. E. Without ocelli, p. 133 NAUCORID^. EE. Ocelli present, p. 133 GALGULID/E. AA. Antennae at least as long as the head, usually free, rarely (/ hy- matid the membrane there are one or two cells, otherwise the membrane is without veins (Fig. 169). More than two hundred species belonging to this fam- ily are known to occur in the United States. Figure 170 represents the Four-lined Leaf-bug. Poecilocapsus lincatus (Pce-cil-o-cap'sus lin-e-a'tus), a yellow bug, with its prothorax and wing- -pcedi- covers marked with black, which is abundant tus. sus linea ' in early summer on the leaves of currant- bushes and of sage. Family PYRRHOCORID^E (Pyr-rho-cor'i-dae). Tlie Red-bug Family. The members of this family are rather stout and heavily formed bugs, and are generally black or brown, marked with red. Some members of the next family resemble these in markings, but the two families can be distinguished by the venation of the membrane of the wing-covers. In this family there are two large cells at the base of the membrane, and from these arise branching veins (Fig. 171). The most important species of this family is the Red-bug, or Cotton-stainer, Dysdercus suturellus (Dys-der'cus su-tu- rel'lus) (Fig. 172). The adult is of a reddish color ; the wing- covers are pale brown, with pale-yellow stripes. The young are bright red, with black legs. They do much damage by piercing the stems and bolls of the cotton-plant and sucking the juices, but do much more damage by staining the cotton in the open- ing bolls. They also puncture the rind of oranges in Florida, so that decay soon sets in, and the FIG. 172. z^j-fruit drops. These insects can be trapped by dercus sutu-. .... . A , laying chips of sugar-cane around the cotton- 142 THE STUDY OF INSECTS. fields. In orange-groves heaps of cotton-seed as well as pieces of sugar-cane will be found useful ; the insects will collect in these places and can be scalded to death. Family LYG^ID^E (Ly-gae'i-dae). The Chinch-bug Family. This, too, is a large family, about one hundred and fifty species being known to occur in the United States. Here the membrane of the wing-covers is furnished with four or five simple veins, which arise from the base of the mem- brane; sometimes the two inner veins are joined to a cell near the base (Fig. 173). This family contains the Chinch-bug, Blissus leucopterus (Blis'sus leu-cop'te-rus), the most destructive member of the Heteroptera occurring in the United States. Although quite widely distributed, its injuries have attracted most attention in the Missis- sippi Valley, where it has destroyed many million dollars' worth of grain. It is a small Fir _ bug, measuring less than one sixth of an inch in length. In Figure 174 it is represented slightly enlarged and greatly enlarged. It is blackish in color, with snowy- white wing -covers, each marked with a dark spot and Y-shaped line, as shown in the figure. The species is di- morphic, there being a short-winged form. There are two generations of the Chinch-bug each year ; they winter as full-grown insects and hide under rubbish. In the early spring they come forth and lay their eggs in fields of grain upon the roots or stems beneath the ground. The eggs hatch in about two weeks. The nymphs are red, and feed at first upon roots ; afterwards they attack the stalks of the plants they infest. In about fifty days they get their growth. About this time the whole brood starts out to find new pastures, and they all march on foot in one direction, like an army. Although they are tiny insects they HEMIPTERA. 143 number millions, and so attract much attention. As soon as they find a new field of grain they lay their eggs there for another brood. No satisfactory means of combating this insect was known until recently. But it has now been ascertained that it is destroyed by a contagious disease which can be spread artificially. Diseased bugs are sent to places where the dis. ease does not exist ; and thus the contagion is spread. Extensive experiments are being carried on in Kansas at the time of this writing, and the results so far seem very encour- aging. Family BERYTID^: (Be-ryt'i-dae). The Stilt-bugs. This family includes a small number of land bugs, in which the body, legs, and antennae are very slender, resembling somewhat the thread-legged bugs (Emesidae). The stilt bugs have the tip of the femora, the tip of the first joint of the antennae, and the last joint of the antennae somewhat enlarged (Fig. 175). Only two species have been found in the United States. These are Ncides muticiis (Ne'i-des mu'ti-cus), which has a prominent spine on the vertex of the head ; and Jalysus spinosns (Jal'y-sus S pj. no'sus), which, although spined in other places, lacks the spine on the vertex. These are sluggish insects, found in the undergrowth of woods and in meadows and pastures. Family COREID^E (Co-re'i-dae). The SquasJi-bug Family. This family is also a very extensive one, including many species. The best character foi distinguishing the members FIG. 175. Jalysus spinosus. M4 THE STUDY OF INSECTS. of it is the nature of the venation of the membrane of the wing-covers. This part is furnished with many veins, most of which spring from a cross-vein near F.G. x 7 6. its base (Fig. 176). The Squash-bug, Anasa tristis (An'a-sa tris'- tis), is a good example of this great family. These when full- grown are brownish-black bugs, with some yellow spots along the edges of the abdomen (Fig. 177), and are dirty yellow on the under side. This bug winters in the adult state, and takes the first opportunity in the spring to lay its eggs on the earliest sprouts of squash and pumpkin vines. As soon as they hatch, the young bugs attack the vines and are apt to destroy them entirely. The remedy is to protect the young tristis. plants by frames covered with netting. Family PENTATOMlDyE (Pen-ta-tom'i-dae). The Stink-bug Family. This is a family the taste and odor of which most of us know to our sorrow. We learn the fla/or in one experience, and conclude that once is enough for a lifetime. To those who live in cities it may always remain a mystery why one berry looking just like another should taste and smell so differently ; but all barefooted boys and sun-bonneted girls from the country who have picked the wild strawberries on the hillsides or scratched their hands and faces in raspberry patches know well the angular green or brown bugs that leave a loathsome trail behind them ; and they will tell you, too, that the bugs themselves are worse than their trail, for it is a lucky youngster that has not taken one of these insects into his mouth by mistake with a handful of berries. It should not be concluded, however, that only members of this family possess this disagreeable odor ; for most of the Heteroptera protect themselves by rendering their bodies unpalatable in this way. Doubtless birds soon learn this HEMIPTERA. 145 fact and leave such bugs alone. But it is to members of this family that the expressive name given above is com- monly applied. This nauseous odor is caused by a fluid which is excreted through two openings, one on each side of the lower side of the body near the middle coxae. In this family the antennae are five-jointed ; the scu- tellum, although large, is less than half as long as the abdo. men ; and the front legs are not fitted for digging (Fig. 178). Some species of this family feed upon other insects, and so are very helpful to the farmer, one species especially being a gallant fighter against the potato-beetle. Other species feed entirely upon vegetables, while others live upon both Fl | tin ^~ A vegetable and animal matter. The Harlequin Cabbage-bug or Calico-back, Murgantia histronica (Mur-gan'ti-a his-tron'i-ca), is very destructive to cabbages, radishes, and turnips in the Southern States and on the Pacific coast. It is black with bands, stripes, and margins of red or orange or yellow. The full-grown bugs live through the winter, and in the early spring each female lays on the under surface of the young leaves about twelve eggs in two parallel rows. The young bugs are pale green, with black spots. They mature in a few days, so there are many generations in one season. It is difficult to find a remedy for this pest, but much can be done by placing cabbage and turnip leaves on the ground in early spring, and thus trapping them when they first come out of their winter quarters. Family CYDNID^E (Cyd'ni-dae). The Burrower-bugs. These are oval, rounded, or elliptical bugs, with five- jointed antennae; with the scutellum large, but less than 11 146 THE STUDY OF INSECTS. in all half as long as the abdomen ; and with the front legs more or less flattened, fitted for digging (Fig. 179). The species are generally black or very dark brown. They are found burrowing in sandy places, r or on the surface of the ground beneath sticks and FIG. 179. cyrtome- stones, or at the roots of grass and other herbage. nus mi- 2> o rabuis. The family is not a large one. The members of it probably feed upon plants ; but it is desirable that further observation be made upon the habits of this family. Family CORIMEUENID^E (Cor-i-me-laen'i-dae). The Negro-bugs. These bugs are mostly black, and are beetle-like appearance ; some have a bluish or greenish tinge, and are very convex. The scutellum is very convex, and, as in the following family, covers nearly the whole of the abdo- men. But in this family there is at the base of the scutellum on each side a short furrow into which the edge of the wing-cover fits when at rest. All of our species belong to the genus Corimel&na (Cor-i-me-lae'na). These insects infest various plants, and often injure raspberries and other fruit by imparting a disagreeable odor to them. Fig. 180 represents one of these bugs, some- what enlarged. Family SCUTELLERID.E (Scu-tel-ler'i-dae). The Shield-backed Bugs. The members of this family resemble the negro-bugs in the shape and size of the scutellum, which covers nearly the whole of the abdomen ; but the sides of the scutellum are not furnished with a groove for receiving the edge of the wing-covers. Fig. 181 repre- sents one of these insects enlarged. They feed upon plants. FIG. \%o.Cori- meleena iitra. FIG. 181. Euryga* ter alttrnaius. HEMIPTERA. Suborder PARASITA (Par-a-si'ta). 147 The Parasita includes certain parasites of man and other mammals, commonly known as lice. They are wingless, and differ from other Hemiptera in having the beak fleshy and not jointed. This suborder is represented in the United States by only one family, the Pediculidce. Family PEDICULID.E (Ped-i-cu'li-dae). The Lice. This family comprises the true lice, which differ from the bird-lice of the order Mallophaga in having sucking mouth- parts. The true lice live on the skin of mammals, and suck their blood. There are three species that infest man : one living on the head, among the hair ; and the other two on the body. Several species infest our domestic animals. The more FIG. ^.Hcematopinus asini. (From Law.) FlG. 183. H. eurysterntts. (From Law.) common of these are the louse of the horse (Fig. 182), and the louse of the cow (Fig. 183). Various substances are used for destroying lice on domes- tic animals : among them are a strong infusion of tobacco, 148 THE STUDY OF INSECTS. an ointment made of one part sulphur and four parts lard, Scotch snuff, powdered wood ashes, and kerosene emulsion. The remedy should be applied thoroughly, and repeated several times at intervals of three or four days, in order to destroy the young which may hatch after the first application. The stable and the places where the cattle are in the habit of rubbing should also be whitewashed or sprayed with kerosene, or strong kerosene emulsion. Suborder HOMOPTERA (Ho-mop'te-ra). Cicadas, Leaf-hoppers, Aphids, Scale-bugs and others. The Homoptera includes insects of widely diversified form, but which agree, however, in having the wings when present of the same thickness throughout, and usually slop- ing roof-like at the sides of the body when at rest, and in having the beak arise from the hinder part of the lower side of the head (Fig. 140, b}. The name is from two Greek words: homos, same; and pteron, a wing. This suborder includes nine families, which are designated as follows : The Cicadas, Family ClCADlD^E (p. 149). The Lantern-fly Family, Family FULGORID^: (p. 151). The Spittle Insects, Family CERCOPID^; (p. 152). The Leaf-hoppers, Family jASSIDyE (p. 153). The Tree-hoppers, Family MEMBRACID^; (p. 154). The Jumping Plant-lice, Family PSYLLID^: (p. 155). The Plant-lice, Family APHIDID^: (p. 156). The Aleyrodes, Family ALEYRODID.E (p. 163). The Scale-bugs, Family COCCID^E (p. 164). CLASSIFICATION OF THE HOMOPTERA. (For advanced students.'] TABLE FOR DETERMINING THE FAMILIES OF THE HOMOPTERA. A. Beak evidently arising from the head ; tarsi three-jointed ; anten- nae minute, bristle-like. HEM IP TERA . 1 49 B. With three ocelli, and the males with musical organs. Usually large insects, with all the wings entirely membranous, p. 149. ClCADID^E. BB. Ocelli only two in number or wanting ; males without musi- cal organs. C. Antennae inserted on the sides of the cheeks beneath the eyes. p. 151 FULGORID/G. CC. Antennae inserted in front of and between the eyes. D. Prothorax not prolonged above the abdomen. E. Hind tibiae armed with one or two stout teeth, and the tip crowned with short stout spines p. 152.. . CERCOPID^:. EE. Hind tibiae having a row of spines below p. 1 53. JASSID^E. DD. Prothorax prolonged into a horn or point above the abdomen, p. 154 MEMBRACID.E. AA. Beak apparently arising from between the front legs, or absent; tarsi one or two jointed ; antennae usually prominent and thread- like, sometimes wanting. B. Tarsi usually two-jointed; wings when present four in number. C. Wings transparent. D. Hind legs fitted for leaping; antennae nine or ten jointed. p. 155 PSYLLID^E. D. Legs long and slender, not fitted for leaping; antennae three to seven jointed, p. 1 56 APHIDID^E. CC. Wings opaque, whitish ; wings and body covered with a whitish powder, p. 163 ALEYRODID.E. BB. Tarsi one-jointed ; adult male without any beak, and with only two wings-; female wingless, with the body either scale- like or gall-like in form, or grub-like and clothed with wax. The waxy covering may be in the form of powder, of large tufts or plates, of a continuous layer, or of a thin scale beneath which the insect lives, p. 164.. COCCID.E. Family ClCADlD^ (Ci-cad'i-dae). The Cicadas (Ci-ca'das). The large size and well-known songs of the more common species of this family render them familiar objects. It is only necessary to refer to the Periodical Cicada (or the seventeen- year locust, as it has been improperly termed) and to the 150 THE STUDY OF IN SECTS. Dog-day Harvest-fly (Fig. 184) to give an idea of the more striking characters of this family. We have several species much smaller than either of these ; but their characteristic form and the presence of three ocelli are sufficient to distinguish them from the members of the other families. The Periodical Cicada, Cicada sep- tendecim (Ci-ca'da sep-ten'de-cim), is very generally known in this country, owing to the great numbers in which it appears, at long intervals of time. This periodical appearance is due to the long time required for the nymphs F,G. ^.-Cicada tilncen. ^ Q obta 'j n their growt h_ e ither SCVCn- teen or thirteen years and to the fact that all the members of one generation appear in the adult state at about the same time. The adult female lays her eggs in slits which she makes in the twigs of trees. Small fruit is sometimes in- jured in this way. The eggs hatch in about six weeks. The young nymphs finding no attraction in a world of sun- shine and of flowers, drop to the ground and bury them- selves in the earth, thus commencing a voluntary seclusion which lasts for years. They live by sucking the juices from the roots of trees. In May of the seventeenth year after their retirement to their earthy cloisters they crawl up to the surface of the ground, like renegade monks ; and, leav ing their nymph-skins clinging to the tree-trunks, like cast- off garments of penance, they come forth, broad-headed, broad-bodied, clear-winged creatures, well fitted to get all the experience possible out of a world whose frivolities they have so long scorned. But, like other creatures, they find a life of dissipation very exhausting, and after a few weeks they sing their last song, lay their eggs, and pass away. In the South these insects live only thirteen years under HEMIPTERA. 15 l ground, but in the North it requires seventeen years for a nymph to reach maturity. More than twenty distinct broods of this species have been traced out. In many localities several broods coexist; this explains the fact that in such places these insects ap- pear several times during a single period of seventeen years. There is a common species of Cicada known as the Dog- y day Harvest-fly or Lyreman, Cicada tibicen (Ci-ca'da ti-bi'cen), which requires only two years for its development, and as there are two broods of this species the adults appear every year. This Cicada (Fig. 184) is black and green in color, and more or less powdered beneath. And its song is the high, sharp trill that comes to us, midsummer noons, from the depths of trees where the singer is hidden amid the foliage, all unconscious that its shrill note has for centuries been a theme for poets. Family FULGORID/E (Ful-gor'i-dae). The Lantern-fly Family. This family is remarkable for certain exotic forms which it contains. Chief among these is the great Lantern-fly of Brazil, which is figured in many popular works on insects. Scarcely less strange are the Candle-flies of China and the East Indies. The popular names of these fnsects refer to the fact that they are phosphorescent, but we know of no native species that possesses this peculiarity. There does not seem to be any typical form of the body characteristic of this family. The different genera differ so greatly, that on superficial examination they appear to have very little in common. Some even resemble butterflies and moths, while others might easily be mistaken for neuropterous genera. The most useful character for recognizing these insects is the form and position of the antennae. These are bristle- shaped, and inserted in a button-shaped base on the side of IS 2 THE STUDY OF INSECTS. the cheek beneath the eyes. Although the Fulgoridae are vegetable feeders, none of our species have attracted the at- tention of agriculturists. There are, however, certain exotic species which do great injury to crops. The two accompanying figures will serve to show the wonderful variations in form of these insects; many other types exist. Figure 185 represents a common species of Sco- lops (Sco'lops), which occurs in grassy places. In this genus the head is greatly prolonged, as with the exotic Candle-flies. FIG. 185. Scolops. FIG. 186. Onnenis septen- trionnlis. Figure 186 represents Ormenis septenttionalis (Or'me-nis sep- ten-tri-o-na'lis), a beautiful pale-green species powdered with white, which feeds on wild grape-vines, drawing nourishment from the tender shoots and mid-ribs of the leaves during its young stages. Family CERCOPID/E (Cer-cop'i-dse). 77/(? Spittle Insects or Frog-hoppers. During the summer months one often finds upon various shrubs and herbs masses of white froth. In the midst of each of these masses there lives a young insect, a member of this family. In some cases as many as four or five insects inhabit the same mass of foam. The froth is supposed to consist of sap, which the insect has pumped from the plant, by means of its beak, and passed through its alimentary canal. It is asserted that these insects undergo all their transformations within this mass ; that when one is about to molt for the last time, a clear space is formed about its body ; the superficial part of the foam dries, so as to form a vaulted roof to a closed chamber, within which the change HEMIPTERA. 1 53 of the skin is made. The adult insects wander about on herbage and trees. They have the power of leaping well. The name frog-hoppers has doubtless grown out of the fact that formerly the froth was called " frog-spittle," and was supposed to have been voided by tree-frogs from their mouths. The name is not, however, inappropriate, for the broad and depressed form of our more common species is something like that of a frog. In this family the antennae are inserted in front of and between the eyes ; the prothorax is not prolonged back of the abdomen (as in the Membracidae) ; and the tibiae are armed with one or two stout teeth, and the tip crowned with short, stout spines, as shown in Figure 187. This figure represents the most com- , TT 1 r* FlG - mon spittle insect of the hastern United btates, ro / / . rangularis. Aphrophora quadrangutarts (A-pnropn o-ra quad- ran-gu-la'ris), and one of its tibiae greatly enlarged. Family JASSID^E (Jas'si-dae). The Leaf -hoppers. The most abundant members of the Homoptera, except perhaps the Aphids, are the leaf-hoppers. Large numbers of them can be easily collected by sweeping grass, herbage, or the foliage of shrubs. The leaf-hoppers are more slender than the spittle insects, and are also distinguished by the form of the hind tibiae, which are nearly or quite as long as the abdomen, curved, and armed with a row of spines on each margin (Fig. 188). FIG. iw.-proco- Among the leaf-hoppers that have attracted nia undata. . , , . . attention on account ot their injuries to vegeta- tion are the following : The destructive Leaf-hopper, Cicadula exitiosa (Ci-cad'u-la ex-it-i-o'sa), which is represented greatly enlarged by Figure 189, sometimes infests winter wheat to a serious extent in the Southern States. The Grape- 154 THE STODY OF INSECTS. - vine Leaf-hopper, Erythroneura vitis (E-ryth-ro- neu'ra vi'tis), is a well-known pest that infests the leaves of the grape. It is about one-eighth inch in length, crossed by two blood-red bands, and a third dusky one at the apex. It is often iinprop. erly called the " Thrip" by grape-growers. But the term Thrip or better Thrips should be restricted to members of the order Physopoda. The Rose Leaf-hopper, Enipoa roses (Em'po-a ro'sae), is also a well-known pest, as it often swarms on the leaves Reponf r o? of foses, doing great damage. Its presence is l879 ' ) usually indicated by numerous white cast skins adhering to the lower side of the leaves. The leaf-hoppers can be destroyed by a strong solution of soap, or with kerosene emulsion. In vineyards, where the use of these substances would injure the fruit, they can be trapped by two persons carrying a screen covered with tarred paper on one side of a row of vines, while a third per- son walking on the other side of the row frightens them from the vines on to the screen. Dead leaves and other rubbish, among which these insects hibernate, should be burned during the winter. Family MEMBRACID.E (Mem-brac'i-dae). The Tree-hoppers. Nature must have been in a joking mood when tree- hoppers were developed, for these little creatures are most FIG. 190. Tree-hoppers. HEMIPTERA. 155 ig2. comically grotesque in appearance. In general outline they resemble beech-nuts, except that many have humps on their backs. The prothorax is prolonged back- ward like a roof over the body, often quite covering it. If the young entomologist wishes to laugh, let him look at the faces of tree-hoppers through a lens (Fig. 190). Their eyes always have a keen, F c^' bu . droll look, and the line that separates the head b from the prothorax gives them the appearance of wearing glasses. In some cases the prothorax is elevated above the head, so that it looks like a peaked nightcap ; in others it is shaped like a Tam-o'- "' Shanter ; and sometimes it has horns, one on each side, which have given one species the name of the Buffalo Tree-hopper. Many species of this family live upon bushes or small trees, and are all good leapers ; hence the com- mon name, Tree-hoppers. Some species ex- crete honey-dew, and are attended by ants. All feed upon plants, but they seldom appear FlG . , 94 ._7>/- in sufficient numbers to do much damage. The accompanying figures will show some of the more common forms seen in this strange family (Figs. 191-194). Family PSYLLID^: (Psyl'li-dae). The Jumping Plant-lice. The jumping plant-lice are comparatively small insects ; our more common species measuring only from one-eighth to one-sixth inch in length, and it is rare that we find any twice that size. When examined with a lens they appear like tiny Cicadas (Fig. 195). T Their hind legs are formed for jumping ; their 1 antennae are nine or ten jointed, and their tarsi are only two-jointed. Figure 197 repre- sents the wings of a common species. The Psyllidae subsist entirely upon the 5 6 THE STUD Y OF INSECTS. juices of plants, and some of them cause serious injuries. Many species form galls ; one of the larger of these infest the Celtis or Hackberry. FIG. 196. The Pea-rtree Psylla, greatly enlarged. FIG. 197. Venation of Wings: .r, stigma; c, clavus ; c. s., elaval suture. The most destructive member of this family in the United States is the Pear-tree Psylla, Psylla pyricola (Psyl'la py-ric'o-la). This is a minute species, measuring only one- tenth inch in length to the tip of the folded wings (Fig. 196). But it occurs in such large numbers that it has destroyed extensive pear orchards, by sucking the sap from the smaller ^mbs and twigs. It can be destroyed by spraying the infested trees with kerosene emulsion imme diately after the leaves have expanded in the spring. Family APHIDID^: (A-phid'i-dae). The Plant-lice or Aphids (Aph'ids]. The plant-lice are well-known insects; they infest nearly all kinds of vegetation in all parts of the country. Our most common examples are minute, soft-bodied, green insects, with long legs and antennae, which appear on various plants in the house and in the field. Among our co'.nmon species are both winged and wingless forms (Fig. FIG. 198. A Group of 198). There are a great number of species, nearly all of HEMIPTERA. 157 which are of small size. In our largest species the body measures only about one-fourth inch in length, and usually these insects are very much smaller. The body is usually more or less pear-shaped. The winged forms have two pairs of delicate, transparent wings. These are furnished with a few simple veins, but the vena- tion is more extended than in either of the two following families. The first pair of wings is larger than the other, and the two wings of each side are usually connected by a compound hooklet. The beak is three-jointed, and varies greatly in length ; sometimes it is longer than the body. The compound eyes are prominent, and ocelli are also usually present. The antennae are from three to seven jointed. On the back of the sixth abdominal segment there is, in many species, a pair of tubes, through which a wax- like material is excreted. In some genera these organs are merely perforated tubercles, while in still other genera they are wanting. The substance known as honey-dew is excreted from the posterior end of the alimentary canal. It is sometimes produced in such quantities that it forms a glistening coat- ing on the leaves of the branches below the plant-lice, and stone walks beneath shade-trees are often densely spotted with it. This honey-dew is fed upon by bees, wasps, and ants. The bees and wasps take the food where they find it, paying little if any attention to its source ; but the ants recognize in the plant-lice useful auxiliaries, and often care for them as men care for their herds. This curious re- lationship will be discussed farther under the head of Ants. It is easy to see what benefit ants derive from this asso- ciation with plant-lice, and how they should learn that it is worth while for them to care for their herds of honey pro- ducing cattle. Little has been done, however, to point out the great benefit that accrues to the plant-lice from this re- lationship. It seems fair to assume that the plant-lice are greatly benefited, else why has the highly specialized appa- 158 THE STUDY OF INSECTS. ratus for producing the honey-dew been developed ? Writers long ago showed that ants protect plant-lice by driving away from them lady-bugs and other enemies. Recently, how- ever, Professor Forbes has demonstrated that, in certain ^ases at least, a more important service is rendered. In his studies of the Corn Plant-louse, ApJtis inaidis (A'phis mai'dis), he found that this species winters in the wingless, agamic form in the earth of previously infested corn-fields, and that in the spring the plant-lice are strictly dependent upon a species of ant, Lasins "alicmis (Las'i-us al-i-e'nus), which mines along the principal roots of the corn, collects the plant-lice, and conveys them into these burrows, and there watches and protects them. Without the aid of these ants, the plant-lice were unable to reach the roots of the corn. In addition to honey dew, many Aphids excrete a white substance. This may be in the form of powder, scattered over the surface of the body, or it may be in large floccu- lent or downy masses ; every gradation between these forms exists. The plant-lice are remarkable for their peculiar mode of development. The various species differ greatly in the de- tails of their transformation, but the following generaliza- tions can be made. There are several distinct forms in each species, each form playing a peculiar part in the history of the species.. If a colony of plant-lice be examined during the summer months it will be found, usually, to consist very largely of wingless individuals ; these are females, which reproduce without the intervention of males. This is the wingless agamic form. In many cases this form gives birth to living young, instead of laying eggs ; and the reproduction of this form is so rapid, that it would be disastrous to the species, by the destruction of the infested plants and the consequent starving of the insects, if another form of the species did not arise. But from time to time young are produced which become winged, and thus the spread of HEM IP TERA . I 59 the species is provided for. This winged form also con- sists entirely of females, and is known as the ^vinged agamic form. They produce in turn the wingless agamic form, a single, winged individual, which has flown to a new plant, starting a new colony. Generally on the setting in of cold weather, or in some cases on the failure of nourishment, the weather being still warm, there is produced a generation including individuals of both sexes. These are known as o the sexual forms. The males may be either winged or wingless, but these true females are always wingless. The sexual forms pair, and the female produces one or more eggb. It is in this state that the species usually pass the winter, and consequently these eggs produced by the sexual form are often called the winter eggs, to distinguish them from eggs produced by the agamic forms of certain species, and which are incorrectly termed pseudova (pseu- do'va). From the winter egg there hatches, usually in the spring-, an agamic female, which, as she is the stock from which the summer generations spring, is often called the stem-mother. The peculiar reproduction of the agamic forms is often termed reproduction by budding. Plant-lice are often very destructive to vegetation. The ordinary methods of combating them are either by the use of a strong solution of soap or with kerosene emulsion. Plant-lice vary greatly in their habits. Certain species live in the ground on the roots of plants. The Lettuce Earth-louse, RJiizobius lactucce (Rhi-zo'bi-us lac-tu'cae), is a good illustration. This occurs on the roots of lettuce, often in great numbers. Other species are found on the roots of grasses or herbaceous plants and usually accompanied by ants. On the other hand, many species, in fact the majority of Aphids, pass their lives on the foliage of plants, infesting especially the tenderer leaves. Familiar examples are the Cabbage Aphis, Aphis brassicce (A'phis bras'si-cae), the Apple- tree Aphis, Aphis mail, the Cherry tree Aphis, Mysus cerasi (My'sus cer'a-si), and the Peach-tree Aphis, Mysus persicce I6O THE STUDY OF INSECTS. (My'sus per'si-cae). The last three are almost invariably attended by ants. The Plant-lice of the genus Lachnus (Lach'nus) are usually found on the limbs of trees and shrubs. To this genus belong our largest Aphids, some of them measuring one-fourth inch in length. Figure 199 represents one of these enlarged. FIG. .-Lachnus. Some sp ecies of plant-lice live both on the roots and on the leaves of plants. One of these is the Grape Phylloxera, Phylloxera vastatrix (Phyl- lox-e'ra vas-ta'trix), which is the most important enemy of the grape. The presence of this insect is manifested by the vines in two ways: first, in the case of certain species of grapes, there appear upon the lower surface of the leaves fleshy swellings, which are more or less wrinkled and hairy ; these are hollow galls, opening upon the upper surface of the leaf, and containing a wingless agamic plant-louse and her eggs; second, when the fibrous roots of a sickly vine are examined, we find, if the disease is due to this insect, that the minute fibres have become swollen and knotty; or, if the disease is far advanced, they may be entirely decayed. Upon these root-swellings we also find an agamic, wingless, egg -laying plant - louse, the author of the mischief. The insects found upon the roots differ slightly from those found within the galls, but their specific identity is now generally accepted. Owing to the great injury which this species has done to the vineyards of France, hundreds of memoirs have been published regarding it. But as yet no satisfactory means of destroying it has been discovered. The difficulty lies in the fact that the insecticide must be one that can penetrate the ground to the depth of three or four feet, reaching all the fibrous roots infested by the insect. It must be a substance that can be cheaply applied on a large scale, and it must also be something that will kill the insect without injury to HEMIPTERA. r6l the vine. Carbon bisulphide has been used to son^e extent for this purpose. Where the vineyards are so situated that they can be submerged for a period of at least forty days during the winter, the insect can be drowned. But this method is obviously of limited application. It is found that vines growing in very sandy soil resist the attacks of the Grape Phylloxera. This is supposed to be due to the difficulty experienced by the insect in finding passage through sirch soil. Another well-known example of the plant-lice that make galls is Coloplia ulinicola (Col'o-pha ul-mic'o-la), which makes the Cockscomb Elm-gall. This gall is shaped more or less like a cock's comb, and is very common on the upper side of the leaves of the elm. There is a group of species of plant-lice known as the Woolly Aphids, on account of a white more or less downy or waxy substance with which the bodies of these insects are covered. Large numbers of one of these species are often found crowded together on the under side of the branches of alder. This species is known as the Alder-blight, Schizoneura tessellata (Schiz-o-neu'ra tes-sel-la'ta). In addition to the white excretion with which the body is covered this insect excretes large quantities of honey-dew. The result is that the branches infested by this insect, and those beneath the clusters of Aphids, become blackened with fungi that grow upon this secretion. There is also a curious fungus which grows in large spongy masses immediately beneath the clus- ters of plant-lice ; this is known to botanists as Scorias spongiosum. It is evidently fed by the honey-dew that falls upon it. The Beech-tree Blight, Schizoneura ijnbricator (im-bri- ca'tor), infests both the twigs and leaves of beech. Like the preceding species it occurs in clusters of individuals, each of which is clothed with a conspicuous downy excre- tion. These clusters often attract attention by the curious 12 162 THE STUDY OF IN" SECTS. habit that the insects have of waving their bodies up and down, the plume-like masses of excretion rendering them very conspicuous. When an infested limb is jarred the Aphids emit a shower of honey-dew. Owing to the abun dance of this secretion, the branches and leaves of an infested tree become blackened by growths of fungi, as with the preceding species. The Woolly-louse of the Apple, Schizoneura lanigera (la-nig'e-ra), is one of the best-known pests of the fruit- grower. In its most conspicuous form it appears on the trunks and limbs of apple-trees, in clusters of individuals, which are conspicuous on account of the woolly excretion with which the bodies are covered. It is especially in- jurious to young trees, the bark of which becomes deeply pitted and scarred by its attacks. The bark apparently ceases to grow at the point of attack, but swells into a large ridge about the cluster of lice, leaving them in a sheltered pit. The lice also frequently congregate in the axils of the leaves and the forks of the branches. This species resembles the Grape Phylloxera in having a root- inhabiting form, which causes knotty swellings on the fibrous roots. It is the presence of this form that makes this pest such a difficult one to combat. For as it works deep in the ground upon the fibrous roots of trees, the same difficulties are met in attempting to destroy it that are pre- sented by the Grape Phylloxera. In fact, except in case of an especially valuable tree, we do not believe that it will pay to attempt to save a tree that has become badly infested by the woolly aphis. It will be cheaper to dig the tree up and burn it, and devote the ground to some other use. Another species of tree can be safely planted in the same place, but not an apple. Great care should be taken in putting out trees from a nursery to see that they are free from this pest. If there is any doubt the trees should be washed, roots and all, in a strong solution of soap. It is well also tc put in the forks of the trees pieces ot h-ird so an. -vhich will HEMIPTERA. 163 be dissolved and washed down by the rains. This will serve to destroy certain other pests, as well as the woolly aphis In case it is desired to rid an infested tree of this pest, the trunk form should be washed off with a strong solution of o soap applied with a sponge, taking care to destroy all eggs ; and the ground should be treated with carbon bisulphide, as for the Grape Phylloxera. Family ALEYROPID.E (Al-eu-rod'i-dse). TJie A ley r odes (Al-cu-ro' des). The insects of the genus Aleyrodcs were for a long time classed with the Coccidae. In their immature state they are scale-like in form (Fig. 200), and often somewhat resemble certain species of Lecanium. But the mature insects differ so much from the Coccids that the genus has been sepa- rated as a distinct family. They are very small insects; the species with which I am acquainted have an expanse of wings of about one eighth of an inch. Both sexes are winged ; and, as with . , TT .1 / -j FIG. 200. Aleyrodet other Hemiptera except the Loccids, there are two pairs of wings. In the adult state, all the species are nearly of the same color ; the wings are white, sometimes spotted ; the body is usually yellowish, sometimes pinkish, and more or less spotted with black. The most striking character presented by the adults, in addition to the fact that both sexes are winged and each has two pairs of wings, is the presence of a whitish powder with which the wings and body are covered. It is this character that suggests the name of the genus, which is from the Greek aleurodes, like flour. 1 64 THE STUDY OF INSECTS. Family COCCID^; (Coc'ci-dae). The Scale-bugs or Bark-lice, Mealy-bugs, and others. The family Coccidae includes the Mealy-bugs, the Scale- bugs or Bark-lice, and certain other insects for which there are no popular names. In this family we find those mem= bers of the Hemiptera that depart most widely from the type of the order. In fact this is a very anomalous group, the species differing greatly in appearance, habits, and meta- morphoses from those of the most closely allied families. Not only do the members of this family appear very unlike other insects, but there is a wonderful variety of forms within the family, and even the two sexes of the same species differ as much in the adult state as members of distinct orders. The males of Coccidae, unlike all other Hemiptera, undergo a complete metamorphosis. The adult males have only a single pair of wings, the hind wings being represented by a pair of club-like halteres. Each of these is furnished with a bristle, which in all the species we have studied is hooked, and fits in a pocket on the wing of the same side (Fig. 202). The male in the adult state has no organs for procuring food, as the mouth-parts disappear during the metamorphosis of the insect, and a second pair of eyes ap- pear in their place. The adult female is always wingless, and the body is either scale-like or gall-like in form, or grub- like and clothed with wax. The waxy covering may be in the form of powder, of large tufts or plates, of a continuous layer, or of a thin scale, beneath which the insect lives. Among the Coccidae are found many of the most serious pests of horticulturists. Scarcely any kind of fruit is free from their attacks, and certain species of scale-insects and mealy-bugs are constant pests in conservatories. The ease with which these insects or their eggs can be transported long distances while yet alive, on fruit or living plants, has HEMIPTERA. I6 5 caused many species that infest cultivated plants to become world-wide in distribution. During recent years much attention has been paid to devising methods of destroying these pests. Various soapy FIG. 202. The Scurfy Bark-louse. Chionasf>is furfurus : i, scales natural size; ia, scale of male enlarged ; i(5, adult male enlarged ; ir, scale of female enlarged. or alkaline washes, and one made of lime, salt, and sulphur, are now used on the trees with deciduous foliage; the wash is applied during the winter while the trees are naked. In the case of orange and lemon trees, which are constantly clothed with leaves, a large tent is lowered over the tree and a 1 66 THE STUDY OF INSECTS. poisonous gas (hydrocyanic-acid gas) is generated within the tent. A number of useful insects belong to this family. Several species furnish dye-stuffs. The best known of these is Coccus cacti, the dried bodies of which are known as Cochi- neal. The stick lac of commerce, from which shell-lac or shellac is prepared, is a resinous substance excreted by a species, Carteria lacca (Car-ter'i-a lac'ca), which lives on the young branches of several tropical trees, and the bodies of these insects, which are obtained from the stick lac, furnish the coloring agents known as lac dye. China wax is another substance for which we are indebted to this family. It is the excretion of an insect known as Pe-la, Ericcrns pc-la (E-ri- ce'rus). In fact many species of this family excrete wax in considerable quantities. Among the more prominent members of this family are the following : The Cottony-cushion Scale, Iccrya pnrcJiasi (I-ce'ry-a pur'cha-si). Tin's beautiful in sect (Fig. 203) was at one time the most dangerous insect f* 1 A pest in California, and did a great amount of injury. It is an introduced Australian spe- cies, and has been subdued to a great extent by the intro- duction of an Australian Lady- bug, J^Y/ much enlarged; 16, scale of female enlarged; ic, scale of male, enlarged. insects themselves, which are found beneath the scales The distinctions between closely allied species are such, that it requires very close observation and much skill in this particular line to make the determinations, a careful prepa- ration of the specimens and an excellent microscope being necessary requisites. The different species of scale-insects vary as regards their food habits. We find that certain species infest particular 174 THE STUDY OF INSECTS. plants and will feed upon no others ; thus, the Red-scale of the Orange does not trouble deciduous fruits. On the other hand, other species have a wide range of food plants. This is the case of the Greedy-scale, which infests a great variety of both cultivated and wild plants. Figure 202, page 165, represents the Scurfy Bark-louse, CJiionaspis furfurus (Chi-o-nas'pis fur'fur-us), a species very widely distributed on apple, pear, and cherry ; Figure 212, the Pine-leaf Scale, CJiionaspis pinifolite (pin-i-fo'li-ae), which occurs on various species of pine and spruce in all parts of the United States where these trees grow; and Figure 213 represents the red scale of California, Aspidiotus aurantii (As-pid-i-o'tus an ran'ti-i), which is very destructive to oranges and lemons. KIG. 214. .Afr/to apiculata. See p. 131. CHAPTER XV. Order NEUROPTERA (Neu-rop'te-ra). The Dobson, Aphis-lions, Ant-lions, and others. The members of this order have four wings ; these are mem* branous and furnished with numerous veins, and usually with many cross veins. The head is not prolonged into a beak. The mouth-parts are formed for biting. The metamorphosis is complete. The name of this order is from two Greek words : neuron, a nerve ; andpteron, a wing. It refers to the numerous nerves, or veins as they are more commonly called, with which the wings are furnished. When the name Neuroptera was first used it was applied to a much larger group of insects than now, a group which has since been divided into many orders. So that now, while the name expresses a character which is true of the order, it is also true of many others.* The order Neuroptera as now restricted is represented in the United States by seven families. These can be separated by the following table : TABLE FOR DETERMINING THE FAMILIES OF NEUROPTERA. A. Prothorax as long as or longer than the mesothorax and the metathorax combined. B. Fore legs greatly enlarged and fitted for grasping, p. 179. MANTISPID^E. * The Neuroptera of the older Entomologists included the following orders : Thysanura, Ephemerida, Odonata, Plecoptera, Isoptera, Corroden- tia, Mallophaga, Neuroptera, Mecoptera, and Trichoptera. 175 176 THE STUDY OF INSECTS. BB. Fore legs not enlarged, and not fitted for grasping, p. 178. RAPHIDIID.E. AA. Prothorax not as long as the mesothorax and the metathorax combined. B. Hind wings broad at the base, and with that part nearest the abdomen (the anal area) folded like a fan when not in use. p. 176 SIALID.E. BB. Hind wings narrow at base, and not folded like a fan when closed. C. Wings with very few veins, and covered with whitish powder. (As this family includes only very rare insects it is not dis- cussed in this book.) CONIOPTERYGID/E. CC. Wings with numerous veins, and not covered with powder. D. Antennae gradually enlarged towards the end, or filiform with a terminal knob. p. 182 MYRMELEONIDVE. DD. Antennae without terminal enlargement. E. Some of the transverse veins between the costa and sub- costa forked (in all common forms), wings brownish or smoky, p. 181 HEMEROBIID^E. EE. Transverse veins between the costa and subcosta simple, wings greenish, p. 180 CHRVSOPID^E. Family SlALID^E (Si-al'i-dae). The Dobs on and others. The members of this family differ greatly in size and ap- pearance ; but they agree in having the hind wings wide at the base, and in having that part of these wings nearest the abdomen (the anal area) more or less folded in plaits when the wings are closed. The species that is most likely to attract attention is the Horned Corydalis, Corydalis cornuta (Co-ryd'a-lis cor-nu'ta). This is a magnificent insect, which has a wing expanse of from four to nearly five and a half inches. Figure 215 represents the male, which has remarkably long mandibles,, The female resembles the male, except that the mandibles are comparatively short. NEUROPTERA. 177 This species is common throughout the United States. The larvae are called Dobsons by anglers and are used by them for bait, especially for bass. Figure 216 represents a full-grown Dobson, natural size. These larvae live under stones in the beds of streams. They are most abundant where the water flows swiftest. They are carnivorous, feeding upon the nymphs of Stone-flies, May-flies, and other insects. FIG. 215. Corydalis cornuta. FIG. 216. Corydalis cornuta, larva. When about two years and eleven months old, the larva leaves the water, and makes a cell under a stone or some other object on or near the bank of the stream. This occurs dur- ing the early part of the summer ; here the larva changes to a pupa. In about a month after the larva leaves the water the adult insect appears. The eggs are then soon laid; 13 178 THE STUDY OF INSECTS. these are attached to stones or other objects overhanging the water. They are laid in blotch-like masses, which are chalky-white in color, and measure from half an inch to nearly an inch in diameter. A single mass contains from two thou- sand to three thousand eggs. When the larvae hatch they at once find their way into the water, where they remain until full grown. There are other common species of the family which closely resemble Corydalis but are smaller, the larger ones measuring less than two and a half inches in length, and having a wing expanse of not more than four inches. These insects also differ from Corydalis in having three ocelli and in lacking the sharp tooth-like angles on the sides of the back part of the head. See Figure 215 of the adult Corydalis. These species belong to the genus Chauliodes (Chau-li'o-des). Chauliodes pecticornis (pec-ti-cor'nis) is a common species with grayish wings and feather-like antennae. Chauliodes serricornis (ser-ri-cor'nis) is also common ; this is a brownish- black species with the wings spotted with white, and with serrate antennae. Family RAPHIDIID^E (Raph-i-di'i-dae.) The Raphidians (Ra-phid 1 i-ans). The members of this family are found in this country only in the far West. They are strange-appearing insects, the prothorax being greatly elongated, like the neck of a camel (Fig. 217). The female bears a long, slender, sickle-shaped ovipositor at the end of the abdomen. The fore legs resemble FlG.217. tfrt//z;W/a, . . female. the other pairs of legs, and are borne at the hinder end of the prothorax. The larvae are found under bark and are carnivorous. We have found them common under the loose bark of the Eucalyptus. They also occur in orchards, and doubtless do good by destroying the larvae and pupae of the Codlin-moth. NEUROPTERA. 1/9 Living specimens of these insects have been sent to Aus- tialia by our government in the hope of introducing the species there, and thus doing something towards repaying the debt that we owe that country for the Australian Lady- bug, which has rendered us great service in the destruction of the Cottony-cushion Scale in California. The family is represented by two genera, Raphidia (Ra- phid'i-a) and Inoccllia (In-o-cel'li-a). In the former there are three simple eyes on the top of the head between the compound eyes ; in the latter these ocelli are wanting. Family MANTISPID^E (Man-tis'pi-dae). The ]\Iantis-like Neuroptcra. The members of this family are even stranger in appear- ance than the Raphidians. Here, as in that family, the prothorax is greatly elongated ; but the members of this family can be easily recognized by their remarkable fore legs, which are greatly enlarged and resemble those of the Praying Mantes in form (Fig. 2 1 8). These legs are fitted for seizing prey; and, in order that they may reach farther forward, they are joined to the front end of the long pro- thorax. In the adult state these insects are predaceous; while the larvae, so far as is F|G known, are parasitic in the egg-sacs of spiders. of the parts " Five species of the family are known from the United States ; four of these belong to the genus Mantispa (Man- tis'pa) and one to Sympliasis (Sym/pha-sis). i8o THE STUDY OF INSECTS. Family CHKYSOPID^ (Chry-sop'i-dae). The Lace-winged-flies or Aphis-lions. If one will search the foliage of herbs, shrubs, or trees, there may be found, running rapidly around on the leaves, sturdy, spindle-formed, little insects that have great sickle- shaped jaws (Fig. 219). These larvae are always hungry, and will kill and eat any insects that they can overpower ; FIG. 219. Eggs, larva, cocoon, and adult of Chrysopa. but as they are especially destructive to plant-lice, they are called Aphis-lions. When an Aphis-lion is full grown it rolls itself up into a tiny ball and weaves around itself a glistening, white cocoon, which looks like a large seed-pearl. It may be supposed that while the Aphis-lion is secluded in this pearly cell it repents its greedy, murderous ways, and changes in spirit ; at least the body changes greatly, for, after a time, a circular lid is made in the cocoon, and out of this emerges a beautiful, dainty creature, with delicate-veined, green wings, a pale green body, slender, brown antennas, and a pair of large eyes that shine like melted gold. It is NEUKOPTERA. l8l sometimes called Golden-eyes, and sometimes, a Lace-winged- fly, from its appearance. The Lace-wing is a prudent mother ; she knows that if she lays her eggs together on a leaf the first Aphis-lion that hatches will eat for his first meal all his unhatched brothers and sisters. She guards against this fratricide by laying each egg on the top of a stiff stalk of hard silk about half an inch high. Groups of these eggs are very pretty, looking like a tiny forest of white stems bearing on their summits round glistening fruit. When the first of the brood hatches, he scrambles down as best he can from his egg perch to the surface of the leaf, and runs off, quite unconscious that the rest of his family are reposing in peace high above his head. The mouth-parts of these larvae are very unusual in form. The mandibles are very long ; on the lower side of each of them there is a furrow the entire length ; into this furrow the long and slender maxilla fits. In this way the mandible and the maxilla of each side form a tube, through which the blood of the prey of the insect can be drawn. This explains why an Aphis lion holds its prey on the tips of its long jaws, at arm's length, as it were, while sucking its blood. Nearly all of the members of this family belong to the genus Chrysopa (Chry-so'pa). Family HEMEROBIID^ (Hem-e-ro-bi'i-dae). The Hemerobians (Hem-e-ro'bi-ans). The common members of this family are rather dark- colored insects, with the wings mottled with dark brown or smoky specks, and with some of the veins between the ccuta and subcosta forked. The most conspicuous member of the family is Polys- tcechotes punctatus (Pol-ys-tcech'o-tes punc-ta'tus), which is represented natural size by Figure 220. The larva is unknown. 1 82 THE STUDY OF INSECTS. The larger number of the species of this family belong to the genus Hemerobius (Hem-e-ro'bi-us). These are small- ish insects, the largest of which expands hardly an inch. They occur in forests, and especially on cone -bearing trees. The larvae bear a strong resem- FIG. 220. Polystoechotes punctatus. blance to the Aphis-lions, and like them feed upon Aphids and other small insects. After sucking the blood from their victims, they make cloaks for themselves of the empty skins. Family MYRMELEONID^: (Myr-me-le-on'i-dae). The Ant-lions and others. The Ant-lions, Myrmeleon (Myr-me'le-on). In sandy places beneath overhanging cliffs, beneath buildings, and along sandy banks where the sun shines warmest, there may be found, in all parts of our land, little, funnel-shaped pits one or two inches across (Fig. 221). The sides are smooth and as steep as the sand will lie ; and at the bottom may be seen two small curved objects. All is still and motionless until some ant, hurrying along with mind intent upon business, carelessly runs over the edge of one of these pitfalls. Then the ant commences to slide down, while some force below throws out the sand from under its struggling feet, until it slides into the bottom, where literally jaws of death are awaiting it. For the curved objects are a pair of jaws, attached to a strong head, and closely connected with a greedy stomach. If we dig out the owner of the jaws we find it a spry, humpbacked creature, which moves backward more easily than forward. It is worth while to collect some FIG. 221. Pitfall of an Ant-lion. NKUROPTERA. 183 of these larvse, and place them in a basin of sand, and watch them build their pits. They do this by using the head for a shovel. Sometimes when an ant seems likely to escape, the Ant-lion will throw up a torrent of sand so that it will descend on the victim, knocking it back into the pit. When ready to change to a pupa the Ant-lion makes for itself a little, round cocoon of sand fastened together and lined with silk. The adult Ant-lion is a graceful insect with long, narrow, delicate wings, and a slender body (Fig. 222). FIG. 222. Larva, cocoon with pupa-skin projecting, and adult of an Ant-lion. Certain members of this family differ from the ant-lions in having long, filiform antennae, which are suddenly en- larged at the end. These belong to the genus Ascalaphns (As-eal'a-phus). CHAPTER XVI. Order MECOPTERA (Me-cop'te-ra). TJie Scorpion-flies and others. The members of this order have four wings ; these are membranous, and furnished ivith numerous veins. The head is prolonged into a beak, at the end of which biting mouth parts are situated. The metamorphosis is complete. This is a small order composed of very remarkable in- sects. The most striking character common to all is the shape of the head, which is prolonged into a beak (Fig. 223). The name Mecoptera is from two Greek words ; mccos, length ; and pteron, a wing. This order includes only a single family, the Panorpidce. Family PANORPIDCE (Pa-nor'pi-dae). The Scorpion-flics and others. We have found representatives of this family quite abundant on rank herbage growing on FIG. 223 Head ^' le banks of a shaded stream; we have also wr/ llof/V found them in damp woods where there was a luxuriant undergrowth of herbaceous plants. These insects take flight readily when disturbed ; they are car- nivorous both in the adult and in the larval state. The larvae larvae so far as known are remarkable on account of their great resemblance to caterpillars. Not only is the form of the body like that of a caterpillar, but the abdomen is fur- nished with fleshy pro-legs. There are, however, eight pairs of these ; while caterpillars, as a rule, have only five. 184 MECOPTERA. I8 5 The most common members of this family are the Scorpion-flies, Panorpa (Pa-nor'pa). These are called Scor- pion-flies on account of the peculiar form of the caudal part of the abdomen of the male (Fig 223). This at first sight suggests the corresponding part of a scorpion ; but in reality the two are very different. The last segment, instead of ending in a sting like that of a scorpion, is greatly enlarged and bears a pair of clasping organs. The wings are nar- row but are well developed, being longer than the body. In our more common species they are FlG 224 ._/> a . yellowish, spotted with brownish black (Fig. 224). " orfa > aduk< Very closely allied to the Scorpion-flies are the insects of the genus Bittacus (Bit'ta-cus). These insects have long narrow wings, long legs, and a slender abdomen. They re- semble crane-flies very closely when on the wing. In this genus the caudal appendages of the male are not enlarged as in Panorpa. The species of the genus Boreus (Bo're-us) are remarka- ble for occurring on snow, in the winter, in our Northern States. CHAPTER XVII. Order TRICHOPTERA (Tri-chop'te-ra). The Caddice-flies or Caddice-worms. The members of this order have four wings; these are membranous, furnished with numerous longitudinal veins but with only feiv cross veins, and are more or less densely clothed with hairs. The month-parts are rudimentary \ The meta- morphosis is complete. The Caddice-flies are moth-like insects which are com- mon in the vicinity of streams, ponds, and lakes; and they are also frequently attracted to lights at night. The body-wall of these insects is soft, being membran- ous or at the most parchment-like, and is thickly clothed with hairs. There are usually four ample wings. These are membranous ; but the fore pair are more leathery than the hind pair. When not in use they are folded against the sides of the abdomen, in an almost vertical position, and give the insect a narrow and elongated appearance (Fig. 225). The wings are more or less densely clothed with hairs ; and in some cases the hairs are scale-like in form. The hind wings are usually broader than the fore wings, and are often longitudi- F,G. 225 .-Caddice-fly. na jj y fo j ded j n repose A11 haye nu _ merous longitudinal veins, but the cross veins are few. The name of the order is from two Greek words : thrix, a hair; and pteron, a wing. The order includes only a single family, the Phryganeidce. 186 TRICHOPTERA. 1 87 Family PHRYGANEID^E (Phryg-a-ne'i-dae). The Caddicc-flies or Caddice-worms. The young naturalist loves to lie face downward on the bank of a brook, and, with shaded eyes, watch the busy life that goes on there. Among the astonishing things he sees are little bundles of sticks or masses of stones moving about the bottom of a quiet pool as if they were alive; and yet if he takes them out they seem dead enough. But when he pulls them apart he finds that each is a tube lined with silk within which a whitish larva lives. This larva, when it wishes to move, puts out the front part of its body, so that it can creep with its legs over the bottom of the stream, or climb up and down water-plants, dragging its house along after it. When molested it draws back into its tube, and is safe. Larvae of this sort are called Caddice- worms ; and the adult insects are known as Caddice-flies. There are very many species of Caddice-worms ; and each species makes a particular kind of tube. Some Caddice- worms are carpenters, building their houses of straws or sticks. These are usu- ally placed lengthwise the body (Fig. 226); but certain species that FIG. 226. make their houses chief- ly of straws fasten the straws crosswise like the logs of a log-house (Fig. 227). These log-house builders often have the curious habit of decorating their houses by fastening snail-shells to the outside. And strangely enough they do not always take empty shells for this purpose; we have found shells containing living snails securely fastened FlG - "'/ to the outside of the house of a Caddice-worm. In this case the snail was afforded comparatively rapid transportation whether it desired it or not. Fortunately the species that 1 88 THE STUDY OF INSECTS. make this style of house live in still water, and may, there- fore, be easily kept alive in aquaria. There are caddice-worm houses closely resembling in plan those just described but differing in appearance, being made of bits of moss. Sometimes the houses are built of leaves ; these may be fastened so as to form a flat case ; or are ar- ranged in three planes, so as to form a tube, a cross-section of which is a triangle. Other Caddice-worms are masons, building their houses of grains of sand or of small stones. Sometimes these houses are tubes very regular in outline, being composed only of grains of sand fastened together with silk ; but certain spe- cies of Mason Caddice-worms fasten larger stones on each side of this tube of sand (Fig. 228). Some of the species that FIG. 228. FIG. 229. build tubes of sand make spiral houses which very closely resemble in form snail-shells (Fig. 229). Whether stones or wood are used to build these houses the material is always fastened together by silk, which the larvae spin from the mouth in the same manner as do cater- pillars. In some species the case is composed entirely of silk. Figure 230 represents the form of such a case, which FlC. 230, . . r i i is common in some of our lakes. Among the simplest of the -various forms of houses built by Caddice-worms are those made by certain species that live under stones in rapid streams. These consist merely of a few pebbles fastened to the lower surface of a larger stone by threads of silk. In the space between these pebbles the worm ma^es a more or less perfect tube of silk, within which TRICHOPTERA. 189 it Jives. Very little respect for the architectural skill of these builders is commanded by their rude dwellings. But if one ^ooks a little farther, something will be found that is Sure to excite admiration. The dweller within this rude re- treat is a fisherman ; and stretched between two stones near by can be seen his net. This is made of silk. It is usually funnel-shaped, opening up-stream ; and in the centre of it there is a portion composed of threads of silk extending in two directions at right angles to each other, so as to form meshes of surprising regularity. It is as if a spider had stretched a small web in the water where the current is the swiftest. These nets occur in rapids between stones, but in many places they are to be found in greater numbers along the brinks of falls. Here they are built upon the surface of the rock, in the form of semi-elliptical cups, which are kept distended by the current. Much of the coating of dirt with which these rocks are clothed in summer is due to its being caught in these nets. We have not yet observed the owners of the nets taking their prey from them ; but we cannot doubt that they are made to trap small insects or other ani- mals that are being carried down-stream ; for the larvae of the sub-family to which these net-builders belong, the Hy- dropsycliince, are known to be carnivorous. It should be noted here, however, that the greater number of Caddice- worms are herbivorous. When a Caddice-worm gets ready to change to a pupa it retires into its house and builds a door to keep intruders out ; but the door always has an opening to allow the water to flow in so that the pupa can breathe. Sometimes a simple grating of silk is made over the entrance. On one occasion the writer had the good fortune to ob- serve a Caddice-fly leave the water and take its first flight. The specimen was one of the net-building species, Hydrop- syche (Hy-drop-sy'che), which I was breeding in an aquarium in my laboratory. It swam to the surface of the water repeatedly, using its long middle legs. When swimming, I9O THE STUDY OF INSECTS. these legs were extended at right angles to the body like a pair of oars. The insect was unable to crawl up the vertical side of the aquarium, and after clinging to it for a short time it would lose its hold and sink back to the bottom. After watching it for a time I lifted it from the water by means of a stick. At this time its wings were in the form of pads, which were but little, if any, longer than the wing-pads of the pupa, as shown by the cast pupa-skin found floating on the water. The instant the creature was free from the water its wings expanded to their full size, and immediately it flew away several feet. In my efforts to catch the insect I found that it had perfect use of its wings, although they were so recently expanded. The time required for the insect to expands its wings and take its first flight was scarcely more than one second ; it was certainly less than two. As these insects normally emerge from rapidly-flowing streams which dash over rocks, it is evident that if much time were required for the wings to become fit for use, as is the case with most other insects, the wave succeeding that which swept one from the water would sweep it back again and destroy it. CHAPTER XVIII. Order LEPIDOPTERA (Lep-i-dop'te-ra). The Mot/is or Millers, tJie Skippers, and the Butterflies. The members of this order have four zvings ; these are membrancns, and covered with overlapping scales. The month- parts are formed for sucking. The metamorphosis is complete. The name of this order is from two Greek words : lepis, a scale ; and pteron, a wing. It refers to the fact that the wings of these insects are covered with scales. Every lad that lives in the country knows that the wings of moths and butterflies are covered with dust, which comes off upon one's fingers when these insects are handled. This dust when examined with a microscope is found to be composed of very minute scales of regular form ; and when a wing is looked at in the same way, the scales are seen arranged with more or less regularity upon it. The body, the legs, and other appendages are also covered with scales. The scales of Lepidoptera are modified hairs. That is, they are hairs which, instead of growing long and slender as hairs usually do, remain short, but grow very wide as com- pared with their length. Every gradation in form can be found from the ordinary hair-like form, which occurs most abundantly upon the body, to the short and broad scale, which is best seen upon the wings. There is a great difference among the insects of this order regarding the regularity of the arrangement of the scales iqi 192 THE STUDY OF INSECTS. upon the wings. With some of the lower moths the scales are scattered irregularly over the wings. But if the wing of one of the higher butterflies be examined with a microscope, the scales will be found arranged in regular, overlapping rows; the arrangement being as reg- ular as that of the scales on a fish or of the shingles on a roof (Fig. 231). In the upper part of the figure the membrane is represented with the scales re- moved. The use of the scales on the wings is to strengthen them. We thus see that the wings of these insects are furnished with much fewer cross veins than are the wings of similar ^j size in other orders. A secondary use of these scales is that of ornamentation ; for the beautiful colors and markings of these insects are due entirely to the scales, and are destroyed when the scales are removed. Upon the body, legs, and FIG. 231. Part of wing- of butterfly, greatly magnified. FIG. 232. Maxillse of cotton-moth, and tip of same enlarged. other appendages, the scales and hairs doubtless serve to protect the insect, being a sort of armor. The mouth-parts of moths and butterflies are especially adapted for sucking nectar from flowers. If the head of a butterfly be examined, there will be found a long sucking LEP1D OP TERA. 1 93 tube, which when not in use is coiled on the lower side of the head between two forward-projecting appendages. This long sucking tube is composed of the two maxillae, greatly elongated, and fastened together side by side. In Figure 232 mere is represented a side view of the maxillae of a moth ; and in Figure 233 a cross-section of these organs. Each Fit;. 233. Cross-section of maxillae. maxilla is furnished with a groove, and the two maxillae are so fastened together that the two grooves form a tube through which the liquid food is sucked. As a rule the maxillae of insects of this order are merely fitted for extracting the nectar from flowers, but sometimes the tips of the maxillee are armed with spines, as shown in Figure 232. This enables the insect to lacerate the tissue of ripe fruits and thus set free the juice, which is then sucked up. Many moths do not eat in the adult state; with these the maxillae are wanting. The two forward projecting organs between which the maxillae are coiled when present are the labial palpi. In some moths the maxillary palpi are also developed. The larvae of Lepidoptera are known as caterpillars. They vary greatly in form and appearance ; but are usually cylindrical, and provided with from eight to sixteen legs, six thoracic legs, and from two to ten abdominal legs. The thoracic legs, which are finally developed into the legs of the adult, have a hard external skeleton ; and are jointed, taper- ing, and armed at the end with a little cla\v. The abdominal legs, which are shed with the last larval skin, are thick. 14 194 THE STUDY OF INSECTS. fleshy, without joints, elastic or contractile, and are generally surrounded at the extremity by numerous, minute hooks (Fig. 234) ; they are termed pro-legs. ~ -. \ ", -^ FIG. 234. Larva of a Hawk-rnoth. Most caterpillars, except the larvae of butterflies, spin cocoons (Fig. 235). In some instances, as in case of the FIG. 235. Cocoon of a moth. silkworms, a great amount of silk is used in the construction of the cocoon; in others the cocoon is composed principally LEPIDOPTERA. 1 95 of the hairs of the larva, which are fastened together with a fine web of silk. In the pupae of Lepidoptera the developing wings and legs are folded upon the sides and breast ; the whole being enclosed in a hard skin (Fig. 236). The members of this order as a rule feed upon plants, and are not aquatic ; some, as the Clothes-moth and the species that destroy Scale-bugs, feed FlG - 2 36.-Pupa of a moth. on animal matter, and a very few feed upon plants below the surface of the water. More than six thousand species of Lepidoptera are known to occur in America, north of Mexico. These rep- resent more than sixty families. In order to give a synopsis of the Lepidoptera it is necessary to enter into rather difficult technical details. Hence this is done in that portion of this chapter designed for advanced students and printed in fine type. The prin- cipal divisions of the Lepidoptera that are appropriately discussed here are three: the moths, the skippers, and the butterflies : TJie Moths. These are the insects commonly called millers. Most of the species fly by night and are frequently attracted to lights. When at rest the wings are either wrapped around the body, or are spread horizontally, or are folded roof-like on the abdomen; they are not held in a vertical position above the body. The antennae of moths are of various forms ; they are usually thread-like or feather- like ; only in rare cases are they enlarged towards the tip. The moths include all but the last six families of Lepidop- tera. The Skippers. The skippers are so called on account of their peculiar mode of flight. They fly in the daytime and dart suddenly from place to place. When at rest they 196 THE STUDY OF INSECTS. usually hold the wings erect in a vertical position like butterflies; often the fore wings are thus held while the hind wings are extended horizontally. The antennae are thread-like, and enlarged towards the tip ; but in most cases the extreme tip is pointed and recurved, forming a hook. The abdomen is usually stout, resembling that of a moth rather than that of a butterfly. This division includes two families. The Butterflies. The butterflies fly by day ; and when at rest they fold the wings together above the back in a vertical position. The antennae are thread-like with a club at the tip, which is never recurved so as to form a hook. The abdomen is slender. This division includes the last four families described in this chapter. Classification of the Lepidoptera. {For Advanced Students.') The study of the classification of the Lepidoptera is beset by a peculiar difficulty. As these insects are clothed with scales com- paratively little of their structure can be examined without injury to the specimens studied. Fortunately, however, it has been found that the various modifications of the framework of the wings afford excellent clues to the relationships of the different groups; and these modifications can be determined in most cases without serious injury to the specimens. The structure of the antennae also can be easily studied, and in many cases affords much help in determining the zoo- logical position of an insect. The first step to be taken in the study of the classification of these insects is to become thoroughly familiar with the nomenclature of the wing veins ; this is given on pages 64 to 66. It is a good plan to take several of the larger moths and butterflies and make draw- ings showing the courses of the veins of the wings in each, carefully indicating the names or numbers of the veins on the drawings. The making of such drawings will be of much use in fixing the ar- rangement of the veins in the student's mind. It should be remem- bered that veins IV and VI are not developed in this order. As the scales on the lower surface of the wings are more closely applied to the wings than are those on the upper surface, the veins can be best seen when the wings are examined from below. The LEPIDOPTERA. veins can be rendered more distinct for a few seconds by putting a drop of chloroform on the part of the wing to be examined ; this can be easily done by means of a camel's-hair brush. Sometimes it is necessary to remove the scales from a small part of the wing in order to determine the nature of some characteristic; this can be easily done with an artist's sable brush. A very small brush is best for this purpose; and care should be taken not to break the wing. The above methods are all that are needed in the majority of cases where the mere determination of an insect is the object. But when a very careful study of the venation of a wing is to be made, it should be bleached and mounted on a card or on a glass slip in order that it may be studied with a compound microscope. The fol- lowing is the method of bleaching wings: 1. Remove the wings carefully so as not to break the frenulum if there be one; it is well to remove the patagium first. 2. Dip the wings in alcohol in order to wet them. 3. Immerse them for an instant in hydrochloric acid (muriatic acid). Use for this purpose dilute acid, one part acid to nine parts water. 4. Put them in Labaraque solution with the upper surface of the wings down, and leave there till the color has been removed from the scales. If a wing bleaches slowly, the process can be hastened by dipping it in the dilute acid and returning it to the Labaraque solution from time to time. This solution can be procured of most druggists. It deteriorates if left exposed in strong sunlight. If it cannot be obtained, use an aqueous solution of chloride of lime. 5. When a wing is bleached put it in alcohol and leave it there till after it floats. This is to wash off the Labaraque solution. The wing can then be mounted on a card. But it is better to mount it as described below. 6. Transfer the wing to a clearing mixture, if it is to be mounted in balsam, and leave it there five or ten minutes. This is to remove any water there may be on it. A good clearing mixture can be made by mixing two parts by weight of carbolic-acid crystals and three parts of rectified oil of turpentine. 7. Put the wing on a glass slip with considerable clearing mixture under it to avoid bubbles ; put Canada balsam on top, and cover with thin glass. In the case of small wings, it is best to transfer them from one solution to another, and to the glass slip by means of a camel's-hair brush. Wings bleached and mounted in this way make an important ad- dition to a collection. The slides should be carefully labelled ; and 198 THE STUDY OF INSECTS. the insect from which the wings were taken should be kept with the slide. It is our practice to remove always the wings from the right side, and then to mount the slide in the collection at the right of the insect from which the wings were taken. Uniformity in this respect adds greatly to the appearance of the collection. The student should study his larger speci- mens first, leaving the smaller ones till he has acquired skill in this work. There are a few spe- cial terms used in de- scribing the wings of the Lepidoptera which should be learned: Frenulum. In most moths there is a strong spine or a bunch of bristles borne by the hind wing at the hume- ral angle (Fig. 237, /); FlG. 237. Wings of Thyridopteryx ephemerceformis. this is the frenulum. Its use is to insure the acting together of the two wings of one side. Except in the Microlepidoptera the frenulum of the male consists of a single strong spine; that of the female of two or more bristles. Jitgum. In one suborder, including only a few rare moths, j there exists, instead of a fren- julum, a lobe borne near the base of the inner margin of the fore wing (Fig. 238,7); this is the jugum. See sub-order Jugatae. Discal Cell. Near the cen- tre of the basal part of the wing there is a large cell lying VII2 VII, FIG. 238. Wings of Hepialus gracilis. between veins III and VII (Fig. 239, d.c.); this is the discal cell. In the more generalized Lepidoptera this cell is divided into two parts by the base of vein V (Fig. 239, hind wing); in such cases the LEP1DOPTERA. 199 cell lying immediately behind vein III is cell III, and that lying immediately behind vein V is cell V. Accessory Cells. In many genera the branches of vein III of the fore wings anastomose so as to form one or more cells beyond the apex of the discal cells (Fig. 239, (i.e.); these are the accessory cells. Discal Vein. - - The cross vein at the outer end of the discal cell is termed the discal vein (Fig. 239, resemble butterflies in usually holding their wings erect LEPIDOPTERA. 2O/ when at rest, but are distinguished by the peculiar venation of the fore wings, vein III being five-branched, and all the branches arising from tiie discal cell. The antennae are enlarged into a club towards the tip. p. 364. Superfamily HESPERIINA. EEE. The Butterflies. Day-flying Lepidoptera that hold their wings erect when at rest, that have clubbed antennae, and that differ from the Skippers in the venation of the fore wings, some of the branches of vein III coalescing beyond the discal cell Superfamily PAPILIONINA. F. Butterflies in which vein VII is apparently four- branched. The Swallow-tail Butterflies, p. 375. Family PAPILIONID/E. FF. Butterflies in which vein VII is apparently three- branched. G. Butterflies exhibiting no tendency to abortion of the fore legs. The Pierids. p. 381 Family PiERID^:. GG. Butterflies exhibiting a marked tendency to abor- tion of the fore legs. The Gossamer-winged Butterflies, p. 388. Family LYC^ENID.'E. The Brush-footed Butterflies, p. 395. Family NYMPHALID^;. TABLE FOR DETERMINING THE PRINCIPAL GROUPS OF LEPIDOPTERA. A. Wingless or with rudimentary wings. This division includes only females. All males of Lepidoptera are winged. B. The larvae case-bearers ; the adult female remaining within the case to lay her eggs. p. 219 PSYCHID.E. BB. The larvae not case-bearers; the wingless adult not in a case. C. The adult remaining upon her cocoon to lay her eggs; the body of the adult clothed with fine hairs, p. 308. LYMANTRIID.E. CC. The adult active, laying her eggs remote from her cocoon; the body of the adult clothed with flattened scales, p. 270. GEOMETRINA. AA. Winged, fore and hind wings similar in form and venation, the radius of the hind wings being, like that of the fore wings, five- branched. (Fig. 238.) (Suborder Jitgatce.} [See also A A A.] 208 THE STUDY OF INSECTS. B. Moths of medium or large size. p. 215 BB. Minute moths, resembling Tineids in appearance, p. 214. MlCROPTERYGIDJE. AAA. Winged, fore and hind wings differing in form and venation; the radius of the hind wings being simple, although frequently apparently two- or three-branched ; this is due to the union of one or two branches of media with it (Figs. 241, 242). (Suborder Frenatce.) B. Antennae of various forms, but never thread-like with a knob at the extremity* (moths in part). C. The fringe on the inner angle of the hind wings as long as, or longer than, the width of the wing; the hind wings often lanceolate, but never fissured, p. 246 TINEINA. CC. The fringe on the hind wings shorter ; the hind wings not lanceolate. D. Wings fissured. E. Each wing divided into six lobes, p. 238. ..ORNEODID^E. EE. Wings never more than four-lobed ; usually the fore wings are bilobed and the hind wings trilobed. p. 237. PTEROPHORID-fli. DD. Wings not fissured. E. Fore wings very narrow, the width at the middle less than one fourth the length of the wing; a considerable part of the hind wings, and in many cases of the fore wings also, free from scales, p. 259 SESIID^E. EE. Wings scaled throughout, or if clear with the fore wings triangular in outline. F. Hind wings with three anal veins. Care must be taken not to mistake a mere fold in the wing for a vein. When there is no thickening of the membrane of the wing along a fold it is not counted as a vein. G. Subcosta and radius of the hind wings grown together for a greater or less distance between the ape:: ~i the discal cell and the apex of the wing, or in some ca^js separate but very closely parallel, p. 228..PYRALIDINA. GG. Subcosta and radius of the hind wings widely sep- arate beyond the apex of the discal cell. * In some moths the antennae are enlarged towards the tip, forming a more or less distinct club ; but this club is quite different in shape from the knob at the extremity of the antennae in the skippers and the butterflies. In the moths with club-like antennae the ocelli are usually present, and the hind wings bear a frenulum. LEPID OP TERA . 2CX) H. Microlepidoptera ; i.e., moths that are in most cases of small or minute size ; with those included here the palpi are well developed, often prominent when the palpi are not prominent the antennae are at. least as long as the front wings ; the fringe on the anal angle of the hind wings is considerably longer than elsewhere. I. The second anal vein of the hind wings forked towards the base. p. 239 TORTRICINA. II. The second anal vein of the hind wings not forked towards the base. p. 246 TINEINA. HH. Macrolepidoptera ; i.e., moths usually of medium or large size. With those included here the palpi are small, rarely projecting beyond the head ; the antennae are of moderate length ; and the fringe on the anal angle of the hind wing is not longer than elsewhere, or but slightly so. I. Subcostaand radius of hind wings grown together to near the end of the discal cell. (Fig. 267.) J. Small black moths, with thinly scaled wings, p. 226 PYROMORPHID^E. JJ. Moths of medium size, and densely clothed with long woolly hairs, which are light colored or brown, p. 218 MEGALOPYGIDJE. II. Subcosta and radius of hind wings distinct or grown together for only a short distance. J. Anal veins of the fore wings anastomosing so as to appear as a branched vein (Fig. 253). p. 219 PSYCHID/E. JJ. Anal veins of fore wings not forked outwardly. K. Vein V s of the fore wings arising from the discal cell nearly midway between veins Vi and V,. L. Vein V 3 of both fore and hind wings coalescing with vein VIIi for a considerable distance beyond the end of the discal cell (Fig. 309). p. 262 DIOPTID^E. LL. Veins V 3 and VII) not coalescing beyond the end of the discal cell. M. Veins III 2 and III 3 coalesced at base, but separate from veins III 4 and III 6 . 15 210 THE STUDY Of INSECTS. which also coalesce (Fig. 438). p. 357. LACOSOMIDiE. MM. Veins III,. Ills, III*, and III 5 united at base (Fig. 419). p. 340. .BoMBYCiD^E. KK. Vein V a of the fore wings emerging from the discal cell nearer to cubitus than to radius, causing cubitus to appear four-branched. L. Fore wings with an accessory cell (Fig. 255) veins Ilia and Ills coalesced at base, also ve : ns III* and Ills; the accessory cell is formed by the anastomosing of veins Ills and Ilh + s. p. 221 CossiD^E. LL. Fore wings without an accessory cell; veins III 3 and III* coalescing to a greater extent than any other branches of radius (Fig. 26 1 ,. p. 223 ... EUCLEID^E. FF. Hind wings with less than three anal veins. G. Fore wings with two distinct anal veins or with the anal veins partially grown together in such a way as to appear as a single branched vein. H. Anal veins of fore wings partially grown together so as to appear as a branched vein (Fig. 253). p. 219 PSYCHID^E. HH. Fore wings with two distinct anal veins, p. 226. PYROMORPHID/E. GG. Fore wings with a single fully preserved anal vein. This is the second anal vein (vein IX) ; the first anal vein (vein VIII) is absent or represented merely by a fold; and the third anal vein (vein XI) is short, not reaching to the margin of the wing, or is wanting; usually when the third anal vein is present it is joined to the second anal vein, so that the latter appears to be forked towards the base. H. Frenulum present. In most cases the humeral angle of the hind wings is not largely expanded. I. The five branches of radius and the three branches of media of the fore wings present, and each one arising from the discal cell (Fig. 404). Small nioths (the largest expanding only three fourths inch) resembling Hawk-moths in form, and with translucent spots on their wings, p. 328. LEPIDOP TERA . 211 II. Some of the branches of radius or of media either wanting or grown together beyond the discal cell. J. Hind wings with subcosta and radius appar- ently distinct but connected by a strong oblique cross vein (Fig. 407). Moths of medium or large size, with spindle-shaped bodies, narrow, strong wings, and usually with the antennae prismatic in form, and more or less thickened in the middle or towards the tip, which is fre- quently recurved in the form of a hook (Hawk- moths), p. 329 SPHINGID/E. JJ. Subcosta and radius of hind wings either dis- tinct or grown together; but not appearing to be connected by a strong, oblique cross vein. K. Vein V s of the fore wings not more c.^sely joined to cubitus than to radius, cubitus being apparently three-branched. L. The basal part of the subcosta of the hind wings extending from the base towards the apex of the wing in a regular curve. Moths resembling Noctuids in form ; i.e., with a large abdomen and with rather narrow, strong, and coarsely-scaled fore wings. M. Vein V a of the hind wings arising much nearer to cubitus than to radius; vein Vi of the hind wings joined to radius at a considerable distance before the apex of the discal cell (Fig. 349). p. 291. CYMATOPHORID^E. MM Vein V of the hind wings either wanting or present, but when present arising either midway between radius and cubitus, or nearer to radius than to cubitus ; vein Vi of the hind wings joined to radius at or beyond the apex of the discal cell (Fig 311). p. 263. NOTODONTIDJE. LL. The basal part of the subcosta of the hind wings joined to radius for a consider- able distance and then making a prominent bend towards the costal margin, as in Cicin- 212 THE STUDY OF INSECTS. ttus (Fig. 438). Veins Ills and III* oi the fore wings separate from each other, p. 357. [See also LLL.] LACOSOMID^E. LLL. The basal part of the subcosta of the hind wings making a prominent bend into the humeral angle of the wing (Fig. 327); veins Ills and III 4 coalesced to near the apex of the wing. In most cases, moths with a slender abdomen, and with rather broad, delicate wings, which are finely scaled, p. 270 GEOMETRINA. KK. Vein V 3 of the fore wings more closely joined to cubitus than to radius ; cubitus be- ing in most cases apparently four-branched. L. Small moths with the apex of the fore wings sickle-shaped, p. 289. . DREPANID^E. LL. Apex of the fore wings not sickle-shaped. M. Small moths with snow-white wings, in which the subcosta of the hind wings ex- tends distinct from radius to a point be- yond the discal cell where the two are united for a greater or less distance (Fig. 344). p. 288 AUZATID^E. MM. The subcosta of the hind wings ex- tending distinct from the radius, or the two joined for a very short distance, near the base of the wing. [See also MMM.J N. Chiefly day-flying moths that are either black with large, white or yellow, rounded patches upon the wings, or have the front wings white, margined with brown, and the hind wings pale yellow^ O. Cubitus of hind wings apparently four-branched (Fig. 384). p. 316 PERICOPID^;. OO. Cubitus of hind wings apparently three-branched (Fig. 379). p. 313. AGARISTID^E. NN. Not such moths as are described under N. O. Antennae pectinate. LEPIDOP TERA. 213 P. Ocelli absent, p. 308. LYMANTRIIDjE. PP. Ocelli present, p. 293 NOCTUID^E. OO. Antennae simple, p. 293. NocxuiDvE. MMM. The subcosta of the hind wings united with the radius for a considerable distance (i.e., for one fifth or more of the length of the discal cell). N. The subcosta and radius of the hind wings united for a considerable distance, but usually separating before the apex of the discal cell. O. Ocelli present, p. 317. ..ARCTIIDJE. OO. Ocelli absent, p. 324..LlTHOSHD^E. NN. The subcosta and radius of the hind wings united into a single vein (Fig. 399), or at most with their tips separate near the apex of the vving. With all the moths included under this head and under the preceding N, vein V ( of the hind wings is present and is joined to radius at or near the apex of the discal cell ; care should be taken not to mistake this vein Vi for radius, p. 326 Z YG^ENIDvE. HH. Frenulum absent; the humeral angle of the hind wings largely expanded and serving as a substitute for a frenulum. I. Cubitus of both wings apparently four-branched, due to the fact that both the second and third branches of media (V 2 and V 3 ) are joined to it. J. Small moths, with slender bodies, and with the apex of the fore wings sickle-shaped ; humeral veins absent, p. 289. DRSPANI^/E. JJ. Moths of various sizes, but with robust bodies! and with the apex of the fore wings not sickle- shaped ; hind wings with humeral veins, p. 359 LASIOCAMPID^E. II. Cubitus of both fore and hind wings apparently three-branched, due to the fact that only the third branch of media (V 3 ) is more closely joined to it than to radius. (The moths included in this 214 THE STUDY OF INSECTS. section of this table are robust, with strong wings, and are of medium or large size. In some of the Geometrina (p. 270), which also have a three- branched cubitus, the frenulum is inconspicuous or even in rare cases (Dyspteris) wanting ; these moths can be distinguished from those included here by their smaller size, more slender body, and weaker wings), p. 339 SATURNIINA. BB. Antennae thread-like with a knob at the extremity. C. With the radius of the fore wings five-branched, and with all of the branches arising from the discal cell (Fig. 445) ; club of antennae usually terminated by a recurved hook. The Skip- pers, p. 364 HESPERIINA. CC. With some of the branches of the radius of the fore wings coalesced beyond the apex of the discal cell (Fig. 455) ; club of antennae not terminated by a recurved hook. The Butterflies. p. 373 PAPILIONINA. Suborder JlIGATVE (Ju-ga'tae). The jugate (Ju'gate) Lepidoptera. The American representatives of this suborder are rare moths, which the student beginning the study of insects is not likely to meet. They can be easily recognized by the peculiar structure of the hind wings, which resemble the fore wings in form and in venation (Fig. 238). In all other Lepidoptera, the two ni s pairs of wings differ in form, and the hind wings are furnished with fewer than are the fore veins wings. The most important characteristic of the sub- order, and the one to which its name refers, is the way in which the two wings of each side are fastened together. There projects backward from the inner margin of the fore V1L VIIi. FIG. Z43. Wings of Hefialus gracilis. LEPID OP TERA . 215 wing near its base a small lobe (Fig. 243, y), which extends under the costal margin of the hind wing; while the greater part of the inner margin of the fore wing overlaps the hind wing. This arrangement assures the acting together of the two wings. This projecting lobe is named thejttgum or yoke ; and the moths possessing this organ are termed the Jugatae or the Jugate Lepidoptera. This suborder includes only two families; one represented by minute moths, the other by moths of medium or large size. Family HEPIALID.E (He-pi-ari-dae). The Sivifts. The members of this family are of medium or large size. Figure 244 represents one of the larger species. Our best FIG. 244. Hepialus argenteomaculatus. known forms are brown or ashy gray in color, with the wings marked with silvery white spots. It is said that these moths fly near the earth, and only in the evening after sunset, hiding under some low plant, or clinging to the stalk of an herb during the day. Some of them fly with extreme rapidity, with an irregular mazy flight, and have, therefore, been named Swifts by collectors. They are attracted to lights. Figure 238 represents the venation of the wings of Hepialus (He-pi'a-lus). 2l6 THE STUDY OF INSECTS. The larvae are nearly naked, and grub-like in appearance, although furnished with sixteen legs. They feed upon wood, and are found at the roots or within the stems of plants. They transform either in their burrows, or, in the case of those that feed outside of roots, within loose cocoons. The pupae have transverse rows of teeth on the abdominal seg- ments ; these aid them in emerging from their burrows. The best known American species bores in the stems of the speckled or hoary alder (Alnus incand). Family MlCROPTERYGlD^; (Mi-crop-te-ryg'i-dae). The Little-winged Jugates (Ju' gates). These are very minute moths, which resemble Tineids in size and appearance. The largest species known to the writer expands but little more than half an inch. Figure 245 represents the venation of the wings. Only a single genus, III, TTT * II III., nr VIII VII 2 viI r V 3 . Winys uf Mii.ropteryx. in . this country. The FIG. 245. Winys uf Mii.ro Microptcryx (Mi-crop'te-ryx), occurs larvae are leaf-miners. Suborder FRENAT/E (Fre-na'tae). The Frenate (Fre'nate) Lcpidoptera. To the Frenatas belong nearly all of our moths, and all skippers and butterflies. With most moths of this suborder LEPJDOP TERA . 2 1 7 tnere exists near the base of the costal margin of the hind wings a strong bristle or bunch of bristles named the frenu- lum, or little bridle (Fig. 237, /). As the frenulum projects forward under the fore wing it tends to depress the hind wing when the fore wing is depressed, thus insuring the act- ing together of the two pairs of wings. Usually the frenulum consists of two or more bristles in females and of a single stronger bristle in males. The difference is due to the fact that in males the bunch of bristles have grown together into ". single strong bristle. There is also another sexual differ- ence. In the males the tip of the frenulum fits into a mem- branous hook borne on the lower surface of the fore wing, thus firmly tying together the two wings (Fig. 237, f.h\ This frenulum hook is rarely found in females. In certain moths there is, besides the frenulum hook, a tuft of hairs projecting forwards from just behind the cubitus of the fore wing near its base, which tends also to keep the frenulum in place. With some moths and with all skippers and all butterflies the base of the costal portion of the hind wings, the humeral angle as it is termed, is largely developed, so that it projects far under the fore wing (Fig. 241). This overlapping of the two wings at the base to so great an extent insures their act- ing together without the aid of the frenulum ; and, conse- quently, there being no use for a frenulum, this organ has disappeared. In other words, the frenulum has been super- seded by the large development of the humeral angle. But as we believe that these moths, skippers, and butterflies have descended from forms which had a frenulum, we class them with the moths that still possess this organ under the sub- order Frenatae. A more easily observed character which serves to distin- guish members of this suborder is a striking difference in the venation of the two pairs of wings, the hind wings hav- ing fewer veins than the fore wings. 2l8 THE STUDY OF INSECTS. Family MEGALOPYGID^E (Me-gal-o-pyg'i-dae). 7 he Flannel-wot /is. Sometimes there is attracted to our evening lamp a whitish moth, whose wings, being densely clothed with long curly hairs, resemble bits of flannel; this is the Crinkled Flannel-moth, Megalopyge cris- pata (Me-gal-o-py'ge cris-pa ta). It is cream-colored, with the fore wings marked with wavy lines of crinkled black and brownish hairs. The male is represented by Fig- ure 246 ; the female is larger, expanding one and three fifths FIG. 246. Megaiopyge inches. In the female the antennae are very narrowly pecti- nate. The larva is said to feed on oak, elm, apple, and rasp- berry. In the Southern States there occur three other species of this family. These moths are easily distin- guished by the structure of their wings (Fig. 247). There are three anal veins in both fore and hind wings ; bu-t in the fore wings the second and third anal veins (veins IX and XI) are partially grown together. The basal part of vein V is more or less distinctly preserved, and divides the discal cell into two nearly equal parts. Veins II and III of the hind wings are grown to- gether nearly to the end of the discal cell. VII, XI VII; IX VIII FIG. 247. Wings of Megalopyge crispata. LEPIDOPTERA. 219 The larvae of the Flannel-moths are remarkable for the possession of ten pairs of legs, three thoracic and seven abdomi- nal. All other known lepidopter- ous larvae, except perhaps those of Micropteryx, have lost some of the abdominal legs. The cocoons of these insects are also remark- FIG. 24 8. Cocoon of able, being furnished with a trap-door (Fig. 248). Family PSYCHID.E (Psy'chi-dae). The Bag-worm Moths. The Bag-worms are those caterpillars that have the curi- ous habit of building each for itself a silken sac covered with little twigs within which it lives (Figs. 249 and 250). When the caterpillar wishes to move from one place to another it pushes forth the front end of its body and creeps along, carrying its house with it. It is said that the species that inhabit Ceylon are be- lieved by the natives to be composed of individuals who in a previous incarnation were human beings and stole kindling-wood, and who now atone for the theft by repeat- ing the act as an insect. FIG. 249. Bag of Oikfticus abbotii. When a Bag-worm is fully grown, it fastens its sac to a twig and changes to a pupa within it. And here the females remain until death, leaving their eggs within their sacs. These females are grub- like creatures But the male way out from wings. without pupa works his the lower end 'fS*' F ' rata. FIG. 251. Psyche confedcrata. of his sac and changes to a winged moth. Figure 250 rep- resents the sac of a male with the empty pupa-skin projecting 220 THE STUDY OF INSECTS. FlG. ziyi from the lower end, and Figure 251 the fully developed male. These figures are of one of our smaller species, which belong to the genus Psyche (Psy'che). Abbot's Bag-worm, Oiketicus abbotii (Oi-ket'i-cus ab- bot'i-i). This species occurs in the more southern part of our country. The larva makes a bag with sticks attached to it crosswise (Fig. 249). T'ie Evergreen Bag-worm, TJiyridopteryx ephenieratfor- mis (Thyr-i-dop'te-ryx e-phem-e-me-for'- mis). This is our best known species, and on this account has been commonly called The Bag-worm. But as it is desir- able to have different names for the dif- ferent species, we call this one the Ever- green Bag-worm ; for although it feeds on many different trees, it prefers red cedar and arbor vitae. The bag of this species is about the same size as that of Abbot's Bag-worm; but it dif- fers in being covered ~ ,~ with bits of leaves of ' cedar or arbor vitae, or with twigs attached lengthwise. The structure of the wings of the Psy- chidae is very char- acteristic (Fig. 253). Both the fore and the hind wings may have either tWO Or FlG - 2 S3- Wings of rhyridopteryx ephemeraformis. three anal veins ; but the anal veins of the fore wings are grown together so as to ap- pear as a single much-branched vein. The base of vein V is preserved and is forked FIG. 254. LEPIDOPTERA. 221 within the discal cell. In the hind wings, veins I and II and veins II and III are grown together in an unusual way. In Figure 254 these veins are represented slightly separated in order to show their relation to each other. Family COSSID^E (Cos'si-dae). The Carpenter-mot '/is. This family includes moths with spindle-shaped bodies, and narrow, strong wings, some of the species resembling Hawk-moths quite closely in this respect. The larvae are wood-borers, living in the solid wood of the trunks of trees. They are often very injurious to forest or shade trees, and one recently imported species is very injurious to pear trees. The wood-boring habits of the larvae suggest the popular name Carpenter-moths for the insects of this family. These moths fly by night, and lay their eggs on the bark vn, VII a XI IX V ' FIG. 255. Wings of Prionoxy*tus robinice , /", frenulum, enlarged. of trees, or within tunnels in trees from which adult Car- penter-moths have emerged. The caterpillars are nearly naked, and, although furnished with pro-legs as well as true legs, are grub-like in form. The pupa state is passed within 222 THE STUDY OF INSECTS. the burrow made by the larva. When ready to change to an adult, the pupa works its way partially out from its bur- row. This is accomplished by means of backward-project- ing, saw-like teeth, there being one or two rows of these on each abdominal segment. After the moths have emerged the empty pupa-skins can be found projecting from the deserted burrows. The Carpenter-moths are of medium or large size. Our more common species are of a pepper-and-salt color, due to strongly contrasting dark and light scales. The antenna:: are usually pectinate in both sexes, but in some species those of the female are simple ; the ocelli are wanting ; and the mouth-parts are obsolete. The structure of the wings is shown in Figure 255 There are two anal veins in the fore wing, and three in the hind wings. The base of vein V is preserved, and is forked within the discal cell. In the fore wings, the branches of vein III anastomose so as to form an accessory cell. The frenulum is rudimentary in most of our genera (Fig. 255), but is strongly developed in others. Our most common species is the Locust-tree Carpenter- . 256. Prionoxystus robinia. moth, Prionoxystus robinice (Pri-on-ox-ys'tus ro-bin'i-ae). Figure 256 represents the female natural size. The male is but little more than half as large as the female. It is much LEPIDOPTERA. 223 darker than the female, from which it differs also in having a large yellow spot, which nearly covers the outer half of the hind wings. This species flies in June and July. As sug- gested by its name, it infests locust ; but its larva also bores in the trunks of oak, poplar, willow, and other trees. It is supposed that the species requires three years to com- plete its transformations. The Leopard-moth, Zeuzera pyrina (Zeu-ze'ra py-ri'na) is a large European species which has become common in the vicinity of New York City, and will doubtless spread to other parts of the country. It is white, spotted with numer- ous small black spots. Its larva is very injurious, especially to maple. It infests other shade trees, and also apple and pear. Family ElJCLElDyE (Eu-cle'i-dae). The Slug-caterpillar Moths. One often finds on the leaves of shrubs or trees elliptica) or oval larvae that resemble slugs in the form of the body and in their gliding motion. As these are larvae of moths they have been termed Slug-caterpillars ; but they present very little similarity in form to other caterpillars. The re- semblance to slugs is greatly increased by the fact that the FIG. 257 Larva of Eulimacodes scapha. FIG. 258. Euclta delphinii, larva. FIG. 259. lower surface of the body is closely applied to the object upon which the larva is creeping, the pro-legs being replaced by mere swellings on the abdominal segments. Some species are naked (Fig. 257); but many of them are armed 224 THE STUDY OF INSECTS. with branching spines (Fig. 258). The larvae when full grown spin very dense cocoons of brown silk ; these are egg-shaped or nearly spherical (Fig. 259), and are usually spun between leaves. The moths are of medium or small size ; they vary greatly in appearance, 3+4 and many of them ?.: very prettily colored. Considerable variation exists in the venation of the wings in this family (Figs. 260, 261). The base of vein V may be preserved or wanting. In some species it is forked within the discal cell, in others not. There is also considerable variation in the coalescence of the branches of radius, but veins III 3 and III 4 co- alesce to a greater ex- tent than any other branches of this vein, and there is no accessory cell. The Skiff Caterpillar, Euliniacodes scapJia (Eu-lim-a-co'des sca'pha). This remarkable larva (Fig. 257) is not uncommon on oak and other forest trees. It is pale apple-green, with a chestnut-brown patch on its back. The moth (Fig. 262) is light cinnamon-brown, with a tan-brown triangular spot on each fore wing. The Spiny Oak-slug, Euclea delphinii (Eu'cle-a del- phin'i-i). This larva (Fig. 258) is one of the most common of our slug-caterpillars. It feeds on the leaves of oak, pear, willow, and other trees. The moth is cinnamon- brown, with a variable number of bright green spots on the fore wings (Fig. 263). VII, VIII FIG. 260. Wings of Adoneta. spinuloides. LEPIDOPTERA. 225 The Saddle-back Caterpillar, Evipretia stimulea (Em- pre'ti-a sti-mu'le-a). This larva can be recognized by Fig- ure 264. Its most characteristic feature is a large green v. XI vn, VI I? IX VIII FIG. 261. Wings of Packardia geminata. patch on the back, resembling a saddle-cloth, while the saddle is represented by an oval purplish-brown spot. The moth is dark, velvety, reddish brown, with two golden dots FlG. 262. Eulimacodes scapha. FlGC 263. Euciea delpkinii. FIG. 264. Emfiretia stimulea, larva. near the apex of the fore wings. The larva feeds on oak and other forest trees. The prick of its spines is said to be venomous. 16 226 THE STUDY OF INSECTS. Family PYKOMORPHID^E (Pyr-o-mor'phi-dae). Tke Smoky-moths. There are but few insects in our country pertaining to this family. These are small moths, that are chiefly of a smoky black color ; some are marked with brighter colors. A tiny representative of the family which seems to be not uncommon in the East is Acoloitlms fal- sanns (Ac-o-loi'thus fal-sa'ri-us). This moth (Fig. 265) expands two thirds of an inch. It is black, with the pro- thorax of an orange color. The venation of its wings (Fig. 266) is peculiar in that subcosta and radius of the hind wings coalesce for only a short , - III 5 V, FlG. ?(><:,. A coloi- tints falsarins. II XI VII 2 vu, distance beyond the mid- dle of the discal cell, and a stump of radius pro- jects towards the base of the wing, from the point of union of the two veins. The larva feeds in early summer on the leaves of grape and of the Virginia creeper. It is said that the pupa state lasts fourteen days and is passed within a parchment-like cocoon. The adult frequents flowers in the daytime. The typical genus of the family is represented in the At- lantic and Western States by Pyromorpha dimidiata (Pyr-o- mor'pha di-mid-i-a'ta). The entire insect is smoky black, except the basal half of the fore wings in front of vein IX, and the basal half of the costa of the hind wings, which are yellow. The wings are thinly scaled, and expand a little more than one inch. Figure 267 represents the venation of the wings. IX VIII FIG. 266. Wings of Acoloithus fulsarius. LEPIDOPTERA. 227 in. In Texas and Arizona there occur several species of Triprocris (Trip'ro-cris). The venation of one of them is shown in Figure 268. (r tir, It is remarkable in that none of the branches of radius of the fore wings coalesce beyond the dis- cal cell. The genus Harrisina (Har-ris'i-na) seems to be closely allied to the preceding and is placed in this family provision- ally. It differs, how- ever, from the typical 1 form of the family in that the anal area Of FIG. 267. Wings of Pyromorpha dimidiate. the hind wings is greatly reduced, there being only two, short, strongly curved anal veins. As in the other members of the family there are two, well-developed anal in the VJIJ VII VII, Til 1 4 m i veins preserved Vi fore wings. In the East the most common species is Har- risina americana (H. a-mer-i-ca'na) (Fig. 269). au FIG. 268. Wings of Triprocris marteni. FIG. 269. Harrisina americana. The wings are long and narrow ; the abdomen is long and widened towards the caudal end. It is greenish black in color, with the prothorax reddish orange. The larva feeds 228 THE STUDY OF INSECTS. on the leaves of grape and of the Virginia creeper. An entire brood of these larvae will feed side by side on a single leaf while young. Harrisina texana (H. tex-a'na) occurs in the Southwest. It closely resembles the preceding; but is bluish black with a reddish orange prothorax. Harrisina coracina (H. cor-a-ci'na) also occurs in the Southwest. This species is entirely black. Superfamily PYRALIDINA (Pyr-a-li-di'na). The Pyralids (Pyr'a-lids). This superfamily includes moths of medium or small size ; but so large a proportion of the species are small that the superfamily is commonly classed with the two following as Microlepidoptera. The members of the different families included in this superfamily differ so greatly in appearance that it is not possible to give a gen- eral description that will serve to distinguish it. It is necessary to study structural char- acters to find evidences of a common bond, and here as in other groups we find the structure of the wings most useful for this purpose. As a rule there are FIG. 270. wings of Nomophiia noctueiia. three anal veins in the hind wings and two in the fore wings. In this respect this superfamily agrees with the preceding families and with the two following superfamilies. But in most cases the Pyralids can be recognized by the fact that the subcosta and radius of the hind wings are separate along the discal cell, but grown LEPIDOPTERA. 229 FIG. 271. Wings of Tlascala reductella. together for a short distance beyond the cell, after which they are again separate (Fig 270). In some gen- era these two veins do not actually coalesce, but extend very near to- gether for a short dis- tance (Fig. 271). The two types, however, are essentially the same. This superfamily in- cludes seven families, which can be separated by the table given below. The Plume -moths are placed last in the series, as we believe that they depart more widely from the primitive type than do any of the other families. A. Wings not fissured. B. Hind wings without a fringe of hairs on the basal part of vein VII. Care must be taken not to mistake scattered hairs on the anal area of the wing for such a fringe. C. Fore wings with veins 1114 and Ills separate, vein III 5 arising from the discal cell (Fig. 272). p. 230 PYRAUSTID/E. CC. Fore wings with veins Ilh and I1I 5 united at base (Fig. 277). p. 232 PYRALJDID^. BB. Hind wings with a fringe of long hairs on the- basal part of ve : r VII. C. Radius of fore wings five- branched. D. Maxillary palpi more or less developed, but not triangular as in the next family, p. 233 GALLERIID^. DD. Labial palpi long, straight, projecting forward ; maxillary palpi well developed, strongly dilated at tip with scales, ap- pearing triangular when viewed from the side. p. 234. CRAMBID^E. CC. Radius of fore wings four-branched, veins III a and III coalescing to edge of wing (Fig. 281). p. 235 ... . FHYCITID^E. 230 THE STUDV OF IX SECTS. AA. Wings fissured. B Wings with less than five fissures; usually the fore wings have one fissure and the hind wings two. p. 237. . . . PTEROPHORID^. BB. Each wing split into six parts, p. 238 ORNEODID^E. Family PYRAUSTID.E (Py-raus'ti-dse). The Pyraustids (Py-r aits' t ids}. The members of this family differ from other Pyralids by the following combination of characters. There is no fringe o t> of long hairs on the basal part of vein VII of the hind wings, and vein III 6 of nr * 3 nr " ^^ the fore wings arises from the discal cell dis- tinct from vein 1 1 1 4 (Fig. 272). This family in- cludes many small moths; but it contains also the majority of the larger species of Pyra- lids. Some of the species are very striking in ap- pearance. FIG. 272. Wings of Nontophila noctuelia. The GraDC Leaf folder, Desmia fnneralis (Des'mi-a fu-ne-ra'lis) is a common species, the larva of which feeds on the leaves of grape. The larva folds' the leaf by fastening two portions together by silken threads. When full grown, changes to a pupa within the folded leaf. The moth is black with shining white spots. The male (Fig. 273) differs from the fe- male in having a knot-like enlargement near the middle of each antenna. There is some variation in the size and shape of the white spots on the wings. In some specimens the white spot of the hind wing is sepa- rated into two or three spots. VII, VII, VIII FlG. 273 Desinia Jttneralis. LEPIDOPl^ERA. 231 The Bass-wood Leaf-roller, Pantographa liniata (Pan- tog'ra-pha Ji-ma'ta). Our bass-wood trees often present a strange ap- pearance from the fact that nearly every leaf is cut more than half way across the middle, and the end rolled into a tube (Fig. 274). Within this tube there lives a bright green larva, with the head and thoracic shield black. This larva resembles cer- at a. FlG. 275. Pantographa limata, tain Tortricid larvae, both in ap- pearance and habits ; but a study of the adult shows it to be a Py- ra ii c ] < The moth expands about one and one half inches; it is straw-colored, with many elaborate markings of olive with a purplish iridescence (Fig. 275). There is one brood a year ; the winter is passed in the larval state. The Melon-worm, Margaronia Jiyalinata (Mar-ga-ro'ni-a hy-a-li-na'ta). This beautiful moth (Fig. 276) is often a serious pest in our southern states, where the larva is very 232 THE STUDY OF INSECTS. destructive to melons and other allied plants, destroying both the foliage and the fruit. The moth is a superb FIG. 2i6.Margaronia hyalinata, larvae, cocoon, and adults. (From the Author's Report for 1879.) creature, with glistening white wings bordered with black, and with a spreading brush of long scales at the end of the abdomen. Family PYRALIDID.E (Pyr-a-lid'i-dae). The Typical Pyralids (Pyr' a-lids]. The moths of this family are distinguished from other Pyr- alids, except the next family, by the absence of a fringe of hairs on the basal part of vein VII of the hind wings; and they are distinguished from that family by the fact that veins III 4 and III 6 of the fore wings are united at base (Fig. 277). It is one of the smaller of the families of Pyralids; fifty-four species are now enumerated in our lists. LEPIDOPl^ERA. 233 The Meal-moth, Pyralis farinalis (Pyr'a-lis far-i-na'lis) is a common species. The larva feeds on ILt meal, flour, and old clover-hay. The moth is commonly found near the food of the larva, but is often seen on the ceilings of rooms sitting with its tail curved over its back. It expands about an inch ; the fore wings are light brown, crossed by two curved white lines, and with a dark chocolate-brown spot on the base and tip of each. The Clover-hay Worm, Pyralis cost alts (Pyr'a-lis cos-ta'- lis). The larva of this species sometimes abounds in old stacks of clover-hay, and especially near the bottom of such stacks. As the infested hay be- comes covered with a silken web spun by the larva, and by its black gunpowder-like excre- ment, much more is spoiled than is eaten by The moth expands about four fifths of an inch. It is of a beautiful lilac color, with golden bands and fringes (Fig. 278). Family GALLERIID^E (Gal-le-ri'i-das). Tlie Bee-mot Ji Family. This is a small family, of which only seven species have been found in our fauna. The best known of these is the Bee-moth, Galleria mellonella (Gal-le'ri-a mel-lo-ncl'la). The VIII FlG. 277. Wings of Pyralis farinalis. FIG. 278. costalis. the insect. 234 THE STUDY OF INSECTS. FIG. mello- nella . larva of this species is a well-known pest in apiaries, it feeds upon wax; and makes silk-lined galleries in the honey- comb, thus destroying it. When full grown the larva is about an inch in length. It lies hidden in its gallery dur- ing the day, and feeds only at night, when the tired-out bees are sleeping the sleep of the just. When ready to pupate the caterpillar spins a tough cocoon against the side of the hive. The moth has purplish-brown front wings, and brown or faded yellow hind wings. The fore wings of the male are deeply notched at the end, while those of the female (Fig. 279) are but slightly so. The female moth creeps into the hive at night to lay her eggs. This pest is found most o'ften in weak colonies of bees, which it frequently destroys. The best preventive of its injuries is to keep the colonies of bees strong. Of course the moths and larvae should be destroyed whenever found. But the moths are slippery like other expert thieves, and run so rapidly when disturbed that it is very difficult to catch them. Family CRAMBID^ (Cram'bi-dae). The Close-wings. Although this is not a large family, there being only seventy-five species known in our fauna, the members of it are more often seen than any other Pyralids. The larvae of most of the species feed on grass; and the adults fly up before us whenever we walk through meadows or pastures. When at rest, the moths wrap their wings closely about the body ; this has suggested the name Close-wings for the , FlG. 280 Cram insects of this family. When one of these l "' li - moths alights on a stalk of grass it quickly places its body LEriDOPTERA. 235 infills 1113*4 parallel with the stalk, which renders it less conspicuous (Fig. 280). Many of the species are silvery white or are marked with stripes of that color. More than fifty of our species belong to the genus Cram- bus (Cram'bus). The moths of this genus are often seen; but the larvae usually escape observation. They occur chiefly near the surface of the ground, where they live in tubular nests constructed of bits of earth or vegetable matter. Family PHYCITID^; (Phy-cit'i-dae). The Pkycitids (P/iyc'i-tids). Our most common members of this family are small moths with rather narrow but long fore wings, which are banded or mottled with various shades of gray or brown. The family is, however, a large one and other types of col- oration occur. The dis- tinctive characteristics are those given in the table above. Figure 281 represents the venation of the wings. The larvae of the dif- erent species vary greatly in habits. Some live in flowers, some fold or roll 1 -. i i i , i FIG. 281 Wings of Tlascala reductella. leaves within which they live and feed; some are borers; others feed upon dried fruits, or flour and meal ; and one, at least, is preda- ceous, feeding on coccids. Usually the larva lives in ;i silken tube or case, lying concealed by day and feeding by night. XI vui 236 THE STUDY OF INSECTS The case made by certain of the leaf-eating species is very characteristic in form (Fig. 282), being strongly taper- ing and much curved ; in this instance the case is composed largely of the excrement of the larva. The Indian-meal Moth, Plodia interpnnc- tella (Plo'di-a in-ter-punc-tel'la) is the best known of the species that infest stored provisions. The larva is the small whitish worm, with a brownish -yellow head, that spins thin silken tubes through meal or among yeast-cakes, or in bags or boxes of dried fruits. The moth expands about five eighths of an inch. The basal two fifths of the fore wing is dull white or cream-colored ; the outer part reddish brown, with irregular bands of blackish scales. The Mediterranean Flour -moth, EpJiestia kiiJiniclla (E-phes'ti-a kiihn-i-el'la), is an even more serious pest than the preceding species, which it resembles in habits. It has become very troublesome in recent years in flouring-mills. The moth expands about one inch, and is grayish in color. Although it is called the Mediterranean Flour-moth, its source is not definitely known. Nor do we know of any easy way of ridding an infested mill of it. Carbon bisul- phide is perhaps the most available insecticide in this case. Zimmermann's Pine-pest, Pinipcstis zimmermanni (Pin-i- pes'tis zim-mer-man'ni), is a common species, the larva of which is a borer. It infests the trunks of pine, causing large masses of gum to exude. The moths appear in mid- summer. The Coccid-eating Pyralid, Lcetilia coccidivora (Lae-til'i-a coc-ci-div'o-ra), differs from the other members of this family in being predaceous. It feeds on the eggs and young of various scale-insects (Pulvinaria, Dactylopius, and Lecaniuni). Figure 283 represents the different stages of this insect enlarged, and the moths natural size resting- on LEPIDOPTERA. 237 egg-sacs of Pulvinaria. Like other members of this family the larva spins a silken tube, within which it lives. On a FIG. 283.- Latilia coccieih'ora ; a, egg; , larva ; c, pupa; d, adult; e, e, moths natural size resting on egg-sacs of Puhiinaria. thickly infested branch these tubes may be found extending from the remains of one coccid to another. Family Pterophoridae (Pter-o-phor'i-dae). The Plume-moths. The Plume -moths are so called on account of the remarkable form of the wings, which are split by longitu- 238 THE STUDY OF INSECTS. dinal fissures into more or less plume-like divisions. In most species the fore wing is separated into two parts, by a fissure extending about one half the length of the wing; while the hind wing is divided into three parts by fissure?, extending farther towards the base of the wing. Sixty species belonging to the family have been found in North America. One of our most common species is the Gartered Plume, Oxyptilus periscelidactylns(Q^-j^'\\\\\^ per-is-cel-i-dac'ty-lus). This is a small moth, expanding about seven tenths of an inch. It is of a yellowish brown color marked with dull whitish streaks and spots (Fig. 284). The larvae hatch early in the FIG. 284 -oxyftiius s P rm g an ^ feed upon the newly-expanded frriscelidactyl. \^ VQ?> Q f grape> They f asten together several of them, usually those at the end of a shoot, with fine white silk; between the leaves thus folded the cater- pillars live either singly or two or three together. They become full grown and change to pupae early in June. The pupa is not enclosed in a cocoon, but is fastened to the lower side of a leaf by its tail by means of a few silken threads, in nearly the same way that the chrysalids of certain butterflies are suspended. The pupa state lasts about eight days. Family ORNEODID^; (Or-ne-od'i-dae). The Many-plume Moths. These insects resemble the Plume Moths in having the wings fissured ; but here the fissuring is carried to a much greater extent than in that fam- ily, each wing being divided into six plumes (Fig. 285). As yet only a single species of this family has been found in North Amer- ica. This is Orneodes hexadactyla (Or- ne-o'des hex-a-dac'ty-la). FlG. 2&5. hexadactyla. LEPIDOPTERA. 239 in, in, Superfamily TORTRICINA (Tor-tri-ci'na). The Tortricids (Tor' tri-cids). The Tortricids are generally small moths ; but as a rule they are larger than the Tineids. They have broad front wings, which usually end squarely. The costa of the front wing curves forward strongly near the base of the wing. When at rest the broad front wings fold above the body like a roof. The moths are variegated in color, but are usually brown, gray, or golden rather than of brighter hues. As a rule the hind wings are of the color of the body and without markings. In the venation of the wings they differ from the Pyralids in having subcosta and radius of the hind wings widely separate beyond the end of the discal cell ; and from the Tineids in having the second anal vein of the hind wings forked towards the base (Fig. 286). T h e larvae vary greatly in habits ; but a large proportion of them are leaf- rollers (Fig. 287). It was this habit that suggested the name Tor- trix (Tor'trix) for the typical genus, from which the names of one family and of the superfamily are derived. A large proportion of the rolled leaves found upon shrubs and trees are homes of Tortricid larvae. But it should be remembered that the leaf-rolling habit is net confined to this family. FIG. 286. Wings of Cacoecia cernsivorana. FIG. 287. Leaf rolled by a larva, probably a Tortricid. 24O THE STUDY OF INSECTS. The rolled leaves serve the Tortricid larvae not merely as homes but also as food, for they feed upon the enclosed portions. Sometimes several leaves are used by a larva, but more often only one, or in many cases merely a tip or one edge of a leaf is used. Some species cut a slit in a leaf and roll only one part of it. They also differ greatly as to the extent to which the leaves are rolled. Some species are gregarious, an entire brood making a common nest. During the latter part of the summer and in the autumn these rolled leaves can be found on almost any tree or shrub. In nearly all cases entomologists in naming Tortricids have formed the specific name with the ending -ana; so that the form of the name indicates the family to which the insect belongs. More than four hundred North American species of Tortricids are known. The superfamily includes three fam- ilies, which can be separated by the following table : A. With a fringe of long hairs on the basal part of vein VII of the hind wings, on the upper side of the wing. Do not mistake a bunch of long hairs arising from the wing back of vein VII for this fringe, p. 240 ............ ............. GRAPHOLITHID^E. A A. Without a fringe of long hairs on the basal part of vein VII o f the hind wings. B. Vein VII 2 of the fore wings arising from the outer fourth of the discal cell, p. 243 .............................. CONCHYLIDJE. BB. Vein VIU of the fore wings arising from a point before the outer third of the discal cell, p. 244 Family GRAPHOLITHID^E (Graph-o-lith'i-dae). TJic Grap/iolithids (Gra-phol' i-thids). These moths are easily distinguished from other Tortri- cids by the presence of a fringe of long hairs on the basal part of cubitus of the hind wing. To this family belong nearly two thirds of our species of Tortricids. The follow ing are some of our more common species : LEPIDOP TERA . 24 1 The Codling-moth, Carpocapsa poinonella (Car-po-cap'sa pom-o-nel'la). This is the best-known and probably the most important insect enemy of the fruit-grower. The larva is the worm found feeding near the core of wormy apples. The adult (Fig. 288) is a beautiful little creature with finely mottled pale gray or rosy fore wings. There is a large brownish spot near the end of the fore wing, and upon this spot irregular, golden bands. The moth issues from the pupa state in late spring and lays its eggs singly on the surface of the fruit or on adjacent leaves. As soon as the larva hatches it bur- rows into the apple and eats its way to the core, usually causing the fruit to fall prematurely. When full grown the larva burrows out through the side of the fruit, and undergoes its transformations within a cocoon, under the rough bark of the tree, or in some other protected place. The species is both single-brooded and double-brooded. The larvae winter in their cocoons, transforming to pupae during early spring. The method of combating this pest that is most com- monly employed now is to spray the trees with Paris- green water, just after the petals fall and before the young apples are heavy enough to droop. The falling spray lodges in the blossom end of the young apple, and many of the larvae which attempt to enter at this point, the usual place of entrance, get a dose of poison with their first meal. The Bud-moth, Tinetocera occllana (Tme-toc'e-ra oc-el- la'na). The larva of this insect is also a pest infesting ap- ple-trees. It works in opening fruit-buds and leaf-buds, of ten eating into them, especially the terminal ones, so that all new growth is stopped. It also ties the young leaves at the end of a shoot together and lives within the cluster thus formed, adding other leaves when more food is needed. Sometimes so large a proportion of the fruit-buds are destroyed as to 17 242 THE STUDY OF INSECTS. seriously reduce the amount of the crop. Th^ pupa state is passed within the cluster of tied leaves or within a tube formed by rolling up one side of a leaf, and lasts about ten days. The moth expands about three fifths of an inch ; it is of a dark ashen gray, with a large, irregular, wl.itish band on the fore wing. FIG. 289. Reii'iiLi <.oinstockia.no,, larva, pupa, adult, and work. (From the Author's Report for 1879.) The Pitch-pine Retinia, Retinia comstockiana (Re-tin'i a com-stock-i-a'na). This species (Fig. 289) illustrates well LEPIDOPTERA. 243 the habits of the boring species. The larva infests the small branches of pitch-pine. It is a yellowish-brown caterpillar, which makes a burrow along the centre of the branch. Its presence may be detected by the resin that flows out of the wound in the twig and hardens into a lump. Two of these lumps are shown in the figure, one of them splits lengthwise, and the other with a pupa-skin pro- jecting from it. The larva, pupa, and adult are also figured. The moth is represented natural size ; the darker shades are dark rust- color, and the lighter, light-gray. The insect winters as a larva; the adult emerges in May and June. The Frustrating Retinia, Rctinia /r?/.y/'ra;/tf(frus-tra'na). Thisspecies infests the new growth of several species of pine, spinning a delicate web around the terminal bud, and pupa, adult, and work. (From mining both the twig and the bases the Author's Report for i8 79 .) of the leaves. The larva, pupa, and adult are represented somewhat enlarged in the figure. An infested twig is also shown (Fig. 290). Family CONCHYLID^; (Con-chyl'i-dae). The ConcJiylids (Con' cJiy-lids). This is the smallest of the three families of Tortricids, less than fifty species occurring in our fauna. The members of it can be recognized by the characters given in the table above. Comparatively little is known about the habits of our species. The Juniper Web-worm, Conchylis riitilana (Con'chy-lis ru-ti-la'na), is an imported species which has attracted atten- 244 THE STUDY OF INSECTS. tion by its injuries to junipers, the leaves of which it fastens together with silk. In this way it makes a more or less per- fect tube within which it lives. The moth expands about one half inch, and has bright, glossy, orange, fore wings. crossed by four reddish brown bands. Family TORTRICID^E (Tor-tric'i-dae). Tlie Typical Tortricids ( Tor' tri-dds). The Tortricidae agree with the preceding family in lack- ing a fringe of long hairs on the basal part of vein VII of the hind wings, but differ in that vein VII 2 of the hind wings separates from the main stem before the outer third of the discal cell. More than one hundred and twenty North American species are known. Several of our best-known members of this family belong to the genus Caccecia (Ca-coe'ci-a). These may be called the Ugly-nest Tortricids, ugly dwelling being the meaning of Caccecia, and also descriptive of the nests of the larvae of these insects. Figure 291 represents the nest of the larva of Caccecia ro- sana (C. ro-sa'na), which we bred on currant ; and Figure 292, the adult of this species. This moth expands three fourths of an inch. The fore wings are olive-brown, crossed by bands of darker color ; the hind wings are dusky. This species differs FIG. 291. Nest of Caccecia. rosana. FIG. 292. -Caccecia rosana. from the two following in that each larva makes a nest for itself. LEP1DOPTERA. 245 The Cherry-tree Ugly-nest Tortricid, Caccecia cerasivo- rana (C. cer-a-si-vo-ra'na), lives upon the choke-cherry and sometimes upon the cul- tivated cherry. The larvae, which are yel- low, active creatures, fasten together all the leaves and twigs of a branch and feed upon them (Fig. 293), an entire brood oc cupying a single nest. The larvae change to pupae within the nest; and the pupae, when about to transform, work their way out and hang suspended from the outer portion of the nest, clinging to it only by hooks at the tail end of the body. Here they transform, leaving the empty pupa- skins projecting from the nest, as shown in the figure. The moths vary in size, the jj^HU wing expanse of those we have bred rang- ing from four fifths of an inch to nearly one and one-fifth inches. The wings are bright ochre-yellow ; the front pair marked with irregular brownish spots and numer- FlG. 293. Nest of Caccecia FIG. 294. Caccecia. certisi- cer ashiar ana. vorana, male. FlG. 295. Caccecia cerasi- vorana, female. ous transverse bands of pale leaden blue (Fig. 294 male, 295 female). The Oak Ugly-nest Tortricid, Caccecia fervadana (C. fer- ra-da /ia). The nests of this species are common on out oak-trees in late summer. They are merely a wad of leaves fastened together. Each nest contains several larvae ; later the empty pupa-skins may be found clinging to the outside of the nest as in the preceding species. The Pine-leaf Tube-builder, Loplioderus, politana (Lo- 246 THE STUDY Of INSECTS. phod'e-rus pol-i-ta'na). One of the most interesting of Tor- tricid nests occurs commonly on white pine. Each nest consists of from six to ten leaves drawn together so as to form a tube, and is lined within with silk. This tube serves as a protection to the larva, from which it comes out to feed upon the ends of the very leaves of which the tube is com- posed ; in this way the tube is shortened. We bred the moth from nests collected at Ithaca, New York; but we have found similar nests as far south as Florida. The moth expands one half inch. Its head, thorax, and fore wings are of a dull rust-red color, with two oblique paler bands cross- ing the fore wings, one a little before the middle, the other beyond, parallel to it. Superfamily TlNElNA (Tin-e-i'na). The Tineids ( Tin'e-ids). The Tineids are nearly all minute moths with narrow wings, which are bordered with wide fringes. A few species are of considerable size, and have broader wings, with nar- rower fringes. The narrow-winged forms can be distinguished from all other moths by the shape of the wings and the great width of the fringes. The moths figured below .(Fig- s - 298, 299, 300, 302) illustrate this. It should be remembered that in each of these figures the insect is represented greatly enlarged ; in most cases the size of the insect is represented by a hair- line near the figure. The wide- winged forms are most surely distinguished by the venation of the wings. In F.G. 29 6.-wings of De/ressaria '** roore general features the heracliana. VCHatlOn of tllC willgS ill this family is similar to that of the Tortricids ; it differs, how- L EPID OP 7 'ERA. 247 ever, in that the second anal vein of the hind wings is not forked towards the base (Fig. 296). The venation of the wings of the more generalized Tineids is quite primitive in type; there are two anal veins in the fore wings, three anal veins in the hind wings, and the base of vein V is preserved throughout the length of the discal cell. But the more specialized members of the superfamily present a wide departure from this gen eralized type. With these the base of vein V has disappeared from both pairs of wings, and the venation of the hind wings is reduced to a greater extent than is seen elsewhere in winged Lepidoptera. Correlated with this great reduction of the hind wings there has been a great expansion of the fringe of the wing. It is evident that the fringe of the wing takes the place of the wing-membrane as an organ of flight. In those Tineids that we have studied carefully the hairs composing the fringe are inserted in the lower side of the wing- membrane a short distance back from the edge of the wing; and the edge of the wing is stiffened above by strong overlapping scales. This arrangement renders the fringe rigid during the downward stroke of the wing, but admits of its depression during the upward stroke; a combination well adapted to facilitate flight. The substi- tution of wide fringes for the wing-membrane occurs in some other minute insects, as Thrips and certain minute, parasitic Hymenop- tera. To this superfamily belong the smallest of the Lepidop- tera ; many of them are so minute that the larvae live until full grown within the tissue of leaves. These tiny moths are often very beautiful, their wings being marked with scales that shine like silver or gold ; but they are so small that it is necessary to examine them with a lens to appreciate their beauty. The larvae of nearly all Tineids feed upon vegetable matter. The majority of them feed upon or within the leaves of plants, but many live within nuts, or seeds, or dried fruits ; a few feed upon dead animal matter, as woolens, furs, and feathers ; and some are predaceous, destroying scale-bugs. Entomologists have a custom of terminating the name of each species of Tineid with -clla. Thus we have Tinea 248 THE STUDY OF INSECTS. granella, Adela ridingsclla, Bucculatrix pomonclla, and many hundreds of others; until the syllable -ella always brings before us a vision of a tiny moth, with narrow wings bear- ing long delicate fringes. The Tineids are very numerous, there being nearly one thousand described American species ; and doubtless there are many undescribed as yet. The superfamily is composed of several families ; but, as the study of these insects is too difficult to be carried far by the beginning student, we will not take the space to define these families in this work. We will merely describe the habits of a few species. At first thought the leaves of our common shrubs and trees seem quite as thin as if they had been cut out of sheets of paper. But the reader has doubtless learned in the study of Botany that the upper and the lower surfaces of a leaf are each covered with a thin skin or epidermis, and that between these two skins there is a fleshy portion called the parenchyma. But if botanists had failed to teach us this lesson, the Tineid larvae would have done so; for many of these little creatures live until full grown between the two skins of a leaf, and derive their nourishment from the paren- chyma. As our coal-miners dig tunnels in the earth, so do these larvae eat out long passages in the substance of a leaf, without breaking through either epidermis. Durincr the late summer and autumn there can be found o on almost any shrub or tree leaves that are more or less dis* colored by white or grayish blotches or by long twisted lines that reveal the abiding-places of leaf-miners. Surely Mr. Lowell must have had these in mind when he wrote : " And there's never a leaf nor a blade too mean To be some happy creature's palace." Not only are very many kinds of plants infested by Tineid larvae, but the mines in the leaves differ greatly in form and in their position in the leaf. These differences in food-plant and in the shape and position of the mines do LEPIDOPTERA. 249 not indicate that these larvae are inconstant in their habits. In fact, the opposite is the case. Each species of Tineid infests a particular species of plant, or, at the most, several closely allied plants. And each species makes a mine of definite shape, although some species exhibit different habits in the different stages of their growth. So constant are these creatures in their habits that in most cases an expert can determine the species of Tineid that made a mine by merely examining the infested leaf. The various kinds of mines can be classed under a few distinct types. The long, narrow, and more or less winding mines are described as linear mines. Some of these are very narrow at their beginning and grad- ually enlarge, resembling in outline a serpent ; fre- quently the larger end is terminated by a blotch- like enlargement, suggest- ing a head. Such mines are termed serpentine mines. The leaves of the wild columbine are often marked by serpentine mines (Fig. 297). Other mines that start from a narrow beginning enlarge more rapidly and extend in a more or less regular curve ; these are trumpet mines. A common example of a trumpet mine is that made by the larva of TiscJicria malifoliella (Tis-che'ri-a mal-i-fol-i-el'la) in the leaves of apple. The mines of many species are mere disk-like blotches ; these are referred to as blotch mines (Fig. 298). Blotch mines differ in position ; some are immediately beneath the upper epider- mis, while others are nearer the lower surface of the leaf. This distinction exists also in most of the other types of FIG. 297. Leaf with serpentine mines 250 THE STUDY OF INSECTS. mines. In some of the blotch mines the epidermis of one side of the leaf is thrown into a fold by the growth of the leaf ; these are tentiform mines. In addition to peculiarities in shape many mines are marked by characteristic lines or spots composed of the droppings of the larva. The following species will serve to illustrate the habits of these remarkable insects. The White-blotch Oak-leaf Miner, LitJiocolletis hamadrya- della (Lith-o-col-le'tis ha-mad-ry-a-del'la). This little miner infests the leaves of many different species of oak, and some- ^Bi "^> v^ J~ - '- "^^ 'Sm"' *^ ' ,.' - - -o- i FIG. 298. Lithocolletis haitiadryTdcllu: a, mine; 6, young larva; c, full-grown, flat-form larva; d, head of same, enlarged; e, antenna of same, enlarged; /", round-form larva from above; g, same from below; A, head of same, enlarged; /, antenna of same, en- larged; , maxilla and palpus of same, enlarged; /, labium, labial palpi, and spinnerets of same; , pupa; , side view of pupal crest; a, front view of same; g, cocoon; Q, moth. (From the Author's Report for 1879.) times it is extremely abundant. We have seen trees infested so badly that there were on an average four or five mines in each leaf. Figure 298 represents a leaf from such a tree. The mine is a whitish, blotch mine in the upper side of the leaf. LFJIDOPTERA. 251 The young larva is remarkable in resembling more the larva of a beetle than the ordinary type of lepidopterous larvae. It is nearly flat ; the lirst thoracic segment is much larger than any of the others ; the body tapers towards the hind end ; and there are only the faintest rudiments of legs discernible. The larvae molt seven times. At the seventh molt the form of the body undergoes a striking change. It now becomes cylindrical in form, there is a great change in the shape of the mouth-parts, and the fourteen feet are well developed. This change in form during the life of the larva is charac- teristic of a large group of Tineids of which this species may be taken as a type. The full-grown cylindrical larva meas- ures about one-fifth inch in length. It spins a cocoon, which is simply a delicate, semi-transparent, circular sheet of white silk, stretched over a part of the floor of the mine. The pupa is dark brown in color, and bears a toothed crest upon its head, which enables it doubtless to pierce or saw its way out from the cocoon. The moth is a delicate little creature, whose wings expand a little more than one-fourth inch. The fore wings are white, with three, broad, irregular, bronze bands across each, and each band is bordered with black on the inner side. The hind wings are silvery. As this insect passes the winter as a larva within the dry leaves, the best way to check its ravages when it becomes a pest is to rake up and burn such leaves. The Palmetto-leaf Miner, Lavcrna sabalclla (La-ver'na sab-a-lel'la) . This species occurs only in the South where the saw-palmetto grows. But it is of general interest as illustrating a peculiar type of larval habit. The larvae can hardly be said to be leaf-miners; for they feed upon the upper surface of the leaf, destroying the skin as well as the fleshy part of the leaf. They are social, working together in small companies, and make a nest consisting of a delicate sheet of silk covering that part of the leaf upon which they are feeding; this sheet is covered with what appears like sawdust, but which is really a mass of the droppings of the 252 THE STUDY OF INSECTS. larvas (Fig. 299). The full grown larva attains a length of half an inch. The pupa state is passed within the nest made by the larvae. The moth is quite large for a Tineid, the wings expanding five eighths of an inch. Its general color is ULNlBHOLBiENb FIG. 2g^.Laverna. sabalella, larva, pupa, adult, and part of injured leaf. (From the Author's Report for 1879.) a delicate silvery gray, with a tinge of lavender in some in- dividuals. The Pine-leaf Miner, Gelechiapinifoliella(Ge-\e r c\i\-a. pin-i- fol-i-el'la). It often happens that the ends of the leaves of pine present a dead and brown appearance that is due to the interior of the leaf having been eaten out. This is the work of the Pine-leaf Miner (Fig. 300). At the right season it is easy to see the long, slender larva in its snug retreat by holding a leaf up to the light and looking through it ; and later the pupa can be seen in the same way. Near the lower end of the tunnel in each leaf there is a round hole through which the larva entered the leaf and from which the adult emerges. We have found this insect in several of the stouter-leaved species of pine, but never in the slender leaves of the white pine. In the North it is most abundant in the leaves of pitch-pine. LEPIDOPTERA. The Apple Bucculatrix, Bucculatrix pomifoliella (Buc cu- la'trix pom-i-fol-i-el'la). This insect differs in habits in sev- FIG. yx>.Geleckia. pinifoliellii, larva, pupa, adult, and leaves mined by the larva. (From the Author s Report lor 1879.; eral respects from any of the other Tineids described here. The larva infests the leaves of apple, and when full grown it makes a small white cocoon which is attached to the lower surface of a twig. These cocoons sometimes occur in great numbers, side by side, on the twigs of an infested tree (Fig. 301). They are easily recognized by their shape being slender, and ribbed lengthwise. It is these cocoons tha*: usually first reveal the presence of this pest in an orchard. They are very conspicuous during the winter when the leaves are off the trees. At this time each cocoon contains a pupa. The adult moth emerges in early spring. The ees are laid on the lower surface of the leaves. Each oo larva when it hatches bores directly from the egg to the upper surface of the leaf, where it makes a brown serpentine 254 THE STUDY OF INSECTS. mine. When these mines are abundant in a leaf it turns yellow and dies. When the larva has made a mine from one-half to three-fourths of an inch long, which it does in from four to five days, it eats its way out through the upper surface. Then somewhere on the upper surface of the leaf it weaves a circular silken covering about one-twelfth inch in diam- eter. Stretched out on this network the larva, which is now about one-tenth inch long, makes a small hole in it near its edge, then, as one would turn a somersault, it puts its head into this hole and disappears beneath the silken covering, where it undergoes a change of skin. It remains in the molting cocoon usually less than twenty-four hours. After leaving this cocoon it feeds upon the leaves without making a mine ; and in a few days makes a second molting cocoon which differs from the first only in being about one- eighth inch in diameter. After leaving this it again feeds for a few days, and then mi- grates to a twig where it makes the long ribbed cocoon within which the pupa state is passed. This very interesting life-history was first worked out by Mr. A. E. Brunn while a student in the writer's laboratory at Cornell University. When it is necessary to combat this pest the smaller twigs bearing cocoons should be pruned as far as practicable during the winter and burned, and those cocoons that remain on the larger branches should be washed with strong kerosene emulsion. The Resplendent Shield-bearer, Aspidisca splendoriferella (As-pi-dis'ca splen-do-rif-e-rel'la). This Tineid is both a miner and a case-bearer. It feeds within apple-leaves, and at first makes a linear mine ; but later this is enlarged into a blotch mine. When full grown the larva makes an oval case FIG. 301. Cocoons of Bucculalrix pom- ifoliella. LEPIDOP TERA . 255 cut from the walls of its mine and lined with silk. It then seeks a safe place in which to fasten this case and pass the winter. This is usually on the trunk or on a branch of the in- fested tree (Fig. 302). Once some of these migrating larvae dropped from a tree upon the writer's hat and carefully ?IG. 302. Aspidisca splendoriferella : a, leaf of apple showing work ; 6, summer larva ; c, larva in case travelling ; i/, cases tied up for winter ; e, hibernating larva ; _/", pup a ; g, moth ; A, parasite. (From the Author's Report for 1879.) faster/ed themselves to the band with misplaced confidence that they could remain there till spring. The adult has gray and golden wings with silvery and dark markings. The Maple-leaf Cutter, Incurvaria acerifoliella (In-cur- va'ri-a a-cer-i-fol-i-el'la). This insect illustrates still another 2 5 6 THE STUD Y OF INSECTS. curious type of larval habits. It infests the leaves of maple, and occasionally is so abundant that it does serious injury. The leaves of an infested tree present a strange appearance (Fig. 303). They are perforated with numerous elliptical holes, and marked by many more or less perfect ring-like patches in which the green substance of the leaf has been destroyed, but each of which incloses an uninjured spot. These inju- ries are produced as follows: The young larva cuts an oval piece out of a leaf, places it over its back, and fastens it down with silk around the edges. This serves as a house beneath which it lives. As it grows this house becomes too small for it. It then cuts out a larger piece which it fastens to the outer edges of the FIG. 303. Leaf infested by Incurvaria. smaller OtlC, the larva being between the two. Then it fastens one edge of this case to the leaf by a silken hinge so that it will not fall to the ground " cradle and all," and then turns the case over so that the larger piece is over its back. When it wishes to change its location it thrusts out its head and fore legs from the case and walks off, looking like a tiny turtle. When it wishes to eat it fastens the case to the leaf and, thrusting its head out, eats the fleshy part of the leaf as far as it can reach. This explains the circular form of the patches, the round spot in the center indicating the position of the case. The insect passes the winter in the pupa state within its case } which falls to the ground with the infested leaf. The moth is of a brilliant steel-blue or bluish-green color without spots; it appears in early summer. LEPIDOPTERA. Other Case-bearers. The two case-bearers described above make their cases out of fragments of leaves ; there are others that use the husks of seeds which they have eaten. Such cases are extremely protective, appearing to be merely seeds. But there are some Tineid case-bearers that make their cases entirely of silk. These are usually more or less nearly cylindrical, and are carried projecting out at a considerable angle from the object upon which the insect walks. When the insect is at rest and when it is undergoing its transformations the mouth of the case is closely fastened to some object, so that the insect is com- pletely concealed. Considerable differences exist in the form of these silken cases. In a quite common type the case is nearly cylindrical, with a flaring lip at the head end, and with the hind end three-sided, as if it had been pinched between one's thumb and two fingers. In another type the hind end of the case is somewhat enlarged and curved down- ward so that the case is shaped like a pistol. The Clothes-moths. These are the dread of every house- keeper. The mere mention of the word "moths" is enough to conjure up visions of household treasures of woolen and fur eaten full of holes, their beauty gone, their usefulness past. It was formerly supposed that these well-known injuries were caused by a single species; but it has since been dis- covered that we have in this country three species of clothes- moths. These differ in habits as well as in structure. The Case-bearing Clothes-moth, Tinea pcllionella (Tin'e-a pel-li-o-nel'la). The larva of this species is a true case- bearer, making a case out of bits of its food-material which are fastened together with silk. As the larva grows it en- larges its case by adding to each end and by slitting it and inserting a piece. Instructive specimens can be obtained by rearing the larvae, and changing them from time to time from flannel of one color to that of another. The shape of the successive additions to the case, being of different colors. can be easily seen. The pupa state is passed within the 18 258 THE STUDY OF INSECTS. case. The adult is a small brown moth with a few dark spots on its fore wings. The Tube-building Clothes-moth, Tinea tapetzella (T. tap-et-zel'la). The larva of this species makes a gallery composed of silk mixed with fragments of cloth. This gal- lery is long and winding and can be easily distinguished from the case of the preceding species. The pupa state is passed within the gallery. The moth differs greatly in ap- pearance from the other two species, the fore wings being black from the base to the middle and white beyond. The Naked Clothes-moth, Tinea biselliella (T. bi-sel- li-el'la). Although this species spins some silk wherever it goes, it makes neither a case nor a gallery. It may be termed, therefore, the Naked Clothes-moth, in contradistinc- tion to the other two species. But when the larva is full grown it makes a cocoon, which is composed of fragments of its food-material fastened together with silk. The adult is of a delicate straw-color, without dark spots on its wings. Protection from Clothes-moths. In late spring or early summer all winter clothing, flannels, furs, and other articles that are to be put. away for the summer should be thor- oughly brushed or examined for these pests, and exposed to the sunlight as long as practicable. Then they should be wrapped carefully in stout paper, or better packed in paste- board boxes, which can be procured at small cost, and the crack between the cover and the box closed by pasting a strip of paper over it. The Angoumois Grain-moth, Gelechia cerealella (Ge- le'chi-a ce-re-a-lel'la). Although this insect is closely allied to the Pine-leaf Miner, its habits are very different. This insect feeds upon seeds, and especially upon stored grain. It occurs throughout our country; but it is especially de- structive in the Southern States. In that part of the coun- try it is extremely difficult to keep grain long on account of this pest and certain beetles that also feed on stored grain. The adult moth is of a very light grayish-brown LEPIDOPTERA. 259 color, more or less spotted with black ; it expands about half an inch. The common name is derived from the fact that it has been very destructive in the province of Angou mois, France. Family SESIID.E (Se-si'i-dae). The Clear-winged Moths or Sesiids (Se' si-ids). The Clear-winged Moths constitute a very rematkable family, many of them resembling bees or wasps in appear- ance more than they do ordinary moths, a resemblance due to their clear wings and in some cases to their bright colors (Fig. 304). There are a few moths in other families, as the Clear- winged Sphinxes, and certain Zygaenids, that have a greater or less part of the wings devoid of scales ; but they are exceptions. FlG - 3*- Here it is the rule that the greater part of one or both pairs of wings are free from scales; hence the common name Clear-winged Moths. These insects are of moderate size ; as a rule they have spindle-shaped antennae, which are terminated by a small silky tuft; sometimes the antennas are pectinate ; the margins of the wings and the veins of even the clear- winged species are clothed with scales ; and at the end of the abdo- FIG. 305. Wings of Sannina exitiosa, female. men there is a fan-like tuft of scales. The fore wings are remarkable for their extreme narrow- XI VII, 260 THE STUDY OF INSECTS. ness and the great reduction of the anal area (Fig. 305); while the hind wings have a widely expanded anal area. There is great variation within the family in the number of anal veins in the hind wings, the number ranging from two to four. The maximum number of anal veins in the Lepi- doptera has generally been considered to be three ; but in certain forms belonging to this family a fourth (vein X) is quite well represented. Another remarkable feature of all tne forms that we have studied is that in the female the bristles composing the frenulum are consolidated as in the male. The females also possess a frenulum hook; but this is not so highly specialized as that of the male. The adults fly very swiftly and during the hotter part of the day. They frequent flowers, thus increasing their resem- blance to bees or wasps. The larvae are borers, living within the more solid parts of plants. Some species cause serious injury to vegetation. Nearly one hundred and fifty species have been found in this country. Doubtless many more exist ; for the family has not been thoroughly studied as yet. The following species have attracted much attention on account of their serious ravages. The Peach-tree Borer, Sannina exitiosa (San-ni'na ex-it-i- o'sa). This is the most important insect enemy of the peach-tree. In some parts of the country it is difficult to find a peach-tree that is not infested by it. The eggs are laid on the bark of the tree near the ground. The larvae bore downward in the bark of the trunk just below the sur- face of the ground. Their burrows become filled by a gummy secretion of the tree. As this oozes out in large masses the presence of the borer is easily detected by it. When full grown the larva comes to the surface of the ground and makes a cocoon of borings fastened together with silk. The perfect insects appear from May till October, but most of them in the latter part of June and early {" July. There is a single generation each year. The adults LEPIDOPTERA. 26 1 differ greatly in appearance. The general color of both sexes is a glassy steel-blue. In the female (Fig. 306) the fore wings are covered with scales, and there is a bright orange-colored band on the abdomen. In the male both pairs of wings are nearly free from scales. No better method of fighting this pest has been found than to care- FlG ' ***'* fully watch the trees and remove the larvae with a knife as soon as discovered. The Pacific Peach-tree Borer, Sannina pacifica (S. pa- cif'i ca). On the Pacific Coast there is a peach-tree borer that is distinct from the above, and appears to be an even more serious pest. The larva is more difficult to remove from the tree, as it bores into the solid wood. The female of this species lacks the orange-colored band on the abdomen. The Currant Borer, Sesia tipuliformis (Se'si-a tip-u-li-for'- mis). This species is closely allied to the two preceding, but is smaller, expanding only about three fourths of an inch. There are but few scales on either pair of wings except on the tip and discal vein of the fore wings and the outer margin of the hind wings. The eggs are laid on the twigs of currant. The larvae penetrate the stem, and de- vour the pith; in this way they make a burrow in which they live and undergo their transformations. The perfect insects appear in June. Before this time the leaves of the infested plant turn yellow. If such plants be cut and burned in May the pest will be destroyed. The Pine Sesian, Hannonia pint (Har-mo'ni-a pi'ni). Frequently there may be seen on the trunks of pine-trees large masses of resinous gum mingled with sawdust-like matter. These are the results of the work of the larvae of this insect, which bore under the bark and into the superficial layers of the wood. The adult resembles the female of the Peach-tree Borer, but the abdomen is more extensively marked with orange. 262 THE STUDY OF INSECTS. The Squash-vine Borer, Melittia ceto (Me-lit'ti-a ce'to). The larva of this species (Fig. 307) does great damage by eating the interior of squash-vines. In some places it is FIG. 307. Melittia ceto, larva in squash-vine. almost impossible to raise squashes on account of its rav- ages. The fore wines of the adult are covered with scales, O c> and the hind legs are fringed with long orange-colored scales. Family DIOPTID^: (Di-op'ti-dae). The Dioptids (Di-op'tids). This family is represented in our fauna by a single known species, Phryganidia californica (Phryg-a-nid'i-a cal-i-for'- FIG. 308. Pliryganidia californica. ni-ca), which occurs in Califor- nia. This is a pale-brown insect, with nearly transparent wings (Fig. 308). The veins of the wings are dark, which renders them prominent. In the males there is a yellowish FIG. 309. Wings of Phryganidia. spot just beyond the discal cell. The venation of the wings LEPIDOPTERA. 263 (Fig. 309) is very different from that of any other insect that occurs in this country. The larvae feed upon the leaves of live-oaks, and some- times occur so abundantly as to almost strip the trees of their foliage. They are said to feed singly, and appear to make little if any use of the anal feet as a means of loco- motion, generally carrying the last segment of the body elevated in the air. Family NOTODONTID^: (No-to-don'ti-dae). The Prominents. This family includes moths of moderate size, only a few of the larger ones expanding more than two inches. With these moths the. body is rather stout and densely clothed with hair, and the legs, especially the femora, are clothed with long hairs. The wings are strong, and not very broad, the anal angle of the hind wings rarely reaching the end of the abdomen. In their general appearance many of these moths bear a strong resemblance to the Owlet Moths or Noctuidae ; but they can be easily distinguished from the Noctuids by the position of vein V 2 of the fore wings, which does not arise nearer to vein VII than to vein III, as it does in that family. In some species the front wing has a prominence or backward - project- ing lobe on the in- ner margin, which has suggested the common name of Prominents for these insects (Fig. 310). The name is J I FIG. y-o.Pheosta nmosa. more generally ap- propriate, however, for the larvae, as a much larger propor- tion of them than of the adults bear striking prominences. 264 THE STUDY OF INSECTS. The characteristic features in the structure of the wings are the following (Fig. 311): the fore wings have a single in, "Ii. VIIi XI Vlb FlG. 311. Wings of Notodonta stragula. upon the leaves of shrubs and trees. anal vein, the hind wings two ; in both wings cubitus is apparently three- branched ; and the subcosta of the hind wings does not make a sharp bend into the humeral angle as it does in the Geometridae (Fig. 323). In some forms the basal part of vein V is more or less distinctly pre- served ; and in some an accessory cell is. present. The larvae feed Our most common species live in folded thinly clothed with species live exposed ; but some leaves. They are either naked or hairs. Many species have only four well-developed pro- legs, the anal pair being rudimentary, or transformed into elongated spikes. Some species are hump-backed; and spines or fleshy tubercles are often present. The trans- formations occur in slight cocoons or in the ground. The family is a large one, more than one hundred species occurring in the United States. The following are some of the more common species : The Handmaid Moths, Datana (Da-ta'na). Among the more common representatives of the Notodontidae are cer- tain brown moths that have the fore wings crossed with bars of a different shade (Fig% 312) and that bear on the LEPIDOPTERA. 265 fore part of the thorax a conspicuous patch of darker color. In most of our species the fore wings are also marked with a dot near the center of the discal ( cell and a bar on the discal vein.' These moths belong to the genus fiatana. The common name, Handmaid, is a translation of the specific name of our most com- mon species, D. ministra (D. mi-nis'tra). But as this species is now generally known as the Yellow-necked Apple-tree Worm, and as all of our species are dressed in sober at- tire as becomes modest servants, we have applied the term Handmaid Moths to the entire genus. The larvae of the Handmaid Moths are easily recognized by their peculiar habits. They are common on various fruit and forest trees, but especially on apple, oak, and hickory. They feed in colonies; and have the habit of assuming the FIG. 312. Dattina. FIG. 313. Dutana, larva. curious attitude shown in Figure 313. The body is black or reddish, marked with lines or stripes of yellow or white. Owing to the gregarious habits of these larvae they can be easily collected from the trees they infest. All of the species that we have studied agree in being single-brooded, the moths appearing in midsummer; the 266 THE STUDY OF INSECTS. eggs are laid in a cluster on a leaf ; the larvae are con- spicuous in August and September. In some of the species the larvae have the curious habit of leaving the branch upon which they are feeding when the time to molt arrives, the whole colony gathering in a large mass on the trunk of the tree, where the molt takes place. The pupa state is passed in the ground, in a very light cocoon or in none at all, and lasts about nine months in the species that we have bred. The White-tipped Moth, Edema albifrons (E-de'ma al'bi-frons). This beautiful moth, which is quite common, can be easily recognized by the accompanying figure (Fig. 314); the white patch, which extends along the costa of the fore wing for half the length from the tip, being very char- acteristic. The larva (Fig. 3 1 5) is quite common in the autumn FIG. 314. Edema, albifrons. on leaves of oak. It is smooth and shining, with no hairs; along each side of the back there is a yellow stripe, and between these, on the back, fine black lines on a pale lilac ground ; on each side below the yellow stripe there are three black lines, the lowest one just above the spiracles. The head is orange-red ; and there is an orange-red hump on the eighth abdominal segment. FIG. y.'-,. Edema albifrons, larva. The Two-lined Prominent, Seirodonta bilineata (Seir-o- don'ta bi-lin-e-a'ta). The larva of this species (Fig. 316) is much more apt to be observed than the adult. It is com- mon in the latter part of the summer and in early autumn, LEPlDOrTERA. feeding on the leaves of oak, elm, and basswood. It measures when full grown about one and one half inches in length. Its FIG. ^.-Seirodonta. bilineata, ground-Color JS Usually green, but larva - sometimes claret-red. There is a pale yellow stripe along the middle of the back, and on each side a stripe of the same color. The course of these side stripes is very characteristic ; passing back from the head, they converge on the prothorax ; on the mesothorax and metathorax they are separated from the dorsal line only by a narrow band of red or purple; on the first abdominal seg- ment they diverge to the lateral margin of the back, but converge again on the seventh and eighth abdominal seg- ments. This yellow subdorsal line is bordered without by a milk-white stripe ; and extending from this stripe over the side of the body there is a whitish shade which fades out below. The moth is ash- colored, with the fore wings crossed by two wavy lines between which the wing is darker ; be- tween the outer wavy line and the outer margin of the wing there is a faint band. The Red-humped Apple -worm, (Edemasia concinna (CEd-e-ma'si-a con-cin'na). The larva of this species (Fig. 3 1 7) is common on apple and allied plants. The head is coral- FIG. 317. CEdemasia concinna, larva. red, and there is a hump of the same color on the back of the first abdominal segment; the body is striped with slender black, yellow, and white lines, and has two rows of black 268 THE STUDY OF INSECTS. spines along the back, and other shorter ones upon the sides. When not eating, the larvae remain close together, some- times completely covering the branch upon which they rest. This species passes the winter in the pupa state. The adults appear in June and July. The Mocha-stone Moths, IchtJiyura (Ich-thy-u'ra). To the genus IchtJiyura belong several species of brownish-gray moths, whose fore wings are crossed by irregular whitish lines. It was these peculiar markings, resembling somewhat those of a moss-agate, that suggested the popular name given above. The larvae feed on poplar and willow, and conceal themselves within nests made by fastening leaves together. Our most common species is the following : The Poplar Mocha-stone Moth, IchtJiyura inclusa (I. in- clu'sa). The adult (Fig. 318) is a brownish-gray moth, with the fore wings crossed by three irregu- lar whitish lines. The basal line is broken near the middle of the wing ; and the intermediate one forms an in-< verted Y, the main stem of which joins FIG. y%.-ichthynra inciusa. the third line near the inner margin of the wing, making with it a prominent V. These lines are bordered without by rust-red ; there is a chocolate-colored spot near the apex of the fore wings, and an irregular row of blackish dots near the outer margin. The hairs of the thorax form a prominent crest, the fore side of which is a rich dark brown. The hind wings are crossed by a wavy band, which is light without and dark within. The eggs are nearly spherical and smooth ; they are deposited in a cluster a single layer deep on a leaf (Fig. 319). When the larvae hatch they make a nest either by fastening several leaves together or, as is the case when they infest poplar, by folding the two halves of a single leaf together; frequently in the latter case the tip of the leaf is folded in as shown in the figure. Within this nest the entire colony lives, feeding on the parenchyma, and causing the LEPIDOPTEVA. 269 leaf to turn brown. Later other leaves are added to this nest or additional nests are made among adjoining leaves. All of these infested leaves are securely fastened to the twig by bands of silk. When the larvae become large they leave their nests at night to feed upon other leaves. These they entirely consume excepting the petioles, midribs, and larger FIG. 319. Eggs, larva, and nest of Ichthyura inclusa. veins. We have seen on poplar a nest composed of only three leaves which contained one hundred and twenty-five half-grown larvae ; all of the leaves, about thirty in number, arising from the end of the branch bearing this nest had been consumed. The full-grown larva measures one and one half inches in length. It is striped with pale yellow and brownish black, and bears a pair of black tubercles close together on the first abdominal segment, and a similar pair on the eighth abdominal segment. The cocoon is an irregular thin web ; it is made under leaves or other rubbish on the ground. The insect remains in the pupa state during the winter, and emerges as a moth in the latter part of June or later. In the South this species infests willow as well as poplar, and is double-brooded. Among the most grotesque of larvre be- FlG - 3~.-G*w< f >*, larva, longing to this family are those of the genus Ccelodasys 270 THE STUDY OF INSECTS. (Cce-lod'a-sys), of which we have several species. One of these is represented by Figure 320. At the left in the figure is shown a front view of the longest tubercle. Superfamily GEOMETRINA (Ge-o-me-tri'na). The Geometrids (Ge-om'e-trids), or the Measuring-worms. The peculiar way in which the larvae of Geometrids walk attracts general attention, and has won for them the name of Measuring-worms (Fig. 321). As children we had the dislike for "worms" that is common to people that are un- educated to the beauties of na- ture. All larvae were " worms "; and we never thought of admir- FIG. 321. A Measuring-worm. . ,, . , . , , , ing their beautiful colors, or of watching them build interesting houses, or of keeping them till they spun their silken cocoons. But the measuring- worms were excepted from this dislike. We always found these delicate, greenish or yellowish caterpillars with their looping motion vastly interesting. We allowed them to measure our fingers with their little tickling feet, and we counted each length as a yard. We were always delighted with the way they had of standing on their hind legs, rear- ing the body up into the air, and moving the head around, as if looking at the scenery. And then, if one became frightened in any way, it would drop suddenly, suspended by a silken cord, which it seemed to have mysteriously con- cealed in its mouth ; and down it would go, doubling and whirling around and around frantically until it reached the ground. Sometimes we found these fellows on branches of trees, clinging by their hind legs, standing out straight, stiff, and motionless, and appearing like twigs of the tree. We had not heard then of protective resemblances, and did not know that the assuming of this strange attitude protected LEPIDOPTERA. 271 III IT these worms from the sharp-eyed birds. If so, we should have been still more interested in them; and we should have been even more so could some one have told us of the transformation of these loopers first into pupae and then into beautiful moths. But in those days comparatively few people thought it worth while to study insects. The larvae of Geometrids have as a rule only the last two pairs of prolegs well developed ; and hence, as the middle part of the body is not supported, they are unable to walk in the way that other caterpillars walk. It is probable, however, that the loss of the first three pairs of prolegs is the result of the looping gait rather than the cause of it. That is to say, the ancient Geometrid lar- vae acquired the habit of looping, after which the prolegs under the middle of the body, being unnecessary and not used, dwindled away in succeeding generations. In the case of a few members of this family three or even four pairs of pro- legs have been re- tained. The Geometrid lar- vae are mostly leaf-eat- ing, and some species, as the Canker-worms, occur in such large numbers as to be serious pests. The pupae are slender, and some species are green or mottled in color in this state. The pupa state is passed in a very flimsy cocoon or in a cell in the ground. v, VII, Vlh FIG. 322. Wings of Caripeta angustiorata. 2/2 THE STUDY OF INSECTS. The moths are of medium size, sometimes small, but only rarely very large. Usually the body is slender, and the wings broad and delicate in appearance. This appearance is due to the fineness of the scales with which the wings are clothed. These moths occur on the borders of woods and in forests, rarely in meadows and pastures. Their flight is neither strong nor long sustained. When at rest the wings are spread horizontally and scarcely overlap each other. The distinguishing features in the venation of the wings of the Geometrina are that vein V a of the fore wings is not more closely joined to cubitus than to radius, cubitus being apparently three-branched, and that the basal part of vein II of the hind vlt wings makes a prominent bend into the hu- F ang.r o 3 f hawing meral angle of the wing (Figs. 322, 323).* Except in the more specialized forms where it has disappeared there is a rudiment of vein I of the hind wings. This usually extends from near the base of the frenulum to the angle in vein II (Figs. 322, 324). In Eudulc (Fig. 323) and allied forms the rudiment of vein I lies some distance from the margin of the wing. There occur in our fauna representatives of five families; these can be separated by the following table : A. Vein V a of the hind wings wanting, being represented merely by a fold in the wing (Fig. 327). p. 277. ENNOMID^K. AA. Vein Va of the hind wings present. B. Vein Va of the hind wings arising much nearer to vein Vi than to vein V 3 (Fig. 343). Wings usually green, p. 287. GEOMETRIES. BB. Vein Va of the hind wings arising nearly midway between veins Vj and V 3 or nearer to vein V 3 than to vein V. Wings rarely green. * In the more specialized forms the humeral angle is greatly expanded (Fig. 343), and in some the frenulum is completely supplanted by it (Fig. 335) The loss of the frenulum in this family, however, occurs only in highly spe- cialized forms ; while in that series of families that we have called the Fren- ulum-losers it has occurred in all except a very few extremely generalized forms. LEPIDOPTERA. 2?$ C. Veins II and III of hind wings extending distinctly separate from each other, except that they are connected by a cross vein near the middle of the discal cell (Fig. 335). p. 282. HYDRIOMENID^E. CC. Veins II and III of hind wings approximated or coalesced lor a greater or less distance. D. Veins II and III of the hind wings closely approximated but not coalesced along the second fourth (more or less) of the discal cell. E. Veins III and Vi of hind wings separating at or before the apex of the discal cell (Fig. 327). p. 277. ENNOMID/E. EE. Veins III and V of hind wings coalesced for a consider- able distance beyond the apex of the discal cell (Fig. 324). p. 273. MONOCTENIIDJE. DD. Veins II and III of hind wings coalesced for a greater or less distance. E. Veins II and III of the hind wings coalesced for a short distance near the beginning of the second fourth of the discal cell, thence rapidly diverging (Fig. 341). p. 286. STERRHID.E. EE. Veins II and III of the hind wings coalesced to or be- yond the middle of the discal cell (Fig. 334). F. Fore wings with one or two accessory ce'ls. p. 282. HYDRIOMENID^;. FF. Fore wings without an accessory cell (Alsophila). p. 273. MONOCTENIIDJE. Family MONOCTENIID^: (Mo-noc-te-ni'i-dEe). The Monocteniids (Mon-oc-te' ni-ids). This family includes only a small number of North American species ; but among them are those that are the most important to us from an economic standpoint of all the Geometrids. The family is also of especial interest from a scientific point of view; for to it belong the most primitive forms of the Geometrina, certain genera, found in Australia, being closelv allied to the Notodontidae, according to the observa- tions of Mr. Meyrick. 19 THE STUDY OF INSECTS. In the typical forms, vein V, of the hind wings is present, and veins II and III of the hind wings are closely approxi- mate, but do not co- alesce along the second fourth of the discal cell Vl (Fig- 3 2 4)- In many gen- era veins III and V, of the hind wings coalesce beyond the apex of the discal cell (Fig. 324). This character is of use in distinguishing certain members of this family from those of the En- nomidae that retain vein V., of the hind wings. In that family a similar coalescence of veins III and V, does not take place till after the loss of vein V,. In one of XI FIG. 324. Wings of Brefhos infam our genera veins II and III of the hind wings coalesce along the second fourth of the discal cell, as they do in the Hydriomenidae ; but the absence of an accessory cell in the fore wings at once distinguishes this genus from the Hydri- omenids. The following species are our best known repre- sentatives of the family. The Firstborn Geometer, BrepJios infans (Bre'phos in'- fans). This interesting species has been found only in the northeastern part of our country ; its range is from Labrador to New York. It is a blackish-brown moth with the fore wings marked with pinkish white and the hind wines with reddish orange FIG. 325. Brephos infans, male. (Fig. 325). The specimen figured is a male. In the female LEPIDOPTERA. the black border on the outer margin of the hind wings is narrower, and the subterminal light band on the fore wings is more distinctly marked. The early stages of this species are unknown ; but the larvae of European species feed upon birch and poplar. With these the prolegs are all present , but the first three pairs are stunted. As this is probably the most primitive Geometer occurring in our fauna, we suggest the popular name Firstborn for it. In Germany an allied species is known as the Jungfernkind. Canker-worms. In many parts of our country Canker- worms are extremely abundant. In such localities they are among the more important of insect pests, often completely stripping the foliage from fruit and shade trees. There are two distinct species of Canker-worms; but they resemble each other so closely that they were long confounded ; and to this day they are distinguished only by entomologists. The two species agree in being loopers or measuring-worms in the larval state, in the possession of ample wings by the adult male, and in the adult female being wingless. They differ in structural characters, as indicated below, and also to a certain extent in habits. In one species the greater num- ber of moths mature in the autumn and emerge from the ground at this season ; in the other species the insects re- main in the pupa state during the winter, emerging as moths in the spring. The two species are therefore appropriately designated as the Fall Canker-worm and the Spring Canker- worm respectively. The Spring Canker-worm, Paleacrita vernata (Pal-e-ac'ri-ta ver-na'ta). The eggs are ovoid in shape, and are secreted in irregular masses, usually under loose scales of bark or be- tween the leaflets of the expanding buds. The larvae hatch about the time the leaves expand, and become full grown in from three to four weeks. They vary greatly in color, and are marked on the back with eight narrow, pale, longitudinal lines which are barely discernible ; the two lateral lines of each side are much farther apart than the others; and there are 276 THE STUDY OF INSECTS. no prolegs on the fifth abdominal segment. The pupa state is passed below the surface of the ground in a simple earthen cell, which is lined with very few silken threads. The adult moths usually emerge early in the spring before the leaves expand ; but they sometimes appear late in the fall, or on warm days during the winter when the ground is thawed. In both sexes the adult of this species is distinguished by the presence of two transverse rows of stiff reddish spines, pointing backwards, on each of the first seven abdominal seg- ments. In the male the venation of the wings very closely resembles that of Brcphos (Fig. 324); veins II and III of the hind wings although closely approximate do not coalesce, and veins III and V, coalesce for a considerable distance be- yond the apex of the discal cell. The Fall Canker-worm, AlsopJiila pomctaria (Al-soph'i-la pom-e-ta'ri-a). The eggs appear as if cut off at the top. and have a central puncture and a brown circle near the border of the disk. They are laid side by side in regular rows and compact batches, and are generally exposed. They hatch in the spring at the time the leaves appear; and the larvae mature in about three weeks. The larva is of a pale brown- ish color marked with dark brown and yellow ; the body is marked on the back with six broad and very distinct pale lines, those of each side equidistant ; and there is a pair of distinct prolegs on the fifth abdominal segment. As in the preceding species the pupa state is passed beneath the ground, but this species makes a perfect cocoon of fine densely spun silk. The adult moth usually emerges in the fall, generally beginning about the middle or latter part of October ; although a con- siderable number come out of the earth in the winter during warm weather and in the spring. The FIG. 326. Alsjphila. pometaria, . . . male. moths ot both sexes lack the ab- dominal spines characteristic of the Spring Canker- worm. LEPID OP TERA . The male is represented by Figure 326. In this species veins II and III of the hind wings coalesce for a considerable distance along the second fourth of the discal cell ; and veins III and V, of the hind wings separate at the apex of the dis- cal cell. The two species of Canker-worms are sufficiently alike in habits to warrant our combating them by similar methods. The fact that in each the female is wingless and is thus forced to climb up the trunks of trees in order to place her eggs in a suitable place has suggested the method of defence that has been most generally used in the past. This is to place something about the trunks of the trees which will make it impossible for the wingless female to ascend them. Some viscid substance, as tar, printers' ink, or melted rubber, either painted on the trunk of the tree or upon a paper band which is tacked closely about the tree, is the means usually adopted. Many other devices have been recommended. In the use of this method of prevention, operations should be begun in the autumn, even when it is the Spring Canker- worm that is to be combated. For in this species some of the moths emerge in the fall or during the winter. Although the method just described is still the most avail- able one when tall shade-trees are to be protected, it is now rarely used in orchards. Here the spraying of the trees with Paris-green water soon after the leaves appear is found more practicable. This method has also the advantage of enabling the fruit-grower to reach other important pests, as the Codlin-moth, at the same time. Family ENNOMID^E (En-nom'i-dae). The Ennomids (En 1 no-mids). Nearly all of the members of this family can be easily recognized as such by the fact that vein V 3 of the hind wings is wanting, being represented merely by a fold. In a few species this vein has been preserved ; these can be recog- 278 THE STUDY OF IiVSECTS. nized by the following combination of characters : Vein V, of the hind wings does not arise much nearer to vein V, than to vein V 3 (as it does in the Geomet- ridae), veins II and III of the hind wings are closely approximate but do not coalesce along the second fourth, more or less, of the discal cell (Fig. 327), and veins III and V, of the hind wings do not coalesce beyond the apex of the discal cell. This last char- acter does not apply to the family as a whole, but merely to those that retain vein V 2 of the hind wings; FIG. 327. Wings of Carifeta angustioratn. jj-j some of tllOSC ill which this vein is lost, the coalescence of veins III and V, is carried beyond the apex of the cell. This is by far the largest of the families of the Geome- trina and contains the greater number of our larger species. The following will serve as illustrations of it : The Notched-wing Ge- ometer, Ennomos magnarius (En'no-mos mag-na'ri-us), is one of the largest of our Geometrids. The larva is a common looper upon maple, chestnut, and birch trees, and measures about two and one third inches in length VII XI VIIj FIG. 328. Ennomos magnarius. LEPIDOPTERA. 279 FIG. 329. Diastictis ribearia. when full grown. It spins a rather dense, spindle-shaped cocoon within a cluster of leaves. The moth (Fig. 328) is ochre-yellow with a reddish tinge. The wings are shaded towards the outer margin with brown, and are thickly spotted with small brown dots. The Currant Span-worm, Diastictis ribearia (Di-as-tic'ti.s rib-e-a'ri-a). There are several species of insects that ar<= popularly known as currant- worms. The most common of these are larvae of saw- flies, which can be easily recognized by the large number of prolegs with which the abdomen is fur- nished. In addition to the saw-flies there is a yellow looper spotted with black, which often appears in such great numbers on currant and gooseberry bushes as to suddenly strip them of their foliage. This larva has been named the Currant or Gooseberry Span-worm. When full grown it measures about one inch in length, and is of a bright yellow color, with white lines on the sides and with numerous black spots and round dots. It has only four prolegs. There is only a single brood; the larva matures in May or June ; the pupa state lasts about a fortnight; the moth flies during the summer months and oviposits on the twigs of the plants ; and the eggs remain un- hatched till the following spring. The moth (Fig. 329) is pale yellow, with the wings marked by ir- regular dusky spots, which sometimes form one or two indefinite bands across them. FIG. w.-Cin t ilia catenaria. ^^ Chaill-dotted Geoni- eter, Cingilia catenaria (Cin-gil'i-a cat-e-na'ri-a). This moth 230 THE STUDY OF INSECTS. has snow-white wings marked with zigzag lines and with dots of black as shown in Fig. 330. The head is ochreous- yellow in front ; and the thorax is yellowish at the base of the patagia. The moth flies during September and October. The larva feeds on various shrubs and trees. The pupa state is passed in a slight but well-formed web of yellow threads, which is formed between twigs or leaves, and through which the pupa can be seen. The Evergreen Cleora, Cleora semiclusaria (Cle'o-ra sem-i-clu-sa'ri-a). This beautiful moth (Fig. 331) is common in the vicinity of pines, spruce, fir, and hemlock during August and September. It varies from a smoky-ash color to almost snow - white ; the wings are marked with black. The larva feeds on the leaves of Conifers. It is reddish yellow above, with FIG. 331. Cleora semiclusaria. \ . i 11 j i_ 1 i M lateral yellow bands below, while on each side are two pairs of black hair-lines. There are black spots above on the segments. When full grown it is a little more than an inch long and spins a loose cocoon among the leaves. The chrysalid is green with white stripes and is very pretty. The Pepper-and-salt Currant- moth, Biston cognatariu (Bis'ton cog-na-ta'ri-a). This moth (Fig. 332) differs remark- ably in appearance from most Geometrids, the body being stouter, and the wings appearing heavier. It can be easily recog- nized by its evenly distributed pepper-and-salt markings. The FlG - 33.-*/ larva feeds on various plants, but is found most often on currant. The Lime-tree Winter-moth, Eraunis tiliaria (E-ran'nis LEPIDOPTEKA. 281 til-i-a'ri-a). This species (Fig. 333) resembles the Canker- worms in many particulars. The larva is a looper which infests both fruit and forest trees; and in the adult state the male has well-developed wings, while the female is wingless. The eggs are oval, of a pale yellow color, and covered with a network of raised lines. They are thrust by the FIG. 333. Erannis tiliaria. (From the Author's Report for 1879.) female under loose bark and in crevices on the trunk and large limbs. They hatch in May, and the larvae attain their full growth in the latter part of June. The larva is yellow, marked with ten crinkled black lines along the top of the back ; the head is rust-colored, and the venter yellowish white; when full grown it measures about one and one fifth inches in length. The pupa state is passed in the ground, from three to six inches below the surface. The moths issue in October, and then the wingless females ascend the 282 THE STUDY OF INSECTS. trees to oviposit as do the females of the Canker-worms. The female is represented in the lower left-hand part of the figure. She is grayish in color, with two black spots on the back of each segment except the last, which has only one. The male has buff fore wings, with a central spot and a band beyond the middle, while the hind wings are much lighter. This insect can be combated by the same methods as are used against canker-worms. Family HYDRIOMENID, (Hyd-ri-o-men'i-dae). The Hydriomenids (Hyd-ri-o-me nids\ The Hydriomenids are easily recognized by the structure of their wings. In the fore wings the branches of radius anastomose so as to form one or two accessory cells; and in the hind wings veins II and III coalesce along the second fourth of the discal cell, the co- alescence extending to or beyond the middle of the inv ii VII, VII, FIG. 334. Wings of Eudule mendica. FIG. 335. Wings of Dyspteris abot tii'aria. LEPIDOPTERA. 283 discal cell (Fig. 334). The only exception to these char- acters known to us is shown by certain genera (e.g., HeteropJi- leps and Dyspteris) in which, owing to a large expansion of the costal area of the hind v/ings, veins II and III have been pulled apart as it were, and are connected only by a cross vein near the middle of the discal cell (Fig. 335). In a single genus (Paleacrita) not belonging to this family veins II and III of the hind wings coalesce to the middle of the discal cell ; but this genus lacks the accessory cell in the fore wings characteristic of this family. This family ranks second in size among the Geometrid families, and contains many common species. The White-striped Black, EiicJiccca albovittata (Eu-choe'ca al-bo-vit-ta'ta). This beautiful little moth, which occurs from the Atlantic to the Pacific, is the most easily recog- nized member of the family. It expands about seven eighths of an inch, and is of a uniform black color, with a single, very broad white band extending across the fore wing from the middle of the costa to the inner angle, where it is usually forked. The fringe of the wings is white at the apical and inner angles of both pairs ; sometimes the white is lacking on the inner angle of the hind wings. The early stages of this beautiful moth are unknown. The Spear-marked Black, Plcmyria Jiastata (Ple-myr'i-a has-ta'ta). This is another black-and-white species, occur- ring from the Atlantic to the Pacific. It is much larger than the preceding, expanding one and four tenths inches. It is black, striped and spotted with white. It varies greatly as to the number and extent of the white markings. The most constant mark is a broad white band crossing the middle of the fore wings, and often continued across the hind wings. Near the middle of its course on the fore wing this band makes a sharp angle pointing outward ; and just beyond the apex of this angle there is usually a white spot. This spot and angular band together form a mark shaped something like the head of a spear. In some sped- 284 THE STUDY OF INSECTS. mens the white predominates; other specimens are almost entirely black, excepting the spear-mark. According to Eu- ropean authorities the larva is brown or blackish brown, with a darker line along the middle of the back, and a row of horse- shoe-shaped spots on the sides. It feeds on birch and sweet gale. It is gregarious, a colony of larvae spinning together the leaves of the food-plant, and thus forming a nest within which they live and feed. The larva has not yet been observed in this country. The Scallop-shell Moth, Calocalpe nndulata (Cal-o-cal'pe un-du la'ta). This is a pretty FIG. 336. Calflcalpe umlulata. moth, with its yellow wings crossed by so many fine, zigzag, dark brown lines that it is hard to tell which of the two is the ground-color (Fig. 336). It lays its eggs in a cluster on a leaf near the tip of a twig of cherry, usually wild cherry. The larvae -make a snug nest by fastening together the leaves at the end of the twig; and within this nest (Fig. 337) they live, adding new leaves to the outside as more food is needed. The leaves die and become brown, and thus render the nest conspicuous. The larvae are black above, with four white FIG. 337. Eggs and nest of Calocalpe undulata. LEPIDOPTERA, 285 stripes, and flesh-colored below. When full grown they descend to the ground to transform, and pass the winter in the pupa state. The Diverse-line Moth, Eustromadiversilineata(}L\\s-\.\'Q f - ma di-ver-si-lin-e-a'ta). This moth has pale ochre-yellow wings, with a brownish shade near the outer margin, and crossed by many diverging brown lines (Fig. 338). It varies from one inch and a half to two inches in expanse. We have often found this moth on the side of our room, resting on the wall, head downward, and with its abdomen hanging down over its head in a curious manner. The larva feeds on the leaves of grape. There are two broods ; the first brood infests the vines during June ; the second, in the autumn and early spring, wintering as larvae. FIG. 338. Eustt-ontii dii'ersilineata. FIG. 339. Eudule mendica. The Beggar, Eudule mendica (Eu-du'le men-di'ca). One of the most delicate winged moths that we have in the Northern Atlantic States is this species (Fig. 339). Although the wings are yellowish white in color they are almost trans- parent. On the fore wings there are two transverse rows of pale gray spots, and a single spot near the outer margin be- tween veins V 3 and VI I x . (This spot was indistinct in the specimen figured.) The moth is common in midsummer. We do not know what fancy led the naturalist that de- scribed this species to name it mendica. But it seems ap- propriate now to call it a mendicant ; for during the thirty years that have elapsed since the species was described it has not been allowed a position in its own family, but has been catalogued in the Lithosiidae, although it was shown to be a Geometrid long ago. 286 THE STUDY OF INSECTS. HI, The Bad-wing, Dyspteris abortivaria (Dys'pte-ris a-bor- ti-va'ri-a). It is easy to recognize this moth (Fig. 340) by the peculiar shape of its wings, the hind wings being greatly reduced in size. It is of a beautiful pea-green color, with two white bands on the fore wings and one on the hind wings. Its color has led to its being placed heretofore in the Geometridae ; FIG. 340. Dyspteris abortivaria. bllt the Structure of its WHlgS sllOWS D it to be an Hydriomenid. The larva feeds on the leaves of grape, which it rolls. Family STERRHID.E (Ster'rhi-dae). The SterrJiids (Ster'rhids). The members of this family are most easily recognized by the venation of the hind wings (Fig. 341). In these veins II and III co- alesce for a short distance near the beginning of the second fourth of the dis- cal cell and then diverge rapidly. The greater number of our common species are of medium size, with whitish wings crossed by from two to four indistinct lines, and with the head black in front ; some are pure white, and others are brown marked with red- \ \ \ x ^-" dish lines. About one hundred species have been found in this country. FlG . 341 ._ W in gs of s yne i ys ennucUata. VII, LEPIDOPTERA. 28; FIG. 342 H&matopis grataria. The Chickweed Geometer, Hcematopis grataria (Hae- mat'o-pis gra-ta'ri-a). This little moth (Fig. 342) is very common in our meadows and gardens during the summer and au- tumn months. Its wings are reddish yellow, with the fringes and two trans- verse bands pink. It is found from Maine to Texas. The larva feeds on the common chick-weed, Stellaria media* Family GEOMETRIDS (Ge-o-met'ri-dae). The Green Geometrids (G e-om' e-trids). As a rule the members of this family are bright green in color. And as we have but one other common Geometrid (Dyspteris, p. 286) of this color, the family may be well termed the Greefi Geometrids. The distinctive structure that characterizes this family is the fact that vein V a of the hind wings arises much nearer to vein V, than to vein V 3 (Fig. 343). In this family the tendency to expan- sion of the humeral angfe of the hind wings, which is exhibited by all Geo- metrina, and which is cor- related with the promi- nent bend into this angle of vein II, characteristic of this super-family, is FIG. 343. Wings of Geometra iriefaria. *This moth is figured and mentioned here because it is one of our most common species, and not as a typical illustration of the Sterrhidae. It 288 THE STUDY OF INSECTS. carried farther than in the other families (except in the Dyspteris division of the Hydriomenidae). In fact, in all of the forms known to the writer, the humeral angle ex- tends a considerable distance beyond the frenulum. In the fore wings there is also a more marked migration of the base of vein V Q towards radius than occurs in other Geometrid families. All these characteristics lead us to consider the Geometridae the most specialized of the Geom- etrina. The Raspberry Geometer, SyncJilora glaucaria (Syn- chlo'ra glau-ca'ri-a). The different species of green Geom- etrids resemble each other to such an extent that it is difficult to describe any one of them in a few words so that it can be surely distinguished. The wings of the Raspberry Geometer are of a delicate pale green color crossed by two lines of a lighter shade, and when expanded measure from one half inch to one inch, there being great variation in size of specimens. The larva is more easily distinguished on account of its curious habits. It feeds on the fruit and foliage of raspberry, but chiefly on the fruit. It covers its body by attaching to it bits of vegetable matter, so that it is masked beneath a tiny heap of rubbish. Family AUZATID^: (Au-zat'i-dae). The Auzatids (Au-za'tids). Only a single species belonging to this family is known to occur in this country. This is a small moth with delicate snow-white wings which expand from three fourths of an inch to one inch. This is Eudeilinea hermiiiiata (Eu-dei- lin'e-a her-min-i-a'ta). In the form of the body and in the structure of the wings (Fig. 34/1) the members of this family closely resemble the differs in important respects from the typical members of the family, and may belong elsewhere. LEPIDOPTEKA. 289 Drepanidae. As in the Drepanidos vein VII appears to be four-branched, and the course of vein II of the hind wings is similar in the two families, except that in the Auzatidae this vein anastomoses with vein III beyond the discal cell ; but the extent of this anastomosis varies greatly in different indi- viduals of our species. In the Auzatidae the apex of the fore wings is not sickle-shaped ; and the branches of radius of the fore wings coalesce as in the Geometridae, Veins III 3 and III 4 COal- FIG. 344. Wings of Eudeilinea herminiata. Discing to near the apex of the wing.* Family DREPANID.E (Dre-pan'i-dae). The Hook-tip Moths. The members of this family are small, slender-bodied moths, which can be easily recognized by the sickle-shaped apex of the front wings (Fig. 345). An approach to this form of wing is pre- sented by some species of the Satur- niidae and by certain Geometrids. But the former are large, stout-bodied moths ; and the latter differ in wing venation, cubitus of the fore wings appearing only FlG. 345. Platypteryx ata. * In the Drepanidae veins III 2 +3 and III 4 +6 do not coalesce from the apex of the discal cell outward (Figs. 346 and 347); but veins III 3 and II I 4 anastomose for a greater or less distance near the apex of the wing, thus forming an accessory cell. 20 290 THE STUDY OF INSECTS. three-branched with them, whereas it appears four-branched in the Drepanidae (Fig. 346). Although the humeral angle of the hind wings is greatly developed in these moths, some of them retain the frenulum. TTI, IX FIG. 346. Wings of Oreta. rosea. FIG. 347. Wings of Platypteryx arcuata. When the frenulum is present it is borne at the end of a long thickened portion of the wing, so that it is at a con- siderable distance from the point where the wing is attached to the body (Fig. 347).* The larvae are remarkable in having the anal prolegs rudimentary, and the caudal segment prolonged into a more * We class the Drepanidae among the Frenulum-conservers, although many of them hf>v.*> 'ost the frenulum. Among the true Frenulum-losers the loss of the frenulum occurs while the race is still in a very generalized con- dition, no trace of a frenulum being found among these insects except a rudi- ment in the most generalized forms (Bombyx, Cicinmts). In the Drepanidae, however, the frenulum is retained by very highly specialized forms. There is a striking similarity in this respect, between this family and the more specialized Geomefids. LEPIDOPTERA. 29 1 or less lizard-like tail. They live upon the foliage of shrubs and trees, and transform in a web between the leaves, or in a case in a rolled leaf. Only a small number of species occur in our fauna ; at present we know only eight ; and all but one of these pertain to the eastern half of the continent. Our most common Hook-tip Moth is Platypteryx arcu- ata (Pla-typ'te-ryx ar-cu-a'ta). This species is of a diity white color marked with dark brownish lines and bands as shown in Figure 345. Its larva feeds upon white birch. Pla- typteryx genicula (P. ge-nic'u-la), another eastern species, re- sembles the preceding, but differs in being of a light ochre- yellow color and in the course of the wavy lines on the front wings. A third similar species occurs in California; this is Platypteryx siculifcra (P. sic-u-lif'e-ra). Family CYMATOPHORlDyE (Cym-a-to-phor'i-dae). The Cyinatophorids (Cym-a-toph' o-rids). The Cymatophoridae include moths of medium size, with elongated wings. The front wings are usually slightly widened at the inner angle (Fig. 348), and in our more common species are conspicuously marked with wavy or zigzag lines. The antennae are filiform and more or less velvety or pubescent in the male, and the maxillae are well developed. The moths fly by day, and when at rest, fold their wings FlG . 348 ._~,,y a serifia , roof-like upon the abdomen. The venation of the wings is illustrated by Figure 349. The important features to be noted are the following: In the front wing vein V, arises midway between veins V, and V 3 ; while in the hind wing vein V s arises much nearer to V, than to V,. In the hind wing the subcosta and radius are distinct, and vein V, is joined to radius by a comparatively 292 THE STUDY OF INSECTS. long cross-vein (Fig. 349, c. v.\ so that the two appear to separate before the end of the discal cell. In the males the tip of the frenulum is knobbed. The larvae are naked, and live upon the leaves of shrubs and trees. They often con- ceal themselves in a case, made by loosely fastening together leaves, or by folding a single leaf. There are in our fauna rep- resentatives of only four or five genera belonging to this family ; and the species that are common hardly exceed this number. One of the more common species is Thyatira scripta (Thy-a-ti'ra scrip'ta). This FIG. 349. Win-suf Thyatira scripta. has faWll-COlorcd frOtlt willgS, conspicuously marked with light bands and zigzag lines (Fig. 348). According to Thaxter, it lays its eggs late in July, in chains of five or six, on the leaves of raspberry, upon which the larvae feed. The mature larva is rich yellow- brown, often almost black, with a distinct dorsal black line. The lateral portions are more yellow with blackish mottlings. When at rest the larva either elevates the cephalic and caudal ends of the body, like the Notodontids, so that the head rests upon the caudal segments, or conceals itself in a case formed by curling down the edge of a leaf. It makes a very slight cocoon late in August. Another common species is Pseudothyatira cymatopJio- roides (Pseu-do-thy-a-ti'ra cym-a-toph-o-roi'des). This spe- cies is slightly larger than the preceding one, expanding nearly two inches. The front wings are silky gray tinted with rose. They are marked with a black spot at the base, a double or triple line, forming a black band at the end of LEPIDOPTERA. 293 the basal third of the wing, two black spots on the outer half of the costa, a black spot at the inner angle, and a row of black points on the outer margin. There is a variety which lacks the black band and the four black spots. The larva of this species has been found on red oak ; it is of a rich yellow-brown, mottled with fine dark lines, and lives in a case made by fastening leaves together. It makes a slight cocoon late in September; the adult emerges in June. Family NOCTUID^E (Noc-tu'i-dse). The Owlet-moths or Noctuids (Noc'tu-ids). This is the largest of all of the families of the Lepido^- tera ; more than eighteen hundred species are now known to occur in America north of Mexico. The great majority of the moths that fly into our houses at night, attracted by lights, are members of this family. The nocturnal habits of these insects, and the fact that often when they are in obscurity their eyes shine brightly, have suggested the name of the typical genus (Noctna, from the Latin for owl), as well as the popular name Owlet-moths, by which they are known. Similar popular names have been given to them in several other languages, Although there is almost no question regarding the lim- its of this family, as yet no structural character has been found by which they can be distinguished from certain other moths. Neither is there a general uniformity of appearance which we can use for this purpose, as the family includes great variations in size, form, and coloring. But most of the species are dull-colored moths of medium size. The greatest difficulty arises in attempting to separate this family from the three following. Of these the first two (Pericopidae and Agaristidae) differ in their highly contrast- ing colors, as pointed out in the analytical table (p. 212, N and NN). In the third of these families (Lymantriidae) the species have pectinate antennae and do not have ocelli. 294 THE STUDY OF INSECTS. vri, Only a few Noctuids have pectinate antennae, and these, so far as they are known to the writer, lack ocelli. The venation of the wings of a member of this family is represented by Fig- in 4 ure 350. Vein V t of \ Us the fore wings arises much nearer to vein V 3 than to vein V, ; there is usually an accessory cell ; and the anal vein may be forked towards the base or not. On the hind wings veins II and III usually coalesce for a short distance near the base of the wing; vein V a may be either well preserved or much weaker than the other veins; and there is considerable variation in the point of origin of this vein. In the typical Noctuids, the body is large in proportion to the size of the wings ; the front wings are strong, some- what narrow, and elongated, the outer margin being shorter than the inner margin ; and when at rest, the wings are folded "upon the abdomen, giving the insect a triangular out- line. The antennae are thread-like, fringed with hairs, or brush-like, rarely pectinate in the males. Two ocelli are al- most always present. The labial palpi are well developed, and in some species quite prominent. The maxillae are quite long and stout in most species. The thorax is heavy and stout. In some species the scales on the dorsal surface of the thorax are turned up more or less, forming tufts. VII, FIG. 350. Wings of A gratis ypsilon. LEPIDOP TEKA. 295 The abdomen is conical and extends beyond the inner angle of the hind wings, when these are spread. The majority of the larvae are naked, of dull colors, and provided with five pairs of prolegs. As a rule they feed on the leaves of plants, but some are borers and some gnaw into fruits. Among them are some of the most important insects injurious to agriculture. Although the Noctuidae is a very large family, the efforts that have been made to divide it into subfamilies have not given satisfactory results. Many subfamilies have been in- dicated ; but in most cases these proposed subfamilies appear to be merely groups of allied genera which cannot be dis- tinguished by any common character from the other similar groups. In the following pages we have given illustrations of a large proportion of these groups, in order to show, as well as we can in a limited space, the variations in form in- cluded in this family. The sequence of groups adopted is that given in the latest catalogue of the family, that by Pro- fessor J. B. Smith ; in some respects we doubt its being natural. There is a group of moths, the Deltoids, which are placed at the foot of this family on account of their apparent re- lationship to the Geometrids and to the Pyralids. These moths are usually of dull colors and of medium size. The name Deltoids was suggested by the triangular outline of the wings when at rest, which is well represented by the Greek letter delta. When hi this position the wings slope much less than with other Noctuids, the attitude being more like that assumed by the Geometrids ; but the hind wings are more nearly covered than with the Geometrids. Many of the Deltoids have very long palpi, resembling in their size those of the Pyralids. The Clover Hypena, Hypena scabra (Hy-pe'nasca'bra), is a common Deltoid. The larva feeds on the leaves of clover, and is a slender green worm. It measures when full grown two-thirds inch in length and only about one-tenth inch in 296 THE STUDY OF INSECTS. width in its widest part ; it has a narrow subdorsal whitish line and a lateral one of the same color. When ready to transform it webs together several leaves and passes the pupa state in the nest thus made. The adult (Fig. 35 1) is a blackish- brown moth, with an irregular grayish shade on the outer half of the fore wings, and with very broad hind wings. The palpi, which are not well shown in FIG. 351 Hypena scab, the figure, are long, wide, and flat- tened ; they project horizontally like a snout. The Hop-vine Hypena, Hypcna hnmuli (H. hu'-mu-li), is closely allied to the preceding and has often been con- founded with it. The larva feeds on the leaves of hop, and is sometimes a serious pest. One of the most abundant of our Deltoids is Pseu* daglossa Inbricalis (Pseu-da-glos'sa lu- bri-ca'lis.) In this species (Fig. 352) the fore wings are chocolate-brown, crossed with yellowish lines ; the hind wings are much lighter. The palpi are long; but they are curved over IG ' the head, so that they appear short when seen from above, as represented in the figure. The larva feeds on grass. Next to the Deltoids there is placed a group of moths which may be called the Similar-winged Owlets, from the fact that both pairs of wings are similarly marked by trans- verse lines. The group includes the largest of our Noctuids. The two following species will serve to illustrate this group. The Lunate Similar- wing, Honwptera lunata (Ho-mop'-te-ra lu-na'ta.) This is a brownish moth FIG. 353- Homoptera lunata. with marbled wingS. It varies greatly in its markings. Figure 353 represents a LEPJDOPTEKA. 297 variety which has been named ednsa, and which does not show well the lunate mark on the hind wings that probably suggested the name of the species. The larva feeds on the leaves of rose, willow, maple, plum, and other plants. The Black Witch, Erebus odor a (Er'e-bus o-do'ra). The most magnificent in size of our Noctuids is this species (Fig. 354). There is much variation in the depth of coloring,. The specimen figured is a female ; in the male the fore wings are more pointed at the apex and the median band is FIG. 354. Erebus odora. indistinct. It is a native of the West Indies, and is not known to breed in the United States. But specimens are found as far north as Canada and west to Colorrdo, and even in California. It is believed that these specimens have flown north from Cuba or from Mexico. Recently some observations have been made which seem to indicate that the moth does breed within our territory ; but the question is not yet settled. Only isolated specimens are found in the North, and these in late summer or autumn. 298 THE STUDY OF INSECTS, Closely allied to the moths just described is another group of species with broad wings, of which the Two-lined Parallelia, Parallelia bistriaris (Par-al-lel'i-a bi-stri'a-ris) is a good example. This moth (Fig. 355) is brown- ish in color, and has the fore FIG. 355 -rarMeiia bistriaris. w j n g s cros sed by two parallel lines. The larva feeds on the leaves of maple. The most striking in appearance of the Noctuids, if we except the Black Witch and one or two allied species, are the moths belonging to the genus Catocala (Ca-toc'a-la). These moths are of large size, often expanding three inches or more. The fore wings are usually brown or gray, marked with wavy or zigzag lines. The ground-color of the hind wings is black; but in many species these wings are con- spicuously banded with red, yellow, or white. This pecu- liarity has suggested the name Underwings by which these FIG. 356. Catocala ilia. insects are commonly known in England. The genus is a very large one ; about eighty species are now known from this country; and many of these are extremely variable, so that about twice that number of named forms are now recognized. The Ilia Underwing, Catocala ilia (C. il'i-aX will serve as an example (Fig. 356). The larvae of the LEPIDOPTERA. 299 Underwings feed on the leaves of various forest-trees. Many species infest oak and hickory. By careful search both the adults and larvae can be found resting on the trunks of these trees ; but it needs sharp eyes to do it, as the colors of these insects are usually protective. Among the more common Noctuids that occur in our meadows and pastures, and that fly up before us as we walk through them, are two species belonging to the genus Dras- teria (Dras-te'ri-a). These may be called the Clover Looping- ovvlets ; for the larvae feed on the leaves of clover, and, as they have only three pairs of prolegs, they walk in a loop- ing manner like the Geometrids. One of these species is Drasteria erechtea (D. e-rech'te-a). This moth (Fig. 357) has dark or light drab-gray fore wings, which are marked by two large dark bands, as shown in the figure. These bands are always separate, dis- tinct, and well defined towards the inner margin in the male ; in the female the markings are much less dis- tinct. The other common species of this genus is Drasteria cras- siuscula (D. cras-si-us'cu-la). In this species the fore wings have either a distinct violaceous brown or a red shade, with the two large dark bands very variable, often shading into the ground-color on the outer edge or coalescing near the inner margin ; all the markings are equally distinct in both sexes. There is a group of Noctuids containing about a score of genera in which the species differ markedly in appearance from the majority of the members of the family. In this group the moths are of small or moderate size ; and some of them bear a strong resemblance to Tortricids. Many of the species are marked with bright colors, and especially with white. The two following species will serve to illus- FIG. 357. Drasteria erechtea. 300 THE STUDY OF INSECTS. FIG. 35 8. Lk.ixt FIG. 359 Acontia candefacta. trate this group. Cliamyris cerintha (Cham'y-ris ce-rin'thal (Fig. 358) is white, with the fore wings marked with shades of olive, brown, and blue. The hind wings have a narrow border of dark scales, within which there may be a cloudy shade as shown in the figure, or this shade may be want- ing. The larva feeds on the leaves of apple. The second of our illustrations of this group is Acontia candcfacta (A-con'ti-a can-de-fac'ta) (Fig. 359). This species is also largely white, with the fore wings marked with shades of olive, brown, and yellow. The amount of yellow varies greatly in different specimens. The larva feeds on the leaves of Ambrosia art emisice folia. The Boll-worm, Heliotliis anuigera (He-li-o'this ar-mig'e- ra). This widely distributed pest is best known in its larval state ; but the larva varies so greatly in color and markings that it is difficult to prepare a description by which it can be recognized. The senior author has published colored figures of this insect, including five varieties of the larva, in his Report on Cotton-insects and also in the Report of the U. S. Department of Agriculture for 1879, Plate VIII. The larva when full grown measures about one and one half inches in length. It is often found feeding on the tips of ears of growing corn. It also frequently infests tomatoes, eat- ing both the ripe and the green fruit. Occasionally it is found within the pods of peas and of beans eating the immature seeds. But the most serious of its injuries is to cotton. The larva bores into the pods or bolls of the cotton, destroy- ing them. The injury thus done to the cotton crop is second in importance only to that done by the Cotton-worm, which destroys the foliage of the plant. Much can be done to check the injury of the Boll-worm to cotton by planting rows of corn in the cotton-field, and collecting the larvae of the early broods from the ears of corn, thus reducing the LEPIDOPTERA. 30 1 number of individuals in the later broods which infest the cotton. The genus Plusia (Plu'si-a) includes a large number of species in which the fore wings are marked with metallic-colored scales. The most common form of this marking is a silvery spot shaped something like a comma near the centre of the wing. Plusia simplex . \ 111 -11 FlG - 36o- Plitsia. simplex. (Fig. 300) is a well-known illustra- tion of this genus. About sixty species of this genus have been described from North America. In some of the species the metallic markings cover a large proportion of the fore wings, and in others they are wanting. The larva of Plusia brassica (P. bras'si-cse) feeds on cabbage and other CrucifercB. In the cotton-growing States the most important insect pest is the Cotton-worm, Aletia argillacea (A-le'ti-a ar-gil-la'- ce-a). The adult of this insect (Fig. 361) is a brownish moth with its fore wings crossed with wavy lines of darker color and marked with a bluish discal spot and two white dots as shown in the figure. This moth is found in the Northern States and even in FlG. 361. Aletia argillacea. ~ . . . . . . Canada in the latter part of the summer and in the autumn. But this occurrence in the North is due to migrations from the South, as the insect can- not survive the winter north of the Gulf States. The larva feeds on the foliage of cotton ; and as there are five or six generations in a year, the multiplication of individuals is very rapid, and the injury to the cotton great. Detailed descriptions and colored figures of this insect in its different stages are given in the works cited above in the description of the Boll-worm. The best known way of combating this pest is by the use of Paris green. 302 THE STUDY OF INSECTS. The Hooded Owlets, Cucullia (Cu-cul'li-a). We have several common grayish moths, in which the fore wings are marked with numerous irregular dashes of dark color, and in which the thorax is furnished with a prominent tuft of scales. These moths belong to the genus Cucnllia. Figure 362 represents Cuciillia speyeri (C. spey'er-i). These insects evidently have FIG 362 -Cucullia speyeri. the pOWCI' of moving this tllft of scales ; for sometimes it projects forward over the head as shown in the figure, while in other specimens of the same species it will be directed backward ; in this case it is much less conspicuous. The larvae of the Hooded Owlets feed upon the leaves of goldenrod and other Compositor. The Scalloped Owlet, Scoleopteryx libatrix (Scol-e-op'ter- yx li-ba'trix). This moth is easily recognized by the shape of the wings, the outer margins of which are deeply cut and scalloped (Fig. 363). The color of the fore wings is soft brownish gray, slightly pow- dered with rust - red, and ^g||BQ^^-yy frosted with white along the ^^H|r costa. There is an irregular F IG - 363. patch of rust-red reaching from the base to the middle of the wing, a single, white, transverse line before the middle, and a double one beyond the middle. The larva feeds on willow. This species is found in all parts of the United States and in Europe. The American Copper Hind- wing, AwpJiipyra pyraniidoides (Am-phip'y-ra pyr-a-mi-doi'des). FlG. <>>. Amphipyra Pyramidoides. The fore Wl'llgS of this moth (Fig. 364) are dark brown, shaded with paler brown, and with dots and wavy lines of a glassy gray or dull whitish LEPIDOPTERA. 303 FIG. 365 Balsa nialana. These are the hue. The hind wings, except the costal third, are reddish, with more or less of a coppery lustre. This suggests the popular name. A closely-allied species found in Europe is known as the Copper Underwing ; but we prefer to reserve the name Underwing for the species of Catocala. The larva feeds on the leaves of grape and Virginia-creeper. The Many-dotted Apple-worm, Balsa malana (Bal'sa ma-la'na). In June, and again in August or September, there is some- times found on apple-leaves, in considerable numbers, a rather thick, cylindrical, light-green worm, an inch or more in length, with fine, white, longitudinal lines and numerous whitish dots, larvae of the little moth represented by Figure 365. The fore wings of this moth are ash-gray, marked by irregular, blackish lines. The larvae feed on the leaves of many other trees besides apple. The moth has been found throughout the eastern half of our country. The Army-worm, Lencania unipuncta (Leu-ca'- ni-a u-ni-punc'ta). The Army-worm is so called because it frequently appears in great numbers, and, after destroying the vegetation in the field where the eggs were laid, marches like an army to other fields. This insect occurs throughout the United States east of the Rocky Mountains, and is present every year; but it attracts attention only when it appears in great numbers. The larva (Fig. 366) is one and one-half inches long when full grown, and is striped with black, yellow, and green. The adult is of a dull brown color, marked in the center of each fore wing with a distinct white spot (Fig. 367). In seasons of serious outbreak of this pest it usually appears first in limited areas, in meadows or pastures. FIG. 366. Leucunia unipuncta, larva. 304 THE STUDY OF INSECTS. If it is discovered before it has spread from these places it can be confined by surrounding the field with a ditch, or it may be destroyed by spraj ing the grass with Paris-green water. Ordinarily, however, the worms are not observed until after they have begun to march and are wide-spread, In such cases it is customary to protect fields of grain in their path by surrounding them with ditches with ver- tical sides; it is well to dig . tfj.Leufania unipuncta. holes like pOSt-holeS at in- tervals of a few rods in the bottom of such ditches. The worms falling into the ditch are unable to get out, and crawl along at the bottom and fall into these deeper holes. We have seen these insects collected by the bushel in this way. The Diver, Bellura gortynides (Bel-lu'ra gor-tyn'i-des). One of the most remarkable exceptions to what are usually the habits of members of this order is presented by the larva of this species. This larva is able to descend into water and remain there for a long time. It lives in the leaf- stalks of the pond-lily. It bores a hole from the upper side of the leaf into the petiole, which it tunnels in some instances to the depth of two feet or more below the surface of the water. This necessitates its remaining below the surface of the water while feeding. The writer has seen one of these larvae remain under water FlG - S^S.-A voluntarily for the space of a half-hour. The tracheae of these larvae are unusually large, and we believe that they serve as reservoirs of air for the use of the insect while under water. The form of the hind end of the larva has also been modi LEPIDOPTERA. 305 ned, so as to fit it for the peculiar life of the insect. The last segment appears as if the dorsal half had been cut away; and in the dorsal part of the hind end of the next to the last segment, which, on account of the peculiar shape of the last segment, is free, there open a pair of spiracles much larger than those on the other segments. When not feeding the larva rests at the upper end of its burrow, with the segment bearing these large spiracles projecting from the water. The adult insect is a brownish moth which varies greatly in size and markings. Figure 368 represents what seems to be the more common form. The Zebra Caterpillar, Mamestra picta (Ma-mes'tra pic'ta). Cabbage and other garden vegetables are often subject to the attacks of a naked caterpillar, which is of a light yellow color, with three broad, longitudinal, black FlG. 369. Mamestra picta, larva. FIG. 370. Mamestra picta, stripes, one on each side and the third on the top of the back. The stripes on the sides are broken by numerous oure white lines (Fig. 369). It passes the winter in the pupa state. The adult (Fig. 370) has dark chestnut-brown fore wings and pale yellowish hind wings. Cut-worms. Few pests are more annoying than the ras- cally little harvesters that nightly, in the spring, cut off our corn and other plants before they are fairly started. There are many species of these cut-worms, but they are all the larvae of Owlet-moths. In general their habits are as follows: The moths lay their eggs during midsummer. The larvae soon hatch, and feed upon the roots and tender shoots of herbaceous plants. At this time, as the larvae are small and their food is abundant, they are rarely observed. On the 21 3O6 THE STUDY OF INSECT*. approach of cold weather they bury themselves in the ground and here pass the winter. In the spring they renew their attacks on vegetation ; but now, as they are larger and in cultivated fields the plants are smaller, their ravages quickly attract attention. It would not be so bad if they merely destroyed what they eat ; but they have the unfortu- nate habit of cutting off the young plants at the surface of the ground, and thus destroy much more than they consume. They do their work at night, remaining concealed in the ground during the daytime. When full grown they form oval chambers in the ground in which they pass the pupa state. The moths appear during the months of June, July, and August. There are some exceptions to these generalizations : some species of cut-worms ascend trees during the night and destroy the young buds ; some pass through two generations in the course of a year ; and a few pass the winter in the pupa state. Cut-worms can be destroyed by poisoned baits of fresh clover or other green vegetation, or with poisoned dough made of bran. Much can be done by making holes in the ground with a sharpened stick, as a broom-handle. The holes should be vertical, a foot deep, and with smooth sides. On the approach of day the cut-worms will crawl into such holes to . . hide, and will be unable to crawl out again. Climbing cut-worms can be jarred from the trees during the night, and caught upon sheets, and then destroyed. One of our cut-worms, which is known as the Spotted Cut-worm, is the larva of the Black-c Owlet, Noctna c-nigrum (Noc'tu-a c-ni'grum). This moth (Fig. 371) is one of the most common species attracted to lights. It occurs throughout our country and in Europe. At the end of the Noctuid series there is placed a group LEPIDOPTERA. 307 FIG. 372. Acronycta moruta. of genera, which contain species that ditfer in appearance from other Noctuids, the larvae of many being hairy like those of Arctiids. The fore wings of the moths are gener- ally light gray with dark spots, and in many species have a dagger-like mark near the anal angle. On this account these moths have received the name Daggers. The Ochre Dagger, Acronycta morula (Ac-ro-nyc'ta mor'u- la). This moth (Fig. 372) is pale gray with a yellowish tinge. Besides the black line forming part of the dagger near the anal angle of the fore wing, there is a similar black line near the base of the wing, and a third near the outer margin between veins V, and V a . The larva feeds on elm and basswood. When full grown it is mottled brown and greenish like the bark, it is clothed with but few // J^r> ~~ scattered hairs, and has a '|| hump on the first, fourth, and 3J eighth abdominal segments. The American Dagger, Ac- ronycta americana (Ac-ro-nyc'- ta a-mer-i-ca'na). This is a gray moth resembling in its general appearance the pre- ceding, but with the black- lines on the fore wings much less distinct. Its larva, how- ever, is very different (Fig. 373). This larva looks like an Arctiid, being densely clothed with yellow hairs. But these hairs are scattered over the FIG. 373. Acronycta atneneana, larva. surface of the body instead of growing from tubercles, as with the larvae of Arctiids. Along 308 THE STUDY OF INSECTS. the sides of the body and at each end are a few scattered hairs that are longer than the general clothing, and there are two pairs of long black pencils borne by the first and third abdominal segments, and a single pencil on the eighth abdominal segment. When at rest the larva remains curled sidewise on a leaf, as shown in the figure. It feeds on maple, elm, and other forest trees. The Witch-hazel Dagger, Acronycta hamamelis (Ac-ro- nyc'ta ham-a-me'lis). In the latter part of summer and in autumn the larva of this species is common on the leaves of witch-hazel, oak, and other forest trees. It differs greatly in ap- pearance from the preceding species, being nearly naked (Fig. 374). When at rest it usually lies curled as shown in the figure. It varies in color from light yellow to reddish brown. Its most characteristic feature is a double row of milk-white spots along the middle of the back. FIG. 374. Acronyctn me I is, larva. hama- Family LYMANTRIID^: (Lym-an-tri'i-dae). The Tussock-moths. The larvae of these moths are among the most beautiful of our caterpillars, being clothed with brightly-colored tufts of hairs ; and it is to this characteristic clothing of the larvae that the popular name Tussock-moths refers. The adult moths are much plainer in appearance than the larvae ; and in the genus NotolopJins, to which our most common species belong, the females are practically wingless, the wings being at most short pads, of no use as organs of flight. The Tussock-moths are of medium size, with the antennae of both sexes when winged pectinate,d, those of the males LEPWVPTERA. 309 ac. i, nil nil in, IX. VIIi very broadly so ; the wingless females have serrate or nar- rowly pectinate antennae. The ocelli are wanting. The legs are clothed with woolly hairs ; when the insect is at rest the fore legs are usu- ally stretched for- ward, and are very conspicuous on ac- count of these long hairs. The venation of the wings is rep- resented by Figure 375 ; in this respect these moths are very similar to the Noc- tuids ; in fact we have been unable to find as yet any con- stant feature in the StrUCtureof the wino-S FlG - 37S- Wings of NoMofJnts hucostigma. of either family that will serve to separate the two. But in the Lymantriidse the antennas are pectinate and the ocelli are absent ; while in the Noctuidae the antennae are usually sim- ple and the ocelli are usually present; and when the antennas are pectinate the ocelli, in all cases known to us, are pres- ent : in this way a distinction is preserved between the two families. Although it is hard to find a distinction between the two that can be put into words, the general appearance of the Tussock-moths is very different from that of the Noctuids, and entomologists have no difficulty in deciding to which family any species belongs. The Tussock-moths are chiefly nocturnal ; but the males of NotolopJius fly in the daytime. The larvae of our native species are very characteristic in appearance. The body is hairy; there are several con- VIIz THE STUDY OF INSECTS. spicuous tufts of hairs on the dorsal aspect of the abdomen, and at each end of the body there are long pencils of hairs; on the sixth and seventh abdominal segments there is on the middle of the back of each an eversible gland supposed to be a scent-organ similar to the osmateria in the larvae of Papilio, and it is stated that a fine spray of liquid is some- times thrown from them. Excepting a few rare forms, our native species fall into two genera NotolopJins and Par orgy ia. In NotolophiiS the males have short, broad wings ; the females are nearly wingless. In Parorgyia both sexes are winged, and the wings are relatively longer than in NotolopJins. Our most common species belong to Notohplius. Of this genus the three best-known species are the following : The White-marked Tussock-moth, Notolophus leucostigma (No-tol'o-phus leu-co-stig'ma). This is our most common rep- resentative of the family. It frequently occurs in such great numbers that it seriously injures the foliage of shade- trees and orchards. The male (Fig. 376) is of an ashy gray color ; the fore stigma. wings are crossed by undulated bands of darker shade and bear a conspicuous white spot near the anal angle. The female is white and resembles a hairy grub FIG. 376. Notohplnis leuco- FIG. 377. Notolophus leucostigma, larva. more than a moth. She emerges from her cocoon and after pairing lays her eggs upon it, covering them with a LEPIDOP TERA. 3 I I frothy mass. The larva (Fig. 377) is one of the most beau- tiful of our caterpillars. The head and the glands on the sixth and seventh abdominal segments are bright vermilion- red. There is a velvety black dorsal band, bordered with yellow subdorsal stripes ; and there is another yellow band on each side just below the spiracles. The prothorax bears on each side a pencil of long black hairs with plume-like tips ; a similar brush is borne on the back of the eighth abdominal segment, and the first four abdominal segments bear dense brush-like tufts of cream-colored or white hairs. When this insect becomes a pest the larvae can be de- stroyed by spraying the infested trees with Paris-green water ; or the egg-bearing cocoons can be collected during the win- ter and destroyed. These cocoons are attached to the trunks of the trees and to neighboring objects, or to twigs. In the latter case they are usually partially enclosed in a leaf. Co- coons not bearing eggs should not be destroyed, as many of them contain parasites. Owing to the wingless condition of the female this pest spreads slowly. The Well-marked Tussock-moth, NotolopJius definita (N. def-i-ni'ta). The male, like that of the preceding species, is of an ashy gray color ; but the markings of the fore wings are much more distinct. The female is light brown. She lays her eggs in a mass on her cocoon, covering them with hair from her body. The larva closely resembles the pre- ceding species in the form and arrangement of its tufts of hair, but differs markedly in color, being almost entirely light yellow. There is a dusky dorsal stripe and a velvety black spot behind each of the tufts of the first four abdominal seg- ments. The head and the glands on the sixth and seventh abdominal segments are, like the body, light yellow. The Old Tussock-moth, NotolopJnis antiqua (N. an-ti'qua). -The male is of a rust-brown color ; the fore wings are crossed by two deeper brown bands and have a conspicuous white spot near the anal angle. The body of the grub-like female is black, clothed with yellowish white hairs ; she lays 312 THE STUDY OF INSECTS. her eggs on her cocoon, but, unlike the two preceding species, does not cover them with anything. The larva differs from either of the preceding in having an extra pair of pencils of plume-like hairs arising from the sides of the second abdominal segment ; the head is jet-black ; the glands on the sixth and seventh abdominal segments are vermilion-red or sometimes bright orange ; and the tubercles on the sides of the back of the second and third thoracic and the sixth and seventh abdominal segments are orange-red or yellow margined with pale yellow. The Gipsy Mot\\,P0rt/ietrtadispar(Por-the'tri-adis'pa.r'). This is a European species which has been introduced into Massachusetts. It has become such a serious pest that the Legislature of that State has appropriated a large sum of money to be expended in efforts to eradicate it ; this work is now going on. The male is yellowish brown ; the female, (.white (Fig. 378). In each the fore wings nre crossed by many dark lines and bear a black lunule on the discal vein. The specimen figured is unusually small. The eggs are laid in a mass on any FIG. 378. Porthetria dispar, female. Convenient object and are covered with hair from the abdomen of the female. The larva differs greatly in appearance from that of the preceding genus, lacking the peculiar pencils and tufts of hair ; but the characteristic glands of the sixth and seventh abdominal segments are present and are red. The body is dark brown or black, finely reticulated with pale yellow, and with narrow yellow dorsal and subdorsal lines. On the dorsal aspect of each segment there is a pair of prominent, rounded tubercles bearing spiny black hairs. The first five pairs of these tubercles are bluish, the others dark crimson-red. There are also two rows of tubercles on each side of the body which bear longer hairs. LEP1DOPTERA. 313 Family AGARISTID.E (Ag-a-ris'ti-dae). The Wood-nymph Moths. These gayly-dressed moths are a delight to the collector. We have but few species of them in this country, and an even smaller number are common. These moths are either black with large, white or yellow, rounded patches upon the wings, or they have the front wings white, margined with brown, and the hind wings pale yellow. They are chiefly day-flying; but some of them are attracted to lights at night. The shape of the antennae varies greatly in the different genera. \r\Euthisanotia the antennae are fili- form ; in Alypia slightly enlarged near the tip ; and in Psychomorpha they are filiform in the female and pectinated in the male. The max- illae are moderately well developed and spirally rolled. The venation of the wings (Fig. 379) is very similar to that of some Noctuids; but there is no difficulty in separating the two fam- ilies, the Wood-nymph Moths being Very dif- FIG. 379. Wings of Cofidryas gloveri. ferent in appearance from any Noctuids. The larvae are but slightly clothed, and live exposed on the leaves of plants. Our more common species feed chiefly on grape and Virginia-creeper, which they some- times injure to a serious extent. In such cases they can be destroyed by the use of Paris green. This substance can THE STUDY OF INSECTS. I be used even in vineyards in the East, as the application would have to be made early in the season, and the sum- mer rains would wash the poison from the vines. The pupa state is passed either in an earthen cell or in a very slight cocoon. The family is one of limited extent ; less than thirty North American species are known. The larger number of these occur in the far West or in the Gulf States. The following are the most common species : The Eight-spotted Forester, Alypia octomaculata (A-lyp'- i-a oc-to-mac-u-la'ta). This species is of a deep velvety-black color. The front wings have two large sulphur-yellow spots ; and the hind wings, two white spots (Fig. 380). The figure represents a male ; the female is some- what larger. The patagia are sulphur- FIG. -go Alypia octo- maculata. yellow. The legs are black with orange- colored scales on the tibiae of the first and second pairs. The larva (Fig. 381) feeds upon the leaves of grape and Vir- ginia-creeper, and sometimes occurs in such large numbers as to do serious injury. The ground-color of the larva is white, with eight black stripes on each segment, and a FlG. 381. Alypia octomaculata, larva. broader orange band, bounded by the two middle stripes ; the orange bands are marked by black, conical, elevated spots. There are usually two broods each year, the moths appearing on the wing in May and August, the caterpillars in June and July, and in September. The pupa state is passed in an earthen cell in the ground. Langton's Forester, Alypia langtonii (A. Iang-to'ni-5), resembles the preceding species in general appearance, but LEP1DOPTERA. 315 _ Psy . / lomor phv can be readily distinguished by the hind wings bearing only a single spot. It is not a common species, and its early stages have not yet been described. The Grape-vine Epimenis, Psychomorpha epimenis (Psy- cho-mor'pha ep-i-me'nis). This is a velvety-black species with a large white patch on the outer third of the front wings and a brick-red patch on the hind wings (Fig. 382). The larva resembles somewhat that of Alypia figured above; but it is bluish and has only four light and four dark stripes to each segment. FlG It feeds upon the terminal shoots of grape and Virginia-creeper in spring, drawing the leaves to- gether by a weak silken thread and destroying them. When ready to transform, which is usually towards the end of May, it either enters the ground or bores into soft wood to form a cell. Within this it remains until the following spring. The Beautiful Wood-nymph, EutJiisanotia grata (Eu-this- a-no'ti-a gra'ta). This moth (Fig. 383) well deserves the popular name that has been applied to it. Its front wings are creamy white, with a glassy surface ; a wide brownish- purple stripe extends along the costal margin, reaching from the base to a little beyond the middle of the wing, and on the outer margin is a band of the same hue, which has a wavy white line running through it, and is margined internally with a narrow olive-green band. On the inner margin is a yel- lowish olive-green cloud. The hind wings are clear pale ochre-yellow, with a brown band on the outer margin. The wing expanse is about one and three-fourths inches. The moth appears during the latter part of June or early in July. The larva of this species is pale bluish, crossed by bands of orange and many fine black lines. It also bears a FIG. 383. Euthisanotia grata. 3i6 THE STUDY OF INSECTS. resemblance to that of Alypia, but may be distinguished by having only six transverse black lines on each segment. It has the same food-plants as the species described above. It transforms in a cell in the ground or in soft wood. The Pearl Wood-nymph, Euthisanotia itnio (E. u'ni-o). This moth closely resembles the species just described, but is smaller, expanding a little less than one and one half inches. The outer border of the front wings is paler and mottled ; and the band on the hind wings extends from the inner angle to the apex. The larva resembles that of E. grata ; it feeds upon the leaves of EnpJiorbia coloratnm, and perhaps on grape also. Family PERICOPID^: (Per-i-cop'i-dae). The Pericopids (Pe-ric' o-pids). These beautiful insects occur within the limits of our country only in the far West and in the Gulf States. They resemble the Woo d-n y m p h Moths in their strongly contrast- ing colors ; but can be distin- guished from them by the po- sition of the ori- gin of vein V, of the hind wings, which appears to be a branch of cubitus(Fig. 384). Our most com- mon species be- long to the genus Gnoph/ egle, larva and are arranged radiately (Fig. 390). When full grown 320 THE STUDY OF INSECTS. the larva makes a felt-like cocoon composed largely of its hairs. The adult has mouse-gray, unspotted wings; the abdomen is yellow, with a row of black spots along the middle of the back. The Hickory Tiger-moth, Halisidota cary