Plate I. A MANUAL OF THK STUDY OF INSECTS by JOHN HENRY COMSTOCK Prof essor of Entomology in Cornell University ANNA BOTSFORD COMSTOCK Member of the Society of American Wood- Engravers feiitemtfi (EMtfon ITHACA, N. Y. THE COMSTOCK PUBLISHING COMPANY 1920 q\ — . % 1 3 b y Copyright, 1895, BV 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 in 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 may be 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, Crayfish, 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 413 XX. Order Siphonaptera, Fleas 49° XXI. Order Coleoptera, Beetles 494 XXII. Order Hymenoptera Bees, Wasps, Ants, and Others.. 599 Index and Glossary 679 ix EXPLANATION OF PLATES PLATE I. (Frontispiece.) nuinm *agb 1. The Carpet Beetle 539 2. The Twelve-spotted Diabrotica 577 3. The Adalia bipunctata 533 4. The Silver-spotted Skipper 370 5. The American Copper 39° 6. The Red Admiral 401 7. The Painted Beauty 4°' 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.) VIGUKB PAGE 1. The Luna Moth 353 2. The Crinkled Flannel-moth 218 PLATE VI. (Page 389.) 1. The Spring Azure 39* 2. The Green Comma 4°4 3. The Hop-merchant 4°5 4. The Banded Flfin 393 5. The Mourning-cloak 4°3 6. The Olive Hair-streak 393 7. The Spring Azure 391 8. The Violet Tip 405 xi A MANUAL FOR THE STUDY OF INSECTS. CHAPTER I. ZOOLOGICAL CLASSIFICATION AND NOMENCLATURE. I. Zoological Classification. {For advaiiced 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 Eived 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 whicb 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 pi life. 2 THE STUDY OF IX SECTS. The diversity of iorms 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 ?s only in recent years that naturalists have come to understand tne blood-relationship referred to above. We find that the Animal and Vegetable Kingdoms a.e made up 01 a vast assemblage of individuals^ each the offspring ci parents similar ZOOLOGICAL CLASSIFICATION. % to itself, and each in turn producing similar offspring. Although the i.ffspring is never exactly like either parent, the decree of variation in a single generation is slight. And thus we find that there exist large numbers of individuals which very closely resemble each other. Such collection of individuals is termed in popular language a.,li?ui, in scientific language a species. Thus the kind of pine trees known as pitch-pine is a species; and scrub-pine, still another. In the same way the name jparrow-hawk indicates a kind or species of hawk; 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 a 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 of 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 untii 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, and 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 Pinits, as it is termed by botanists. There are many species of 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 Conifer a, or cone-bearing plants, of botanists. The Owl Fam- ily {Strigida). the Falcon Family (Falconida:), and the Vulture Family (Vulturidce) constitute the Order Rap/ores, or Birds of Prey. Closely-allied orders are grouped together to form classes. Thus all the orders of birds taken together constitute 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, cuttlefish, 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. 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 students.} 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. 6 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 in different 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 Sparrow-hawk is Falco sparverius ; 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 name snckleyi. When, therefore, it is desired to refer to the Black Merlin as distinguished from the typical Pigeon-hawk the term Falco columbarius snckleyi 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. 7 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. suckleyi or /*'. c. sitckleyi. 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 by 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 turnus ; 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 glaacus 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,/, ajax tclamonides ; 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., IpJu'clides 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 z'of -idee in family names is short, and consequently the accent falls on the syllable preceding this letter; while the i of -ince 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 tne accent falls on the antepenult. CHAPTER II. INSECTS AND THEIR NEAR RELATIVES. Branch ARTHROPODA (Ar-throp'o-da). The Arthropods (Ar'thro-pods). If an insect, a spider, a scorpion, a centipede, or a lobster be examined, the body will be found to be composed of a series of more or less similar rings or seg- ments joined together; ai.d some of these segments will be fcund to bear jointed legs (Fig. i). All ths animals possessing these characteristics are classed together as the Branch Arthropoda. A similar segmented form of the body is found among worms; but these are dis- tinguished from the Arthropods by the absence of legs. It should 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. 1. — 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. -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. u Crustacea. AA. With one pair of antenna; 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 of 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 arc aquatic Arthropoda, zvhich breathe by true gills. They have two pairs of antenna' and at least Jive pairs of legs. The most familiar illustrations of the Crustacea are thf 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 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 Fig. 3. — A Cray-fish. 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; b, . Cyclops,- c, Daphnia. water aquarium. In Figure 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 FSow-b^ 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 cephalotliorax, which have four pairs of legs fitted for walk- 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 cephalotliorax (ceph-a-lo-tho'rax) bears six pairs of INSECTS AND THEIR NEAR RELA TIVES. 13 Fig. 6. — Lower side of cephalothorax of a spider : ntd, man- dible: wjt, maxilla; /, palpus ; /, lower lip ; s, 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'lae). 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-ra;). The maxilla (Fig. 6, mx) lie just behind the mandibles, one on each side of the mouth. Each maxilla bears a large feeler or palpus (Fig. 6, p). 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/tt/z^z^/ (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 : 1, coxa (cox'a) ; 2, trochanter (tro-chan'- ter) ; 3, femur (fe'mur); ^patella (pa-tel'la); spider. ^ 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 14 'THE 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 flot 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 vvhip-lash-like tarsi. {Whip- sccrpions.) {Phrynidce.) 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. SOLPUGIDA. 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 pincers. As the palpi are very large, with stout pincers, they resem- ble in a striking man tier 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 of 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 tracheae, which open through three Fjg. 9. — A Jointed-spider, Datames - . . . 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 JNSE C TS A ND 77/ E/ A' NEA R A' E LA 1 7 VES. I J 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 cf 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- _,.,., e , Fig. 10.— A Pseu- mg. They breathe by means of 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-parpi). The Whip-scorpions. These strange creatures are found only in the extreme southern part of our country, being tropical animals. In ib THE STUDY OF IX SECTS. 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 Thelyphoxid^: (Thel-y-phon'i-das). The Tail Wliip-scorpions. This family is represented in the United States by only a single species, the Giant Whip - scorpion, TlnlypJiomis gigaiitiits (The-lyph/o-nus gi-gan • te'us). This species measures when full grown from four to five inches in length. Figure 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 VxG.xx.—Tketyphonusgiganteus. can find no direct evi- INSECTS AND THEIR NEAR RELATIVES. 1 9 dence that it is so. They destroy their prey by crushing it with their palpi. Family PHRYNID/E (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). The 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 20 THE STUD V 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. 'tj~ 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 RELATIVES. 21 segmented ; and the abdomen bears at its end organs for spinning silk (Fijj. 13). Fig. 13—Pencetia 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). F,0Gf- e^aioZLx'of The greater number of spiders have four dib?eideLV''ma:uiia: pairs of eyes (Fig. 17), but there may be %??%?i^0™ Fig. 15.— Tip of claw of Fig. t6. — Maxilla and Fig. 17.— Head of spider, mandible of spider. palpus of male house- showing eyes anr rnb.n.''"- 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 is 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 fig. 19. broad, wavy band across the center of a web. We As^rn°^°! have observed a spider seize a large grasshopper ^auy 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 Fie. 18. — End of abdomen of spider, showing six spinner- ets spread apart: in front of these is the spiracle, and be- hind ihem the open.ng of the alimentary canal. INSECTS AND THEIR NEAR RELATIVES. 23 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 Dictynidte and Uloboridce have spinning organs differing from those of all other Fig. 20. — Viscid silk from an orbweb. Fig. 21. — Spinnerets of a Dictynid spider. The middle pair of spinnerets are con- cealed by the first pair, c, cribellum. Fig. 22. — Last two segments of hind leg of spider, show- ing calamistrum. spiders. They have in 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. 24 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 1^ / season a large number of eggs — five hun- ^2/ 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.— E^-sac of the spring those which survive emerge (Frtm ' wiide'/./1' 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 plumipes (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 AMD 7 HEIR 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)0 Every onp 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._Eef,.sac of a ing the rate of its descent by spinning Drassid. 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 lino 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 20 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 two 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^. 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^E. DD. All of the spinnerets short. E. With cribellum and calamistrum. Spiders making webs in which there are curled threads, or double threads. INSECTS AND THEIR NEAR RELATIVES. 2^ JF. The side eyes not as far apart as the middle eyes; a considerable space between the eyes and the front edge of the head. Spiders making irregular webs. p. 32. DlCTYNIDJE. FF. The side eyes as far or farther apart than the middle eyes; eyes very close to the front edge of the head. Spiders making regular webs. {Uloborus.) p. 38. Uloborid^e. EE. With neither cribellum nor calamistrum. Spiders mak- ing webs in which there are no curled threads. F. Eyes not near the front edge of the head, the space be- tween the two being greater than that occupied by the eyes (Fig. 37). Spiders that spin irregular webs, in or near which they live, hanging back downwards, p. 34. Theridiid^e. FF. Eyes near the front edge of the head, the space be- tween the two being less than that occupied by the eyes (Fig. 42). Spiders that make regular webs, consisting chiefly of lines radiating from the centre, and a spiral or looped sticky line. p. 35. Epeirid^e. BB. The eyes unequal in size and arranged in three or four rows. C. With cribellum and calamistrum. Spiders which make webs. (Hyp/ioies.) p. 38 Uloborid/E. CC. With neither cribellum nor calamistrum. Spiders which do not spin webs for catching prey. D. The largest eyes not in the front row. {Running spiders?) p. 40 Lycosid^e. DD. The largest eyes in the front row. {Jumping spiders?) p. 42 Attid.e. Family THERAPHOSID/E (Ther-a-phos'i-dae). The Tarantulas and the Trap-door Spiders. Those who live in the warmer parts of our country know well the large spiders commonly called Tarantulas. These are the giants among spiders, some of them being the largest known ; but some species of this family are not very large. They are dark-colored, hairy spiders, and can be distinguished from the other families mentioned here by the fact that the 28 THE STUDY OF INSECTS. claw of the mandibles works up and down instead of side- wise. The members of this family do not construct true webs, but they dig long tubes in the earth, which they line with silk, or line their hiding-places in clefts in trees or elsewhere with a layer of silk. They live only in warm countries. One of the best known of the Tarantulas is Enrypelma hentzii (Eu-ryp'el-ma hentz'i-i). This species occurs in the South and in the Middle West, and is the largest of our spiders (Fig. 26). Several closely allied species are found in California. Fig. 26.— A Tarantula, Eurypelma hentzii. But the members of this family that have attracted most admiration on account of their habits are the Trap-door Spiders. These dig a tube in the ground, as do many other members of this family ; but this tube is lined with a denser Fig. 27. — Entrance to nest of a trap-door spider. layer of silk, and is provided with a hinged lid, which fits the opening of the tube with wonderful accuracy (Fig. 27). INSECTS AND THEIR NEAR RELATIVES. 29 The spider hides in this nest when not seeking its prey. Some species take the precaution to build a branch to their nest, and to provide this branch with a door. As this door forms a part of one side of the main tube, it is not likely to be observed by any creature which may find its way past the first door of the nest. Several species of Trap-door Spiders occur in the South- ern and Southwestern States. Family DRASSID/E (Dras'si-dae). The Drassids, or Tube Weavers in part. There are certain dark-colored spiders that spin no web, but wander about at niglit in search of prey, and hide under leaves and stones during the day-time. Many of them make silken tubes, in which they hide in winter or while moulting or laying eggs. Hence they have been termed Tube Weavers, a name which is also applied to certain other spiders. We will therefore call the members of this family the Drassids (Dras'sids). In this family the body is long, and is usually flattened above. It is carried near the ground in walking. The legs are rather short and stout ; the second pair are not longer than the fourth, and the feet are furnished with only two claws (Fig. 28). The eyes are in two nearly straight rows, and the maxillae are concave or fur- nished with a furrow (Fig. 29). One of the most common Fig. 28.— Foot of a Drassid. Fig. 29.— Maxilla of a Drassid. Fig. 30. — Drassus saccatus. species in the East is Drassus saccatus (Dras'sus sac-ca'tus) (Fig. 30). It lives under stones, in a large bag of silk, in which the 30 THE STUDY OF INSECTS. Fig. 31. — Clubi- ona canadensis. female stays with her egg-sac. In early summer a male and female live together in the nest. Family Clubionid^e (Clu-bi-on'i-dae). The Clubionids, or Tube Weavers in part. There may be found during summer, in flat tubular nests on plants, usually in rolled leaves, spiders that spin no webs to entrap their prey. These spiders very closely re- semble the Drassids in structure, but are usually lighter in color, with the legs a little longer and more slender, and the abdomen more nearly cylindrical (Fig. 31). f.g. ,2.-Maxiiia of They are also distinguished by aClubion.d. the form of the maxillae> which are convex (Fig. 32). . These spiders belong to the family Clubionidae. As we have no appropriate common name for these spiders, they may be called the Clubionids (Clu-bi- on'ids). During the winter the Clubionids hide under bark or stones, and make tubular nests in these places. Family AGALENIDyE (Ag-a-len'i-dae). The Funnel-web Weavers.* Even the most careful observers seldom realize what an immense number of spider-webs are spun upon the grass in the fields. But occasionally these webs are made visible in the early morning by the dew which has condensed upon them. At such times we may see the grass covered by an almost continuous carpet of silk. The greater number of the webs seen at such times are of the form which we term funnel-webs. They consist of a concave sheet of silk, with a funnel-shaped tube at one side,. INSECTS AND THEIR NEAR RELATIVES. 3' and numerous lines extending in all directions to the sup- porting- spears of grass (Fig. 33). The tube serves as a hiding-place for the owner of the web; from this retreat the spider runs out on the upper surface of the web to seize any insect that alights upon it. The tubes open below, near the roots of the grass; so that the spider can escape from it if a too formidable insect comes upon the web. The funnel-web weavers (family Agalenida) are long- legged, brown spiders, in which the head part of the cephalo- thorax is higher than the thoracic part, and distinctly separated from it by grooves or marks at the sides. The eyes are usually in two rows, but in Agalena the middle eyes of . . li-ii Fig. 34. — Agalena neevia. both rows are much higher than the others. The feet have three claws. The posterior pair 32 THE STUDY OF INSECTS. of spinnerets are two-jointed, and usually longer than the others. The common grass spider, which abounds in all parts of the United States, is Agalena ncevia (Ag-a-le'na nas'vi-a (F'g- 34). Family DlCTYNID^E (Dic-tyn'i-dae). The Curled-tJircad Weavers with Irregular Webs. The Dictynids (Dic-tyn'ids). Certain spiders are remarkable for using two kinds of silk in the formation of their webs. Thus, as explained later, the Orb Weavers build the framework of their orbs of dry and inelastic threads, and attach to this framework a thread which is sticky and elastic ; while most spiders which make irregular webs use only one kind of silk. There are, however, certain species of irregular web-weavers which use two kinds of silk. One of these is a plain thread like that spun by other spiders, and the other is a peculiar curled thread or a delicate band of tissue in which there are curled threads. The curled-thread weavers represent two families, one of which makes irregular webs; the other, those which are of definite form. The first of these is the Dictynidce. The curled -thread or tissue-like band is made in the same way by both families. It is composed of silk spun from a special spinning-organ, situated in front of the ordinary spinnerets, and named the cribellum (cri-bel'lum) ; and is combed into its peculiar form by means of a comb of stiff hairs, the calamistrum (cal-a-mis'trum), which is borne by the metatarsus of the hind legs (see page 23). In mak- ing the curled thread the spider turns one of its hind legs under the abdomen so that the calamistrum is just under the cribellum, and the foot rests on the ether hind leg. It then moves its hind legs back and forth rapidly, so that the calamistrum combs out from the spinning-tubes, and at the same time tangles, a band of fine threads. INSECTS AND THEIR NEAR RELATIVES. 33 This band of tangled or curled threads is easily seen in the webs of these spiders, being wider than the ordinary threads and white in color. In old webs it becomes conspicuous by the large amount of dust which it collects. Figure 35 shows the appearance of this band when magnified, and the way in which it is attached to the plain threads. Our more common Dictynids make webs of various shapes, on fences, under stones, in holes in rotten logs, and Fig. 35.— Curled thread of a Dictynid, en- larged. PiC. 3fi.~Web of a Dictynid, on a dead branch of Ceanothus, somewhat enlarged. on plants. These webs are especially common among the flowers of Golden-rod and other plants having clusters of 34 THE STUD Y OF INSECTS. small flowers (Fig. 36), and exhibit a slight degree of regularity. Family Thertdiim: (Ther-i-di'i-dae). The Cobtucb Weavers. Many are the kinds of webs spun by different spiders. Some of them, as the orb-webs and the funnel-webs, delight us with their wonderful regularity of form; while others appear to be a mere shapeless maze of threads. Such are the structures whose presence in the corners of our rooms torment thrifty housewives, and which are disrespectfully termed cobzvebs. The cobweb weavers (Family Theridiidd) are small spiders with unusually slim legs. The space between the eyes and the front edge of the head is greater than the Fig. 37. — Face of Fig. 38 —Foot of spider Fig. 39. — Mimetus house spider. with three claws. inter/ecior. region occupied by the eyes (Fig. 37); the eyes are in two rows ; and the feet are furnished with three claws (Fig. 38). This family includes many species, being in fact the largest of all of the families of spiders. Figure 39 represents a widely distributed species. Although the house spiders are the most familiar mem- bers of this family, the greater number of species spin their webs in the fields on bushes. These webs usually consist of a flat or curved sheet, under which the spider hangs back downward. This sheet is supported by threads running in all directions to the neighboring objects. Frequently there is a large number of these supporting threads above the web, which serve the additional purpose of impeding the flight of INSECTS AND THEIR NEAR RELATIVES. 35 insects, and causing them to fall into the web, where they are caught. Some of these spiders do not remain in their webs, but have a nest in a neighboring crack or corner, from which they rush to seize their prey. And sometimes there is a funnel-shaped tube leading to this nest. But these spiders differ from the true funnel-web weavers in running back down- wards on the lower side of their web. Family EPEIRID^E (E-pei'ri-dae). The Orb Weavers. Few if any of the structures built by lower animals are more wonderful than the nets of orb-weaving spiders, but these beautiful objects are so common that they are often considered hardly worthy of notice. If they occurred only in some remote corner of the earth, every one would read of them with interest. The nets of the different species of orb weavers differ in the details of their structure, but the general plan is quite similar. There is first a framework of supporting lines. The outer part of this framework is irregular, depending upon the position of the objects to which the net is attached; but the more central part is very regular, and consists of a number of lines radiating from the center of the net (Fig. 41). All of these supporting lines are dry and inelastic. But there is spun upon the radiating lines in a very regular manner a thread which is sticky and elastic (Fig. 20, p. 23). Usually this sticky thread is fastened to the radiating lines so as to form a spiral, but a few species make nets in which this thread is looped back and forth. Many of the orb weavers strengthen their nets by spin- ning a zigzag ribbon across the center. This ribbon is made by spreading the spinnerets apart so that the minute threads from the spinning tubes do not unite to make a single thread, as is usually the case. Some of the orb weavers live in their nets hanging head 36 THE STUDY OF AV SECTS. downwards, usually near the center of the net ; others have a retreat near one edge of the net, in which they hang back Fig. 41. — Partially completed web of Epeira. downwards. While resting in these retreats they keep hold of some of the lines leading from the net, so that they can instantly detect any jar caused by an entrapped insect. When an insect in its flight touches one of the turns 'of the sticky line, the line sticks to it ; but it stretches so as to allow the insect to become entangled in other turns of the line. If it were not for this elasticity of the sticky line, most insects could readily tear themselves away before the spider had time to reach them. In making its web an orb weaver first spins a number of lines extending irregularly in various directions about the place where its orb is to be. This is the outer supporting framework. Often the first line spun is a bridge between two quite distant points. This is done as described on p. 25. Having a bridge across the place where the web is to be, it is an easy matter for the spider to stretch its other lines where it wishes them. In doing this it fastens a thread to one point, and then walks along to some other point, spin- INSECTS AND THEIR NEAR RELATIVES. M ning the thread as it goes, and holding it clear of the object on which it is walking by means of one of its hind legs. When the second point is reached the thread is pulled tight and fastened in place. After making the outer framework the radiating line: are formed. A line is stretched across the space so as to pass through the point which is to be the center of the orb. In doing this the spider may start on one side, and be forced to walk in a very roundabout way on the outer framework to the opposite side. It carefully holds the new line up behind it as it goes along, so that it shall not become entangled with the lines on which it walks ; one or both hind feet serve as hands in these spinning operations. The spider then goes to the point where the centre of the orb is to be, and fast- ening another line there, it walk back to the outer frame- work, and attaches this line an inch or two from the first. In this way all of the radiating lines are drawn. The next step is to stay these radii by a spiral line which is begun at the center, and attached to each radius as it crosses it. The turns of this spiral are as far apart as the spider can con- veniently reach, except at the center of the web. All of the threads spun up to this stage in the construction of the web are dry and inelastic. The spider now proceeds to stretch upon this framework a sticky and elastic line, which is the most important part of the web, the other lines being merely a framework to support it. In spinning the sticky line the spider begins at the outer edge of the orb, and passing around it fastens this line to each radius as it goes. Thus a second spiral is made. The turns of this spiral are placed quite close together, and the first spiral, which is merely a temporary support, is destroyed as the second spiral pro- gresses. Figure 41 represents a web in which the second spiral is made over the outer half of the radii. In this fig- ure, aa represents the temporary stay-line ; bb, the sticky spiral ; and cc, the fragments of the first spiral hanging from the radii. 38 THE STUDY OF INSECTS. Fig. 43. — Foot of Epeira. The orb weavers (Family Epeiridce) are usually plump spiders, the abdomen bein large, and often nearly spher- ical. The space between the eyes and front edge of the F,Face"of head is less than the region Epeira- occupied by the eyes (Fig. 42). The eyes are arranged in two rows. The front legs are longer than the others. The feet have three claws (Fig. 43), and the spinnerets are all short. In some species of this family the male is much smaller than the female. Family Uloborid^ (U-lo-bor'i-dae). The Curled-thread Weavers with Regular Webs. The Uloborids {U-lo-bo'rids). We have already described the thread-curling habits of the Dictynids (p. 32), and the curious organs called cribel- lum and calamistrum (Fig. 44), by which these curled threads are made (p. 23). Similar organs and a similar habit are possessed by the spi- ders of the family Uloborida. These spiders, however, make webs which are regular in form. There are only two genera belonging to this family in the United States; but as the webs made by these are very different, we will de- scribe both. The Triangle Spider, Hyptiotes cavatus (Hyp-ti'o-tes ca- va'tus). — This spider is common all over New England and the Middle States, and has been found as far to the south- west as Texas. Its web is most often found stretched be- tween the twigs of a dead branch of pine or spruce. At first sight this web appears like a fragment of an orb web (Fig. 45); but a little study will show that it is complete. The accompanying figure, by Dr. Wilder, who first described Fig. 44.— Calamistrum of Hyptiotes. INSECTS AND THEIR NEAR RELATIVES. 39 the habits of this spider (see Popular Science Monthly, 1875), illustrates the form of the web. It consists of four plain lines corresponding to the radiating lines of an orb web, and a series of double cross lines, which are spun by the cribel- lum and calamistrum. From the point where the radiating lines meet a strong line extends to one of the supporting twigs. Near this twig the spider rests, pulling the web tight Fig. 45.— Web of Hyptiotes cavatus. (From Wilder.) so that there is some loose line between its legs, as shown in the enlarged figure. When an insect becomes entangled in one of the cross lines, the spider suddenly lets go the loose line so that the whole web springs forward, and the insect is entangled in other cross threads. The spider then draws the web tight and snaps it again. This may be repeated several times before the spider goes out upon the web after its prey. Uloborus (U-lob'o-rus). — The spiders of this genus make round webs which resemble at first sight those of the Orb Weavers ; but they differ from the ordinary orb webs in that 40 THE STUDY OF INSECTS. the spiral thread is made of curled or hackled silk. These webs are nearly horizontal, and are usually made between stones or in low bushes. The spiders of this genus are not common, but they are widely distributed. They have not, however, been reported as yet from the Pacific coast. Family ThomisiDjE (Tho-mis'i-dae). The Crab Spiders. There are certain spiders which are called crab spiders, on account of the short and broad form of the body, and the curious fact that they can walk more readily sidewise or backward than forward. These spiders spin no webs, but lie in wait for their prey. They live chiefly on plants and fences, and in the winter hide in cracks and under stones and bark. Most of the spe- cies are marked with gray and brown, like the bark upon which they live. Some species conceal themselves in flow- ers, where they lie in wait for their prey. These are brightly colored, like the flowers they inhabit ; so that insects visiting flowers may alight within reach of a spider before seeing it. In this family the legs are turned outward and forward more than downward ; so that the body is carried close to the ground. The second pair of legs are as long as or longer than the fourth pair. The eyes are small, nearly equal in size, and ar- ranged in two rows. ^mena'litia.1 One of the best-known members of > this family is the female of Misumena vatia (Mi-su'me-na va'ti-a). This is milk-white, with sometimes a light crimson mark on each side of the abdomen, and is found within flowers (Fig. 46). Family Lycosid^: (Ly-cos'i-dae). The Running Spiders. Every collector of insects who has searched for speci- mens under stones and logs is familiar with the large, dark- -olorecf, hairy spiders often found in these places. These INSECTS AND THEIR NEAR RELATIVES. 4 1 spiders frequently attract especial attention by dragging after them a large gray ball (Fig. 47) ; this is the egg-sac, which the female carries about with her attached to her spinnerets. These spiders run swiftly ; and as they depend Fig. 47. — Lycosa and egg-sac. on the use of their legs for the capture of their prey, they are well termed Running Spiders. These spiders resemble in general appearance and in habits the Tarantulas of the South and the West. But none of our species attain the great size of some of the Tarantulas, and in the Running Spiders the claw of the mandibles moves horizontally instead of vertically. In this family the body is hairy and usually much longer than broad. The eyes differ markedly in size, and are arranged in three or four rows. The larger eyes are not in the front row. The legs are rather long and quite stout. Like the Tarantulas, some of the Running Spiders build tubular nests in the ground, which they line with silk. Some- times the entrance to these nests is concealed by small sticks and leaves, and sometimes the spi- der builds a regular turret over the entrance of its tube (Fig. 48). These nests are used merely as retreats, the spiders wandering forth in search of their prey. The larger members of our common species belong to the , ^en US LyCOSa (Ly-Co'sa). These SP,der< Lycosa ^enicola. (After Marx.) i-ag after them their egg-sacs as described above ; and 42 THE STUDY OF INSECTS. when the young hatch they climb on their mother's back, and are carried about for a time. The females of the genus Dolomedes (Dol-o-me'des), which also belongs to this family, carry their egg-sac in their mandibles until the young are ready to hatch. At this time the mother fastens the egg- sac in a bush, and spins a web of irregular threads about it, among which the young spiders remain for a time. Family ATTID/E (At'ti-dae). The Jumping Spiders. The Jumping Spiders are of medium size, with a short body and short stout legs (Fig. 49). They are common on plants, logs, fences, and the sides of buildings. They are very apt to attract attention by their pecul- iar appearance ; their short stout legs, bright colors, conspicuous eyes, and quick, jumping movements being very different from those of ordinary spiders. The eyes are arranged in three or four rows ; FlG -J? ~flttus the front middle pair are the largest, and are nubilus. (From r & ' Re o^onCot^ very conspicuous. These self-possessed spiders ton insects.) are ab]e to stare an ordinary observer out of countenance. They move sidewise or backward with great ease, and can jump a long distance. They make no webs except nests in which they hide in winter or when moulting or laying eggs. In certain members of this family the body is longer than in the typical forms, and ant-like in appearance. Order Acarina (Ac-a-ri'na). The Mites. In this order the abdomen is unsegmented and fused with the thorax, giving the entire body a more or less sac- like appearance. In many the body is marked by numerous INSECTS AND THEIR NEAR RELATIVES. 43 transverse, fine lines, which are so impressed as to appear like the divisions between minute segments (Fig. 52). The majority of mites are very small ; but some, as certain Ticks, are of considerable size. With the exception of a single family the members of which bring forth living young, all mites are produced from eggs. As a rule, the newly-hatched mites have only three pairs of legs; but a fourth pair are added during growth,, In Phytoptus, which infests plants, there are only two pairs of legs. The mode of life of the different members of this order varies greatly: some are parasitic upon animals; others infest living plants ; and many feed upon dead animal or vegetable matter, thus acting as scavengers. Among the mites that are parasitic upon animals are the various Ticks, which are very common in the warmer parts of our country. Figure 50 rep- resents the Cattle-tick of the Southern States. It should be remembered in this connection that the so-called Sheep-tick is a true insect, Fig. 5o. — The , . , 1 't-v Cattle-tick, fe- belonging to the order Diptera. male. The Itch-mite is a well-known parasite, infesting man and causing the disease known as the itch. The sensation character- istic of this disease is due to the burrowing of the mites in the skin ; and the efficiency of sulphur oint- ,om ment in checking this disease is beiow ; b, from above. due to the fact that by the use of it the mites are killed. Figure 51 represents an itch-mite greatly enlarged. Parasitic mites are frequently found attached to insects ; a common species occurs beneath the wings of locusts. The best known of the mites that infest plants is the one commonly called the Red Spider. This lives upon house- plants ; and in the warmer parts of the country, where there 44 THE STUDY OF INSECTS. is a dry season, it infests fruit-trees in the open air. As it thrives only in a dry atmosphere, it can be subdued upon house-plants by a liberal use of water. When it occurs upon plants in the open air it can be combated with any of the washes found useful in destroying scale insects. Some of the mites that infest plants produce galls. These galls are of various forms, but differ from those pro. duced by gall-flies (Family Cynipidcz of the Order Hymetu opterd) in having open mouths, from which the young mites escape. A common disease of the pear, known as the pear-leaf blister, is produced by a four-legged mite, Phytoptus pyri (Phy-top'tus py'ri) (Fig. 52). The blisters characteristic of Fig. 52. — Phytoptus pyri, greatly enlarged. the disease are swellings of the leaf, within which there is a cavity affording a residence for the mites. Figure 53 repre- Fig. 53. — Diagram of gali of Phytoptus pyri : g, gall; n, «, normal structure of leaf ; o, open- ing of gall ; e, eggs. (After Soraur). sents a section of a leaf through one of these galls. Here the leaf is seen to be greatly thickened at the diseased part. On the lower side there is an opening through which the mite that started the gall entered, and from which young INSECTS AND THEIR NEAR REIATJVES. 45 Elites developed in the gall can escape, in order to start new galls. In addition to the swelling of both surfaces of the leaf its internal structure is seen to be modified. In some parts there is a great multiplication of the cells, and in others a large part of the cells have been destroyed. Two eggs of mites are represented in this gall. As the season advances, and the galls become dry and brownish or black, the thickening of the leaf becomes less marked. In fact, in some cases there is a shrinkage of the parts affected. Fig- Fig. 54. — Section of leaf showing structure of gall in autumn : g, gall ; », n, uninjured part of leaf ; o, opening of gall. ure 54 represents a section through a leaf collected and studied in October. Among the scavenger mites there are some that infest food products. Thus mites are sometimes found in cheese, in sugar, and in preserved meats. Class MYRIAPODA (Myr-i ap'o-da). The Centipedes and the Millipedes. The members of this class are air-breathing Arthropods, in which the head is distinct from the thorax, and the thorax and abdomen form a continuous region, with from six to two hundred segments, each bearing a pair of legs. The head bears a single pair of antenna;. The thousand-legged worms, as they are commonly called, are well-known and generally feared creatures. But few students find them attractive subjects of study ; never- theless it is well to know something about them, for some of them are dangerous animals, and some are harmless. A few species are injurious to agriculture, while others are to be 46 THE STUDY OF INSECTS. classed among our friends. And all of them are of interest to the naturalist as representatives of a distinct type of Arthropods. If we omit certain small and rather uncommon forms, th^ Myriapods may be classed in two orders ; one consisting o" the Centipedes, the other of the Millipedes. Order CHILOPODA (Chi-lop'o-da). The Centipedes. The centipedes can be recognized at a glance by the fact that each segment of the body bears a single pair of legs (Fig. 55). The body is usually flattened, and the antennae are long and many- jointed. Many species of centi- Fig. 55.— a Centipede. pedes are venomous. The poison glands open through the claws of the first pair of legs, which are bent forward so as to act with the mouth parts. These creatures abound in all parts of the United States; those which are found in the North are comparatively small, and rarely, if ever, inflict serious injury to man ; but the larger species, which occur in the warmer regions, are said to bo extremely venomous. The centipedes are predaceous, feeding on insects ; they usually live under stones, logs, and bark. There is one spe- cies, Cermatia forceps (Cer-ma'ti-a), which has very long legs, and only fifteen pairs of them, which is often found running on the walls of houses, especially in the Southern States. We have never heard of this centipede biting a human be- ing, and as it feeds upon insects, especially cockroaches, it may be regarded as a welcome visitor in houses. INSECTS AND THEIR NEAR RELATIVES. 4/ Order CHILOGNATIIA (Chi-log'na-tha). The Millipedes. The millipedes differ from the centipedes in having two pairs of legs on each of the body segments except the first three. The body in most of them is not flattened as with the centipedes, and the antennae are comparatively short and few jointed (Fig. 56). Fig. 56. — A Millipede. The millipedes, as a rule, live in damp places and feed or. decaying vegetable matter. They are harmless, except that occasionally they feed upon growing plants. CHAPTER III. Class Hexapoda (Hex-ap'o-da). The Insects. The members of V his class are air-breathing Arthropoda, with distinct head, thorax, and abdomen. They have one pair of antenna, three pairs of legs, and usually one or two pairs of zvi?igs in the adult state. There are about us on every side myriads of tiny crea- tures that are commonly passed unnoticed, and even when observed, they are usually thought to be unworthy of serious consideration. But all life is linked together in such a way that no part of the chain is unimportant. Frequently upon the action of some of these minute beings depends the mate- rial success or failure of a great commonwealth. The intro- duction and spread of a single species of insect (the Cot- tony-cushion Scale) in California threatened the destruction of the extensive orchards of that State ; thousands of trees perished. The introduction of a few individuals of a partic- ular kind of Lady-bug {Vedalia cardinalis), which feeds upon this pest and multiplies rapidly, soon checked the evil, and has nearly removed the pest from the State. But insects are of interest to us for other reasons than the influence they may have upon our material welfare ; the study of them is a fruitful field for intellectual growth. It is not a small matter to be able to view intelligently the facts presented by the insect world, to know something of what is going on around us. And so rich is this field that no one gains more than a mere smattering concerning it. 48 HEX A POD A. 49 We know as yet comparatively little about the minute structure of insects ; the transformations and habits of the greater number of species have not been studied; and the blood-relationship of the various groups of insects is very imperfectly understood. If, therefore, one would learn something of the action of the laws that govern the life and development of organized beings, and at the same time ex- perience the pleasure derived from original investigation, he cannot find a better field than is offered by the study of in- sects. But it is not necessary that one should have the tastes and leisure required for careful scientific investigation in order to profit by this study. It can be made a recreation, a source of entertainment when we are tired, a pleasant oc- cupation for our thoughts when we walk. Anyone can find out something new regarding insect architecture — the ways in which these creatures build nests for themselves or fo; their young. It is easy to observe remarkable feats of en- gineering, examples of foresight, wonderful industry, unre- mitting care of young, tragedies, and even war and slavery. The abundance of insects makes it easy to study them. They can be found wherever man can live, and at all seasons. This abundance is even greater than is commonly supposed. The number of individuals in a single species is beyond com- putation : who can count the aphids or the scale-bugs in a single orchard, or the bees in a single meadow? Not only are insects numerous when we regard individ- uals, but the number of species is far greater than that of all other animals taken together. The number of species in a single family is greater in several cases than the number of stars visible in a clear night. The word insect is often applied incorrectly to any mi- nute animal ; and even among naturalists there is some lack of uniformity in its use. Some writers include under this term the Arachnida and Myriapoda, as well as the Six-footed Insects. But the great majority of entomologists restrict 50 THE STUDY OF INSECTS. the term to the Hexapoda, and it is in this sense that we use it. The name Hexapoda is from two Greek words: hex, six ; 3iY\d pons, foot. It refers to the fact that the members of this order differ from other Arthropods in the possession of only six feet. Insects breath by means of a system of air-tubes (tra- cheae) which extends through the body. This is true even in the case of those that live in water and are supplied with gill-like organs (the tracheal gills ; see p. 75). The head is distinct from the thorax, and bears a single pair of antennas ; in these respects they are closely allied to the Myriapods. But they can be easily distinguished by the number of their feet, and, usually, also by the presence of wings. The Metamorphoses of Insects. Nearly all insects in the course of their lives undergo re- markable changes in form. Thus the butterfly, which de- lights us with its airy flight, was at one time a caterpillar; the bee, which goes so busily from flower to flower, lived first: the life of a clumsy, footless grub ; and the graceful fly was developed from a maggot. In the following pages considerable attention will be given to descriptions of the changes through which various insects pass. It is our wish in this place merely to define certain terms which are used in describing these changes. Development wit Jwnt Mctamor pilosis. — In one of the orders of insects, the Thysanura, the young insect just hatched from the egg is of the same form as the adult insect. These insects merely grow larger, without any more marked change in form than takes place in our own bodies during our life. They are said, therefore, to develop without metamorphosis. Incomplete MetamorpJiosis. — There are many insects which undergo a striking change of form during their life-, although the young greatly resembles the adult. Thus a young locust just out from the egg can be easily recognized as a locust. HEXAPODA. 5* It is of course much smaller than the adult, and is not fur- nished with wings. Still the form of the body is essentially the same as that of the adult (Fig. 57). (The hair-line above the figure indicates the natural size of the insect.) After a time rudimentary wings appear; and these increase Fig. 57. — Nymph of Melanoplus, first stage. (After Emerton.) Fig. 58.— Nymph of Melanoplus, second stage. (After Emerton.) Fig. 59. — Nymph of Melanoplus, third stage. (After Emerton.) FiG. 60.— Nymph of Melanoplus, fourth stage. (After Emerton.) Fig. 6r. — 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 ac 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- 52 THE STUDY OE 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. Hozv Insects groiv — Molting. — The skin of an insect is hard- ened more or less by a horny substance known as chitine (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 it in turn must be shed. Fig. 62«.— Exuviae of nymph of Dragon-fly. This shedding of the skin is termed 'molting, and the cast skin is some- II EX A POD A. 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. 63.— Egg- of Cotton-worm, greatly enlarged. ( From the Author's Report and pitted (Pig. 63), 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, Fig. 6s. — A pupa of a large moth. j r „ „«.l ,i v v s 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 coccons largely of their own hairs, which they fasten together with a film of silk. The Nyv.ph. — The terms larva and pupa are only ap- plied to the early stages of those insects that have a com- HEXAPODA. 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- »*&i t --ryf. Fig. 66. — A large cocoon within a rolled leaf. phosis it is called a nymph. 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 May-beetle. (After Str.ius 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. 68.— 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 Pig. 69.— a Mole Cricket, or less movable upon each other. Such a hardened portion of the body-wall is termed a sclcrite (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). 58 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, thorax, 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 an appearance very different from that of the eye of higher animals ; its surface is divided into a large number of six-sided divisions Fig. 72. »- Part of com- pound Jarged. pour.d eve, greatly en- iai HEXAPODA. 59 (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 p 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 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. Fig. 73. — Three ommatidia from the compound eye of a May-beetle. (After Grenach- er. ) The pig- ment has been dissolved away from two of them. F, corneal facet ; K, crystal- line cone ; /, pig- ment-sheath ; P, chief pigment- cell ; p" , pig- ment-cells of the second order ; R, retinulae. 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- wards the tip. 3. Moniliform (mo-nil'i-form) or 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. 5. 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 MoutJi-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, 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 labrum {Wbrum) (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, cli 10); the lower pair, the maxilla (max-il'lae) (Fig. 75, 11). There may be also within the mouth one or two tongue-like organs, the epipharynx (ep-i-phar'ynx) and hypopharynx (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. 76.— Maxilla of a hand, are very complicated organs, each COm- Tiger Beetle. , . , ... t^ u -n posed of several sclentes. .bach 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 prothorax ; the second thoracic segment is the mesothorax ; and the third, the metathorax. The Legs. — Each leg consists of the following parts, beginning with the one next to the body (see Fig. Jj): 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. jy, t), 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 ; b. Ichneumon-fly; c, Bee ; /, trochanter; fit, 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 tenent hairs, and from which ex- udes an adhesive fluid that enables the insect to walk on the lower surface of objects. The wings. — 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, «, b) ; the outer margin (Fig. 78, b, 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 ; 54 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 in, in 3 ni3 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 cubitus (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. HEX A POD A. 65 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 M 3 Cur* 3d A 2d A 1st A Fig. 79. — Diagram representing the typical arrangement of the wing-veins, includ- ing the four more important cross-veins : k, humeral cross-vein ; r-m, radio- medial cross-vein ; m, medial cross-vein ; tn-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, 6 66 THE STUDY OF INSECTS. the five branches of the typical radius, or vein III, are designated either thus, Rl5 R2, R3, R4, R5 ; or thus, III!, III2, Ills, III* III5. When two or more branches of a branched vein coalesce, the compound vein is designated by an expression indicating this coalescence, as III2^3 or R2+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 V2 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 {Thysaniird) 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 setcs. 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- 11EXAP0DA. 67 cles, through which a waxlike material is excreted : these are commonly called honey-tubes; they are also termed cornicles, nectaries, or siphuncles\ 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, 01 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 {m) ; 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 (/i) 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 (n) 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 OE INSECTS. PLATE II. r - * A Caterpillar ^Cossus ligniperda). (After Lyonet.) Fte. t. — Caterpillar opened on the ventral middle line. Fig. 2.— Caterpillar opened op the dorsal middle line. 1, principal longitudinal tracheae ; 2, central nervous sy!y tem : 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. C>9 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 wit.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 an immense number of distinct fibres, which are not enclosed in tendinous sheaths as with Vertebrates. But the muscles that move the appendages ol 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 muscle3 of insects, they are teally very strong. One has only to observe the power of leaping possessed by many species to be convinced of this, 7o THE STUDY OF INSECTS. PLATE III. A Cockroach (Perifllaneta orientalis). (From Rolleston). «, antennae; b\, iz, £3, tibiae; c, anal cerci ; d, ganglion on recurrent nerve upon the crop ; e, salivary duct ; /J salivary bladder; ^, gizzard ; h, hepatic cceca; », chylific stomach ; /, Malpighian vessels; £, small intestine; /, large intestine ; «*, rectum; ft-, first abdominal ganglion ; o, ovary ; /, sebaceous glands. HEX APOD 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. -So); and on Plate III, illustrating the anatomy of a cockroach, its form in that insect is shown. In larvae it is a nearly straighftube, 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 larvae. The Blood-vessels. — In insects all parts of the body cavity that are not occupied by the internal organs are filled with blood. I \ Thus the alimentary canal is completely surrounded with 1/4 vj blood, and all the spaces between the muscles are filled 7 ^ by this fluid. This is a very different arrangement from S I I what occurs in our own body, where the blood is con- -$J^1 tained in a system of tubes, the arteries and the veins. ( \ We find, however, that insects are not entirely deprived of ™ ^ 1 blood-vessels. For there is one which lies above the ali- mentary canal, just within the middle line of the back, grlm~oi*l. See Figure 80, h, and Plate II, 1. This extends from near Part of the 0 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 72 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 wings of the heart (Plate II, 6, and Fig. 83, c). In Figure c they are represented cut away valves ; c ventral aspect of from the caudal 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; d, dorsal through the thorax and into the head, is aspect of heart. termed the 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 laid in masses and overlaid with a hard covering- of silk; the top of the masses having the appearance of be- ing braided (Fig. 117). Fig. 117.— Egg-mass of a Mantis. I0& THE STUDY OF INSECTS. Family Phasmid^E (Phas'mi-dae). The I Va Iking-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, Diapheromera femorata, (Di-aph-e- rom'e-ra fem-o-ra'ta), and that is wingless (Fig. Il8). Walking- sticks feed upon foliage. Their eggs, which are large, are dropped on the ground under the trees by Fig. h8.— a Waiking-stick. the mother, who trusts entirely to fate to preserve them. Family Acridiml (A-crid'i-dae). Locusts, or Short-homed 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. IO9 rhfc 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 Locustidae. 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-covcrs. HO THE STUDY OF INSECTS. 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 FlGI2° 'br""'- continent. Here the Rocky Mountain Locust, Melanoplus spretus, 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, Encoptolophns sordidns (En-cop-tol'- o-plius 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 KlG- ™.—Encqfitoiofkus sordid**. color is dirty brown, mottled with darker spots. ORTHOPTERA. Ill The Carolina Locust, Dissostcira 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 conspersum (Chry- soch'ra-on con-sper'sum) (Fig. 122), is a common species. 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 F1G. i22.—Chrysochraon consfersum. West we find several genera in which the body is very long and slender. Leptysma marginicolle (Lep-tys'ma mar-gin-i- FiG. 123.— Leptysma marginicolle. 1'1\ Isj-- T„„\ "11 J col le) (rig. 123), Will serve as an illustration of the form of these insects. There is a group of small locusts of which Tettix (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- 124- 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^e (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 — Leg- of organs, when present, are situated near the eKar^ked;rgahnOWing 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- FlG Fig. 126. — Wing-cover of Male Meadow Grasshopper. Fig. 127. — Wing-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 ORTUOPTERA. II 3 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 Meadow 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 128 represents one F,G' ***-xW**™ 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 wha4" 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 antennae, 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 H4 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 Ceutliophilus (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, Hadenaecus (Had-e- nce'cus), found in caves. Fig. 130. — Ceuthophiliis. OA' THOP TERA. 115 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 FlG- w-*%~** 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. 132. — Stenopclmatus. 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 (Gryl'li-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 antennae are long ji6 THE STUDY OF INSECTS. and slender, like those of the Locustidse ; 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 rilled 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 ORTHOPTERA. 117 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 wing-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 wing-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 Fig, 134 — Gryllotalpa serious pests. %nmd*. II. The True Crickets. — To this group belong our com- mon, black acquaintances that peep at us from the cracks IIS THE STUDY OF INSECTS. name of this 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. zis-Gryiius abbreviate. 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 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, CEcantJms nivens (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. 136. — CEcanthus niveus, male. CHAPTER XIII. Order PHYSOPODA (Phy-sop'o-da). Thrips. The members of this order have four zvings ; these are similar in form, long, narrozv, membranous, not folded, with but few or no veins, and only rarely with cross veins ; they are fringed with long hairs, and are laid horizontally along the back when at rest. The metamorphosis is incomplete. The mouth-parts are probably used chiefly for sucking; they are intermediate in form between those of the sucking and those of the biting insects {Fig. 138); the mandibles are bristle -like ; the maxilla are triangular, flat, and furnished with palpi ; and the labial palpi are also present. The tarsi are two- jointed, bladder-like at tip, and without 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, Limothrips poaphagus (Lim'o-thrips po-aph'a- IIQ 120 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). Fig. 137 .— Thrips. Fig. 138.— Mouth-parts of Thrips. (Drawn by J. M Stedman, under the author's direction.) 8, labrum; 10, mandible; it, maxilla; 12, labium. The insect infesting grapes, called "The Thrips," is not a Thrips at all, but a leaf-hopper belonging to the HomoDtera. The name Physopoda is from two Greek words : physao, to blow up, and pons, 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 others. The winged members of this order have four wings; in cie sub-order the 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 wings are of the same thickness throughout, and usually slope at the sides of the body. The mouth-parts are formed for sucking. The metamorphosis is incomplete. The order Hemiptera 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 THE 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. it, 9 — Mouth-parts of Bug. (Af- ter Muhr.) Fig. 140, a. — Head of an heter- opterous insect. Fig. 140, b. — Head of an homopterous 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 Heteroptera, 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 Homoptera, includes some forms that HEMIPTERA. 123 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 ns. 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. Parasitica. AA. Hemiptera with or without wings, but with a jointed beak. B. First pair of wings thickened at the base, 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.148.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. Bugs that live within water. The Water-boatmen, Family Corisidce. (p. 129.) The Back-swimmers, Family Notonectid/E. (p. 130.) The Water scorpions, Family Nepidce. (p. 130.) The Giant Water-bugs, Family Belostomidce. (p. 131.) The Creeping Water-bugs, Family Naucorid^. (p. 133.) Bugs that live near water. The Toad-shaped Bugs, Family GalguliD/E. (p. 133.) The Long-horned Bugs. Bugs with antennas 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/E. (p. 134.) The Broad-shouldered Water-striders, Family Veliid^E. (p. 1 34-) The Water-striders, Family Hydrobatidce. (p. 135.) The Marsh-treaders, Family LlMNOBATlDCE. (p. 136.) The Land-bugs. The Land-bugs with four-jointed anlennce. The Thread-legged Bugs, Family Emesidce. (p. 136.) The Assassin-bugs, Family Reduviidce. (p. 137.) The Damsel-bugs, Family Nabidce. (p. 138.) The Ambush-bugs, Family Phymatidce. (p. 138.) The Flat bugs, Family Aradidce. (p. 139.) The Lace-bugs, Family Tingitidce. (p. 139.) The Bed-bug and the Flower-bugs, Family ACANTKHDiE, (p. 140). The Leaf-bugs, Family Capsid^E. (p. 140.) The Red-bug Family, Family Pyrrhocorid^E. (p. 141.) The Chinch-bug Family, Family Lyg.^idje. (p. 142.) The Stilt-bugs, Family Berytidce. (p. 143.) The Squash-bug Family, Family Coreid^E. (p. 143.) The Land-bugs with five-jointed antenna. The Stink-bug Family, Family Pentatomid^E. (p. 144.) The Burrovver-bugs, Family Cydnidce. (p. 145). The Negro-bugs, Family Corimel.enidce. (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, cl)\ this is distinguished as the c/avus (cla'vus). The other broader part is the corium (co'ri-um) fig~i4i.— 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 cuneus (c\i'ne-us) (Fig. 141, at). In certain other cases, a narrow piece on the costal) margin of the corium is separated by a suture; this is the embolium (em-bo'li-um) (Fig. 141,^). Fig. 142. Nabida. Fig. 143. Acanthiida. Fig. 144. Capsida. Fig. 145. Pyrrhocoridce. Fig. 146. Lygceidce. Fig. 147. Coreidcz. 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. Corisid^e. 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 Naucoridje. EE. Ocelli present, p. 133 Galgulid^e. AA. Antennae at least as long as the head, usually free, rarely {Fhy- matidcg) fitting in a groove under the lateral margin of the pro- notum. B. Body linear; head as long as the three thoracic segments. p. 136 LlMNOBATIDjE. BB. Body of various forms, but, when linear, with the head shorter than the thorax. C. Last segment of the tarsi more or less split, and with the claws inserted before the apex. D. Body usually elongated ; prothorax narrow ; beak four- jointed ; second and third pairs of legs extremely long and slender, p. 135 Hydrobatid^e. DD. Body usually stout, oval, and broadest across the protho- rax; beak three-jointed; legs not extremely long. p. 134. VELIID.E. CC. Last segment of the tarsi entire, and with the claws inserted at the apex. D. Antennae four-jointed.* E. Wing-covers resembling network, and very rarely (Piesma with any distinction between the corium and the mem- brane, p. 139 Tingitid^:. EE. Wing-covers of various forms or absent, but not of the form presented by the Tingitidae. See Fig. 165. F. Beak three-jointed. * In certain families there are minute intermediate segments between the principal segments of the antennae. For the purposes of this table these intermediate segments are not counted. HEMIPTERA. 1 2"] G. Wing-covers when well developed with an embolhim (Fig. 143) ; those forms in which the adult has rudimen- tary wing-covers have no ocelli, p. 140. . . Acanthi id>E. GG. Wing-covers when well developed without an em- bolium ; those forms in which the adult has rudimentary ys-{ru\t drops. These insects can be trapped by reUui. ' * 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/EID/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 Fic! ~.lBiissui 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 Neides muticus (Ne'i-des mu'ti-cus), which has a prominent spine on the vertex of the head ; and Jalysus spinosus (Jal'y-sus spi- 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 Squash-bug Family. This family is also a very extensive one, including many species. The best character for distinguishing the members Fig. 175.— Jalysus spinosus. '44 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 its base (Fig. 176). 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 _. r J Fig. 177. — Anasa entirely. The remedy is to pntect the young trutu. plants by frames covered with netting. Family PentatomiDjE (Pen-ta-tom'i-dae). The Stink- bag 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. H5 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^u~ 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 CYDNlDiE (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. Fig. 179.- 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, or on the surface of the ground beneath sticks and cyrio'me- stones, or at the roots of grass and other herbage. nus mi- ' o © rabiiis. 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 CORIMEL^NID^E (Cor-i-me-laen'i-dae). The Negro-bugs. These bugs are mostly black, and are beetle-like in appearance ; some have a bluish or greenish tinge, and all 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 [■/mTIpV. which the edge of the wing-cover fits when at rest. All of our species belong to the genus Corimel&na (Cor-i-me-lce'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^ (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- FlG l8i.~-Eury£as sents one of these insects enlarged. They feed upon plants. Fig. 180. — Cori- fneliena alra. ter atternatus. 11 EM I r j 'ERA. 147 Suborder PARASITA (Par-a-si'ta). 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 Pediculidcs. 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. 182. — Hcematopinus asini. (From Law.) Fig. 183. — H. eurysternus. (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, 14^ 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 CICADID.E (p. 149). The Lantern-fly Family, Family FULGORID^E (p. 151). The Spittle Insects, Family CERCOPID^E (p. 152). The Leaf-hoppers, Family Jassid^: (p. 153). The Tree-hoppers, Family Membracid^e (p. 154). The Jumping Plant-lice, Family PsYLLID^E (p. 155). The Plant-lice, Family APHIDID.E (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. HEMIPTERA. 1 49 B. With three ocelli, and the males with musical organs. Usually large insects, with all the wings entirely membranous, p. 149. ClCADIDJE. 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^e. CC. Antennas 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/E. EE. Hind tib'ae having a row of spines below p. 153. JassiDjE. 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^;. D. Legs long and slender, not fitted for leaping; antennae three to seven jointed, p. 1 56 Aphidid^:. 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 CocciDjE. Family ClCADlD/E (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 INSECTS. 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- tendecivi (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. 184-cw* tuicen. tQ obtaJn theif growth_either seven- 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 rinding 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 1 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- day Harvest-fly or Lyreman, Cicada tibiccn (Cica'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^ (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 insects 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 I52 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. — Ormenis septen- trionalis. Figure 186 represents Ormenis septentrionalis (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^ (Cer-cop'i-dae). The 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 tiie 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. 153 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- mon spittle insect of the Eastern United States, rophora quad- " rangularis. Aphrophora quadra ngularis (A-phroph 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 JJg/' hind tibiae, which are nearly or quite as long as YH^ the abdomen, curved, and armed with a row of W spi"es on eacn margin (Fig- !88). Fig. x%%.-Proco- Among the leaf-hoppers that have attracted maundata. attentjon on acCount of 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 STUDY CF INSECTS. vine Leaf-hopper, Erythroiiciira 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 improp. 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 ¥icicad*uu. Leaf-hopper, Empoa'rosce (Em'po-a ro'sae), is also a (From'the well-known pest, as it often swarms on the leaves Reportfor °f roses, doing great damage. Its presence is l8y9) 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 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 bod)*, 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,Fcvr«*9l»~ droll look, and the line that separates the head ' 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'- Fc/ielwpaf/»~ Shanter ; and sometimes it has horns, one on each cUta" 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. <^2i All feed upon plants, but they seldom appear FlG. I94._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). Their hind legs are formed for jumping; their antennae are nine or ten jointed, and their tarsi are only two-jointed. Figure 197 repre- sents the wings of a common species, ^'enilr^"^ The PsylHdae subsist entirely upon the 1 56 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., claval 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 Mmbs 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 common species are both winged and wingless forms (Fig. Fig. 198.— a Group of Aphids. 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 cases at least, a more important service is rendered. In his studies of the Corn Plant-louse, Aphis viaidis (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, Lasitis alienns (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 HEMIPTERA. I 59 the species is provided for. This winged form also con- sists entirely of females, and is known as the zuiuged 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 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 eggs. 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, Rhizobius lactncee (Rhi-zo'bi-us lac-tu'eae), 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 brassices (A'phis bras'si-cae), the Apple- tree Aphis, Aphis mali, the Cherry tree Aphis, Mysus cerasi (My'sus cer'a-si), and the Peach-tree Aphis, Mysus per sices l6o 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. ., , , Some species of plant-lice live both on Fig. 199. — Lachnus. * r the roots and on the leaves of plants. One of these is the Grape Phylloxera, Phylloxera vastatrix (Phyl- lox-eVa 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 HEM1PTERA. iOT the vine. Carbon bisulphide has been used to sor^e extent for this purpose. Where the vineyards are so situated that they can be submerged for a period of at least fort)' 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 such soil. Another well-known example of the plant-lice that make galls is ColopJni ulmicola (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 imbricator (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 1 62 THE STUDY OF TAT 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, ScJiizoneura 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 to put in the forks of the trees pieces ot fonfd s^ai\ ^vbich will HEMIPTERA. »b3 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 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-dae). The Aleyrodes (Al-eu-ro'des). The insects of the genus Aleyrodes 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 other Hemiptera except the Coccids, F,G- 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. I&4 THE STUDY OF INSECTS. Family COCCIDAE (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- ike 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. I65 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. Chionaspis furfurus : 1. scales natural size; m, scale of male enlarged ; 16, adult male enlarged ; ic, 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 lae'ea), 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, Ericerus 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, Icerya purchasi (I-ce'ry-a pur'cha-si). — This beautiful in sect (Fig. 203) was at one time the most dangerous insect 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, Vcdalia (Ve-da'li-a), which preys upon it. The body of the adult female is scale-like, dark orange-red, and has the dorsal surface more or less Fir,. 20^. — Icerva purchasi. Females, adult mvprp-rl with a wllitp nr upl- and young, on orange. (From the Author's COVerea Willi a Willie Or Yei- Kepon for 1880.) lowish-white powder. The in- sect secretes a large egg-sac, which is beautifully ribbed. Th^ Mealy-bugs, Dactylopias (Dac-ty-lo'pi-us). — The HEMIPTERA. 167 Fig. l>o5. — Dactylopius ci'trt, fe- male, enlarged. (From the Author's Report for 1880.) Fig. 204. — Dactylopius longispi- nus, female, enlarged. (From the Author's Report for 1880.) Fig. 206.— Ket mes sp., on Quercus agrifolis. Adult females on stem; immature males uii leaves. (From the Author's Report for 1880.) 1 68 THE STUDY OF INSECTS. Mealy Bugs are the most common and the most noxious of green-house pests ; and in the warmer regions, as in Florida, they infest plants in the open air. Two species are shown greatly enlarged in Figures 204 and 205. These insects are extremely difficult to combat, as the white powder with which the body is clothed protects them from the sprays and washes ordinarily used. Kermes. — Species of this genus are common upon oaks wherever they grow. These insects are remarkable for the wonderful gall-like form of the adult females. So striking is this resemblance, that the)- have been mistaken for galls by many entomologists. Figure 206 represents a species of this genus upon Quercus agrifolia. The gall-like swellings on the stem are the adult females ; the smaller scales on the leaves are the immature males. Orthezia (Or-the'zi-a). — The members of this genus occur not uncommonly on vari- ous weeds. They are remark- able for the calcareous secretion with which the body is clothed. This is in the form of long plates. Figure 207 represents a nymph; in the adult female the secretion becomes more elongated posteriorly, and forms a sac containing the e^crs mixed with a fine down. Later when the young are born, they remain in the sac till they have themselves secreted a sufficient FlG' STutS^^^s*^ °m amoullt of the lamellar matter to cover them. Pidvinaria (Pul-vi-na'ria). — This genus includes species in which the body of the female resembles Lecanium, de- scribed below, but which excrete a large cottony egg-sac. This egg-sac is not ribbed, but is of the form shown in HEMIPTERA. 169 Figure 208. The species figured here is sometimes very injurious to maple-trees ; it also infests grape-vines and other plants. Fig. 20S. — Pulvinaria ir.nutnerabilis. Female on grape, natural size. (From the Author's Report for 1880.) Lecanium (Le-ca'ni-um). — The species of the genus Le- canium abound everywhere ; they occur on all kinds of Fig. 209. — Lecanium olece ; ia, insect enlarged. (From the Author's Report for 1880.) plants, both in conservatories and in the open air. Some of hem are known to gardeners as " soft-scales." But the I JO 1HE STUDY OF J X SECTS. scientific name is coming into general use; it is a common thing now to hear fruit-growers speak of the Lecaniums, especially in California. The Lecaniums are naked scale insects, the scale being the body of the insect. These insects are flattish or more or less hemispherical, the differ- ent species differing in form, and are usually dark brown in Fig. 210.— Lecanium hesperidum. (From the Author's Report for 1880.) color. The eggs, or the young in the viviparous species, are deposited beneath the scale-like body of the female. Figure 209 represents Lecanium olece (o'le-ae), which is very com. mon in California, where it is known as the black scale; Figure 210, the soft scale, Lecanium hesperidum (hes-per'i- dum), which is common on various plants in all parts of REMITTER A. \"]\ this country; and Figure 211, the hemispherical scale, Lecanium hemisphcericum (hem-i-sphser'i-cum), which occurs in conservatories everywhere, and in the open air in Cali- fornia. The Armored-scales Sub-family Diaspince (Di-as-pi'nae). — The great majority of the common scale insects of this FfG, 11U—Lecanium hemisphcericum »• 3^, insect enlarged. (From the Author's Re por, for 1880.) country differ from the forms described above in that the body of the insect, except for a very short period after birth, is covered with a scale composed in part of an excre- tion of the insect and partly of molted skins. Thus in the Lecaniums the scale-like object is the body of the insect; but in the case of the Oyster-shell Bark-louse, the Pernicious \*]2 THE STUDY OF IX SECTS. Scale, and of many other forms, the scale-like object com- monly seen is not the insect, but an armor beneath which it lives. The young insects of this sub-family resemble in general appearance those of other scale insects. Their active stage, however, is much shorter. After crawling about over the rs-c23m riG. 212. — Chionaspis pinifolicE : 2, scales on Pinus strrbus, natural size, leaves stunted; 2a, leaves of P. strobus not stunted by ?ca:e :r.s cts; ■zb, scale of female, usual form, enlarged; 2c, scale of female, wide fjrra, ei:iarj3d ; zd, scale of male en- larged. cwigs of a tree for a few days, the young scale :nsect settles upon a suitable place and immediately begins to excrete a cottony substance which soon becomes compacted into a thin pellicle covering the body. As the insect grows and needs to shed its skin, this cast skin is joined to the excretion and forms a part of the scale. This is the bright-colored, nipple-like prominence, seen in the centre of the Pernicious HEMIPTEKA. 173 Scale and of the Red Scale of the Orange ; and it may be seen at the smaller end of the scale of the Oyster-shell Bark-louse. The position of this cast skin in the scale differs in differ- ent genera, and forms a good character for classification. Closely allied species differ but little in the form of the scale. To distinguish these it is necessary to study the Fig. 213. — Aspidiotus auratitii : scales on leaves of orange, natural size; i«, adult male> ' much enlarged ; i£, 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 furfurns (Chi-o-nas'pis fur'fur-us), a species very widely distributed on apple, pear, and cherry ; Figure 212, the Pine-leaf Scale, CJiionaspis pinifolice (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 au-ran'ti-i), which is very destructive to oranges and lemons. Kig. i\i,.—Nepa 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 mcui. branous and furnished with numerous veins, and usually with many cross veins. TJie 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 ; and pteron, 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. Mantispim:. * 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 CF INSECTS. BB. Fore legs not enlarged, and not fitted for grasping, p. 178. Raphidiidje. 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 (die anal area) folded like a fan when not in use. p. 176 SlALIDiE. 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 Myrmeleonida:. 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. l8l HeMEROBIIDjE. EE. Transverse veins between the costa and subcosta simple, wings greenish, p. 180 Chrysopidje. Family SIALID.E (Si-al'i-dae). The Dobson 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. NEUROPTEKA. 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 RapJiidians {Ra-phid1 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. — Raphidia, . ... . 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. XELKOfTEKA. 179 Living specimens of these insects have been sent to Aus- tralia 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, Rapliidia (Ra- phid'i-a) and Inocellia (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 Mantis-like Neuroptera. 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. 218). 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 known, are parasitic in the egg-sacs of spiders. Five species of the family are known from the United States; four of these belong to the genus Mantissa (Man- tis'pa) and one to Symphasis (Sym'pha-sis). Fig. 218. — Mantissa. In the specimen figured the fore legs were twisted somewhat in order to show the form of the parts. 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 Chrysoj>a. 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 antennae, and a pair of large eyes that shine like melted gold. It is NE UROP TERA. 1 8 1 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 hutches 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 Clirysopa (Chry-so'pa). Family HEMEROBIID/E (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 browr. or smoky specks, and with some of the veins between the cojta and subcosta forked. The most conspicuous member of the family is Polys- tcechotes panctatas (Pol-ys-tcech'o-tes punc-ta'tus), which is represented natural size by Figure 220. The larva is unknown. 182 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- 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. Fig. 220. — Polystaechotes punctatus. Family MYRMELEONID^E (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. NF.UROPTERA. 183 of these larvae, 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 Ascalaphiu (As-eal'a-phus). CHAPTER XVI. Order MECOPTERA (Me-cop'te-ra). The Scorpion-flies and others. The members of this order have four wings ; these are membranous, and furnished zvitli 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 ; mecos, length ; and pteroji, a wing. This order includes only a single family, the Panorpidce. Family PANORPID/E (Pa-nor'pi-dae). The Scorpion-flies and others. We have found representatives of this family quite abundant on rank herbage growing on Fig 223— Head *he banks of a shaded stream; we have also ™£)a}°iPa 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 MECOPTEKA. I85 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 yellowish, spotted with brownish black (Fig. 224). 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. Fig. 224. — Pa- norpa, adult. CHAPTER XVII. Order Trichoptera (Tri-chop'te-ra). The Caddice-fiies or Caddice-worms. The members of this order have four zvings ; these are membranous, furnislied with numerous longitudinal veins but with only few 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. -Caddice-fly. naUy folded jn repose AU haye „„. 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 TRICHOP TERA . 1 8/ Family PHRYGANEID^; (Phryg-a-ne'i-dse). 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- 22'/- 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 Fig. 230, • . , , , 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 mai'e.c a more or less perfect tube of silk, within which TR1CH0P TERA . 1^9 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 3ure 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- dropsychin ce, are known to be carnivorous. It should be noted here, however, that the greater number of Cadchce- 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, 190 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 Moths or Millers, the Skippers, and the Butterflies. The members of this order have four wings ; these are membranous, and covered with overlapping scales. The mouth- 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 191 192 THE STUDY OF IX SECTS. 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 wins[s of similar 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 %m^H Fig. 231. — Part of wing- of butterfly, greatly magnified. Fig. 232.— Maxillae 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 LEP1D0PTERA. 193 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 Fig. 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 maxillae 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 claw. 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-moth. Most caterpillars, except the larvae of butterflies, spin cocoons (Fig. 235). In some instances, as in case of the /ig. 235. — Cocoun of a moth. silkworms, a great amount of silk is used in the construction of the cocoon ; in. others the cocoon is composed principally LEPIDOP TERA . 1 95 of the hairs of the larva, which are fastened together with a fine web of silk. In the pupa; 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- -Pupa of a molh- 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 : — The 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 antennas 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 indicaiing 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. 197 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 wino- 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. HI, 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 acquked 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, /); Fig. 237.— Wings of Thyridopteryx ephemeraformis. 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- ulum, a lobe borne near the base of the inner margin of the fore wing (Fig. 238, /) ; this is the jugum. See sub-order Jugatse. Discal Cell. — Near the cen- tre of the basal part of the wing there is a large cell lying 11 in. VIIs VIIi 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 LEPIDOPTERA. 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 „ m, thmit, more cells beyond the apex of the discal cells (Fig. 239, a.c.) ; 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, d.v.). Patagia. — At the base of each fore wing there is a scale-like ap- pendage; these are the patagia. The patagia are borne by the protho- rax, and in many cases are capable of consider- able movement. In descriptions of Lepidoptera reference is often made to the palpi. These form the double beak-like projection which extends forward from the lower surface of the head. In most Lepidoptera only the labial palpi are well developed ; but in some of the more generalized forms the maxillary palpi are also present. "wwtwai^,*. The presence or absence of ocelli is a character which is sometimes of considerable importance. - These or- gans are situated, one on each side, above the compound eye and near its margin (Fig. 240). But it requires some Fig. 240.— Head of moth, showing .... - , . . , position of ocellus. skill to find them when they are present, on account of the long scales clothing the head. The Phylogeny of the Lepidoptera. — Since the general acceptance of the theory of evolution — that is, the theory that the higher animals and plants have been developed from lower ones — it has become evi- dent that the only sure basis for classification is a knowledge of the Fig. 239. — Wings of Notolophus leucostigma. 200 THE STUDY OF INSECTS. history of the various races of animals and plants, or phylogeny (phy- log'e-ny), as it is termed. The scope of this book has not permitted an extended treatment of this phase of the subject. There is space for only a few hints re- garding the phylogeny of the families of a single order; but these hints will serve as an illustration of a method of study. The Lepi- doptera is chosen for this purpose, as the method has been applied to this order more fully than it has to others. It is a well-known fact that every kind of animal and plant trans- mits a general likeness with individual differences to its offspring. According to the Darwinian theory of natural selection these dif- ferences or variations may be of any kind and in any direction. And as many more animals are born or plants germinated than can live to reach maturity, owing to the tendency of each kind to increase in a geometrical ratio, each individual is subjected to a severe struggle for existence. The result of this struggle is that any individual possessing a for- tunate variation — that is, one that enables it to get its living and escape its dangers more easily than its fellows — will be more apt on this account to reach maturity and propagate its kind than will less fortunate individuals. Thus there is a thinning-out process which tends to the production of more and more specialized forms of animals and plants, i.e., forms adapted to the special conditions under which they exist. It should be remembered that the difficulties surrounding exists ence may be met in different ways; and that thus there may have descended from a common ancestor very different forms, each well fitted to meet the struggle for existence. See Chapter I, pp. i and 2. Just what changes have taken place in the structure of the mem- bers of any race is a difficult matter to determine, for, although many fossils have been found, the record is still very incomplete. But for- tunately something can be learned regarding this by the study of living animals. For not all members of the same family, or order, or class are equally specialized. Some retain more nearly than others the form of their remote ancestors ; and by the study of these general' ized forms, as they are termed, we can gain some idea of the struc- ture of the animals of past ages, and of the ways in which existing animals have been modified. We will state very briefly some of the conclusions that we have reached regarding the phylogeny of the families of the Lepidoptera. These conclusions are based largely on a study of the wings. It is hoped that other parts will be studied in the same way ere long. LEPIDOPTERA. 201 In the flight of insects it is important that the two wings of each side should act together, and we find that this is secured in most orders by uniting them in some way. In the Lepidoptera two dis- tinct methods are employed ; in some it is done by means of & jugum, in others by means of a frenulum or its substitute. As neither the jugum nor the frenulum could be derived from the other, we infer that the primitive Lepidoptera possessed neither of these organs, but had wings that were quite distinct from each other. In the course of time there was developed in some of the descendants of these primi- tive forms a jugum ; while in others there was developed a frenulum. Of course in each case the development was a gradual one, extending through many generations. Thus the frenulum at first was probably merely a bunch of hairs like those elsewhere on the wings; but these became stiffer and stiffer in succeeding genera- tions. The descendants of those ancient Lepidoptera in which a jugum was developed constitute the suborder Jugatce ; while the descendants of those in which a frenulum was developed con- stitute the suborder Frenatce. We know but little of the Jugatae, as nearly all of them have perished. There remain only two small families, the Hepialidae and the Microptery- gidae. But these families are very widely separated, and hence it is safe to assume that they are the remnants of what was in past times a large fauna. In the Frenatae, however, there exist to-day many families, each exhibiting its own methods of specialization. In some of these families the frenulum has been preserved and perfected to a greater or less extent. But in others a curious change has taken place. It is obvious that if the two wings of each side overlap to a great extent, their acting together will be assured by this fact. And this is Fig. 241. — Wings of Ancea andria. 202 THE STUDY OF INSECTS. what has taken place with the butterflies, the skippers, and certain moths. With these insects the humeral angle of the hind wing has been greatly enlarged, so that it projects far beneath the fore wing (Fig. 241). When this has taken place there is no longer any need of a frenulum, and consequently this organ is no longer preserved by natural selection. We find, therefore, that several families of Lepi- doptera that belong to the suborder Frenatae, being descendants of VIII Fig. 242. — Wings of Bombyx mori. ancient frenulum-bearing moths, no longer possess a frenulum. These are classed in the following synopsis as the frenulum-losers. It is a very interesting fact, and one that bears out the theory just stated, that in the more generalized of the frenulum-losing moths, as the Bombycidse, the frenulum has not yet entirely dis- appeared, but is preserved in a rudimentary state (Fig. 242). We place the frenulum-losers last in a serial arrangement of the fami- LEPIDOPTERA. 203 lies of Lepidoptera, regarding them as those that depart most widely from the primitive type. From the foregoing it will be seen that a study of the relation to each other of the fore and hind wings gives us important hints as to the probable courses development has taken in the different families. Equally suggestive hints may be derived from a study of the venation of the wings. By an extended study of fossil forms and the more generalized of living forms, the details of which study cannot be given here,* it has been determined that in the primitive Lepidoptera vein V of both fore and hind wings was well developed, and extended from the base of the wing out through the discal cell. We find that in certain families of existing moths this vein is still preserved (see p. 221), while in others it has been lost. Those families of the Frenatse in which it is best and most uniformly preserved are grouped together as the Generalized Fretiata (see the following synopsis), while those in which it is lost or nearly so are considered more specialized. With the loss of the base of vein V there occurs a connection of its branches with veins III and VII, so that in the more specialized forms these branches of vein V appear to be branches of those veins (Fig. 241). A study of the extent to which this change has gone gives much aid in determining the zoological position of the different o-enera and families. In certain families vein Vs tends to become united to vein III ; in others it tends to become united to vein VII. This too is an important character, of which use is made in the following synopsis. The number of anal veins is another character the study of which throws much light on the relative position of the different forms. It has been determined that the ancient Lepidoptera had at least three anal veins in both fore and hind wings. This number has been pre- served in one or both pairs of wings of the more generalized of living moths, but has been reduced to two or even to one in the more specialized families. Enough has been said, without going into further details here, to show that the way to determine the relationships of organized beings is to determine the primitive form of their organs and the changes that have been brought about in these organs by the action of natural * The data upon which these conclusions are based are given at greater length in an essay, by the senior author, entitled Evolution and Taxonomy. This essay forms a part of the Wilder Quarter-Century Book, published by the Comstock Publishing Company, Ithaca, N. Y. 204 THE STUDY OF INSECTS. selection. The classification of animals and plants should not be merely the assorting of them into convenient pigeon-holes, but a serious study of their blood-relationships. The following synopsis will serve to show what we believe to be the relations of the principal divisions of the order. Following this synopsis there is a table for use in classifying specimens. SYNOPSIS OF THE LEP1D0PTERA. (See page 207 for a table for determining specimens.) A. The Jugate Lepidoptera. — Moths in which the two wings of each side are united by zjitgum (Fig. 238, J), p. 214. Suborder JuGATVE. B. The Swifts or Macrojugatce, p. 215 Family Hepialid^e. BB. The Little- wing Jugates or Microjugatce, p. 216. Family MicropterygiDjE. AA. The Frenate Lepidoptera. — Moths, skippers, and butterflies in which the two wings of each side are united by a. frenulum (Fig. 237./) or by its substitute, a large humeral angle of the hind wing (Fig. 241), p. 201 Suborder Frenatae. B. The Generalized Frenatae. — Moths that are supposed to retain more nearly than any other Frenatae the form of the primi- tive Frenatae, those that were the first to appear on earth. In these generalized moths the wings approach the typical form; the base of vein V of one or both pairs of wings is preserved throughout a considerable part at least of the discal cell ; and the anal veins are well preserved, there being two or three in the fore wing and three in the hind wing. The frenulum is usually well preserved. The Flannel-moths, p. 218 Family Megalopygid^e. The Bag-worm Moths, p. 219 Family Psychid/E. The Carpenter-moths, p. 221 Family CossiD^E. The Slug-caterpillar Moths, p. 223 Family Eucleid^e. The Smoky-moths, p. 226 Family Pyromorphid^e. BB. The Specialized Frenatae. — Moths, skippers, and butter flies that depart more widely than do the Generalized Frenatr: from the primitive type of Lepidoptera, being more highly modi- fied for special conditions of existence. An indication of the specialized condition of these insects is the modified form of the wings. In nearly all the base of vein V has been lost and the branches of this vein joined to veins III and VII. LEPIDOP TERA . 205 C. The Microfrenat^e. — Frenulum-bearing moths, which are usually of small, often minute, size. The anal area of the hind wings is not reduced, having usually three anal veins except in certain minute forms where a broad fringe has been substituted for the membrane of this area. The Pyralids, p. 228 Superfamily Pyralidina. The Tortricids, p. 239 Superfamily Tortricina. The Tineids, p. 246 Superfamily Tineina. The Clear-winged Moths, p. 259 Family SESIID.E. CC. The Specialized MacrofrenatjE. — Specialized Frenatae which are usually of medium or large size. This division includes certain moths and all skippers and butterflies. In these insects the anal area of the hind wing is reduced, con- taining only one or two anal veins. D. The Frenulum-cotiservers. — Specialized Macrofrenatae in which the two wings of each side are united by a frenulum. This group includes only moths. E. Moths that appear to have a three-branched cubitus, only vein V3 being closely connected with vein VII. Vein V9 either retains its primitive position midway between veins III and VII or arises from the discal vein nearer to vein III than to vein VII* The Dioptids, p. 262 Family Dioptid^;. The Prominents, p. 263 Family NOTODONTID/E. The Measuring-worm Moths, p. 270. Superfamily Geometrina. EE, Moths that appear to have a four-branched cubitus, the base of vein V3 of one or both pairs of wings being more closely connected with vein VII than with vein III. F. Moths in which the humeral angle of the hind wings is greatly extended, but which as a rule possess the frenulum in one sex at least. The Auzatids, p. 288 Family Auzatid^e. The Hook-tip Moths, p. 289 Family Drepanid^e. FF. Moths in whicli the humeral angle of the hind wings is not greatly extended. G. The Noctuids and their Allies. — Moths in which some of the branches of vein III of the fore wings coalesce * In many Hawk-moths vein V2 nearly or quite retains its primitive position ; but when it has moved from this position, it is nearer to vein VII than to vein III. This family is placed, therefore, in the next division (EE) of this synopsis. 206 THE STUDY OF INSECTS. beyond the discal cell, and which do not have what appears to be a cross vein between veins II and III of the hind wings. The Cymatophorids, p. 291 .Family Cymatophorid^e. The Owlet-moths, p. 293 Family NoctuiDjE. The Tussock-moths, p. 308 Family Lymantriid^e. The Wood-nymph Moths, p. 313. Family Agaristidje. The Pericopids, p. 316 Family Pericopid^e. The Tiger-moths, p. 317 Family ArctiiDjE. The Footman-moths, p. 324 Family Lithosiid^e. The Zygsenids, p. 326 Family ZYCENiDiE. GG. The Window-winged Moths. — Moths in which vein III of the fore wings is five-branched and in which all of these branches arise from the discal cell (Fig. 404), p. 328 Family THYRlDiDiE. GGG. The Hawk-moths. — Moths in which there appears to be a cross vein between veins II and III of the hind wings (Fig. 407), p. 330 Family SPHlNGlDiE. DD. The Frenuhun-losers. —Specialized Macrofrenatae, in which the frenulum has been supplanted by a greatly extended humeral area of the hind wings. In some of the more gen- eralized forms a rudimentary frenulum persists (Bombycidse and Lacosomidae). This division includes three groups of families: the Frenulum-losing Moths, the Skippers, and the Butterflies. The grouping together of the families included in this division is merely provisional, as it is probable that the loss of the frenulum has arisen independently in several of them. E. The Frenulum-losing Moths. — In these moths the antennae are usually pectinate ; they are never enlarged into a club at the tip. F. Moths with cubitus of the fore wings apparently three* branched. G. Moths in which veins III3 and III4 coalesce to a great extent. The Saturnians. p. 339. Superfamily Saturniina. GG. Moths in which veins III3 and 1 1 14 do not coalesce beyond the discal cell. p. 357. .Family LACOSOMlDiE. FF. Moths in which cubitus of the fore wings is apparently four-branched, p. 359 Family Lasiocampid^E. EE. The Skippers. — These are day-flying Lepidoptera which resemble butterflies in usually holding their wings erect LEPIDOPTERA. 207 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 the 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 Papilioxid.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.E. GG. Butterflies exhibiting a marked tendency to abor- tion of the fore legs. The Gossamer-winged Butterflies, p. 3S8. Family Lyc.exid.e. The Brush-footed Butterflies, p. 395. Family Nymphalid.E. 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 Jugatce.) [See also AAA.] 208 THE STUDY OF INSECTS. B. Moths of medium or large sire. p. 215 Hepialid^e. BB. Minute moths, resembling Tineids in appearance, p. 214. MlCROPTERYGID^E. 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. ..ORNEODlDiE. EE. Wings never more than four-lobed ; usually the fore wings are bilobed and the hind wings trilobed. p. 237. Pterophorida:. 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 SESllDiE. 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:: zi the discal cell and the apex of the wing, or in some ca~es 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 . 209 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 antenna; 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 cowards 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. Subcosta and 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 PVROMORPHIDiE. JJ. Moths of medium size, and densely clothed with long woolly hairs, which are light colored or brown, p. 218 MEGALOPYGIDiE. 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 PSYCHJD^E. JJ. Anal veins of fore wings not forked outwardly. K. Vein V2 of the fore wings arising from the discal cell nearly midway between veins Vi and V3. L. Vein V3 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 DlOPTID^E. LL. Veins V3 and VIIi not coalescing beyond the end of the discal cell. M. Veins III2 and II I3 coalesced at base, but separate from veins 1 1 14 and I He. 15 ilO THE STUDY OF INSECTS. which also coalesce (Fig. 438). p. 357. LACOSOMIDiE. MM. Veins III,. Ills, III*, and Ills united at base (Fig. 419). p. 340. .BoMBYCiDiE. KK. Vein Va 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 veins III4 and III5; the accessory cell is formed by the anastomosing of veins Ilia and III4 + 6. p. 221 Cossid.e. LL. Fore wings without an accessory cell; veins II I3 and II I4 coalescing to a greater extent than any other branches of radius (Fig. 261 ,. p. 223 EucleiDjE. 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 moths (the largest expanding only three fourths inch) resembling Hawk-moths in form, and with translucent spots on their wings, p. 328. Thyrididje. LEPIDOPTERA. 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 antennas 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 Va 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 Va 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. CYMATOPHORIDiE. MM Vein Va 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 V! of the hind wings joined to radius at or beyond the apex of the discal cell (Fig 311). p. 263. NOTODONTIDiE. 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' M2 TJJE STUDY OF INSECTS. nus (Fig. 438). Veins Ills and Ilh o! Uie 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 III3 and III* 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» 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 AUZATIDiE. 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 MM M.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. Pericopidje. OO. Cubitus of hind wings apparently three-branched (Fig. 379). p. 313. Agaristidje. NN. Not such moths as are described under N. O. Antennae pectinate. LEPIDOP TERA. 213 P. Ocelli absent, p. 308. LYMAXTRIIDjE. PP. Ocelli present, p. 293 NoCTUlDiE. OO. Antennae simple, p. 293. NoCTUlDiE. 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. ..Arctud^;. OO. Ocelli absent, p. 324..Lithosiid;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 wing. 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 Zyg^enid,e. 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 (V2 and V3) 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 DRj>panid/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 (V3) 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 JUGAT/E (Ju-ga'tae). The Jugate {J u' 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 n n!i fore wings in form and in venation (Fig. 238). In all other Lepidoptera, the two *^\ V N* ^*v-J< ^\ \ \/'llh pairs of wings differ in ■^ ' form, and the hind wings ~vii,V3 are furnished with fewer veins than are the fore wings. The most important characteristic of the sub- vil. vii. ' order, and the one to which Fig. 143.— Wings of Hefiaius gracilis. jts 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 LEP1D0PTERA. 215 wing near its base a small lobe (Fig. 243,/), 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 \\\zjugum 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-al'i-dae). The Swifts. The members of this family are of medium or large size. Figure 244 represents one of the larger species. Our best Fig. 244. — Hepialus argenteoniaculatus. 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 {A Inns incanci). Family MiCROPTERYGlD^ (Mi-crop-te-ryg'i-dae). The Little-zvinged Jngates ( ' Jn'gatcs). 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, viii vnavnr V3 Fig. 245. — Wings of Microjiteryx. Microptcryx (Mi-crop'te-ryx), occurs in this country. The larvae are leaf-miners. Suborder Frenatve (Fre-na'tae). The Frenate (Fre'nate) Lepidoptera. To the Frenatae belong nearly all of our moths, and all skippers and butterflies. With most moths of this suborder LEPJDOP TERA . 2\"J 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 Jiumeral 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. 218 THE STUDY OF INSECTS. Family Megalopygim; (Me-gal-o-pyg'i-dae). The Flannel-moths. 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, Fig. 246.— Megalopyge crisfata. expanding one and three fifths 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 ; but 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- IX VIII Fig. 247.— Wings of Megalopyge crispata. gether nearly to the end of the discal cell. \ LEP1D0PTERA. 2IQ 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 Microptcryx, have lost some of the abdominal legs. The cocoons of these insects are also remark- fig. 248.— Cocoon of able, being furnished with a trap-door (Fig. 248). ilopyge. Family PSYCHID^: (Psy'chi-dae). The Bag-tvorvi 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. When a Bag-worm is fully grown, it oiketu'us abbotu. 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 without wings. But the male pupa works his way out from the lower end r , . , , Fig. 2so.— Bag of Fig. 251.— Psyche Of hlS SaC and Changes tO a psyche con/ede- confederate winged moth. Figure 250 rep- resents the sac of a male with the empty pupa-skin projecting 220 THE STUDY OF INSECTS. 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). The Evergreen Bag-worm, Thyridopteryx ephemenzfor- mis (Thyr-i-dop'te-ryx e-phem-e-rae-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- FlG. 252. — I hyndopteryx x ephtmera/ormis. 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 ^IC. 253 — Wings of Thyridopteryx ephemerceformis. three anal veins ; but the anal veins of the n fore wings are grown together so as to ap- pear as a single much-branched vein. The Fig. 254. base of vein V is preserved and is forked LEPIDOPTEKA, 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 arc represented slightly separated in order to show their relation to each other. Family Cossim: (Cos'si-dae). The Carpenter-moths. 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 in. Ilia XI ix Fig. 255.— Wings of Prionoxytus 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 antennae 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- FlG. 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 EUCLEID.E (Eu-cle'i-dae). The Slug-caterpillar Mollis. 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. —EucUa dclphinii, 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, and many of them arc- 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 1 1 13 and III4 co- alesce to a greater ex- tent than any other branches of this vein, and there is no accessory cell. The Skiff Caterpillar, Eulimacodcs scaplia (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). VIII Fig. 260. — Wings of Adoneta. spinuloides. LEP1D0PTEKA. :25 The Saddle-back Caterpillar, Empretia 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 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 Fig. 262. — Eulimacodes scapka. Fig. 263.— Euclea delpliinii. Fig. 264. — Empretia stimulea, lania. 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. 16 126 THE STUDY OF INSECTS. Fig. 26$. — A coloi- thus falsarius. III. in, rn3+4 Family Pyromorphid^e (Pyr-o-mor'phi-dae). The 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 Acoloithus fal- sarius (Ac-o-loi'thus fal-sa'ri-us). This motli (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 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 PyromorpJia 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 falsarius. j.EPJnor i era. 227 In Texas and Arizona there occur several species of Triprocris (Trip'ro-cris). The venation of one of them is ui.. ir '"■ shown in Figure 268. It is remarkable in that none of the branches of radius of the fore wings coalesce beyond the dis- cal cell. The gen u s 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 form of the family in xT^^1* VJIJ that the anal area Of FlG. 267.— Wings Of Pyromorpha dhnidiata. the hind wings is greatly reduced, there being only two, short, strongly curved anal veins. As in the other members in, m. °f the family there are nil Fig. 268. — Wings of Triprocris marteni. [h two,well-developed anal ms veins preserved in the v* fore wings. In the East the most common species is Har- risina americana (H. a-mer-i-ca'na) (Fig. 269). 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 NomopkUa noctzteiia, 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 bv the fact that the subcosta and radius of the hind wings are separate along the discal cell, but grown VII, VII, LEPIDOPTERA. 229 TT niiiir* nr^4 — - nis Vi 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. Fig. 271. — Wings of Tlascala reducttlla. 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 III4 and III5 separate, vein Ills arising from the discal cell (Fig. 272). p. 230 Pyraustid;e. CC. Fore wings with veins III4 and Ilia united at base (Fig. 277). p. 232 PyRALIDIDjE. "BB. Hind wings with a fringe of long hairs on the basal part of ve:n 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/E. 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 Ills and III* coalescing to edge of wing (Fig. 281). p. 235 PHYCiTlDiE. 230 THE STUDY OF AV 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. . . . Pterophoridje. BB. Each wing split into six parts, p. 238 ORNEODlDiE. Family PYRAUSTID.E (Py-raus'ti-dae). The Pyranstids (Py-raus'tids). The members of this family differ from other Pyralids by the following combination of characters. There is no fringe of long hairs on the basal part of vein VII of the hind m TTr wings, and vein III6 of rrr III; 1Ji3 Tjr the fore wings arises from the discal cell dis- tinct from vein III4(Fig. 2"]2). 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 Nomophila noctuelia. The Crrane T eaf folder, Desmia funeralis (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, it 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, Fig. 273 — Desmia Juneralis. LEPIDOPTKRA. 231 The Bass-wood Leaf-roller, Pantographa limata (Pan- tog'ra-pha li-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- 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- FiG.274.-Nestofiaryaof/w^«//mraiid. The moth expands about tun at a. L 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 V Fig. ii§.—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« and 1 1 16 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. LEPIDOPTERA. 235 HI, The Meal-moth, Pyralis farinalis (Pyr'a-lis far-i-na'lis) is a common species. The larva feeds on Trr Illr 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 costalis (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 Fig. 278.— Pyralis larva, and by its black gunpowder-like excre- costalis. . . ..... . ment, much more is spoiled than is eaten by the insect. 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-dae). The Bee-moth 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-neria). The FlG. 277. — Wings of Pyralis farinalis. 234 THE STUDY OF INSECTS. Fig. i-]t). — Gnlleria mello- netta. 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 often 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^e (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 insects of this family. When one of these moths alights on a stalk of grass it quickly places its body Fig. 280. — Cram ius. LEPIDOPTERA. ?35 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. iiir'nif nr3*4 Family PHVCITID/E (Phy-cit'i-dse). The Phycitids {Phyc'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 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 a silken tube or case, lying concealed by day and feeding by night. Fig. 281. — Wings of Tlascala reductella. 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 interpunc- 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 kilhniella (E-phes'ti-a kuhn-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 flou ring-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 {Pufoinaria, Dactylopius, and Lecaniuni). Figure 283 represents the different stages of this insect enlarged, and the moths natural size resting on LEPID0P1ERA. 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 coccidivora : a, egg; i, larva ; <-, pupa; d, adult; e, e, moths natural size resting on egg-sacs of Pulvinaria. 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 OE 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 fissures 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 periscelidactylus (Ox-yp'ti-lus 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. ^.-oZyfitiius spring, and feed upon the newly-expanded perisceiidactyiu*. ieaves 0f grape. They fasten 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.E (Or-ne-od'i-dae). The Many-plume Moths. These insects resemble the Plume Moths in having the wings fissured ; but here the Assuring 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. 285.— Orneodes hexadactyla. LEPIDOPTERA. 239 Superfamily TORTRICINA (Tor-tri-ci'na). The Tor triads {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 wins?. 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). in, in, The 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 Fig. 286. -Wings of Cacmcia cerasivorami. 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. 287. — Leaf rolled by a larva, probably a Tortricid. 240 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. AA. Without a fringe of long hairs on the basal part of vein VII of the hind wings. B. Vein VII2 of the fore wings arising from the outer fourth of the discal cell, p. 243 Conchylid^e. BB. Vein VII2 of the fore wings arising from a point before the outer third of the discal cell, p. 244 Tortricidje. Family GRAPHOLITHlD^E (Graph-o-lith'i-dae). The GrapJiolitJiids (Gra-phol i-tliids). 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 pomonella (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 Fl^fpoZon"JuT 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 larvas 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, Tmctocera 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, often 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. The 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, whitish band on the fore wing. Fig. 289. — Ret in in lomstockiana, larva, pupa, adult, and work. (From the Author's Report for 1879.) The Pitch-pine Retinia, Rctinia comstockiana (Re-tin'i-a com-stock-i-a'na). — This species (Fig. 289) illustrates well LEPIDOPTEKA. 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 harden? 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 frustrana(lrus-tra.'na.). — This species infests the new growth of several species of pine, spinning a delicate Web around the terminal bud, and FlG- 29°— Retiniafrustrana, larva, pupa, adult, and work, (From mining both the twig and the bases the Author's Report for 1879.) 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.E (Con-chyl'i-dae). The Conchy lids {Con' cliy-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 rutilana (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 Tortricids (Tor-tric'i-dae). The Typical Tortricids {Tor' tri-cids). 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, 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. LEPIDOPTERA. 245 The Cherry-tree Ugly-nest Tortricid, Caccecia cerasivo- ra?ia (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 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- r;i; iM* Fig. 293.— Nest of Caccecia cerasivorana. Fig. 294. — Caccecia cerasi- vorana, male. Fig. 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- -a-da na). — The nests of this species are common on our 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, LopJioderia 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 (Figs. 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 Fig. 296.-wings of Depressaria >ts more general features the ktraciiana. venation of the wings in this family is similar to that of the Tortricids; it differs, how- LEPIDOPTERA. ?47 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 tvpe. 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 ; manv 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 ail 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 -ella. Thus we have Tinea 248 THE STUDY OF INSECTS. granella, Adela ridingsella, Bucculatrix pomonella, 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 larvse 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. During the late summer and autumn there can be found 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 LEPIDOPTEKA. 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 Tischeria 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 tentifonn mines. In addition to peculiarities in shape many mines are marked by characteristic lines or spots composed of the droppi'ngs 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 leaver of many different species of oak, and sornc- Fig. 298. — Lithocolletis Jiamadryidella: a, mine; i, young larva; c, full-grown, flat-form larva; d, head of same, enlaced; e, antenna of same, enlarged; _/", round-form larva from above; g, same from below; h, head of same, enlarged; i, antenna of same, en- larged; k, maxilla and palpus of same, enlarged; /, labium, labial palpi, and spinnerets of same; m, pupa; «, side view of pupal crest; o, 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. LEPIDOPTJ.KA. 2.—Gelechia pinifoliella, larva, pupa, adult, and leaves mined by the larva. (From the Author s Report for 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 eggs are laid on the lower surface of the leaves. Each 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- Fig. 301. — Cocoons of Bucculatrix pom- ifoliella. 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 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 larvse dropped from a tree upon the writer's hat and carefully ?ig. 302. — Aspidisca splendori/erella : a, leaf of apple showing work ; 6, summer larva; cy larva in case travelling ; d, cases tied up for winter ; e, hibernating larva ; /, pupa ; g, moth ; k, parasite. (From the Author's Report for 1879.) fastened 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, Inciirvaria acerifoliella (In-cur- va'ri-a a-cer-i-fol-i-el'la). — This insect illustrates still another 256 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 one, 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. LEP1D OP TERA . 257 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 undercoin^ 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 pellionella (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 cercalella (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 Fig. 30*. 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 Sesiim: (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. 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 antennae 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- in, 3. 26o 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 me 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 \r July. There is a single generation each year. The adults ^J?^** 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 . 1 • 1 1 r 1 .1 Fig. -?o6. — Sannina exitiosa. this pest has been found than to care- J 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, Harmonia 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 larvas 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 wings of the adult are covered with scales, and the hind legs are fringed with long orange-colored scales. Family DlOPTlD^: (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'- FlG. 308. — Phryganidia 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 F.c.3»9.-wingsof«r«a««/<,. 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^e (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 V2 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 more generally ap- propriate, however, for the larvae, as a much larger propor- tion of them than of the adults bear striking prominences. FlG. 310. — Pheosia rimosa. 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 nir m, ius anal vein, the hind ^inv 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. Fig. 311.— Wings of Notodonta stragula. The larV86 feed upon the leaves of shrubs and trees. Our most common species live exposed ; but some species live in folded leaves. They are either naked or thinly clothed with 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, D at ana (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. 512) 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 Lat ana. 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. — Datana. Fig. 313. — Datana, 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 20t> 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 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. 314. — Edema albifrons. Fig. 315. — 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, LEPIDOPTEKA. 20J feeding on the leaves of oak, elm, and basswood. It measures when full grown about one and one half inches in length. Its Fig. ^.-seir'adonta biiineata, ground-color is 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, CEdemasia concinna (CEd-e-ma'si-a con-cin'na). — The larva of this species (Fig. 317) 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, IcJitliynra (Ich-thy-u'ra). — To the genus Iclithyura 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, IcJitliynra incliisa (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&.-ichthyura 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 leal 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 LEPID0PTE1A. 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 halt-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 larvae be- F,G- v*-Cmio*»y*> larva. longing to this family are those of the genus Ccelodasys 270 THE STUDY OF INSECTS. (Coe-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 Geomctrids (Ge-om'e-trids), or the Mcasuring-zvorms. 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 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. 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„ 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 wings makes a prominent bend into the hu- Fang,ro3fl"d wlS meral angle of the wing (Figs. 322, 323).* of Euduu. 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 Eudide (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 Va of the hind wings wanting, being represented merely by a fold in the wing (Fig. 327). p. 277. Ennomid.*. AA. Vein Va of the hind wings present. B. Vein Va of the hind wings arising much nearer to vein Vi than to vein V3 (Fig. 343). Wings usually green, p. 287. GEOMETRIDvE. BB. Vein Va of the hind wings arising nearly midway between veins Vi and Vs or nearer to vein Va than to vein Vi. 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. 273 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. HYDRIOMENIDiE. 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 Vi of hind wings coalesced for a consider- able distance beyond the apex of the discal cell (Fig. 324). p. 273. MONOCTENIID.«. 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. Sterrhidje. 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^e. FF. Fore wings without an accessory cell (Alsofi/ula). p. 273. Monocteniid^e. Family MONOCTENIID^E (Mo-noc-te-ni'i-dae). 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 Notodontidse, according to the observa- tions of Mr. Meyrick. 19 -74 THE STUDY OF INSECTS. In the typical forms, vein Va 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 nis fourth of the discal cell Vl (Fig- 324)- 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 VII, VII, Fig. 324. — Wings of Brephos infatu 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, Brephos 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 wings with reddish orange (Fig. 325). The specimen figured is a male. In the female Fig. 325. — Brephos infans, male. LEPIDOPTERA. 2?$ 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 prob ibly 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 ^76 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 BrcpJios (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, AlsopJdla pometaria (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. ?,-2(>.—Alssf>hiLi pometaria, i o male. moths of both sexes lack the ab- dominal spines characteristic of th<=> Spring Canker-worm. LEPIDOPTERA. 2JJ 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 ha^e 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 Exnomid^E (En-nom'i-dae). The Ennomids (Eri ' 110-mids). Nearly all of the members of this family can be easily recognized as such by the fact that vein V2 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 INSECTS. nizcd by the following combination of characters : Vein V, of the hind wings does not arise much nearer to vein V, than to vein V, (as it does in the Geomet- ridre), 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 V2 of the hind wings; Fig. 327.— Wings of Caripeta angustiorata. jn some of tllOSe in 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 Fig. 328. — EnnomOs magnarius. LEPIDOPTERA. 279 FlG. 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'tis rib-e-a'ri-a). — There are several species of insects that are 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. f.g. ^.-ant-ma catenaria. The chain-dotted Geom- eter, Cingilia catenaria (Cin-gil'i-a cat-e-na'ri-a). — This moth 26o 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 scmiclusaria (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. xxx. — Cleora semiclusaria. i , i n , 111 1 -i 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 cognataria (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 Fic- &*- Bision "*»***"«• larva feeds on various plants, but is found most often on currant. The Lime-tree Winter-moth, Eraiuiis tiliaria (E-ran'nis LEPIDOPTERA. 28l 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 1*879. ) 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 HYDRIOMENIDS (Hyd-ri-o-men'i-dse). The Hydriomenids (Hyd-ri-o-me' nidi). 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 mv VII, rv, 'VII, Fig. 334. — Wings of Eudule mendica. VII, Fig. 335. — Wings of Dyspteris abortivaria. LEP1D0PTERA. 283 discal cell (Fig. 334). The only exception to these char- acters known to us is shown by certain genera (e.g., Heteropk- leps and Dyspteris) in which, owing to a large expansion of the costal area of the hind wings, 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, EncJiceca albovittata (Eu-chce'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, Plemyria hastata (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 speci- 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 undulata (Cal-o-cal'pe un-du-la'ta). — This is a pretty Fig. 336. — Calocalpe undulata. 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 joutside as more food is needed. The leaves die and become brown, and thus render the nest tonspicuous. The larvse 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, Enstroma diversi/zneata (Eus-tro'- 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. — Eustroma diversilineata. Fig. 339. — Eudule ntcndica. 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 V3 and VII,. (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. 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. but the Structure of its willgS shoWS 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 ni3 m hind wings (Fig. 341). In these veins II and III co- X]//Y^^'^ \ 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- dish lines. About one hundred species have been found in this country. F|G. 34I._Wings of Synelys ennucltata. LEPIDOPTERA. 287 Fig. 342. — Hamatopis grataria. The Chickweed Geometer, Hcematopis grataria (Hse- 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 Geometrid^E (Ge-o-met'ri-dae). The Green G comet rids {Ge-om ' c-trids). As a rule the members of this family are bright green in iiij color. And as we have 1 4 but one other common Geometrid {Dyspteris, p. 286) of this color, the family may be well termed v-» the Green Geometrids. vrii The distinctive structure that characterizes this family is the fact that vein V4 of the hind wings arises much nearer to vein V, than to vein V3 (Fig. 343). In this family the tendency to expan- sion of the humeral angle 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 vir Fig. 343.— Wings of Geometra iridaria. * 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, 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^E (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 herminiata (Eu-dei- lin'e-a her-min-i-a'ta). In the form of the body and in the structure of the wings (Fig. 344) the members of this family closely resemble the differs in important respects from the typical members of the family, and may belong elsewhere LEP1D0PTERA. 289 Drepanidae. As in the Drepanidae 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, VIIa Veins 1 1 13 and 1 1 14 COal- Fig. 344.— Wings of Eudeilinea herminiata. *iscing to near the apex of the wing.* Family DREPANIDAE (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 so'.ne species of the Satur- niidse 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 Fig. 345. — Platypteryx arcu ata. * In the Drepanidae veins III2+3 and 1 1 I4-f-s do not coalesre from the apex of the discal eel! outward (Figs. 346 and 347); but veins 1 1 13 and III* 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 Drepanidne (Fig. 346). Although the humeral angle of the hind wings is greatly developed in these moths, some of them retain the frenulum. 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 hpvp '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, Cicinnus). 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 Geometnds. 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 dirty 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 situlifera (P. sic-u-lif'e-ra). Family Cymatophorid^E (Cym-a-to-phor'i-dae). The Cymatophorids {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._r/i>«/*v« scripta. 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 V3 ; while in the hind wing vein V2 arises much nearer to V, than to V,. In the hind wing the subcosta and radius are distinct, and vein Vj 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 larva; arc 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 has fawn-colored front wings, 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 Pseudothyaiira 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 Fig. 349. — Winjjs of Thyatira scripta. LEPIDOP TERA . 2Q$ 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^: (Noc-tu'i-dae). The Ozvlct-motJis or Noctuids (Noc'tii-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 (Noct?ta, 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 (Lymantriidse) the species have pectinate antennae and do not have ocelli. 294 THE STUDY OF INSECTS. Only a few Noctuids have pectinate antennas, 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- jii4 ure 350. Vein V, of s the fore wings arises much nearer to vein V3 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 Va may be either well preserved or much weaker than Fig. 350. — Wings of Agrotis ypsilon. 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. LEPIDOP TEA' A. 29 j 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 in 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. 1 width in its widest part; it lias a narrow subdorsal whitish line and a lateral one of the same color. When ready to transform it' I ether several l and passes the pupa 1 the nest thu ilt(F ig. 35 1 is a blackish- brown moth, with an irregular graj b the outer half of the fore wings, and with very broad hind wings. J he palpi, which arc not well shown in the figure, arc long, wide, and flat- tened ; they project horizontally like a snout. The Hop-vine rlypena, Hypena humuli (H. hu'-mu-li), is do ely allied to the preceding and has often been con- founded with it. The larva feeds on the leaves of hop, and is sometin pest. One of the most abundant of our Deltoids is Pseu* lossa lubr kalis (P lu- bri 1 /lis.) In tin' i speci< | F ig. 352; the fore wingS are thocolate-bi own, err- ith yellowish lines; the hind win much li The palpi arc long; but they are curved over the head, -.0 that they appear short when seen from above, i in the figure. The larva on grass. ■ to the Deltoids there is placed a ■ roup of moths which may be called the Similar-win 'nvlcts, from the fact that both pairs of wings are similarly marked by trans- verse lines. The group includes the lai I of our Noctuids. The two following species will serve to illustrate this Lunate Similar- wing, Ilomoptera lunata (I Io-mop'-te-ra lu-na'ta.) — This is a brownish moth 1. with marbled wings. It varies greatly in its markings. Figure 353 represents a I --* LEF1D0PTERA. 29; variety which has been named tdusOy and which does not show well the lunate mark on the hind wings that probably suggested the name of the species. The larva on the leaves of rose, willow, maple, plum, and other plants. The Black Witch, En ■ Er'e-bus ■ ru\ — The most magnificent in size of our Noctuids is this speci< - Fig. 354). There is much variation in the depth oi coloring. The specimen figured is a female ; in the male the fore wings are more pointed at the apex and the median ban s Fig. 3^4. — i. 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 Colorado, 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. Onlv isolated specimens are found in the North, and these in late summer or autumn. 2Q3 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. 3S5.-ParaZMia6i*tr£aru. wJngS crossed 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. iTi-a ), will serve as an example (Fig. 356). The larvae of the LEP1D0PTEKA. 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. Anions: 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- owlets ; 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 Drasttria erecJitea (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- FlG- zn—OrasUria erecktea. 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- 30o THE STUDY OF INSECTS. Fig. 359 — Acontia camiefacta. trate this group. Chamyris cerintha (Cham'y-ris ce-rin'tha) (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 Fig. 358. — Chamyris cc- in the figure, or this shade may be want- rintha. ing. Ihe larva feeds on the leaves of apple. The second of our illustrations of this group is Acontia candefacta (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 artcmisicefolia. The Boll-worm, Heliotlris armigera (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. 30I Fig. 360. — Plusia simplex. 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. Phi sin simplex (Fig. 360) 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 brassicce (P. bras'si-cae) feeds on cabbage and other Cruciferce. 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 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. FlG. 361. — Aletia argillacea. 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 Cucullia. Figure 362 represents Cucullia speycri (C. spey'er-i). These insects evidently have Fig. 362.— Cucullia sf>eyeri. the power of moving this tuft 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 Compositae. 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 frosted with white along the costa. There is an irregular F'G- 363.— Scoieopuryx matrix. 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, Amphipyra pyramidoides (Am-phip'y-ra pyr-a-mi-doi'des). FlG, 364.— Amphipyra pyramidoides. The fore willgS of this motll (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 malana. 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 Undervving ; 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, Leucania 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. — Leucania unipuncta, larva. 3°4 THE STUDY OF INSECTS. Fig. 367. — Leucania unipuncta. 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 spraying 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 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 F,G- 368.-2?*//*™ gortynides. 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- LEPIDOPTEKA. 305 fied, 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 Fig. 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 21 306 THE STUDY OF INSECTS. 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 Fig. 371.— Noctua c-nigrum. 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, Noctua c-nigrum (Noc'tu-a c-ni'grumj. 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 tnorura. of genera, which contain species that differ 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„. 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 scattered hairs, and has a hump on the first, fourth, and 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 surface of the body instead of growing from tubercles, as with the larvae of Arctiids. Along FlG. 373. — Acronycta americana, larva. 508 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 ™Zt£\g£ ha""" row of milk-white spots along the middle of the back. Family Lymantriid^e (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 Notolophus, 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 pectinated, those of the males LEPIDOPTERA. 309 very broadly so ; the wingless females have serrate or nar- rowly pectinate antennae. The ocelli are wanting. The legs are clothed with _ m _, 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 Wines FlG- 37S —Wings of Notolofhus leucostigma. o of either family that will serve to separate the two. But in the Lymantriidae the antennae 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 antennae 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 Notolophus fly in the daytime. The larvae of our native species are very characteristic in appearance. The body is hairy; there are several con- io 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 — Notolophus and Par orgy ia. In Notoloplius 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 Notoloplius. Our most common species belong to Notoloplius. 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 Fig. 376. — Notolophus leuco- . , . 11111 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. 377. — Notolophus leucostigma, larva. more than a moth. She emerges from her cocoon and after pairing lay.; 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, Notolophus 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, Notolophus 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 Moth, Porthetria dispar (Por-the'tri-a dis'par). — 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 are 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 Fic-i7z.—Portkeiriadis/>ar,ttm3.\c. 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 seventli 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. LEPIDOPTERA. 313 Family AgaristiDjE (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. \wEnthisanotia the antennae are fili- form ; in Alypia slightly enlarged near the tip ; and in PsycJiomorpJia 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 glovert. 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 3T4 THE STUDY OF INSECTS. 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 lar^e 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. 380. — Alypia octo- ° r ° ~ macuuta. 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. lang-to'ni-i), resembles the preceding species in general appearance, but LEPIDOPTERA. 315 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 epimcnis (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 ^-Psvckomorphv 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- 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. lowish olive-green cloud. 316 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, Enthisanotia unio (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 Euphorbia coloratum, 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 ^ggKm* Wood-nymph \ms Moths in their vi strongly contrast- Vi 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). Ourmostcom- mon species be- long to the genus Gnophcsla (G n o- Fig. 384 —Wings of Gnophala hopfferi. phae'la). These are black with conspicuous yellow spots. G. vermiculata LEPIDOPTERA. 317 (G. ver-mic-u-la'ta) occurs in Colorado ; it is represented by Figure 385. G. hop/- feri (G. hopf'fe-ri) is found in California, in the foot-hills of the Sierra Nevadas. It has three yellow spots near the mid- dle of the fore wing, and a transverse row of from three to five spots near the outer margin ; on the hind wings there are two spots near the base and another pair between these and the apex of the Fig. 385. — Gnopk&la veriniculata. wing. Family ARCTIIDiE (Arc-ti'i-dae). The Tiger-moths, or Arctiids (Arc'ti-ids). The Arctiidae includes stout-bodied moths, with moder- ately broad wings, which in the majority of cases are con- spicuously striped or spotted, suggesting the popular name Tiger-moths ; some of the species, however, are unspotted. A large proportion of n ^^^^==-~^ the species are exceed- ingly beautiful ; this renders the family a favorite one with collec- tors. As a rule, when at rest, the wings are folded roof-like upon the body. The moths fly at night, and are at- tracted to lights. These moths differ from the following fam- ily in having ocelli; these are often prominent, at other times they are difficult to see on account of the long hairs with which the head is Fig. 386.— Wings of tlalisidota tessellata. 3i8 THE STUDY OF INSECTS. clothed. The palpi are short, usually but little developed; and the maxillae are present. The most important features in the venation of the wings (Figs. 386, 387) is the union of veins Va and V, of the fore wings with cubitus, making it apparently four-branched ; and the growing together of subcosta and radius of the hind wings for a considerable distance. The extent of the union of these two veins varies greatly in the different genera ; but so far as we have ob- served it is always less m2 rn3 w4 rrr, IT 4 711, than four fifths of the length of the discal cell. This character is of use in separating these insects from the Zygaenidae in which the union of these two veins is carried farther. The larvae of the Tiger-moths are clothed with dense clusters of hairs. In fact a large proportion of our com- mon hairy caterpillars are members of this of the clusters of hairs are much larger than the others, resembling in this respect the clothing of the Tussock-moths. Most larvae of the Arctiids feed upon herbaceous plants, and many species seem to have but little choice of food-plant ; but certain common species feed upon leaves of forest- trees. About one hundred and fifty North American species have been described. The following are some of the more common representatives. Among the more beautiful of the Tiger-moths is a genus the species of which are snow-white or light yellow with the Fig. 387. — Wings of Pygoctenucha funerea. family. In some species, certain LEPIDOP 1EKA. 319 fore wings banded with dark brown. In most species the hind wings are unspot- ted and are snow- white, but in some the hind wings are yellow. These moths constitute the genus Haploa (Hap'lo-a). A species common in the Atlantic States and rep- F,G' resented by Figure 388 is Haploa contigua (H. con-tig'u-a). The insects of this genus vary greatly in their markings. The Bella-moth, Utetheisa bella (U-te-thei'sa bel'la) is a .whitish moth with lemon-yellow or orange-colored fore wings, crossed by six transverse white bands, each containing a series of black dots (Fig. 389); the hind wings are pink, with a black outer margin, which is bordered within by a narrow white line. The species occurs throughout the Atlantic States. The Harlequin Milkweed Cater- pillar, Cycnia egle (Cyc'ni-a eg'le). — This larva is the most common cat- erpillar found on milkweed. It is clothed with tufts of orange, black, and white; those at each end of the body are longer than the others, and are arranged radiately (Fig. 390). When full grown Fig. 389.— Utetheisa bella. Fig. 390. — Cycnia egle, larvi 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 caryce (Ha-I:s-i- do'ta ca'ry-ae). — One of the most abundant of caterpillars in the Atlantic States and westward during the months of August and September is one clothed with dense tufts of finely barbed white hairs (Fig. 391) ; there is a ridge or crest Fig. 391. — Halisidota caryee > larva. of black hairs on the middle of the back of the abdominal segments, a few long white hairs projecting over the head from the thorax, and others projecting back from the last seg- ment ; there are also two pairs of pencils of black hairs, one on the first and one on the seventh abdominal segment, and a similar pair of pencils of white hairs on the eighth abdominal segment. This larva feeds on hickory, butternut, and other forest-trees. Its grayish cocoons, composed almost entirely of the hair of the larva, are often found under stones, fences, and other similar places. The fore wings of the adult (Fig. 392) are dark brown spotted with white. Fig. 392. — Halisidota caryte. LEPIDOP TERA. 3 2 1 The Salt-marsh Caterpillar, Estigmene acrcea (Es-tig-me'ne a-crde'a). — The popular name of this insect was given to it by Harris, and was suggested by the fact that the salt- marsh meadows about Boston were overrun and laid waste in his time by swarms of the larvae. But the name is mis- leading, as the species is widely distributed throughout the United States. The moth (Fig. 393) is white, marked with yellow and black. There are many black dots on the wings, a row of black spots on the back of the abdomen, another row FlG- 393-— £**'*»"** *<*<"*- on the venter, and two rows on each side. The sexes differ greatly in the ground-color of the wings; in the female, this is white throughout ; in the male, only the upper surface of the fore wings is white, the lower surface of the fore wings and the hind wings above and below being yellow. The num- ber and size of the black spots on the wings vary greatly. There are usually more submarginal spots on the hind wings than lepresented in our figure. The Fall Web-worm, Hyphantria cunea (Hy-phan'tri-a cu'ne-a). — Avery common sight in autumn in all parts o. our country is large ugly webs enclosing branches of fruit or forest trees. These webs are especially common on apple and on ash. Each web is the residence of a colony of larvae which have hatched from a cluster of eggs, laid on a leaf by a snow-white moth. There is a variety of this moth in which the fore wings are thickly studded with dark brown spots. Every gradation exists between this form and those thac are spotless. The species winters in the pupa state, and the moths emerge during May or June. The webs made by this insect should not be confounded with those made by the Apple-tree Tent-caterpillar The webs of the Fail Web-worm are made in the autumn, and 00 322 THE STUDY OF INSECTS. are much lighter in texture, being extended over all of the leaves fed upon by the colony. The Isabella Tiger-moth, Pyrrharctia Isabella (Pyr-rharc'- ti-a is-a-bel'la). — "Hurrying along like a caterpillar in the fall" is a common saying among country people in New England, and probably had its origin in observations made upon the larva of the Isabella Tiger-moth. This is the evenly clipped, furry caterpillar, reddish brown in the middle and black at either end, which is seen so commonly in the autumn and early spring (Fig. 394). Its evident haste to get somewhere, in the autumn, is almost painful to witness. A nervous anxiety B^ is apparent in every undulat- FlG. 1Q4.— Pyrrharctia isabella. larva. • . r • , i t 3y4 ' nig movement of its body; and frequently its shining black head is raised high in the air, and moved from side to side, while it gets its bearings. Occasionally after such an observation it evidently finds it is mistaken, and turns sharply and hastens along faster than ever in another direction. So far as we can judge, its ex- citement comes from a sudden fear that winter will over- take it before it can find a cosy, protected corner in which to pass its winter sleep. In the spring it comes forth again, and after feeding for a time makes a blackish-brown cocoon composed largely of its hair. The adult is of a dull grayish tawny-yellow, with a few black dots on the wings, and fre- quently with the hinder pair tinged with orange-red. On the middle of the back of the abdomen there is a row of about six black dots, and on each side of the body a similar row of dots. The Yellow-bear, Spilosoma virginica (Spil-o-so'ma vir- gin'i-ca). — The larva of this species is one of the most com- mon hairy caterpillars found feeding on herbaceous plants. It was named by Harris the Yellow-bear on account of the long yellow hairs with which the body is clothed. These hairs are uneven in length, some scattered ones being twice LEPIDOPTRRA. 32$ as long as the greater number of hairs. The long hairs are more numerous near the caudal end than elsewhere, but are nowhere gathered into pencils as with the Tussock-cater- pillars. This larva varies greatly in color. The body is most often of a pale yellow or straw color, with a black, more or less interrupted, longitudinal line along each side, and a more or less distinct transverse line of the same color be- tween each of the segments. Sometimes the hairs are foxy red or light brown, and the body brownish or even dark brown. The head and the ends of the feet and forelegs are yellowish, and the venter is dusky. The larva feeds on almost any plant. The cocoon is light, and is composed almost entirely of the hairs of the caterpillar. This insect passes the winter in the pupa state ; and it is probable that there are usually two or more broods each year ; but these are not well marked. The moth (Fig. 395) is snowy white, with the wings marked by a few black dots ; these vary in num- ber, but there are rarely more than three on either wing. There is a row of black spots on the back of the abdomen, and another on each side, and between these a longitudinal deep yellow stripe. A very large number of species of Tiger-moths belong to the genus Eyprepia (Ey-pre'pi-a). These are perhaps the most striking in appear- ance of all members of the family. The fore wings are velvety black marked with F.G.396^*"/t« virgo. yellowish or pink bands ; in some species the lighter color predominates, so that the fore wings appear to be yellow or pink, spotted 1 Fig. 395 — Spilosoma virginica. 324 THE STUD V OF INSECTS. with black. The hind wings are red, pink, or yellow, and are margined or spotted with black. The thorax is usually marked with three black stripes, of which the lateral ones are borne by the patagia. There is also a black line or a row of black spots along the middle of the back of the ab- domen, and a similar row of spots on each side. Our most common species of this genus is Eyprepia virgo (Fig. 396). The larva of this species feeds on pigweed and other un- cultivated plants. Family LlTHOSIID^ (Lith-o-si'i-dae). The Footman-mot lis or Lithosiids {Li-tho si-ids). The Lithosiidae include small moths with rather slender bodies, filiform antennae, and usually narrow front wings and broad hind wings. As a rule they are closely scaled insects of sombre colors, a fact that has won for them the title of Footman-moths; but in case of some of the species their livery is very gay. Some species fly by day, while others are attracted to lights at night. This family is closely allied to the Arctiidae ; in fact it is sometimes difficult to tell to which of these families a species belongs. Usually the Footman-moths can be distinguished by the absence of ocelli ; but some species possess very small ones. The palpi are small or moderately developed; the maxillae are present and quite well developed. The vena- tion of the wings differs greatly in the different genera ; but in its more important features it resembles that of the Arc- tiidae. The larvae, are cylindrical and covered with short, stiff hairs. The majority of the species whose transformations are known feed upon lichens. They transform in very deli- cate cocoons or have naked pupae. Among our more com- mon species are the following: — The Pale Footman, Crambidia pallida (Cram-bid'i-a pal'- li-da. — This moth is of a uniform drab color, with the abdo- men and the inner part of hind wings paler ; it expands nine LEPIDOPTERA. 3^5 tenths of an inch. The moths of the genus Crambidia can be recognized by the fact that veins V, and V3 of the fore wings are both wanting, leaving cubitus only two-branched. The Two-colored Footman, Lithosia bicolor (Li-tho'si-a bi'co-lor). — This is larger than the preceding species, expand- ing from one to one and one half inches. It is slate-colored, with the palpi, the prothorax, the costa of the fore wings, and the tip of the abdomen yellow. Vein V, of the fore wings is wanting, leaving cubitus apparently three-branched The Striped Footman, Hypoprepia miniata (Hy-po-pre' pi-a min-i-a'ta). — This beautiful moth is of a deep scarlet color, with three broad lead-colored stripes on the front wings. Two of the stripes extend the entire length of the wings; while the third is between these and extends from the end of the discal cell to the outer margin (Fig. 397). The outer half of the hind wings is also slate-colored. Vein V3 of the fore wings is pres- FlG- 397.-^/'/™//* miniata. ent ; but vein V, of the hind wings is wanting. The larva feeds upon lichens, and may be found under loose stones or on the trunks of trees. It is dusky, and thinly covered with stiff, sharp, and barbed black bristles, which grow singly from small warts. The cocoon is thin and silky. The Painted Footman, Hypoprepia fucosa (Hy-po-pre'pi-a fu-co'sa). — This species is very similar to the preceding and has been confounded with it. With the Fainted Footman the ground-color of the fore wings is partly yellow and partly red. The Clothed-in-white Footman, Clemensia albata (Cle- men'si-a al-ba'ta). — The specific name of this insect is some- what misleading ; for although the general color of the moth is white, there are so many ashen and gray scales, and dark spots, that the general effect is gray. On the front wings the more prominent black spots are six or seven on the costa, one on the discal vein, and a row of small ones on the 126 THE STUDY OF INSECTS. outer margin. The hind wings are white, but finely dusted with gray scales. With this species vein V, is present ii» both fore and hind wings. The Banded Footman, Cisthene unifascia (Cis-the'ne u-ni-fas'ci-a). — This little beauty (Fig. 398) occurs in the Atlantic States from New York to Texas. The fore wings are lead-colored, and crossed by a Fig s— cisthene yeU°w band, which extends also along the inner uni/ascia. margin to the base of the wings. The hind wings are pink except the apex, which is lead-colored. There is much variation in the width of the yellow band. in. Family Zyg.enid^e (Zy-gaen'i-dae). The Zygcenids (Zy-gce' nids). These moths are most easily distinguished from the allied families that are rep- resented in this coun- m, try by the structure of the hind wings. Here we find the tendency of veins II and III to coalesce carried to the great- est extreme, aiey being joined clear to the margin of the wing (Fig. 399); oc- casionally forms are found in which the tips of these two veins are separate for a short distance near the apex of the wing; Fig. 399— Wings of Ctenucha virginica. and usually they are separated for a short distance near tht base of the wing, as shown in the figure. In some of the more 11 + in LEPIDOP TERA. 327 specialized forms, as Cosmosoma (Fig. 400), the hind wings are greatly reduced in size, and the branches of radius and cubitus coalesce to a remarkable degree. To the first division of this family belong a small number of bluish-black or brown moths which have more or less vermilion U,i 1 1 4-U^.. .,. Fig. 400. — Cosmosoma auge. ow on the head, prothorax, * and patagia. These moths are of medium size, expanding from one and one fifth to two inches. The dull color of the wings is usually relieved by the bright color of the head and patagia, and by a layer of blue scales covering the thorax and abdomen ; but in some species these are wanting. The larvae feed on grasses. Some of them strongly resemble those of the Arctiidae in appearance as well as in habits, being thickly clothed with hair; they also spin cocoons simi- lar to those of Arctiids. Our common forms represent two Fig. 401. — Cic/iui/ui virginica. Fig. 402 — Scepsis fzilvicollis. genera, CtenncJia (Cte-nu'cha) and Scepsis (Scep'sis). In the East we have only a single species of each of these genera, Ctennclia virginica (C. vir-gin'i-ca), which is represented by Figure 401, and Scepsis fulvicollis (S. ful-vi-col'lis), repre- sented by Figure 402. The second division of the family includes a much larger number and a much greater variety of forms. Our most common species is Lycomorpha pholus (Ly-co-mor'pha pho'lus). This is black with the basal half of the fore wings and the basal third of the hind Fig. 403 — Lycomorpha pholus. 128 THE STUD V OF INSECTS. wings yellow (Fig. 403). A variety of this species occurs in California in which the lighter parts of the wings are pinkish instead of yellow. These moths occur in stony places, where the larvae feed on lichens growing on rocks. In the extreme southern part of our country and in the regions south of that, there occur highly specialized mem- bers of this family, in which the hind wings are greatly re- duced in size, and the veins of the hind wings coalesce to a remarkable degree. In some of these forms the discal por- tion of the wings bears but few if any scales. Cosmosoma aicge (Cos-mo-so'ma au'ge) from Florida (Fig. 400) will serve as an example of these. In this species the body and legs are bright red, with the head, end of abdomen, and a dorsal band blue-black ; the veins and borders of the wings are also black. Family Thyridid^e (Thy-rid'i-dae). The Windoiv-winged Moths. These little moths can be easily recognized by the presence of curious white or yellowish translucent spots upon the wings ; it is these spots that suggests the name Window- winged Moths for the family. In this family the antennae are either strictly filiform or slightly thickened in the middle; L5 the ocelli are wanting ; the palpi |v, project horizontally, and are 'vn, somewhat longer than the head ; and the maxillae are strongly developed. The venation of the wings differs from that of all other families of moths, in that all five branches of radius of the fore wings are preserved and arise X1 "ix from the discal cell (Fig. 404).* Fig. 4o4.-Wings of ThyrU maculata. J\ Sjmjlar type of venation is * In a single genus of the Pyromorphidae, Triprocris (p. 227, Fig. 268), all the branches of radius arise from the discal cell. LEPIDOPTERA. 329 possessed by the Skippers (Hesperina); but the Window- winged Moths differ from the Skippers in having a well- developed frenulum. The early stages of our species are not known ; but the larva of a European species lives upon the leaves of Cle- matis, which it rolls like a Tortricid. Tin's larva is said to appear like that of a Chrysomelid beetle. It descends to the surface of the ground and makes a dense silken cocoon, more or less mixed with grains of sand. The most common representative of this family in the Eastern and Middle States is the Spotted Thyris, Thyris metadata (Thy'ris mac-u-la'ta). This species (Fig. 405) is brownish black, sprinkled with rust- yellow dots; the outer margin of the wings, especially of the hind wings, is deeply scalloped, 1 y o ' i J r 1 Fig. 405. — Thyrn. with the edges of the indentations white. macuiata. There is on each wing a translucent white spot ; that of the hind wing is larger, kidney-shaped, and almost divided in two. This species occurs also in the West, as there are specimens from Montana in the Cornell University collection. The Mournful Thyris, Thyris lugubris (Thy'ris lu-gu'bris), is a larger species found in the Southern States. It can be recognized by Figure 406, It is brownish black, marked with yellow, Fig 406— Thyris and with the translucent spots yellowish. lugubris. x J Family SPHINGID^: (Sphin'gi-dae). The Hawk-moths or Sphinxes. Hawk-moths are easily recognized by the form of the body, wings, and antennae. The body is very stout and spin- dle-shaped ; the wings are long, narrow, and very strong ; the antennae are more or less thickened in the middle or towards the tip, which is frequently curved back in the form of a hook ; rarely the antennae are pectinated. The sucking-tube (maxillae) is usually very long, being in some instances twice 33° THE STUD Y OF INSECTS. as long as the body; but in one subfamily it is short and membranous. When not in use it is closely coiled like a watch-spring beneath the head. None of the species have ocelli. The venation of the wings (Fig. 407) is quite character- istic ; the most distinctive feature is the presence of what Fig. 407. — Wings of Pklegethontius celeus. appears to be a cross-vein between subcosta and radius ot the hind wing. This apparent cross-vein is due to the fact that veins II and III are grown together for a short distance, and then vein II separates and joins vein I. The obvious presence of vein I in the hind wings is unusual ; but it occurs in the Psychidae, in the Bombycidae, and in the Anthroceridae (a family not represented in our fauna) also. This basal part • of vein I is probably preserved in other cases where it appears to be the base of vein II. Thus in CitJieronia (Fig. 417) there :s a rudiment of the so-called cross-vein, which has entirely disappeared in tho more specialized forms of the family to LEPID OP 1 ERA . 331 which this genus belongs. In the Hawk-moths the frenu lum is usually well preserved, but in a few it is wanting or rudimentary. In many genera vein III, of the fore wings coalesces with vein III, to its tip, so that vein III is only four-branched. Some of the Hawk-moths are small or of medium size ; but most of them are large. They have the most powerful wings of all Lepidoptera. Asa rule they fly in the twilight, and have the habit of remaining poised over a flower while extracting the nectar, holding themselves in this position by a rapid motion of the wings. This attitude and the whir of the vibrating wings gives them a strong resemblance to hum- ming-birds, hence they are sometimes called Humming-bird Moths ; but they are more often called Hawk-moths, on ac- count of their lone, narrow wings and strong flight. Of all the beautifully arrayed Lepidoptera some of the Hawk-moths are the most truly elegant. There is a high-bred tailor-made air about their clear-cut wings, their closely fitted scales, and their quiet but exquisite colors. The harmony of the combined hues of olive and tan, ochre and brown, black and yellow, and grays of every conceivable shade, with touches here and there of rose color, is a perpetual joy to the artistic eye. They seldom have vivid colors except touches of yel- low or pink on the abdomen or hind wings, as if their fas- tidious taste allowed petticoats only of brilliant colors always to be worn beneath quiet-toned overdresses. The larvae of the Sphingidae feed upon leaves of various plants and trees, and are often large and quite remarkable in appearance (Fig. 408). The body is cylindrical and naked and usually has a horn behind near the end of the body on the eighth abdominal segment. Sometimes instead of the horn there is a shiny tubercle or knob. We cannot even guess the use of this horn, unless it is ornamental, for it is never provided with a sting. These caterpillars when resting rear the front of the body up in the air, curl the head down in the most majestic manner, and remain thus 332 THE STUDY OF INSECTS. rigid and motionless for hours. When in this attitude they are supposed to resemble the Egyptian Sphinx, and so the typical genus was named Sphinx and the family the Sphingidae. But we think they deserve the name independently of their habits because of the riddle they constantly propound to us as to why they wear this horn on the rear end of the body instead of on the head, where it ought to be in order to be of Fig. 408.— Sphinx ckersis, larva. any use whatever as a horn. These caterpillars are usually of some shade of green and often are ornamented with a series of diagonal stripes along each side. Most species pass the pupa state in the ground in simple cells made in the earth ; some, however, transform on the surface of the ground in imperfect cocoons composed of leaves fastened together with silk. Nearly one hundred species of Hawk-moths occur in this country. The following are some of the more common ones. LEP1D0PTERA. 333 The Modest Sphinx, Marumba modesta (Ma-rum'ba mo des'ta). — It was, probably, the quiet olive tints in which the moth is chiefly clothed that suggested the name modesta for it, but it is one of the most beautiful of our Hawk-moths. The body and basal third of the fore wings are pale olive; the outer third of the fore wings is a darker shade of the same color ; while the middle third is still darker (Fig. 409). FlG. 409 ■ — Marumba modesta. The hind wings are dull carmir.e-red in the middle ; there is a bluish-gray patch with a curved black streak over it near the anal angle. The larva feeds on poplar and cotton- wood. When full grown it is three inches long, of a pale green color, and coarsely granulated, the granules studded with fine white points, giving the skin a frosted appearance. The Twin-spotted Sphinx, Smerinthus geminatus (Sme- rin'thus gem-i-na'- tus). — This exquis- itely colored moth expands about two and one half inches. The thorax is gray with a velvety dark brown spot in the .... „, - Fig. 410.— Smerinthus geminatus. middle. I he fore wings are gray, with a faint rosy t;nt in some specimen:. 334 THE STUDY OF INSECTS. and tipped and banded with brown as shown in Figure 410. The hind wings are deep carmine at the middle, and are bordered with pale tan or gray. Near the anal angle there is a large black spot in which there is a pair of blue spots, which suggested the name geminatus. The larva feeds upon the leaves of apple, plum, elm, ash, and willow. Harris's Sphinx, Ellema harrisii (El-le'ma har-ris'i-i). — This sphinx has interested us chiefly on account of the habits and markings of its larva (Fig. 411). It feeds upon the foliage of pine, and is colored with alternating green and white longitudi- nal strips ; the dorsal stripe is green spotted with red. It has a way of hanging head downward in a pine tas- sel that conceals it entirely from the sight of all but very sharp eyes, its stripes giving a close resemblance to a bunch of pine leaves. The moth ex- pands about two inches ; it is gray with the fore wings marked by several series of small brown spots. The Pen marked Sphinx, Sphinx chersis (Sphinx cher'sis). — This moth is of an almost evenly distributed ashy- gray color. This sombre color is relieved somewhat by a black band on each side of the abdomen, marked with four or five white transverse bars ; by two dark brown, smoky bands which cross the hind wings ; and by a series of black dashes on the fore wings, one in each cell between the apex of the wing and the anal vein. These dashes appear as if drawn casually with a pen. The larva (Fig. 408) is not uncommon upon ash and lilac ; it is greenish or bluish white above, and darker below ; there are seven oblique yellow bands on the sides of the body, each edged Fig. 411. — Ellema harrisii, larva. LEPID OP TEKA . 355 above with dark green. When disturbed it assumes the threatening attitude shown in the figure. The Tomato-worm, Phlegethontius celeus (Phleg-e-thon'- ti-us ce'le-us). — This larva is the best known of all our Sphinxes, as it ma)- be found feeding on the leaves of tomato, tobacco, or potato wherever these plants are grown in our country. It resembles in its general appearance the larva of Sphinx dicrsis (Fig. 408); but its favorite attitude is with the fore end of the body slightly raised. It is usu- ally green, but individuals are often found that are brown, or even black. There appear at frequent intervals in the newspapers accounts of people being injured by a poison excreted by the caudal horn of this larva ; but there is absolutely no foundation whatever for such stories. The pupa (Fig. 412) is often ploughed up in gardens, and attracts attention on account of its curious tongue-case, which is free, resembling the handle of a pitcher. The moth is a superb creature, expanding four Fig. v,.-pa or five inches. It is of many delicate shades of ash-gray, marked with black or very dark gray ; there are a few short black dashes on the fore part of the thorax, and some irregular black spots edged with white on the posterior part ; the abdomen is gray with a black middle line, and five yellow, almost square spots along each side. Each of these spots is bordered with black, and has a white spot above and be- low, on the edge of the segment. The hind wings are crossed by four blackish lines, of which the two interme- diate are zigzag. The Tobacco-worm, Phlegethontius Carolina (Phleg-e-thon'- ti-us car-o-li'na). — This species closely resembles the preced- ing, and the two are often mistaken the one for the other. The larvae have similar habits, feeding on the same plants. But the moths are easily distinguished. This species is brown- 33& THE STUDY OF INSECTS. isli gray instead of ashy gray; at the end of the discal cell of the fore wings there is a distinct white spot; and the two dark bands crossing the middle of the hind wings are not zigzag, and are less distinctly separate ; often they are united into a single broad band. The Hog-caterpillar of the Vine, Ampelophaga myron (Am-pe-loph'a-ga my'ron). — There is a group of Hawk moths the larvae of which have the head and first two thoracic segments small, while the two following segments are greatly swollen. These larvae from a fancied resemblance to fat swine have been termed Hog-caterpillars; and the present species, which is common on grape, has been named the Hog-caterpillar of the Vine. It is a comparatively small species, the full-grown larva being but little more than two inches long. There is a row of seven spots varying in color from red to pale lilac, each set in a patch of pale yellow, along the middle of the back. A white stripe with dark green margins extends aloncj the side from the head to the caudal horn, and be- riG. 473. — Ampclopliaga myron, larva with cocoons of parasites. ]QW ^jg are seVen oblique stripes. This larva is often infested by Braconid parasites; and it is a common occurrence to find one of them with the cocoons of the parasites attached to it (Fig. 413). The pupa state is passed on the surface of the ground within a rude cocoon made by fastening leaves together with loose silken threads. The adult expands about two and one fourth inches. The fore wings are olive-gray, with a curved, olive-green, oblique band crossing the basal third, a discal point of the same color, and beyond this a large triangular spot with its apex on the costa and its base on the inner margin. The Pandorus Sphinx, Philampclus pandoras (Phi-lam'pe- lus pan-do'rus). — This magnificent moth expands from four to four and one half inches. The ground-color of its wings I LEP1DOPTEKA, 337 is pale olive, verging in some places into gray ; the markings consist of patches and stripes of dark, rich velvety olive, sometimes almost black (Fig. 414). Near the inner margins of both pairs of wings the lighter color shades out into pale yellow, which is tinged in places with delicate rose-color. Fig. 414 — Philampelus pandorus. These markings show a harmony of contrasting shades rarely equalled elsewhere by nature or art. The larva is one of the Hog-caterpillars. It feeds upon the leaves of Virginia-creeper. When young it is pinkish in color, and has a long pinkish caudal horn; as it matures it changes to a reddish brown, and the horn shoitens and curls up like a dog's tail and finally disappears, leaving an eye-like tuber- cle. The caterpillar has on each side six cream-colored oval spots, enveloping the spiracles. The White-lined Sphinx, Deilepliila lineata (Dei-leph'i-la lin-e-a'ta). — This moth can be easily recognized by Figure 415. Its body and fore wings are olive-brown; there are three parallel white stripes along each side of the thorax ; the outer one of these extends forward over the eyes to the base of the palpi ; on the fore wings there is a buff stripe extending from near the base of the inner margin to the apex, and veins 1 1 1& to IX are lined with white; the hind 23 338 THE STUDY OF IX SECTS. wings are black with a central reddish band. The larva is extremely variable in color and markings. It feeds on many plants, among which are apple, grape, plum, and currant. Fig. 415. — Deilepliila lineata. The Thysbe Clear-wing, Hemaris tJtysbe (He-ma'ris thys'be). — There is a group of Hawk-moths that have the middle portion of the wings transparent, resembling in this respect the Sesiidae and certain Zygaenids; but they are easily recognized as Hawk- moths by the form of the body, wings, and antennae. One of the more common of these is the Thysbe Clear- wing (Fig. 416). The scaled portions of the wings are of a dark reddish brown ; but this Fig. 416. — Hemaris thysbe. • • -i j- .; 4 species is most easily distin- guished from our other common species by a line of scales dividing the discal cell lengthwise and representing the po- sition of the base of vein V. The larva of this species feeds on the different species of Viburnum, the snowberry, and hawthorn. The Bumblebee Hawk-moth, Hemaris diffinis (He-ma'ris dif-fi'nis). — This Clear-wing appears to be about as common LEPIDOPTERA. 339 as the preceding, and resembles it somewhat. It lacks, however, the line of scales in the discal cell, and the body is more nearly yellow. This color probably suggested the name Bumblebee Hawk-moth, given to this insect nearly one hundred years ago by Smith and Abbot. The larva feeds on the bush honeysuckle {Diervilla) and the snow- berry (Symphoricarpus). Superfamily SATURNIINA (Sa-tur-ni-i'na). The Satumians {Sa-tur' ni-ans). The group of families constituting the superfamily Sa- turniina includes the largest of our native moths ; in fact nearly all of our very large moths belong to it ; but it also includes a considerable number of species of moderate size. These moths are most easily distinguished from other moths by the structure of the wings (Fig. 417). Here, as with the Skip- pers and the Butterflies, the frenulum is lost (or nearly so in the low- est family), and its place is taken by a greatly ex- panded humeral angle of the hind wing, which, projecting under the fore wing, insures the acting together of the two in flight without the aid of a frenulum. This losing of the frenulum is also characteristic of the Lasiocampidae. But the Saturnians differ Fig. 417. — Wings of Citkeronta regahs, from this family in that vein Va arises midway between radius and cubitus, or is 340 THE STUDY OF INS EC 7 6. more closely united to radius than to cubitus, leaving the latter apparently three-branched ; while in the Lasiocampidae cubitus appears to be four-branched. This superfamily includes the Bombycidoe which are represented in this country only by the Chinese Silkworm and three families of native moths. These can be separated by the following table : — A. Vein V2 of the fore wings arising midway between veins V! and V3. p. 340 . Bombycidoe. AA. Vein V2 of the fore win^a arising nearer to vein Vi than to vein V3. B. Hind wings with two anal veins. C. The stalk of veins Vj and V2 of the fore wings separating from radius before the end of the discal cell (Fig. 420, c. v.). p. 342 Hemileucidje. CC. Vein Vi of the fore wings separating from radius beyond the apex of the discal cell. D. Veins Vi and Vaof the hind wings joined to radius by a dis- tinct Stalk (Fig. 417, C. V.). p. 343 ClTHERONIIDiE. DD. Vein Vi and Va of the hind wings not stalked (Co/oradia). p. 350 Saturniidoe. BB. Hind wings with only one anal vein. p. 350. . .SaturniiDjE. Family Bombycid^: (Bom-byc'i-dse). The Silk-worm. The Bombycidae as now restricted are not represented in our fauna ; but a single species, the Silk-worm, is frequently bred in this .^Jh-'HH I country, and is usually as#^^p'"';1^^i^*^SB I present in collections of ■J-^lKx^B^^^ Lepidoptera. kVMl'BdS'^mvC^m The Silk-worm, Bombyx ]$>,WL: \j*M I mori (Bom'byx mo'ri). — The moth (Fig. 418) is of a Fig. ^a.- Bombyx mori. cream-color with two or three more or less distinct brownish lines across the fore LEP1D0P TEA' A. 341 wings and sometimes a faint double bar at the end of the discal ceil. The head is small ; the antennae are pectinated broadly in both sexes ; and the ocelli, palpi, and maxillae are wanting. The abdomen and thorax are densely clothed with woolly hair. The distinctive feature in the venation of the wings (Fig. 419) is the obvious presence of vein I on the hind wings. The usual food of the Silk-worm is the leaf of the mul- berry. Our native species, however, are not suitable. The species that are most used are the *s s /CT3 white mulberry (A for us alba), of which there are several varieties, and the black mul- berry {Morns ni- gra); the former is the better. The leaves of osage orange {Madura aurantiacd) have also been used as silk-worm food to a considerable ex- tent. In case silk- worms hatch in the springbefore either mulberrv or osage- orange leaves can be obtained, they may be quite SUC- F'G- 4ig.— Wings of Bombyx mori. cessfully fed, for a few days, upon lettuce-leaves. The newly-hatched larva is black or dark gray, and is covered with long stiff hairs, which spring from pale-colored tubercles. The hairs and tubercles are not noticeable after vin 342 THE STUDY OF INSECTS. the first molt, and the worm becomes lighter and lighter, until in the last larval period it is of a cream-white color There is a prominent tubercle on the back of the eighth ab- dominal segment, resembling those borne by certain larvae of the Sphingidae. There are many special treatises on this insect, some of which should be consulted by any one intending to raise silk- worms. Family Hemileucid;e (Hem-i-leu'ci-dse). The Hemileucids (Hem-i-lcu'cids). This is a small family containing rather large and con- spicuously marked insects. The antennae are broadly pec- tinated in the males and narrowly so or nearly serrate in the females. There is only a single pair of teeth to each segment of the antennae. The thorax and abdomen are usually thickly clothed with long woolly hair; but in some species the cloth- ing of the antennae is less woolly and more scale-like. As to the wings, the frenu- lum is wanting, the humer- al angle of the hind wings being largely developed (Fig. 420) ; and in both fore and hind wings veins Vi and V2 are joined to radius by a common stalk. Our best-known repre- sentative is the Maia-moth, Hemileuca mala (Hem-i-leu'ca ma'i-a). In this species (Fig. 421) the wings are thinly scaled, sometimes semi-transparent', FlG. 420. — Wings of Hemileuca maia. Plate IV. LEPIDOPTERA. 343 they are black with a common white band near their middle ; and the discal veins are usually white and broadly bordered with black. There are great variations in the width of the white band on the wings. The larva feeds on the leaves of oak ; it is brownish black, with a lat- F,G *"-m eral yellow stripe ; and is armed on each segment with large branching spines. This species pertains to the eastern part of the continent ; but there are several western species belonging to the genus. In the West there occur also two species of the genus Pseudohasis | Pseu-do-ha'zis |. These are P. Jura \ P. he'ra), in which the ground-color of the wings is white i^Plate IV), and P. eglanterina (P. eg-lan-te-ri'na), in which the ground-color is brown. Both species are spotted and striped with black. In each the abdomen is ringed with black; there is a large discal spot on each wing, which frequently has a white center due to white scales borne by the discal vein. The base of the wings is dusky. There is a transverse band at the end of the basal third, which is sometimes wanting on the hind wings ; and a broader, wavy, transverse band crossing both wings at the end of the basal two thirds ; and on each wing there is a series of six or seven triangular black spots situ- ated on the ends of the veins, at the outer margin of the wing. It should be said that both in the ground-color and in the markings these two forms vary much ; and it is possi- ble that they are merely varieties of one species. Family ClTHERONIlD.E < Ci:h-e-ro-ni'i-dae). The Royal-mot lis. The Royal-moths are stout-bodied and hairy, with sunken heads and strong wings. The species are of medium or large 344 THE STUDY OF INSECTS. size, some of them being nearly as large as the largest of our moths. The most obvious character limiting this family is the structure of the antennae of the male. These agree with those of the Saturniidae in having two pairs of teeth to each segment, but differ in being pectinated for only a little more than half their length. These moths also differ from most Saturniidae in having two anal veins in the hind wings. Al- though the antennae of the male are broadly pectinated, those of the female are filiform. The palpi and maxillae are very small. The thorax and abdomen are densely clothed Fig. 422. — Wings of Citheronia regalis. FlG. 423. — Wings of Anisota virgi-f with long hairs. The wings are strong, with prominent veins. The frenulum is wanting, and the humeral angle of the hind wings is very largely developed. In the fore wings vein V, arises from the discal vein (Figs. 422, 423). The larvae are armed with horns or spines, of which those on the second thoracic segment, and sometimes also LEP1DOP TERA* US 8 "to G I M 346 THE STUDY OF INSECTS. those on the third, are long and curved. These caterpillars eat the leaves of forest-trees, and go into the ground to trans- form, which they do without making cocoons. The rings of the pupa bear little notched ridges, the teeth of which, to- gether with some strong prickles at the hinder end of the body, assist it in forcing its way upwards out of the earth. This is a small family ; it is not represented in Europe, and less than twenty species are known to occur in this country. The more common ones are the following : — The Regal-moth, Citheronia regalis (Cith-e-ro'ni-a re-ga'- lis). — This is the largest and most magnificent of the Royal- moths (Fig. 424). The fore wings are olive-colored, spotted with yellow, and with the veins heavily bordered with red scales. The hind wings are orange-red, spotted with yellow, and with a more or less distinctly marked band outside the middle olive. The wings expand from four to six inches. When fully grown the larva measures from four to five inches in length. It is our largest caterpillar, and can be readily recognized by the very long spiny horns with which it is armed. Those of the mesothorax and metathorax are much longer than the others. Of these there are four on each segment; the inte. mediate ones measure about three fifths inch in length. This larva feeds on various trees and shrubs. The Imperial-moth, Basilona imperialis (Bas-i-lo'na im- pe-ri-a'lis). — This moth rivals the preceding species in size, expanding from four to five and one half inches. It is sulphur-yellow, banded and speckled with purplish brown. The full-grown larva (Fig. 425) measures from three to four inches in length. It is thinly clothed with long hairs, and bears prominent spiny horns on the second and third thoracic segments. In the early larval stages these thoracic horns are very long and spiny, resembling those of the larva of the Regal-moth. The larva feeds on hickory butternut, and other forest-trees. The Two-colored Royal-moth, Spliingicampa bicolor LEPIDOPTERA. 347 (Sphin-gi-cam'pa bi'co-lor). — In this species the upper side of the fore wings and the under side of the hind wings are yellowish brown, speckled with black. The under side of the fore wings and the upper side of the hind wings are to a con- Fig. 425. — Basilona imperialis, larva. siderable extent pink. There is usually a dark discal spot on the fore wings, upon which, especially in the males, there may be two white dots. This species is more common in the Southern States than in the North. The expanse of wings in the male is two inches ; in the female, two and one half inches. The larva feeds on the leaves of the Honey- locust and of the Kentucky Coffee-tree. Anisota (An-i-so'ta). — To the genus Anisota belong three species of moths that occur in the Eastern United States. These moths are dark yellow, purplish red, or brownish in color, and agree in having the fore wings marked with a white discal dot. The larvae feed on the leaves of oak; they are more or less striped and are armed with spines. These insects hibernate as pupae. In determining these moths the student should remem- ber that the two sexes of the same species may differ more in appearance than do individuals of different species but of the same sex. The sexes can be distinguished, as already indicated, by the antennae. The three species can be sepa- rated as follows :— 34« THE STUD V OF INSECTS. The Rosy-striped Oak-worm, Anisota virginiensis (A vir- gin-i-en'sis). — The wings of the female are purplish red, blended with ochre-yellow ; they are very thinly scaled, and consequently almost transparent ; and are not speckled with small dark spots (Fig. 426). The wings of the male are Fig. 427. — Anisota virginiensis, Fig. 426. — Anisota virginiensis, female. male. purplish brown, with a large transparent space on the middle (Fig. 427). The larva is of an obscure gray or greenish color, with dull brownish yellow or rosy stripes, and with its skin rough with small white warts. There is a row of short spines on each segment, and two long spines on the mesothorax. The Orange-striped Oak-worm, Anisota senatoria (A. sen- a-to'ri-a). — The wings of the female are more thickly scaled than in the preceding species and are sprinkled with numer- ous blackish dots ; in other respects the two are quite similar in coloring. The male differs from that of A. virginiensis in lacking the large transparent space on the middle of the wings. The larva is black, with four orange-yellow stripes on the back and two along each side ; its spines are similar to those of the preceding species. The Spiny Oak-worm, Anisota stigma (A. stig'ma). — The female closely resembles that of A. senatoria ; and as both species are variable it is sometimes difficult to determine to which a given specimen belongs. In A. stigma the wings are rather darker and have a greater number of blackish spots, and the hind wings are furnished with a middle band which is heavier and more distinct than in A. senatoria. The male differs from that of the other two species in quite closely LEPIDOI'TERA. 349 Dryocampa rubicunda. resembling the female in coloring, and in having the wings speckled. The larva differs from the other species of Ani- sota in having long spines on the dorsal aspect of the third thoracic and each abdominal segment in addition to the much longer spines on the mesothorax. It is of a bright tawny or orange color, with a dusky stripe along its back and dusky bands along its sides. The Rosy Dryocampa, Dryocampa rubicunda (Dry-o- cim'pa ru-bi-cun'da).— The wings of this moth (Fig. 428) are pale yellow, banded with rose-color. The dis- tribution of the color varies greatly in different speci- mens. In some the pink of the fore wings predomi- nates, the yellow being re- duced to a broad discal band, while in one variety the ground-color is yellowish white and the pink is reduced to a shade at the base and a narrow stripe outside the mid- dle. The hind wings may be entirely yellow, or may have a pink band outside the middle. The expanse of wings in the male is one and one half to one and three fourths inches ; in the female, two inches or more. The larva of this species is known as the Green-striped Maple-worm, and is sometimes a serious pest on soft-maple shade-trees. It measures when full grown about one and one half inches. It is pale yellowish green, striped above with eight very light, yellowish-green lines, alternating with seven of a darker green, inclining to black. There are two prominent horns on the second thoracic segment, and two rows of spines on each side of the body, one above and one below the spiracles. And on the eighth and ninth abdomi- nal segments there are four prominent dorsal spines. The species is one- or two-brooded, and winters in the pupa state. 35° THE STUDY OF INSECTS. Family SATURNIID/E (Sat-ur-ni'i-dae). The Giant Silk-zvorms. The large size of the members of the Saturniidae, and the ease with which the cocoons of most of the species can be collected, render them well known to every beginner in the study of entomology. The family includes our largest lepi- dopterous insects ; and all of the species known to us are above medium size. They are stout-bodied, hairy moths, with more or less sunken heads, and strong, wide wings. They may be distinguished from the Citheroniidae, some of which rival them in size, by the form of the antennae of the males, and by the fact that except in the lowest genus, Coloradia, which is a rare insect from the far West, the hind wings are furnished „ 1U> In5 with only one inner vein. Ju< The adults fly at night, and /IITs are attracted by lights. The head is small and deeply sunken in the thorax; the antennae are either fili- form or pectinated in the females, but always pecti- nated in the males ; and the pectinations extend to the tip. Where the antennae of both sexes are pectinated, the males can be distil guished by the larger size of their antennae. The palpi are small, and the maxillae but little developed, often obsolete. v, ,-J' >^ r5 — An, An, IX II So^^ *""" Am W "• N. 'VII, "VII, IX Fig. 429. — Wings of Samia cecropia The thorax is densely clothed with hair. The wings are broad, and are often furnished with transparent, window- like spots. The frenulum is wanting. The humeral angle LEPIDOrTKRA. 351 01 the hind wing is largely developed, and is usually strength- ened by a deep furrow, the bottom of which is sometimes thickened so as to appear like a humeral vein (Fig. 429). The larvae live exposed on the leaves of trees and shrubs ; they are more or less armed with tubercles and spines, and are very conspicuous on account of their large size. They transform within silken cocoons, which are usually very dense, and in some cases have been utilized by man. These cocoons are often attached to trees and shrubs, and are sometimes inclosed in a leaf. They can be easily collected during the winter months, and the adults bred from them. The following species are those that the young student is most likely to find : — The Io-moth, Aatomeris io (Au-tom'e-ris i'o). — This is the most common of the smaller species of the family. The female is represented by Figure 430. In this sex the Fig'- 430 — Autoitieris io. ground-color of the fore wings is purplish red. The male differs greatly in appearance from the female, being some- what smaller and of a deep yellow color, but it can be easily recognized by its general resemblance to the female in other respects. The larva is one that the student should learn to recog. nize in order that he may avoid handling it : for it is armed 352 THE STUDY OF INSECTS. with spines the prick of which is venomous (Fig. 431). It is green, with a broad brown or reddish stripe, edged below with white, on each side of the abdo. men. The spines are Fig. w.-A*tomerisio, larva. tjpped wjth Wack The Polyphemus-moth, Tclea polyphemus (Te'le a pol-y- phe'mus). — This is a yellowish or brownish moth with a window-like spot in each wing. There is a gray band on the costal margin of the fore wings ; and near the outer mar- gin of both pairs of wings there is a dusky band, edged Fig. 432. — Tele , polypkemus, larva. without with pink ; the fore wings are crossed by a brok-en dusky or reddish line near the base, edged within with white or pink. The transparent spot on each wing is divided by the discal vein, and encircled by yellow and black rings. Plate V. L El' J OOP TERA . 353 On the hind wings the black surrounding the transparent spot is much widened, especially toward the base of the wing, and is sprinkled with blue scales. The wings expand from five to six inches. The larva (Fig. 432) feeds on oak, butternut, bassvvood, elm, maple, apple, plum, and other trees. When full grown it measures three inches or more in length. It is of a light green color with an oblique yellow line on each side of each abdominal segment except the first and last ; the last segment is bordered by a purplish-brown V-shaped mark. The tubercles on the body are small, of an orange color with me- tallic reflections. The co- coon (Fig. 433) is dense and usually enclosed in a leaf ; it can be utilized for the manufacture of silk. When the adult is ready to emerge, it excretes a * fluid which softens the cocoon at one end, and FlG" «3.-t>/«* toiyphemu,. breaking the threads it makes its exit through a large round hole. The Luna Moth, Tropcea lima (Tro-pas'a lu'na). — This magnificent moth is a great favorite with amateur collectors (Plate V). Its wings are of a delicate light green color, with a purple-brown band on the costa of the fore wings; there is an eye-like spot with a transparent center on the discal vein of each wing; and the anal angle of the hind wings is greatly prolonged. The larva feeds on the leaves of wal- nut, hickory, and other forest-trees. It measures when full grown about three inches in length. It is pale bluish green with a pearl-colored head. It has a pale yellow stripe along each side of the body, and a transverse yellow line on the back between each two abdominal segments. The cocoon lesembles that of the preceding species in form, but is very thin, containing but little silk. 24 354 THE STUDY OF INSECTS. The Promcthea Moth, Callosaniiap?'oiiicthca{C,a\-\o-sa.'m\-a. pro-me'the-a). — This is the most common of the Giant Silk- worms. The wings of the female (Fig. 434) are light reddish Fig. 434. — Callosatnia promethea, female. brown ; the transverse line crossing the middle of the wings is whitish, bordered within with black ; the outer margin of the wings is clay-colored, and each wing bears an angular discal spot. The discal spots vary in size and distinctness in different specimens. The male differs so greatly from the female that it is liable to be mistaken for a distinct species. It is black- ish, with the transverse lines very faint, and with the discal spots wanting or very faintly indicated. The fore wings also differ markedly in shape from those of the female, the apex being much more distinctly sickle shaped. The larva when full grown measures two inches or more in length. It is of a clear and pale bluish-green color; the legs and anal shield are yellowish ; and the body is armed with longitudinal rows of tubercles. The tubercles are black, polished, wart-like elevations, excepting two each on the second and third thoracic segments, which are larger and rich coral-red, and one similar in size to these but of a yellow color on the eighth abdominal segment. This larva feeds on the leaves LEPIDOPTERA. 355 of a large proportion of our common fruit and forest trees; but we have found it more frequently on wild cherry and ash than on others. The cocoons can be easily collected during the winter from these trees. This is the best way to obtain fresh specimens of the moths, which will emerge from the cocoons in the spring or early summer. The cocoon (Fig. 435) is interesting in structure. It is greatly elongated and is enclosed in a leaf, the petiole of which is securely fast- ened to the branch by a band of silk extending from the co- coon ; thus the leaf and enclosed cocoon hang upon the tree throughout the winter. At the upper end of the cocoon there is a conical valve like arrange- ment which allows the adult to emerge without the necessity of making a hole through the cocoon. This structure is char- acteristic of the cocoons of the moths of this and the following genus. The Angulifera Moth, Callo- samia angulifera (C. an-gu-lif'e- ra). — This is a somewhat rare in- sect which so closely resembles the Promethea Moth that by many it is considered a variety of it. Specimens of it are usu- ally a little larger than those of 0,. promethea, and the transverse line and discal spots are more angular. The most important diffeiences, however, are pre- sented by the male, which quite closely resembles the female Fig. 435. — Callosamia promethea, cocoon. 356 THE STUDY OF INSECTS. of the Promethea Moth in color and markings, and thus differs decidedly from the male of that species. The Cecropia Moth, Sa/uia cecropia (Sa.'m'i-a. ce-cro'pi-a). — This is the largest of our Giant Silk-worms, the wings of the adult expanding from five to six and one half inches. The ground color of the wings is a grizzled dusky brown, espe- cially on the central area. The wings are crossed beyond the middle by a white band, which is broadly margined without with red, and there is a red spot near the apex of the fore wing just outside of a zigzag line. Each wing bears near its center a crescent-shaped white spot bordered with red. The outer margin of the wings is clay-colored. The larva is known to feed on at least fifty species of plants, including apple, plum, and the more common forest trees. When full grown it measures from three to four inches in length and is dull bluish green in color. The body is armed with six rows of tubercles, extending nearly its entire length, and there is an additional short row on each side on the ventral aspect of the first five segments follow- ing the head. The tubercles on the second and third thoracic segments are larger than the others, and are coral-red. The other dorsal tubercles are yellow, excepting those of the first thoracic and last abdominal segments, which with the lateral tubercles are blue ; all are armed with black bristles. The Fig. 436. — Samia cecropia, pupa. FlG. 437. — Samia cecropia, cocoon. LEPIDOPTERA. 357 pupa is represented by Figure 436 and the cocoon by Figure 3/« The Cecropia-moth occurs from the Atlantic coast to the Rocky Mountains. In the far West its place is taken by very closely allied forms, which are supposed to be distinct. In these the ground-color of the wings is usually a reddish or dusky brown. The form occurring in Utah and Arizona is Samia gloveri (S. glov'er-i) ; that found on the Pacific coast is Samia californica. The Ailanthus-worm, Philosamia cynthia (Phil-o-sa'mi-a cyn'thi-a), is an Asiatic species that has been introduced into this country. It has become a pest in the vicinity of New York, where it infests the Ailanthus shade-trees. The moth differs from all our native species of this family in having rows of tufts of white hairs on the abdomen. The cocoon resembles that of the Promethea-moth. Family Lacosomid^e (Lac-o-som'i-dae). The Sack-bearing Frenulum- losers. This family so far as is now known includes only two species that are found in the United States, and both of these are rare ; farther south several other species occur. They are our only native Frenulum-losers that retain a rudi- ment of the frenulum, but, as in the silk-worm, this frenulum is very small and the humeral angle is greatly expanded, so it is probable that the frenulum is of but little if any use (Fig. 438). It was the presence of this rudiment that first suggested to the writer that those families of the Lepidop- tera that we have termed Frenulum-losers were descended from frenulum-bearing ancestors. The Lacosomidae seem to be the sole survivors of a very distinct line of descent. In many respects they appear to be closely allied to the Saturniina, especially to the Bom- bycidae. But they differ markedly both in the structure and in the habits of the larvae; and, too, the wings of the adult, 358 THE STUDY OF INSECTS, although at first sight resembling those of the silk-worm, are nr, really quite different. In the coalescence of the branches of ra- dius of the fore wings veins 1 1 13 and III4 remain separate, while in the Satur- niina these are the first branches to coa- lesce. And in the hind wings there is no indication that vein I becomes joined to the base of vein II as is shown to be the case in the most generalized Satur- niina (Figs. 417 and 419). The members of Fig. 438. — Wings of Cicinnus melsheimerii. this family in the lar- val state feed upon leaves, and protect themselves by mak- ing a case of leaves within which they live (Fig. 439). YIIj Fig. 439. — Case of larva of Cicin n us. Fig. 440. — Cicinnus melsheimerii. Melsheimer's Sack-bearer, Cicinnus melsJuimerii (Ci-cin'- nus mels-hei-me'ri-i). — The larva of this species feeds on oak. The adult moth (Fig. 440) is of a reddish gray color, finely sprinkled all over with minute black dots; there is a small black spot at the end of the discal cell of the fore wings ; LEP1D0PTEKA. 359 and both pairs of wings are crossed by a narrow blackish band. This species is quite widely distributed ; but is quite rare in most places. The other representative of this family found in the United States is Lacosoma chiridota (Lac-o-so'ma chir-i-do'- ta). This species is even more rare than the preceding; it is somewhat smaller, and dark yellowish brown in color ; but its general appearance is very similar. The venation of the wings is also similar to that of Cicinnus except that vein VIII of the hind wing is wanting. Family Lasiocampid^: (Las-i-o-cam'pi-dae). The Lasiocampids {Las-i-o-cairi ' pids). This family includes the Tent caterpillars and the Lap- pet-caterpillars. The adults are stout-bodied, hairy moths of medium size. The antennae are pectinated in both sexes, and are from one fourth to one half as long as the front wings ; the teeth of the an- tennae of the male are usu- ally much longer than those of the female. The ocelli art- wanting ; and the palpi are usually short and woolly. But the most distinctive char- acteristic is found in the wings. The frenulum is want- ing, there being instead, as in the Saturniina, a largely- expanded humeral angle of the hind wings. But these moths differ from the Satur- niina in having CubitUS ap- FlG 44'-— Wings of Clisiocampa americana. parently four-branched and in having the humeral angle 360 THE STUDY OF INSECTS. strengthened by the development of some extra veins, the humeral veins (Fig. 441, h. v.).* The larvae of the Lasiocampids feed upon the foliage of trees, and are frequently very destructive. The family is a small one, less than thirty North Ameri- can species being known to entomologists. Our more com- mon ones represent three genera : Clisiocampa (Clis-i-o-cam'- pa), which includes the Tent-caterpillars, and Phyllodesma (Phyl-lo-des'ma) and Tolype (Tol'y-pe), which include the Lappet-caterpillars. There are several species of Tent-caterpillars in this country. Most of them belong to the Pacific coast ; but two are common in the East. Of these the most com- mon one is the Apple-tree Tent -caterpillar, Clisiocampa americana (C. a-mer-i-ca'na). This is the insect that builds large webs in apple and wild cherry trees in early spring. Figure 442 represents its transformations. The moth is dull yellowish brown or reddish brown, with two transverse whitish or pale yellowish lines on the fore wings. The figure represents a male; the female is somewhat larger. These moths appear early in the summer. The eggs are soon laid, each female laying all her eggs in a single ring-like cluster about a twig; and here they remain unhatched for about nine months. This cluster is covered with a substance which protects it during the winter. The eggs hatch in early spring, at the time or just before the leaves appear. The larvae that hatch early feed upon the unopened buds till the leaves expand. The larvae are social, the entire brood that hatch from a cluster of eggs keeping together and building a tent in which they live when not feeding. The figure represents a specimen in our collection. In this case the tent was begun near the cluster of eggs. But usu- *So far as we know, humeral veins occur nowhere else in the Lepidoptera, although in many butterflies vein I of the hind wings is preserved and appears like a humeral vein. The humeral veins of the Lasiocampidae do not 'epresent any of the primitive veins, but are developed secondarily. LEPlDuPTERA. 36l ally the larvae soon after hatching migrate down the branch towards the trunk of the tree until a fork of considerable size is reached before they begin their tent. This is neces- sary, as the completed tent often measures two feet or more in length. The larvae leave the nest daily in order to feed ; and spin a silken thread wherever they go. The larvae be- Fig. 442. — Clisiocampa americana, eggs, tent, larva, cocoons, and adult. come full grown early in June ; one of them is represented on a partially-eaten leaf in the figure. When ready to transform they leave the trees and make their cocoons in some sheltered place. These cocoons are quite peculiar in appearance, having a yellowish white powder mixed with the silk. The pupa state lasts about three weeks. The easiest way to fight this pest is to destroy the webs containing the larvae as soon as they appear in the spring. This should be done early in the morning, or late in the 362 THE STUDY OF INSECTS. afternoon, or on a cold day, when the larvae are not scat- tered over the tree feeding. The other Eastern species of this genus is the Tenc-cater- pillar of the Forest, Clisiocampa disstria (C. dis'stri-a). This species resembles the preceding in habits. It is more apt, however, to feed upon forest-trees. The moth differs from C. americana in having the oblique lines on the wings dark instead of light; the larva differs in having a row of spots along the back instead of a continuous narrow line; and the egg-masses differ in ending squarely instead of being rounded at each end. The more common species of the Pacific coast are Clisio- campa californica, whose nests may be found on oaks in March and April, and Clisiocampa constricta, which infests fruit-trees later in the season. The caterpillars of the last- named species do not make a tent, although they live in colonies. The larvae of Tolype and Phyllodesma are remarkable for having on each side of each segment a little lappet or flat lobe ; from these many long hairs are given out, forming a fringe to the body. When at rest the body of the larva is flattened, and the fringes on the sides are closely applied to the surface of the limb on which the insect is. Thus all ap- pearance of an abrupt elevation is obliterated ; the colors of these larvae are also protective, resembling those of the bark. The genus Tolype includes only two common North American species ; both of these occur in the East. The more com- mon of the two is the Velleda Lappet, Tolype velleda (Tol'y-pe vel'le-da). The body of the moth is milk-white, with a large black- ish spot on the middle of its back Fig. 443.— Tolype velleda. (Fig. 443). That part of this spot which is on the thorax is composed of erect scales ; the cau- LEPIDOPTERA. 363 dal part, of recumbent hairs. The wings are dusky gray, crossed by white lines as shown in the figure. The figure represents the male ; the female is much larger. The moths are found in August and September. The larva feeds upon the leaves of apple, poplar, and syringa. Its body is bluish gray, with many faint longitudinal lines ; and across the back of the last thoracic segment there is a narrow velvety-black band. The larva reaches maturity during July. The cocoon is brownish gray, and is usually attached to one of the branches of the tree on which the larva has fed. The second species of this genus is known as the Larch Lappet, Tolype /arias (T. lar'i-cis). This is a smaller species, the females being about the size of the male of the preced- ing species, and the males expanding only about one and one fourth inches. The wings of the females are marked much like those of T. velleda, except that the basal two thirds of the front wings are much lighter, and the dark band on the outer third is narrower and much darker than the other dark bands. The males are bluish black, with the markings indistinct. The larva feeds upon the larch. When mature it is of a dull brown color and less than one and one half inches in length. When extended the front of the first thoracic segment is pale green, and the incision between the second and third is shining black. The larva matures during July. The cocoon is ash-gray, flattened and moulded to the limb to which it is attached, and partially surround- ing it. The moths appear in August or September. The winter is passed in the egg state. The genus Phyllodesma includes three Californian and two Eastern species. The more common one of the latter is the American Lappet, P. americana (Fig. 444). The moth is reddish brown, with the inner angle FlG. w.-P^nodes„!a ameri. of the front wings and the costal margin of the hind wings deeply notched. Beyond the mid- 3&4 THE STUDY OF INSECTS. die of each wing there is a pale band edged with zigzag, dark brown lines. The larva lives upon apple, cherry, oak, birch, maple, and ash. When full grown it measures two and one half inches in length and one half inch in breadth. The upper side is slate-gray, mottled with black, with two transverse scarlet bands, one on the second and one on the third thoracic segments. There is a black spot at each end and in the middle of each of these bands. The larva is found during July and August. It is said that the cocoons are attached to limbs like those of Tolype ; but the larvae of this species which we have bred made their cocoons between leaves, or in the folds of the muslin bag enclosing the limb upon which they were feeding. The species passes the winter in the pupa state; \rns and the moth appears in Y' June, when it lays its v* eggs upon the leaves of 'v, the trees it infests. Superfamily Hesperiina (Hes-per-i-i'na). 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 most species hold the wings erect in a vertical position like butterflies; in some the fore wings are thus held while the hind wings are extend- Pig.445— Wings of Etar&reustityrus. ed horizontally ; and a few extend both pairs of wings horizontally. The antennae LEP1D OP TERA . 365 are thread-like, and enlarged toward 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. The skippers are most easily distinguished by the peculiar venation of the fore wings, vein III being five-branched, and all the branches arising from the discal cell (Fig. 445). In some butterflies all the branches of vein III appear to arise from the discal cell ; but this is because two of the branches coalesce to the margin of the wing. In such butterflies vein III appears to be only four-branched. This superfamily includes two families — the Giant Skip- pers, Megathynnidce, and the Common Skippers, Hesperiidee. These can be distinguished as follows : — A. Head of moderate size ; club of antenna large, neither drawn out at the tip nor recurved. Large skippers, with wing expanse of two inches or more. p. 365 Megathymid^. AA. Head very large ; club of antenna usually drawn out at the tip, and with a distinct recurved apical crook. In a few forms the crook of the antennae is wanting; such forms can be distin- guished from the Megathymidse by their smaller size, the wing expanse being less than one and one fourth inches, p. 368. HESPERIID/E. Family MEGATHYMID^l (Meg-a-thym'i-dae). The Giant Skippers. This family includes a small number of large skippers, which are found in the South and far West. In the idult insect the head is of moderate size, the width, includ- ing the eyes, being much less than that of the metathorax. The club of the antennae is large ; and, although the tip is turned slightly to one side, it is neither drawn out to a point nor recurved. The body is very robust, even more so than in the Hesperiidae. These insects fly in the day- time and with a rapid, darting flight. When at rest they fold their wings in a vertical position. In the more general features of their venation the wings / 366 THE STUDY OF INSECTS. closely resemble those of the Hesperiidae. But the Giant Skippers exhibit a very peculiar specialization of wing struc- ture in the male sex. Here the two branches of vein VII of the fore wings separate from each other and from the cross- vein connecting them with vein V3, near the base of the wing (Fig. 446). In this sex this cross-vein, the branches of Fig. 447. — Wings of Megathymui co/agui, female. \-^^ VII2 XI IX. Fig. 446. — Wings of Megathyntus yucca, male. vein VII, and vein IX are all very stout. The strengthening of these veins is evidently a specialization that increases the power of flight of this sex. For these stout veins must aid in depressing the hind wings during the downward stroke of the wings, as the hind wing is overlapped by that part of the fore wing traversed by these veins. The separation of the branches of vein VII from each other and from the cross- vein, so near the base of the wing, is directly correlated with the strengthening of these veins. In the course of the perfecting of the powers of flight in the male these LEPIDOPTERA. 367 Fig. 448. — Megathymus cofaqui. veins have split apart, so that they overlie the hind wings to a greater extent than they do in the female (Fig. 447), which probably represents a more primitive condition. It is a common occurrence for the wings of the male to be more highly specialized than those of the female, for, in the seeking of mates, the males fly more than do the females. But it is unusual for veins to coalesce to a smaller extent in specialized forms than in those more generalized. In other words, the ordinary course of specialization is for veins to grow together instead of to split apart. This family is represented in the United States by a single genus, of which only three species are known. The female of one of these, Megathymus cofaqui (Meg-a-thy'mus cof-a-qui'), is represented by Figure 448. The male differs in the smaller size of the spots on the fore wing, in lacking the band of spots on the hind wing, and in having the upper surface of the hind wing nearly covered with long fine black hairs, which stand nearly erect. This species has been found in Florida and Colorado. A much better known species is the Yucca-borer, Mega- thymus yucca (M. yuc'cae). The female of this species differs from that of the preceding in having much darker wings, all of the spots being smaller, and in having only one or two white spots on the lower surface of the hind wings. The male lacks the erect hairs on the hind wings. The larva bores in the stem and root of the Yucca or Spanish Bayonet. It differs greatly in appearance from the larvae ot the Hesperiidoe, having a small head. This species is widely distributed through the southern part of our country. 368 THE STUDY OF INSECTS. The third species, MegatJiymtis neumcegeni (M . neu-mce- gen'i), occurs in Arizona. Family Hesperiid^E (Hes-pe-ri'i-dae). The Common Skippers. The family Hesperiidce includes all skippers found in the United States except irn5 the three species de- ^^Jv, scribed above as the /v, Giant Skippers. In ad- 'v, dition to the differences indicated in the table (p. 305), it may be said that the males in the Hesperiidae lack the pecu- liar thickening and split- ting apart of the branches of vein VII of the fore wings characteristic of the Giant Skippers. But there exists instead in the males of nearly all spe- cies peculiar scent-organs, which are described later. Figure 449 represents the venation of a male mem- ber of this family. Fig. 449.— Wings of Epargyreus tityrut. The larvae of the Common Skippers pre- sent a very characteristic appearance, having large heads and strongly con- stricted necks (Fig. 450). They usually live con- cealed in a folded leaf or in a nest made of several leaves &, imm i£5? Fig. 450. — Epargyreui tityrus, larva. LEPIDOPTERA. 369 fastened together. The pupae are rounded, not angular, resembling those of moths more than those of butterflies. The pupa state is passed in a slight cocoon, which is gen- erally composed of leaves fastened together with silk, and thinly lined with the same substance. The family Hesperiidae includes three subfamilies; but only two of them are represented in this country, the third being confined to South and Central America. Our forms can be separated as follows : — A. Vein V2 of the fore wings arising nearer to vein Vj than to vein Vs. p. 369 HESPERIIf.iE. AA. Vein V2 of the fore wings arising midway between veins Vi and V3 or nearer to vein V3 than to vein Vi. B. Vein V2 of the fore wings arising nearly midway between veins V, and V3. C. Discal cell of fore wings more than two thirds as long as the costa. Males usually with costal fold in fore wings, p. 369. HESPERIIN/E. CC. Discal cell of fore wings less than two thirds as long as the costa. Males usually with a discal patch on fore wings. p. 372 PaMPHILINjE. BB. Vein V2 of the fore wings arising much nearer to vein V3 than to vein Vi. p. 372 Pamphilin^e. Subfamily Hesperiin^e (Hes-pe-ri-i'nae). Skippers witJi a Costal Fold. This subfamily includes the larger of the Common Skippers, as well as some that are of moderate size. Most of the species are dark brown, marked with white or trans- lucent, angular spots. The antennae usually have a long club, which is bent at a considerable dis- tance from the tip (Fig. 451). But the most distinctive feature of the sub- family is exhibited by the males alone, and is lacking in some species. It consists of a fold in the fore wing near FlG- «x — Tkanaos martiaiis. the costal margin, which forms a long slit-like pocket, con- 370 THE STUDY OF INSECTS. taining a sort of silky down. This is supposed to be a scent-organ. When this pocket is tightly closed it is diffi- cult to see it. Nearly seventy species belonging to this subfamily have been found in America north of Mexico. The following are some of the more common of these: — The Silver-spotted Skipper, Epargyrens tityrns (Ep-ar- gy're-us tit'y-rus). — This skipper is represented on our colored plate (Plate I, Fig. 4). It is dark chocolate-brown, with a row of yellowish spots extending across the fore wing and with a large silvery-white spot on the lower side of the hind wing. It is found in nearly the whole United States, from Massachusetts to California, except in the extreme Northeast and Northwest. The larva (Fig. 450) feeds upon various papilionaceous plants. We have found it common on locust. It makes a nest, within which it re- mains concealed, by fastening together, with silk, the leaf- lets of a compound leaf (Fig. 452). Fig. 452.— Nest of larva of Epargymts tityrus. The Long-tailed Skipper, Eudamus proteus (Eu'da-mus pro'te-us). — This Skipper by the shape of its wings reminds one of a swallow-tail butterfly, the hind wings being furnished with long tails. It expands about one and three fourths inches; and the greatest length of the hind wings is about one and one fourth inches. The wings are very dark choc- olate-brown ; the front wings contain several silvery-white spots ; and the body and base of the wings bear metallic- LEP1D0P TERA . 371 green hairs. The larvae feed upon both Leguminosae and Cruciferae. In the South it is sometimes a pest in gardens, cutting and rolling the leaves of beans, turnips, and cabbage, and feeding within the rolls thus formed. It is found on the Atlantic border from New York southward into Mexico. There are two common skippers which are nearly as laree as the two described above, but which have neither the yellow band of the first nor the long tails of the second ; neither do they have the brown spots characteristic of the following genus. These two skippers belong to the genus Thorybes. The wings are of an even dark brown ; the fore wings are flecked with small or very small irregular white spots, and the hind wings are crossed beneath by two rather narrow, parallel, inconspicuous darker bands. These skippers are distinguished as follows : — The Northern Cloudy-wing, Thorybes pylades (Thor'y-bes pyl'a-des). — In this species the white spots on the fore wing are usually mere points, although their number and size vary. The species is found in nearly all parts of the United States. The larva commonly feeds on clover. The Southern Cloudy-wing, Thorybes bathyllus (T. ba-thyl'lus). — In this species the white spots are larger than in the preceding, almost forming a continuous band. This skipper is widely distributed over the eastern United States, except the more northern portions. To the genus Thanaos belong a large number of species which on account of their dark colors have been named Dusky-wings. These species resemble each other so closely in markings that it is very difficult to separate them with out longer descriptions than we can give here. The one following will serve as an example. Martial's Dusky-wing, Thanaos martialis (Than'a-os mar-ti-a'lis). — The wings are grayish brown with Fig. 453.— Thanaos martiaiu. many dark brown spots evenly distributed and with several $72 THE STUDY OF INSECTS. minute white ones on the outer half of the fore wings (Fig. 453). This skipper is found throughout the greater part of the United States east of the Rocky Mountains. Among the smalier members of this subfamily are the skippers of the genus Pholisora. The most widely dis- tributed species of this genus is the Sooty-wing, Pholisora catullus (Phol-i-so'ra ca-tul'lus). The expanse of the wings is a little more than one inch. The wings are nearly black, marked with minute white spots, which vary in size and number. This species is found throughout the United States except along the extreme northern border. The genus Hesperia includes a considerable number of small skippers, which are easily recognized by their check- ered markings of white upon a dark brown ground. Small white spots on the wings are common in this subfamily, but in this genus the white spots are unusually large, so large in some cases that they occupy the greater part of the wing. One of the more common species is the Variegated Tessellate, Hesperia tessellata (lies- pe'ri -a tes-sel -la'ta). This is distributed from the Atlantic to the Pacific, and is the only one common in the Eastern United States. In this species more than one half of the outer two thirds of both fore and hind wings is white. Subfamily Pamphilin.e (Pam-phi-li'nae). Skippers with a Discal Patch. This subfamily includes the greater number of our smaller skippers. Some of the species, however, surpass in size many of the Hesperiinae. To the Pamphilinae belong all of our common tawny skippers, as well as some black or dark brown species. The antennae usually have a stout club, with a short, recurved tip ; sometimes this tip is Fig. 454. — Limochotes pan- tiac, male. wanting. In the majority of our species the males can be recognized at a glance by a conspicuous LEP1D OP 1 ERA . HI discal patch, which usually appears to the naked eye like a scorched, oblique streak near the center of each fore wing (Fig. 454)- This patch is a complicated organ, com- posed of tubular scales that are outlets of scent-glands and other scales of various shapes. The females can be recognized by their resemblance in other respects to the males. In some species the discal patch is wanting in the males also. This subfamily is an exceedingly difficult one to study. More than one hundred species have been described from America north of Mexico ; and in many cases the differences between allied species are not well marked. The following two are named merely as examples, The first is easily recognized. But it is not worth while for the beginning student to attempt to distinguish other members of this subfamily. The Least Skipper, Ancyloxipha numitor (An-cy-lox'i-pha nu'mi-tor). — This skipper is the smallest of our common species, and is also remarkable for lacking the recurved hook at the tip of the antennae. The wings are tawny, broadly margined with dark brown. In some specimens the fore wings are almost entirely brown. The larger in- dividuals expand about one inch. The larva feeds upon grass in damp places. The Black Dash, Limochores pontiac (Li-moch'o-res pon'ti-ac). — The male of this species is represented by Figure 454. It is blackish brown, with considerable yellow on the basal half of the fore wings. The discal patch is velvety black. This species is distributed from Massachu- setts to Nebraska. Superfamily PAPILIONINA (Pa-pil-i-o-ni'na). The Butterflies. The butterflies differ from moths in that they have clubbed antennae, fly only in the daytime, and hold the 374 THE STUDY OF INSECTS. wings erect above the back when at rest. There are some moths that have m4 n m.5 v, clubbed antennae, and others that fly by day but no moth presents all three of the charac- teristics given above. It is more difficult to distinguish the but- terflies from the skip- pers ; yet this can be easily done. In but- terflies the club of the antenna is bluntly rounded at the tip instead of being fur- nished with a re- curved point as in most skippers ; the abdomen is very slen- der ; and some of the branches of radius of the fore wings co- Fig. 455.— Wings of Basilarchia astyanax* aleSCe beVOnd the apex of the discal cell (Fig. 455). There are butterflies in which all of the branches of radius present arise from the discal cell ; but this is due to the fact that two of the branches coalesce to the edge of the wing, as is shown by the fact that in these butterflies radius has less than five branches. This superfamily includes four families, which can be separated as follows: — A. Cubitus of the fore wings apparently four-branched (Fig. 456). p. 375 Papilionim:. AA. Cubitus of the fore wings apparently three-branched (Fig. 455). B. With six well-developed legs, although in some species the fore LEPIDOPTERA. 375 legs of the male are a little shorter, and the tarsi of these lack one or both claws ; radius of the fore wings, with rare exceptions, only three- or four-branched. To determine the number of branches of radius, count the two cubital and the three medial branches first ; the branches left between veins Vi and II belong to radius. C. Vein V1 of the fore wings arising at or near the apex of the discalcell (Fig. 465) except in Feniseca tarquinius,\x\ which the wings are dark brown, with a large fulvous spot on each. p. 388 Lyc^nid^e. CC. The first branch of media of the fore wings united with the last branch of radius for a considerable distance beyond the apex of the discal cell (Fig. 460). Ground color of wings white, yellow, or orange, p. 381 Piekidje. BB. With only four well-developed legs, the fore legs being un- used, much shorter than the others, and folded on the breast like a tippet (except in the female of Hypatus). Radius of fore wings five-branched (Fig. 467), p. 395 NymphaliDjE. Family Papilionid^E (Pa-pil-i-on'i-dae). The Swallozv-tails and the Parnassians. This family includes the swallow-tail butterflies, which are common throughout our country, and the Parnassians, which are found only on high mountains or far north. These insects are distinguished from all other butterflies by the fact that vein V, of the fore wings appears to be a branch of cubitus, making this vein appear four-branched (Fig. 456), and also by the fact that the anal area of the hind wings is more reduced than the anal area of the fore wings, the former containing only a single anal vein, the latter two or three. The caterpillars are never furnished with spines, but are either naked or clothed with a few fine hairs. In a single species in our fauna {Laertias philenor) the body of the larva bears fleshy filaments. A striking peculiarity of the larvae of this family is the presence of a pair of bright-colored fleshy " horns," which can be projected from a slit in the dorsal wall of the pro- 37<5 THE STUDY OF INSECTS. thorax. These have been termed osmateria (os-ma-te'ria), and are supposed to be organs of defence ; for they exhale when pushed mi out an odor which in some species is exceedingly dis- agreeable. The chrysalids are thickened in the middle and taper considerably at each end ; they are more or less angulated, and have certain parts excessively produced ; they are sus- pended by the tail and by a loose girth around the middle. This family includes two well-marked subfami- lies, which are distil guished as follows : — A. Hind wings with a tail- like prolongation ; ground- color of wings black ; radius of fore wings five-branched; the base of vein VIII of fore wings preserved as a spur-like branch of vein VII (Fig. 456). p. 376 pAPILIONINiE. AA. Hind wings without tail-like prolongation ; ground color of wings white; radius of fore wings four-branched ; vein VIII of fore wings wanting, p. 380 Parnassiin^e Fig. 456. — Wings if Papilio polyxenes. Subfamily Papilionin.e (Pa-pil-i-o-ni'nae). The Swallow-tails. These magnificent butterflies are easily recognized by their large size and the tail-like prolongations of the hind wings. The ground color of the wings is black, which is LEPIDOPTRRA. 177 usually marked with yellow, and often with metallic blue or green. There are about twenty-five species of swallow-tails in America north of Mexico. The following well-known spe- cies will serve as illustrations. The Black Swallow-tail, Papilio polyxenes (Pa-pil'i-o po- lyx'e-nes). — The larva of this swallow-tail (Fig. 457) is well known to most country children. It is the green worm, ringed with black and spotted with yellow, that eats the leaves of caraway in the back yards of coun- try houses. It feeds also on parsnip and other umbelliferous plants. These caterpillars always fascinated us in our childhood ; we have spent many idle moments in poking them with straws to see them rear upward and project their yellow horns, which gave off a sickening odor. When ready to transform the caterpillar crawls away to a fence or the side of the house and changes to an angular pupa, sus- pended by the tail and by a little silken girth around the middle. In the adult the wings are black, crossed with two rows of yellow spots, and with marginal lunules of the same color. The two rows of spots are much more distinct in the male than in the female, the in- ner row on the hind wing forming a continuous band crossed Fig. 457. — Papilio polyxenes, larva. 378 THE STUDY OF INSECTS. with black lines on the veins. Between the two rows of spots on the hind wings there are many blue scales ; these are more abundant in the female. Near the anal angle of the hind wing there is an orange spot with a black center. On the lower surface of the wings the yellow markings become mostly orange and are heavier. This species is found throughout the United States and in the southern parts of Canada. The Tiger Swallow-tail, Jasoniades glancus (J as-o-nira-des glau'cus). — The larva of this butterfly (Fig. 458) is even more striking in appearance than that oi the preceding species. When full grown it is dark green, and bears on each side of the third thoracic segment a large greenish- yellow spot, edged with black, and enclos- ing a small purple spot bordered with black. This caterpillar has the curious habit of weaving upon a leaf a carpet of silk, upon which it rests when not feed- ing ; when nearly full grown, instead of spinning a simple carpet as before, it stretches a web across the hollow of a leaf and thus makes a spring bed upon which it sleeps (Fig. 458). In the adult state two distinct forms of this insect occur. These differ so greatly in appearance that they were long con- sidered distinct species. They may be Fig. 458. — yasoniaties glau- ,. . . . . r 11 cus, larva upon its bed. distinguished as IOUOWS : (1) The Turnus Form, Jasoniades glaucns tnrnus. — The wings are bright straw-yellow above, and pale, faded straw- yellow beneath, with a very broad black outer margin, in which there is a row of yellow spots. On the fore wings there are four black bars, extending back from the costa ; the inner one of these crosses the hind wings also. This form LEPIDOPTEKA. 379 is represented by both sexes, and is found in nearly all parts of the United States and Canada. (2) The Glaucus Form, Jasoniades glaucus glaucus. — In this form the disk of the wings is entirely black, but the black bands of the Turnus form are faintly indicated, espe- cially on the lower surface, by a darker shade. The mar- ginal row of yellow spots is present, and also the orange spots and blue scales of the hind wings. This form is rep- resented only by the female sex, and occurs only in the more southern part of the range of the species, i.e., from Delaware to Montana and southward. The Zebra Swallow-tail, IpJiiclidcs ajax (Iph-i-cli'des a'jax). — This butterfly (Fig. 459) differs from all other swal- low-tails found in the eastern half of the United States in hav- ing the wings crossed by several bands of greenish white. This is one of the most in- teresting of our but- terflies, as it occurs under three distinct forms, two of which were considered for a long time distinct species. Without tak- ing into account the FlG- w}-—i**iciides ajax. more minute differences these forms can be separated as follows : — (1) The Early-spring Form, Iphiclides ajax marcellus (mar-cel'lus).— This is the form figured here. It expands from two and six tenths inches to two and eight tenths inches ; and the tails of the hind wings are about six tenths inch in length and tipped with white. (2) The Late-spring Form, Iphiclides ajax telamonides 580 THE STUDY OF INSECTS. (tel-a-mon'i-des). — This form is a little larger than marcellus and has tails nearly one third longer ; these tails are bordered with white on each side of the distal half or two thirds of their length. (3) The Summer Form, IpJiiclides ajax ajax. — The sum- mer form is still larger, expanding from three and two tenths inches to three and one half inches, and has tails nearly two thirds longer than the early-spring form. The life-history of this species has been carefully worked out by Mr. W. H. Edwards. He has shown that there are several generations each year, and that the winter is passed in the chrysalis state. But the early-spring form and the late-spring form are not successive broods; these are both composed of individuals that have wintered as chrysalids, those that emerge early developing into marcellus, and those that emerge later developing into telamoiiidcs. All of the butterflies produced from eggs of the same season, and there are several successive broods, are of the summer form, ajax ajax. The larva feeds upon papaw {Asimina). This insect is found throughout the eastern half of the United States except in the extreme north. Subfamily Parnassiin^E (Par-nas-si-i'nae) The Parnassians {Par-nas' si-ans). The Parnassians differ from the Swallow-tails in lacking- the tail-like prolongations of the hind wings and in that the ground-color of the wings is white ; but resemble them in the general plan of the venation of the wings, and in pos- sessing similar scent-organs (osmateria) in the larval state. The wings of the butterflies are usually conspicuously marked with black spots and shades, and with red spots. Only four species have been found in North America. These belong to the genus Parnassius (Par-nas'si-us). They are found only on high mountains or far north. LEPIDOPTERA. 38i Family PiERID^E (Pi-er'i-dae). The Picrids {Pi-cr'ids). These butterflies are usually of medium size, but some of them are small; they are nearly always white, yellow, or orange, and are usually marked with black. They are the most abundant of all our butterflies, being common every- where in fields and roads. Some species are so abundant as to be serious pests, the larvae feeding on cultivated plants. The characteristic features of the venation of the wings are the following (Fig. 460) : Vein V, of the fore wings is more closely connected with radius than with cubitus, the latter appear- ing to be three-branched; vein V, of the fore wings coalesces with radius for a considerable distance beyond the apex of the discal cell ; and only three or four of the branches of radius remain distinct. In this family the fore legs are well developed in both sexes, there being no tendency to their reduc- tion in size, as in the two following families. The larvae are usual- ly slender green worms clothed with short, fine Fig. 460. — Wings of Pontia protodice. hairs ; the well-known Cabbage-worms are typical illus- trations (Fig. 461). The chrysalids are supported by the tail and by a loose girth around the middle. They maybe distinguished at a glance by the presence of a single pointed projection in front (Fig. 461). 382 THE STUDY OF INSECTS. Our genera of this family can be separated into three groups, which seem hardly distinct enough to be ranked as Fig. 461. — Pier is rafitz, larvae and pupa. subfamilies. These are the Whites, the Yellows, and the Orange-tips. I. The Whites. — The more common representatives of this group are the well-known Cabbage-butterflies. They are white butterflies more or less marked with black. Occa- sionally the white is tinged with yellow ; and sometimes yel- low varieties of our white species occur. About a dozen North American species of this group are known. The Cabbage-butterfly, Pieris rapes (Pi'e-ris ra'pae). — The wings of this butter- fly are dull white above, occasionally tinged with FlG. 462. — Pieris rapt?. J ° yellowish, especially in the female; below, the apex of the fore wings and the entire LEPIDOPTERA. 383 surface of the hind wings are pale lemon-yellow. In the female there are two spots on the outer part of the fore wing besides the black tip, in the male only one (Fig. 462). There is considerable variation in the intensity of the black markings, and in the extent of the yellow tinge of the wings. The larva of this species (Fig. 461) feeds principally on cabbage, but it also attacks many other cruciferous plants. Its color is the green of the cabbage-leaf, with a narrow, greenish, lemon-yellow dorsal band, and a narrow, inter- rupted stigmatal band of the same color. The body is clothed with very fine short hairs. Pieris rapes is without doubt the most injurious to agri- culture of all our species of butterflies. It is an introduced species, but has spread over the greater part of this coun- try. As it is three-brooded in the North and probably more in the South, it is present nearly the entire season, so that it needs to be fought constantly. Owing to the im- practicability of using poison upon cabbage, and to the fact that the larva bores into the heart of the cabbage beyond the reach of applications to the plant, it is an exceedingly difficult insect to combat. Obviously it is important in fighting this insect to thoroughly subdue the spring and summer broods, so that the bulk of the fighting can be done before the cabbage begins to head. For this purpose pyrethrum and kerosene emulsion have been found most useful. The Gray-veined White, Pieris oleracea (Pi'e-ris ol-e-ra'- ce-a). — The wings are white above and below, with a scarcely perceptible tinge of greenish yellow. Sometimes there is a dark spot on the fore wing between veins V3 and VII, , but usually the wings are unspotted. The base of the wings, however, and the basal half of the costa of the front wings, are powdered more or less with dark scales, and the veins of the wings, especially on the lower side, are grayish. This species occurs throughout Canada and in the more 384 THE STUDY OF INSECTS. northern portions of the United States. The larva feeds on cabbage. The Checkered White, Pontia protodice (Pon'ti-a pro- tod'i-ce). — The two sexes of this species differ greatly in appearance, the female being much more darkly marked than the male. The wings are white, marked above with grayish brown. There is a bar of this color at the end of the discal cell ; beyond this there is in the male a row of three more or less distinct spots, and in the female an almost continuous band of spots. Besides these there is in the female a row of triangular spots on the outer margin of both fore and hind wings, and on the hind wings a submar- ginal zigzag bar. The larva of this species is colored with alternating stripes of bright golden yellow and dark greenish purple, upon which are numerous black spots. It feeds upon cab- bage and other cruciferous plants, and occurs in nearly the whole of the United States. Both this and the preceding species seem to become greatly lessened in numbers by the increase of the imported Pieris rapce. II. The Orange-tips. — These, like the butterflies compris- ing the preceding group, are white, marked with black. Their most characteristic feature is the presence on the lower surface of the hind wings of a greenish network, or a marbled green mottling. This usually shows through the wing so as to appear as a dark shade when the wings are seen from above (Fig. 463). Many species have a con- spicuous orange spot on the api. cal portion of the front wings. This has suggested the common name Orange-tips for the group. But it should be remembered that some species lack this mark, and that in some others it is confined to the males. Nearly all of our species are confined to the far West. The two following occur in the East. Fig. 463. — Synchloe olympia. I.EPJDOPTERA. 385 The Falcate Orange-tip, AnthocJiaris genutia (An-thoch'- a Ws ge-nu'ti-a). — In this species the apex of the fore wings i* hooked, reminding one of the Hook-tip Moths. In the rrales there is a large apical orange patch. This butterfly is found throughout the southeastern part of the United States, not including Florida. It occurs as far north as New Haven, Conn. It is nowhere abundant. Synchloe olympia (Syn'chlo-e o-lym'pi-a). — In this species the orange patch is wanting in both sexes. There is a con- spicuous black bar at the end of the discal cell of the fore wings, and the apical portion of these wings is gray, includ- ing a large irregular white band (Fig. 463). This species occurs in the Mississippi Valley. III. The Yellows. — The Yellows are easily recognized by thsir bright yellow colors, although in some species whitish ferns occur. They abound almost everywhere in open fields, and are common about wet places in roads. To this gioup belong the larger number of our Pierids. The Clouded Sulphur, Eurymns philodice CEu'ry-mus phi- lod'i-ce). — The wings above are rather pale greenish yellow, with the outer borders black- ish brown. Figure 464 repre- sents the male ; in the female the border on the fore wings is broader, and contains a sub- marginal row of yellow spots. The discal dot of the fore wings is black, that of the hind wings is orange. The under surface is sulphur-yellow. This species is dimorphic. The second form is repre- sented only by the female sex, and differs in having the ground-color of the wings white instead of yellow. The Clouded Sulphur occurs from the mouth of the St. Lawrence to South Carolina and westward to the Rocky Mountains. Its larva feeds upon clover and other Legu- minosae. Fig. 464. — Eurymus philodice, 386 THE STUDY OF INSECTS. The Orange Sulphur, Eurynuis curytheme (E. eu- ryth'e-me). — This species closely resembles philodice in- size, shape, and markings. The typical form differs from pJiilodice in being of an orange color above instead of a yellow. The Orange Sulphur is a Western species, occurring in the Mississippi Valley and west to the Pacific Ocean. It is one of the most polymorphic of all butterflies ; the forms differ so much in appearance that four or five of them have been described as distinct species. The larva feeds on clover. The Dog's-head, Zerene c&sonia (Ze-re'ne cae-so'ni-a.) — The wings are lemon-yellow above, bordered on the outer margin with black. On the hind wings the border is nar row, but on the fore wings it, is broad. The outline of the yellow of the fore wings suggests a head of a dog or of a duck, a prominent black spot on the discal vein serving as the eye. This is an abundant species in the Southeastern and Southwestern States, extending from the Atlantic to the Pacific. The larva feeds on clover, The Black-bordered Yellow, XantJiidia nicippe (Xan- thid'i-a ni-cip'pe). — The wings above are bright orange, marked with blackish brown as follows : on the fore wings a narrow bar at the apex of the discal cell, the apical portion of the wings, and the outer margin ; on the hind wings, the outer margin. In the female the outer marginal band is in- terrupted at the anal angle of each wing, and on the hind wings it may be reduced to an apical patch. The expanse of wings is from one and six tenths inches to one and nine tenths inches. The species occurs from Southern New England to Florida and west to Lower California. The larva feeds on several species of Cassia. The Little Sulphur, Eurema lisa (Eu-re'ma li'sa). — Although this species is larger than the following one it is considerably below the average size of our yellows, the LEPIDOP 7 ERA. 387 larger specimens expanding less than one inch and a half. Tiie wings are canary-yellow above, with the apex of the fore wing and the outer margin of both fore and hind wings blackish brown. The border of the hind wing is narrow and sometimes wanting. The distribution of this species is similar to that of the preceding. The larva feeds on Cassia. The Dainty Sulphur, Nathalis iole (Na-tha'lis i'o-le). — • This little butterfly can be distinguished from all others de- scribed here by its small size, as it expands only from less than one inch to one and one fifth inches. It is of a pale canary-yellow color, with dark brown markings. There is a large apical patch on the fore wings, and a broad band par- allel with the inner margin ; on the hind wings there is a stripe on the basal two thirds of the costa, and spots on the ends of the veins ; these are more or less connected on the margin of the wing, especially in the female. This species also is found from Southern New England to Florida and west to Lower California. It, too, feeds on Cassia. The Cloudless Sulphur, Callidryas eubule (Cal-lid'ry-as eu-bu'le).- — This large butterfly differs greatly in appearance from those described above. It expands two and one half inches. The wings above are of uniform bright canary- yellow. In the male they are without spots, except fre- quently an inconspicuous brown dot at the tip of each vein, and a lilac -brown edging of the costal border. In the female there is a discal dot on the fore wing and a mar- ginal row of brown spots at the ends of the veins. This is a southern species which occasionally extends as far north on the coast as New York City, and in the Missis- sippi Valley as far as Southern Wisconsin. The larva feeds on Cassia. 3^8 THE STUDY OF INSECTS, Family LYCyENID^E (Ly-caen'i-dae). The Gossamer-winged Butterflies. The family Lycaenidae includes butterflies which are of small size and delicate structure. In size they resemble the smaller Hesperiidae ; but they can be distinguished at a glance from the skippers, as they present an entirely differ- ent appearance. The body is slender, the wings delicate and often brightly colored, and the club of the antenna straight. The antennae are nearly always ringed with white, and a conspicuous rim of white scales encircles the eyes. An easily-observed combination of characters by which the members of this fam- ily .-^-v*** ily can be distinguished is the absence of one or two of the branches oi radius of the fore wings, VHi this vein being only three- or four-branched, and the origin of vein V, of the fore wings at or near the apex of the discal cell (Fig. 465). In all other butterflies occurring in our fauna in which radius is only three- or four-branched, vein V, of the fore wings coalesces with radius for a considerable distance beyond the apex of the discal cell. An excep- Fig. 465.— wings of chrysoj>hanus thoe. tion to the characters of the Lycaenidae is presented by Feniseca, as indicated in the table of families, p. 375. A remarkable characteristic of this family is that while in Vi v3 VII, Plate VI. LEPIDOPTERA. 389 the female the front legs are like the other legs, in the male they are shorter, without tarsal claws, and with the tarsi more or less aborted. This reduction of the fore legs is carried even farther in the next family, where it extends to both sexes, and the fore legs are unused. The caterpillars of the Lycaenidae present a very unusual form, being more or less slug-like, reminding one of the larvae of the Eucleidae. The body is short and broad ; the legs and prolegs are short and small, allowing the body to be closely pressed to the object upon which the insect is moving — in fact some of the species glide rather than creep; and the head is small, and can be retracted more or less within the prothorax. The body is armed with no conspic- uous appendages ; but some of the species are remarkable for having honey-tubes which can be pushed out from the seventh and eighth abdominal segments, and through which honey-dew is excreted for the use of ants. Certain other species are remarkable in being carnivorous ; one American species feeds exclusively upon plant-lice. The chrysalids are short, broad, ovate, and without angu- lations. They are attached by the caudal extremity, and by a loop passing over the body near its middle. The ventral aspect of the body is straight and often closely pressed to the object to which the chrysalis is attached. The Lycasnidae include two subfamilies; these can be be separated as follows : — A. Vein II of the hind wings without a branch near the base of the wing (Fig. 465) Lyctenin^e. AA. Vein II of the hind wings giving off a spur (the tip of vein I) near the base of the wing. p. 394 LEMONHNiE. Subfamily Ly(LENI]sle (Ly-cae-ni'nae). The Common Gossamer-zvinged Butterflies. This subfamily includes all of our common members ol the Lycaenidae ; it is composed of three well-marked groups 39° THE STUDY OF INSECTS. of genera, which have been distinguished as the Coppers, the Blues, and the Hair-streaks. I. The Coppers. — The Coppers are easily distinguished from other gossamer-winged butterflies by their orange-red and brown colors, each with a coppery tinge, and conspicu- ous black markings. They are the stoutest of the Lycaenidae. About twenty species are known to occur in this country; the three following will serve as illustrations: — The American Copper, Heodes hypoplilceas (He-o'des hyp-o-phlae'as). — This is the most common of our coppers in the Northeastern States and in Canada. Its range ex- tends also along the boundary between the United States and Canada to the Pacific Ocean, and southward into Cali- fornia ; and in the east along the Alleghany Mountains south to Georgia. It is represented on Plate I (Fig. $). The fore wings are orange-red above, spotted with black, and with a blackish brown outer border ; the hind wings are coppery brown, with a broad orange-red band on the outer margin ; this band is indented by four black spots. The larva feeds on the common sorrel (Rumex acetoselld). The Bronze Copper, CJirysophanus thoe (Chrys-o-pha'nus tho'e). — This is larger than the preceding species, the wings expanding one and one half inches or more. In the male the wings are coppery brown above, spotted with black, and with a broad orange-red band on the outer margin of the hind wings. The female differs in having the fore wings orange-red above, with prominent black spots. This species occurs in the Middle and Western States from the Connecticut Valley to Nebraska. The larva feeds on curled dock (Rumex erispus). The Wanderer, Feniseca tarquinius (Fe-nis'e-ca tar-quin'i- us). — This butterfly can be readily distinguished from all other Lycaenids in our fauna by the fact that vein V, of the fore wings coalesces with radius for a considerable dis- tance beyond the apex of the discal cell. The upper surface of the wings is dark brown, with a large, irregular, orange- LEPIDOPTERA. 39 l yellow patch on the disk of the fore wing, and one of the same color next the anal angle of the hind wing. This species is of unusual interest, as the larva is carniv- orous in its habits. It feeds on plant-lice ; and, so far as observed, it feeds only on the woolly aphids. It is found more often in colonies of the Alder Blight {Schizoneura tes- sellata) than in those of the allied species. It is found from Maine to Northern Florida and westward to Kansas. It is a very local insect, being found only in the neighborhood of water where alder grows. II. The Blues. — The Blues may be distinguished from the other gossamer-winged butterflies by the slender form of the body, and the blue color of the upper surface of the wings. About fifty North American species have been de- scribed; but most of these occur only in the far West. This is a rather difficult group to study owing to the fact that in several cases a single species exists under two or more distinct forms, and also that the two sexes of the same species may differ greatly. It often happens that two indi- viduals of the same sex but of different species resemble each other more closely in the coloring of the upper sur- face than do the two sexes of either of the species. In each of our eastern species the upper surface of the wings of the female is much darker than that of the male. The Spring Azure, Cyaniris pseudargiolus (Cy-a-ni'ris pseud-ar-gi'o-lus). — In this species the hind wings are with- out tails, the eyes are hairy, and the lower surface of the wings is pale ash-gray. This combination of characters will distinguish it from all other blues occurring in the Eastern United States. But the species is not confined to this re- gion, as it occurs in nearly all parts of the United States and in a large part of Canada. This butterfly exhibits polymorphism to the greatest degree of any known species ; nine or ten forms have been described. Two of these are represented on Plate VI (Figs, i and 7). The larva feeds on the buds and flowers of various 392 THE STUDY OF INSECTS. plants, especially those of Cornns, Cimicifuga, anj.— "Wings ol Basilarchiaastyanax. ported only by the tail, which is fastened to a button of silk. 396 THE STUDY OF INSECTS. This is the largest of the families of butterflies. It not only surpasses the other families in number of species, but it contains a greater number and variety of striking forms, and also a larger proportion of the species of butterflies familiar to every observer of insects. There may be in any locality one or two species of yellows or of whites more abundant, but the larger number of species commonly ob- served are four-footed butterflies. Five subfamilies of the Nymphalidae are represented in our fauna. These can be separated by the following table, which is based on one given by Mr. Scudder : — A. With none of the veins of the fore wings unusually swollen at the base. B. Antennae clothed with scales, at least above. C. Fore wings at least twice as long as broad, p. 397. Heliconin^e. CC. Fore wings less than twice as long as broad. D. Palpi much longer than the thorax, p. 396. . LibytheiNjE. DD. Palpi not as long as the thorax, p. 398. . .Nymphalin^;. BB. Antennas naked, p. 397 EuPLCElN/E. AA. With some of the veins of the fore wings greatly swollen at the base. p. 410 Satyrin^e. Subfamily LIBYTHEIN.E (Li-byth-e-i'nae). The Loiig-beaks. The Long-beaks can be easily recognized by their ex- cessively long, beak-like palpi, which are from one fourth to one half as long as the body and project straight forward (Fig. 468). The outer margin of the fore wings is deeply notched ; the males have only four well-developed legs, while Fig. ifii.—Hypatus bachmanni. the females have SIX. Only three species have been found in America north of Mexico; and of these but one occurs in the Eastern United States. LEP1D0P TERA . 397 The Snout Butterfly, Hypatus bachmannii (Hyp'a-tus bach-man'ni-i). — The wings are blackish brown above, marked with orange patches and white spots. The species occurs throughout the Eastern United States, excepting the northern part of New England and the southern part of Florida. The larva feeds on Celtis occidentalis. Subfamily HELIC0NIIN,*E (Hel-i-co-ni-i'nse). The Heliconians (Hel-i-co' ni-ans). This subfamily consists chiefly of tropical butterflies ; a few species, however, extend into the southern portion of our territory. They are of medium or rather large size, and are easily recognized by their narrow and elongated fore wings, which are usually more than twice as long as broad. Subfamily Euplcein^e (Eu-ploe-i'nae). The Euplceids (Eu-plce' ids). These are butterflies of large size, with rounded and somewhat elongated wings, the apical portion of the fore wings being much produced. The absence of scales on the antennae is the most available character for distinguishing these insects. Only a very few species occur in our fauna. The best known of these is the following : — The Monarch, Anosia plexippus (A-no'si-a plex-ip'pus). — The upper surface of the wings is light tawny brown, with the borders and veins black, and with two rows of white spots on the costal and outer borders as shown in Figure 469. The figure represents a female ; in the male the veins of the wings are more narrowly margined with black, and there is a black pouch next to vein VI Ia of the hind wings, containing scent-scales or androconia. The larva feeds upon different species of milk-weed, As- clepias. When full grown it is lemon or greenish yellow, broadly banded with shining black. It is remarkable for bearing a pair of long fleshy filaments on the second thoracic segment, and a similar pair on the seventh abdominal seg- 398 THE STUDY OF INSECTS. merit. The chrysalis is about one inch in length. It is bright green, dotted with gold. This species occurs throughout the greater part of the United States, and is distributed far beyond our borders. Fig. 469. — Anosia plexippus. It is believed, however, that the species dies out each year in a large part of the Northern States, and that those butter- flies which appear first in this region, in June or July, have flown hither from the South, where they hibernate in the adult state. In the extreme South they fly all winter. Great swarms, including many thousands of individuals of this species, are sometimes seen. Subfamily NYMPHALINiE (Nym-pha-li'nae). The Typical NympJialids {Nym-pJia' lids). The butterflies of this subfamily vary so much in the outline and ornamentation of the wings that it is impossible to briefly characterize them. The student, however, will have no difficulty in distinguishing them by means of the table of subfamilies already given. Our genera represent five quite distinct groups, as follows: — I . The Crescent-spots or the Melitceids (Mel-i-tae'ids). — This group includes some of the smaller members of the Nym- LEPIDOPTEKA. 399 phalinae. The color of the wings is sometimes black, with red and yellow spots ; but it is usually fulvous, with the fore wings broadly margined, especially at the apex, with black, and crossed by many irregular lines of black. About fifty species occur in this country. The Baltimore, EupJiydryas phaeton (Eu-phyd'ry-as pha'- e-ton). — The wings above are black, with an outer marginal row of dark reddish-orange spots, and parallel rows of very pale yellow spots; on the fore wings a third row is more or less represented. The wings expand two inches or more. The larvae feed on a species of snakehead {Che lone glabra) ; they are gregarious, and build a common nest by weaving together the leaves of their food-plant. The species occurs in Ontario and the northern half of the United States east of the Rocky Mountains. It is very local, the butter- flies remaining near the bogs »or moist meadows where the food-plant of the larva is found. The butterflies of the genus PJiyciodes (Phy-ci-o'des) and the allied genera abound throughout our country. They are of small size, and of a fulvous color, heavily marked with black. Each species varies considerably in mark- ings, and different species resemble each other quite closely, making this a difficult group for the begin- , -!->• , „„ Fig. 470. — Phyciodes nycteis. ning student. figure 470 repre- sents a common species. II. The Fritillaries (Frit'il-la-ries) or the Argynnids (Ar- gyn'nids). — This group includes butterflies varying from a little below to somewhat above medium size. The color of the wings is fulvous, bordered and checkered with black, but not so heavily bordered as in the crescent-spots. The lower surface of the hind wings is often marked with curving rows of silvery spots. This is a large group containing many species, which are extremely difficult to separate. More than fifty species occur in America north of Mexico. The larvae feed upon the leaves of violets. 4oo THE STUD Y OF INSECTS. The Great Spangled Fritillary, Argynnis cybele (Ar-gyn'« nis cyb'e-le). — This species (Fig. 471) will serve to illustrate FlG. 471. — Argynnis cybele. the appearance of the larger members of this group, those belonging to the genus Argynnis. In this genus vein III, of the fore wings arises before the apex of the discal cell. There are a number of common fritillaries which resem- ble the preceding in color and markings but which are much smaller, the wings expanding considerably less than two inches. These belong to the genus BrentJiis (Bren'this). In this genus vein III2 of the fore wings arises beyond the apex of the discal cell. The Variegated Fritillary, Euptoieta claudia (Eup-toi-e'ta clau'di-a). — This butterfly agrees with the smaller fritillaries {Brenthis) in the origin of vein III, of the fore wing beyond the apex of the discal cell, but differs from them in the shape of the fore wing, the apex of which is much more produced Fig. w.-Euptoieta cUudia. ^pjg> ^^ an(j ^g outer margin, except at the apex, concave ; it is also considerably larger. This species occurs throughout the United States east of LEPIDOP TERA. 40I the Rocky Mountains ; but it is very rare in the northern half of this region. ^ III. The Angle-wings or the Vanessids (Va-nes'sids). — To this group belong many of our best-known butterflies. With these the outer margin of the fore wings is usually decidedly angular or notched as if a part had been cut away. A large proportion of the species hibernate in the adult state, and some of them are the first butterflies to appear in the spring. Some of the hibernating species, however, remain in conceal- ment till quite late in the season. The Red Admiral, Vanessa atalanta (Va-nes'sa at-a- lan'ta). — The wings are purplish black above. On the fore wing there is a bright orange-colored band beginning near the middle of the costa, and extending nearly to the inner angle ; between this and the apex of the wing are several white spots, as shown in Figure Fig. 473. — Vanessa atalanta. 473 ; on the hind wing there is an orange band on the outer margin inclosing a row of black spots. The lower surface of the wings is shown on Plate I, Fig. 6. The larva feeds chiefly on nettle and on hop. When first hatched it folds together a half-opened leaf at the sum- mit of the plant ; when larger it makes its nest of a lower expanded leaf. There are two broods ; both butterflies and chrysalids hibernate. This butterfly occurs over nearly the whole of the European and North American continents. The Painted Beauty, Vanessa hunt era (Va-nes'sa hun'- te-ra) — The wings above are very dark brownish black, with large irregular spots of golden orange. In the apical portion of the fore wings there are several white spots, as shown 402 THE STUDY OF INSECTS. in Figure 474. The lower surface of the wings is repre- sented on Plate I, Fig. 7. A characteristic feature is the presence of two submarginal eye-like spots on the hind wing. The larva feeds on everlasting {Gnaphaliuni) and allied plants. The species occurs in Ontario and nearly the whole of the United States. FlG. 474. — Vanessa kuntera. The Cosmopolitan Butterfly, Vanessa carditi (V. car'dll-i). — The butterfly resembles the preceding very closely in color and markings. There is, however, a smaller propor- tion of orange markings ; and on the lower surface of the hind wings there is a submarginal row of four or five eye- like spots. The larva feeds upon Compositae, especially thistles. This species is very remarkable for its wide distribution. Mr. Scudder states that "with the exception of the arctic regions and South Ameri- ca it is distributed over the entire extent of every continent." The American Tor- toise-shell, Aglais milberti (Ag'la-is mil-ber'ti).— The wings above are brownish F,t black, with a broad orange- fulvous band between the middle and the outer margin. LKP1D0P IERA. 403 There arc two fulvous spots in the di seal-cell of the front wing (Fig. 475). The larvae feed upon nettle {Urtica) ; they are gregarious in their early stages. This species occurs. in the northern portions of the United States and in Canada. The Mourning-cloak, Euvanessa antiopa (Eu-va-nes'sa an-ti'o-pa). — The wings above are purplish brown, with a broad yellow border on the outer margin sprinkled with brown, and a submarginal row of blue spots. The upper surface is represented by Figure 476, the lower by Plate VI, Fig. 5- The larvae live on willow, elm, poplar, and Celtis ; they are gregarious, and often strip large branches of their leaves. The species is usually two-brooded. " This butter- Fig. 476. — Euvanessa antiopa. fly is apparently distributed over the entire breadth of the Northern Hemisphere below the Arctic Circle as far as the thirtieth parallel of latitude " (Scudder). The Compton Tortoise, Eugonia j-album (Eu-go'ni-a j-al'- bum). — This butterfly (Fig. 477) resembles in its general appearance those of the genus Polygonia, but it is sharply dis- tinguished from them by the inner margin of the fore wings being nearly straight, by the heavier markings of the fore 404 THE STUDY OF INSECTS. wings, and by the presence of a whitish spot on both fore and hind wings, near the apex, and between two larger black patches. On the lower surface of the hind wings there is a small L-shaped silvery bar. This species occurs Fig. 477. — Eugenia j-album. throughout Canada and the northern portion of the United States east of the Rocky Mountains. Polygonia (Pol-y-go'ni-a). — The butterflies of this genus resemble the preceding species in having a metallic spot on the lower surface of the hind wings, but differ in having the inner margin of the fore wings roundly notched beyond the middle. Nearly a dozen species occur in this country. These differ principally in the coloring and markings of the under surface of the hind wings. The following are some of the more common ones : — The Green Comma, Polygonia /annus (P. fau'nus). — The silvery mark of the hind wings is usually in the form of a C or a G, the ends being more or less expanded (Plate VI, Fig. 2), but sometimes it is reduced to the form of an L. The lower surface of the wings is more greatly variegated than in any other species of this genus ; and there is a larger amount of green on this surface than in any other of the eastern species, there being two nearly complete rows o' green spots on the outer third of each wing. The larva feeds upon black birch, willow, currant, and LEPWorrERA. 405 wild gooseberry. This is a Canadian species ; but it is also found in the mountains of New England and of New York, and in the northern portions of the Western States, extend- ing as far south as Iowa. The Hop-merchant, Polygonia comma {¥. com'ma). — As in the preceding species, the silvery mark of the hind wings is in the form of a C or a G (PI. VI, Fig. 3) ; but the general color of the lower surface of the hind wings is very different, being marbled with light and dark brown ; and the green spots so characteristic of /annus are repre- sented here by a few liliaceous scales on a submarginal row of black spots. Two forms of this species occur. In one, P. comma dryas, the hind wings above are suffused with black on the outer half, so that the submarginal row of fulvous spots is ob- scured, and on the lower side the wings are more yellowish than in the other form. The latter is known as P. comma harrisii (P. c. har-ris'i-i). The larva feeds upon hop, elm, nettle, and false-nettle. It is often abundant in hop-yards, and the chrysalids are commonly known as hop-merchants, from a saying that the golden or silvery color of the metallic spots on the back of the chrysalis indicates whether the price of hops is to be high or low. This species is found in Canada and the northern part of the eastern half of the United States; its range extends south to North Carolina, Tennessee, Arkansas, and Indian Territory. The Gray Comma, Polygonia progne (P. prog'ne). — In its general appearance this butterfly closely resembles P. comma, but it can be readily distinguished by the form of the silvery mark, which is L-shaped and tapers towards ':he ends. The larva feeds on currant, wild gooseberry, and rarely elm. This species occurs in Canada and in the northern por- tion of the United States except in the extreme West. The Violet Tip, Polygonia interrogationis (P. in-ter- 406 THE STUDY OF INSECTS. ro-ga-ti-o'nis). — This butterfly (Plate VI, Fig, 8) is some- what larger than the preceding species of Polygonia, and differs in the form of the silvery mark, which consists of a dot and a crescent, resembling somewhat an interrogation- mark, but more nearly a semicolon. On the upper side the outer margins of the wings and the tails of the hind wings are tinged with violet. This species is dimorphic ; and the two forms differ so constantly and in such a marked manner that they were described as distinct species. In P. interrogations fabricii (P. i. fa-bric'i-i) the upper surface of the hind wings is not much darker than that of the fore wings, and there is a submarginal row of fulvous spots in the broad ferruginous brown border. In P. intcrrogationis umbrosa (P. i. um-bro'sa) the outer two thirds of the upper surface of the hind wings is blackish, and the submarginal fulvous spots are obliterated, except some- times faint traces near the costal margin. This species is found in Canada and throughout the United States east of the Rocky Mountains. IV. The Sovereigns. — These butterflies differ from other Nymphalinae in having the club of the antennae marked by four slightly elevated lines, and in that veins I, II, and III of the hind wing (Fig. 467, p. 395) separate at the same point. This group includes some of our most elegant but- terflies ; the larvae are grotesque in appearance, being very irregular in form and strikingly mottled or spotted. The Banded Purple, Basilarchia artJiemis (Bas-i-lar'chi-a ar'the-mis). — The upper surface of the wings is velvety chocolate-black, marked with a conspicuous white bow (Fig. 478). This is a Canadian species which extends a short distance into the northern part of the United States ; the larva feeds on birch, willow, poplar, and many other plants. The Red Spotted Purple, Basilarchia astyanax (B, as-ty'a-nax). — The upper surface of the wings is velvety indigo-black, tinged with blue or green. There are three LEPIDOPTEKA. 407 rows of blue or green spots on the outer third of the hind wings : the spots of the inner row vary greatly in width in different individuals. On the lower surface there is a reddish orange spot in the discal cell of the fore wings, and one on the discal vein ; on the hind wings there are two orange spots- similarly situated, a third at the base of cell II, and a row of Fig 478. — Basilarchia arthetnis. seven spots just within a double row of submarginal blue or green spots. This species occurs throughout nearly the whole of the Eastern United States south of the 43d parallel of latitude. The larva feeds on many plants ; among them are plum, apple, pear, and gooseberry. The Hybrid Purple, Basilarchia astyanax-arthemis. — There occurs, along a narrow belt of country extending from southern Wisconsin and northern Illinois eastward to the Atlantic coast of New England, a butterfly that closely re- sembles the Red-spotted Purple, but which has more or less of the white band of the Banded Purple. This is believed to be a hybrid between these two species. The region in which it occurs is that in which the ranges of the two species overlap. North of this region, of these three forms only the Banded Purple occurs ; south of it only the Red-spotted Purple is found. The Viceroy, Basilarchia archippus (B. ar-chip'pus). — The wings vary in color from a dull yellow orange tinged 408 THE STUDY OF INSECTS. slightly with brown to a dark cinnamon color ; they are bordered with black, and all the veins are edged with the same color (Fig. 479). The fringe of the wings is spotted with white, and the black border on the outer margin con- tains a row of white spots. Fig. 479 — Basilarchia arc/iippus. This species is remarkable for its resemblance to the Monarch (Anosia plexippus, Fig. 469). But aside from the structural characters separating the two subfamilies which these butterflies represent, the Viceroy can be easily distin- guished from the species it mimics by its smaller size, and by the presence of a transverse black band on the hind wings. It is believed that the resemblance of these two species is not merely accidental, but is a result of the action of the law of natural selection. The butterflies of the subfamily to which the Monarch belongs (Euplccince) are exempt from the attacks of birds. It is supposed that this exemption is due to the possession by these butterflies of a disagreeable odor. With such an odor the conspicuous coloring of the butterflies is protective, the birds soon learning that such butterflies are not fit for food. And it can be seen that these birds will naturally leave undisturbed any other butterflies LEPIDOPTERA. 4O9 that resemble the ill-smelling ones, even though they do not possess a similar odor. According to the theory of natural selection these resemblances have been produced as follows. In the case of a variable species that is unprotected by any disagreeable quality, any variation towards a protected spe- cies will tend to preserve the life of the individual possessing it. And in turn such offspring of these individuals as still more nearly resemble the protected species will be most likely to be preserved. The continued action of this natural selection will result in producing a species that closely re- sembles the protected one, even though it may be very different structurally from the one that it mimics. Many instances of unconscious mimicry of this kind are known. They are especially abundant in the tropics where the foul-smelling Hcliconince are most abundant. The bad odor of these butterflies when living is so marked that it can be detected by the human nose; and it is found that many species of them are mimicked by other butterflies, and especially those of the Pieridae. The mimicry is not con- fined to similarity in coloring, but extends to the shape of the wings and manner of flight. The larva of the Viceroy feeds upon willow, poplar, balm of gilead, aspen, and Cottonwood. The species two- or three- brooded, and hibernates as a partially grown larva in a nest made of a rolled leaf. This nest is lined with silk, and the leaf is fastened to the twig with silk so that it can- not fall during the winter. Mr. Scudder states that so far as is known to him all of the species of the Sovereigns hi- bernate as larvae in nests of this kind. It is worthy of note that only the autumn brood of caterpillars make these nests. So that the nest-building instinct appears only in alternate generations, or even less frequently when the species is more than two-brooded. B. arcJiippus is found over nearly the whole of the United States as far west as the Sierra Nevada Mountains, and has been found sparingly even to the Pacific coast near our northern boundaries. 4IO THE STUDY OF INSECTS. As Anosia plexippus has been termed the Monarch, this species is aptly called the Viceroy. V. The Emperors. — The butterflies of this group are found chiefly in the southern part of our country. The fol- lowing is the best known species : — The Goat-weed Butterfly, Aneza andria (A-nae'a an'- dri-a). — The female of this species can be easily recognized by Figure 480. The male is smaller, with wings of a rich Fig. 480. — Aniza andria. dark orange, margined with brown, and without the light- colored band characteristic of the female. This species is found in the Western States from Illinois to Texas. The larva feeds on goat-weed (Crotoii). Subfamily SATVRINyE (Sat-y-ri'nae). The Meadow-broxvus or Satyrs. This subfamily includes chiefly brown butterflies whose markings consist almost entirely of eye-like spots. Some western species, however, are bright-colored. Our forms can be easily recognized by their having some of the veins of the fore wings greatly swollen at the base. The larvae are cylindrical, tapering more or less towards each end. The caudal segment is bifurcated, a character that distinguishes them from all other American butterfly LEPIDOPTEKA. 411 A L &*W, Fig. 4S1. — Satyrodes eurydice. larvae excepting those of some of the Emperors (C/i/orippe), not described in this book. Nearly sixty species belonging to this subfamily have been described from America north of Mexico. The Eyed Brown, Satyrodes eurydice (Sat-y-ro'des eu- ryd'i-ce). — The upper surface of the wings is soft mouse- brown on the basal half and paler beyond, considerably so in the female ; each wing bears a row of four or five small black eye-like spots (Fig. 481). This species is found in Onta- rio, and throughout the east- ern half of the United States. The Dull-eyed Grayling, Cercyonis nephele (Cer-cy'o-nis neph'e-le). — The two most conspicuous of the Meadow- browns that occur east of the Rocky Mountains are this and the following one ; they are comparatively large species, expanding from two inches to two and one fourth inches ; both are dark brown. In this species there are on the upper surface of the fore wing on the outer third of the wing two black spots with white or bluish centers ; sometimes the wing is tinged with yellow in the vicinity of these spots, but generally the tinge is very slight, and it is never so deep as in the next species; the hind wing is with or without a spot in cell VII, , and sometimes with a spot on either side of this one. On the lower surface the eye-like spots of the fore wings are distinctly ringed with yellowish ; and the hind wings are with or without eye-like spots, usually with six of them. (See the Hybrid Graylings, below.) The Blue-eyed Grayling, Cercyonis alope (C. al'o-pe). — This species closely resembles the preceding, but it is dis- tinguished by the presence of a distinct yellow or pale orange band on the outer half of the fore wings. 412 THE STUDY OF INSECTS. The larvae of both of these species feed upon grass ; the butterflies fly during the latter half of the summer, and the larvae begin hibernating as soon as hatched. The Hybrid Graylings, Cercyonis alope-nephele. — The Dull-eyed Grayling is a northern species, occurring in Canada and the northern part of the United States. The Blue-eyed Grayling is found throughout the greater part of the United States east of the Rocky Mountains, except in the extreme North and South. The ranges of the two overlap in the southern portions of New England, New York, Michigan, Wisconsin, Iowa, and Nebraska; and in the northern portions of Illinois, Indiana, and Ohio. In this belt both species occur, and also intergrades between them ; these intergrades may be called Hybrid Graylings. The White Mountain Butterfly, CEneis semidea (CE-ne'is se-mid'e-a). — Comparatively few students who study this book will collect this butterfly; but we refer to it on ac^ count of its remarkable distribution. It is found only on the higher parts (above 5000 feet) of the White Mountains in New Hampshire, and on the highest peaks of the Rocky Mountains of Colorado, above 12,000 feet. These two widely separated colonies of this butterfly are believed to be the remnants of an Arctic fauna which was forced southward during the Ice Age. At the close of this period, as the Arctic animals followed the retreating ice northward, the tops of these mountains became colonized by the cold-loving forms. Here they found a congenial resting place, while the main body of their congeners, which occupied the intervening region, was driven northward by the increasing heat of the lower land. Here they remain, clinging to these islands of cold projecting above the fatal sea of warmth that fills the valleys below. CHAPTER XIX. Order DlPTERA (Dip'te-ra). The Flies. The members of this order have only two wings ; these are borne by the mesothorax. The metathorax is furnished with a pair of knobbed threads, the haltercs. The mouth- parts are formed for sucking. The metamorphosis is com- plete. To the order Diptera belong all insects that are properly termed flies, and only these. The word "fly" forms a part of many compound names of insects of other orders, as butterfly, stone-fly, May-fly, and Chalcis-fly ; but when used alone, it is correctly applied only to dipterous insects. To some flies other common names have been applied, as mosquito, gnat, and midge. The name Diptera is from two Greek words : dis, two, and pteron, a wing. It was suggested by the fact that the flies are distinguished by the possession of a single pair of wings; for no fly has more than two wings, and only a few are wingless. The wings of flies are thin, membranous, and usually either naked or clothed with microscopic hairs; but with mosquitoes the wings bear scales, and with the moth-like flies (Psychodidae) and some others the clothing of hairs is very conspicuous. The hind wings are represented by a pair of knobbed threads, the halteres (hal-te'res) ; these can be easily seen in a crane-fly (Fig. 482). The function of 413 414 THE STUDY OF INSECTS. these rudimentary wings is not known ; but they doubtless have some important use, for they are present in nearly all flies, even when the front wings are wanting. The mouth-parts of flies are formed for sucking, and sometimes also for piercing. Their structure differs greatly in different families; and in some cases it is exceed- ingly difficult to determine the correspondence of the different parts. In the more typical forms the mouth-parts consist of six bristle -like or lance -like organs enclosed in a sheath, and a pair of jointed palpi. A difference of opinion exists as to the corre- FlC. 482.-A crane-fly, showing wings and SpOlldeilCe of these parts ; halteres- but according to the most generally accepted view the six bristles represent the upper lip (labrutti), the tongue (JiypopJiarynx), the two man- dibles, and the two maxillae, and the sheath enclosing these bristles is the lower lip {labium). The palpi which are not enclosed in the sheath are the maxillary palpi. At the tip of the lower lip there is, on each side, a lobe-like appendage ; these are the labial palpi. The labial palpi of certain flies are quite large ; in the House-fly, for example, they are ex- panded into broad plates, which are fitted for rasping. In their transformations flies pass through a complete metamorphosis. The larvae are commonly called maggots. These are usually cylindrical and are footless; some possess a distinct head, others do not; the form of the mouth-parts varies greatly in the different families; and there are re- markable variations in the form of the respiratory organs, especially as to the number and position of the spiracles. The pupse are usually either naked or enclosed in the last DJPTERA. 415 larval skin. A few are enclosed in cocoons. When the pupa state is passed within the last larval skin the body of the pupa separates from the larval skin more or less com- pletely ; but the larval skin is not broken till the adult Ax- is ready to emerge. In this case the larval skin, which serves as a cocoon, is termed a pupariiun (pu-pa'ri-um>. In some families the puparium retains the form of the larva; in others the body of the larva shortens, assuming a more or less barrel-shaped form (^Fig. 483, 2), before the change to a pupa takes place. This is a large order, both in number of species and individuals. The spe- cies differ much in habits. Some are very annoying to man. Familiar examples are the mosquito, which attacks his person : the flesh-flies, which infest his food ; the bot-flies and gad- flies that torment his cat- tle ; and the gall-gnats that destroy his crops. Other species are very beneficial. T|lncp helnncrincr to the Fig. 483.- The Apple-maggot: i. larva: 2. pupa- inose Deionging 10 tne rium . 3 adult . ia> head of larTa (rom side ^-rnVnrl:** anH fn rrif» c,,K showing mouth-parts and cephalic spiracle ; c?\ rpnias, ana to me sud- id head of larTa from bei0w: ic. caudal family Tachinin^ of the spiracle of larva" Muscidae destroy many noxious insects ; and very many species, while in the larval state, feed upon decaying animal and vegetable matter, thus acting as scavengers. Although the habits of these creatures, which revel in all kinds of filth, are very disgusting, we cannot help admir- ing that arrangement by which a mass of filth, instead of 416 THE STUDY OF INSECTS. Fig. 484. being left to poison the atmosphere, is transformed into myriads of living beings, whose swift flight and delicate forms lend life and beauty to the landscape. SYNOPSIS OF THE DIPTERA. The Straight- Seamed Flies.— Flies in which the pupa escapes from the larval skin through a T-shaped opening, which is formed by a lengthwise split on the back near the head end and a crosswise split at the front end of this (Fig. 484), or rarely through a crosswise split be- tween the seventh and eighth abdominal segments, adults without a frontal lunule.* Suborder Orthorrhapha (Or-thor'rha plia). The Long-horned Orthorrhapha or Nematocera (Nem-a-toc'e-ra). Flies with four- or five-jointed pendulous palpi and with many- jointed antennae, which are usually long. The segments of the antennae, except the basal two, are similar in form, and are more than six in number; they are often fringed with hairs or bristles. f * The frontal Inutile is a small crescent-shaped piece immediately above the antennae, which is characteristic of the second suborder, the Cyclor- rhapha. In most of the members of this suborder there is a suture separating the lunule from that part of the head above it, the frontal suture; and frequently this suture extends down on each side to near the mouth (Fig. 485). But as the suture is wanting in several families of the Cyclorrhapha, it is often difficult to determine whether the lunule is present or not. The following statement will enable the student to recognize nearly all of the members of the first suborder. The suborder Orthorrhapha includes : — All flies in which the antennas are more than three-jointed, not counting a bristle or style borne by the third segment. All flies with three-jointed antennae in which vein III is four-branched. Such of the flies in which vein VII3 appears like a cross-vein, or curves back towards the base of the wing, as lack the suture above the antennae. This section includes only a few Empididae and the families Do'ichopodidae and Lonchopteridae. Nearly all of the flies in which vein VII3 is of the form described here possess the suture above the antennae, and hence belong to the Cyclorrhapha. f The two types of antennae characteristic of the Nematocera and Brachycera respectively are connected by intermediate forms. These Fig. 485. — Head showing frontal suture DIPThRA. 417 The True Nematocera. The antennae usually long and frequently bearing whorls of long hairs, especially in the males ; legs long and slender; abdomen usually long and slender. The Moth-like Flies, Family PsYCHODlDiE. p. 428. The Midge-like Flies. The Crane-flies, Family TiPULiDiE. p. 429. The Net-winged Midges, Family BlepharoceriDjE, p. 432. The Dixa-midges, Family DixiDiE. p. 436. The Mosquitoes, Family CuliciDjE. p. 437. The Midges, Family Chironomid^e. p. 440. The Fungus-gnats, Family Mycetophilid/E. p. 442. The Gall-gnats, Family Cecidomyiid/e. p. 444. The Anomalous Nematocera. The antennae are composed of many segments, but are shorter than the thorax, and without whorls of long hairs. The segments of the antennae are short and broad and closely pressed together. Except in the first family, the abdomen is comparatively stout, and the legs are shorter and stouter than in the True Nematocera. The False Crane-flies, Family Rhyphid^E. p. 448. The Solitary-midge, Family OrphnephiliDjE. p. 449. The March-flies, Family Bibionidje. p. 449. The Black-flies, Family Simuliid^e. p. 451. The Short -homed Orthorrhapha or Brachycera (Bra-chyc'e-ra). Orthorrhapha with one- or two-jointed, porrect palpi, and with usually short, three-jointed antennae. The third segment of the antenna is sometimes distinctly ringed, showing that it is really composed of many segments grown together; and sometimes the antennae are four- or five-jointed. The Anomalous Brachycera. The third segment of the antenna is ringed, showing that it is composed of" several segments grown together. The body is not furnished with strong bristles. The Horse-flies, Family Tabanidje. p. 453. occur in those families grouped below as the Anomalous Brachycera (see Figs. 489, 490, and 492). The Nematocera and Brachycera are more sharply distinguished by the form of the palpi, as indicated in this Synopsis ; but sometimes it is difficult to see the palpi. A more easily seen distinction is presented by the venation of the wings. In the Anomalous Brachycera cell Va is divided by a cross-vein and cell VIII is closed before the margin of the wing or is greatly narrowed at the margin of the wing (see Figs. 539, 545, and 551). In the Nematocera cell VIII is never closed, and cell Va is divided only in the Tipulidae and Rhyphidae, and in these families the antennae are distinctly composed of many segments. 23 41 S THE STUDY OF INSECTS. The Soldier-flies, Family Stratiomyiid/E. p. 455. The Snipe-flies (in part), Family Leptid/E. p. 456. The True Brachyccra. The antennae are usually three-jointed, but sometimes four- or five-jointed ; the third segment is not ringed, but usually bears a style or bristle.* The body is usually furnished with strong bristles. True Brachycera with the empodia pulvilliform. Flies in which there are three membranous lobes beneath the tarsal claws (Fig- 495)-t The Snipe-flies (in part), Family Leptid^e. p. 456. The Small-headed Flies, Family Acrocerid^e. p. 458. The Tangle -veined Flies, Family Nemistrinid^e, p. 459. True Brachycera with the empodia 7iot pulvilliform. Flies in which there are only two membranous pads beneath the tarsal claws (Fig. 494). Vein III of the wings four-branched. The Robber-flies, Family Asilid^e. p. 460. The Midas-flies, Family Midaid/E. p. 461. The Apiocerids, Family Apiocerid^e. p. 462. The Bee-flies, Family BombyliDvE. p. 463. The Stiletto-flies, Family Therevim:. p. 464. The Window-flies, Family Scenopinid^e. p. 465. The Dance-flies (in part), Family Empidid^;. p. 466. Vein III of the wings three-branched. The Dance-flies (in part), Family Empidid^E. p. 466. The Long-legged Flies, Family Dolichopodid^e. p. 467. The Spear-winged Flies, Family Lonchopterim:. p. 469. The Circular-Seamed Flies. — Flies in which the pupa escapes from the larval skin through a circular orifice made by push- ing off the head end of it (Fig. 486). Adults with a frontal lunule. Suborder Cyclorrhapha (Cy-clor'rha- pha). Cyclorrhapha without a frontal suture (Aschiza). The Syrphus-flies, Family SyrphiD/E. p. 470. The Big-eyed Flies, Family Pipunculida:. p. 473. Fig. 486. ^he Flat-footed Flies, Family PlatypeziDjE. p. 474. The Humpbacked flies, Family Phorid.e. p. 475. * A similar type of antenna is possessed by the Cyclorrhapha, which were formerly on this account included in the Brachycera ; but this term is now restricted to the Short-horned Orthorrhapha. f The empodia are pulvilliform in the Anomalous Brachycera also ; but that group is easily distinguished by the form of the antennae. DIPTERA. 419 Cyclorrhapha with a frontal suture (Schizophora) Normal Schizophora. The Thickhead-flies, Family CONOPID^E. p. 476. The Bot-flies, Family CESTRID/E. p. 477. The Muscids, Family Muscid.e. p. 479. The Pupa-bearing Flies (Pupipara). The Louse-flies, Family Hippo roscidje. p. 487. The Bat-ticks, Family Nyctf.ribiid/E. p. 489. The Bee-louse, Family BRAULiDiE. p. 489. Classification of the Diptera. {For advanced students.) In the following table for determining the families of the Diptera use is made chiefly of characters based on the form of the head, an- tennae, and wings. The more important of the characters presented by the head are the presence or absence of the frontal lunule, and the presence or ab- sence of the frontal suture when the lunule is present. (See page 416, note.) In those families that possess the frontal suture there exists a large bladder-like organ, the ptilinum (ptil'i-num), which is pushed out through this suture when the adult is about to emerge from the puparium. In this way the head end of the puparium is forced off, making a large opening through which the adult escapes ; afterwards the ptilinum is withdrawn into the head. If a specimen is captured soon after its emergence from the puparium, there may be seen in- stead of the frontal suture the bladder-like ptilinum projecting from the head, immediately above the antennae. The form of the antennae is of prime importance in determining to what family a fly belongs. In the more generalized families the antenna consists of many segments, which, except the basal two, are similar in form (Fig. 487). Frequently such antennae bear whorls of long hairs (Fig. 488). In the more specialized families there is a re- duction in the number of segments of the antenna. This is brought about either by a more or less complete consolidation of the segments beyond the second into a single segment (Figs. 489 and 490), or by a dwindling of the terminal segments, so that they form merely a slen- der style (Fig. 491) or bristle (Fig. 492). Such a bristle is termed by many writers the arista (a-ris'ta). In most cases where a stvle or arista exists it is borne by the third segment, and this segment is then usually greatly enlarged. When the enlargement of this segment has taken place evenly the style or arista is terminal; but frequently one part of the third segment is expanded so that it projects beyond the 420 THE STUD V OF INSECTS. insertion of the arista (Fig. 493) ; then the arista is said to be dorsal. The legs vary greatly in length and in stoutness. The coxae are usually long, and in most of the fungus-gnats (Mycetophilidae) they are very long. When pulvilli are developed they are membranous pads, one beneath each tarsal claw. A third appendage, the etnpo- dium (em-po'di-um), often exists between the two pulvilli of each tar- FlG. 487. Fig. 488. Fig. 489. Fig. 490. Fig. 491. sus. The empodia may be bristle-like, or tapering (Fig. 494), or membranous, resembling the pulvilli in form (Fig. 495); in the last case they are described as pulvill/form. Variations in the form and venation of the wings afford charac- ters that are much used in the classification of flies. In many fami- Fig. 492. Fig. 493. Fig. 494. Fig. 495. lies there is a notch in the inner margin of the wing near its base (Fig. 496, a e) ; this is the axillary excision; that part of the wing lying between the axillary excision and the base of the wing is the posterior lobe (Fig. 496,/). In certain families there is a membrane beneath the base of the wing and above the halter or rudimentary DIPTERA. 421 hind wing; this is the. alula (al'u-la) or alulet (al'u-let). The alula? are well developed in the common House-fly. Each alula, in those species where the alulae are Well developed, consists of two lobes which fold over each other when the wings are closed. The alulse are called the tegulce by many writers on Diptera; but the term tegula 1TII1 iTTTm 2114+s Vlh+IX Fig. 496. — Wing of Conops; ae, axillary excision ; /, posterior lobe. was first used in insect anatomy for the cup-like scale which covers the base of the wing in certain insects, as most Hymenoptera, and should be restricted to that use. The terms alula and alulet are also often misapplied, being used to designate the posterior lobe of the The plan of the venation of the wings can be easily learned by a study of the wing of Rhyphus (Fig. 497), which is very generalized in structure, except that vein III is only three-branched, while in cer- tain still more generalized forms it is five branched (e.g., Protoplasa, Fig. 504; and Psychoda, Fig. 500). In the figures of wings in this chapter both the veins and the cells are numbered. The numbers outside of the margin of the wing refer to the veins; those within, to the cells, except when otherwise indicated by a dotted line or by an arrow. It should be remembered that each cell bears the same num- ber as the vein that forms its front margin when the wings are spread. When a cell is divided by a cross-vein the two parts are numbered 1st and 2d. Thus in Rhyphus, cell Va is divided, and the parts are designated as the 1st cell V2 and the 2d cell V2 (Fig. 497, 1st Va , 2d V»). A cross-vein is marked cv. In the Diptera veins IV and VI are not developed. Vein lex- tends along the costal margin of the wing ; it usually ends somewhere near the apex of the wing; in Rhyphus it ends at the tip of vein III4+» (Fig. 497). In some families it extends entirely around the wing; it is then called the ambient vein. Vein II is simple. Vein III is typi- cally five-branched ; but the number of branches is usually reduced to 422 THE STUDY OF INSECTS. four or to three. Vein V is three-branched in the more generalized forms. Vein VII is two-branched. Vein VIII is usually merely a concave fold just behind vein VII and parallel with that vein; it is represented in most of the figures of wings by a dotted line. Vein IX is usually present; and sometimes vein XI also exists. One of the most marked features in the specialization of the wings of Diptera is a tendency of the veins to coalesce from the margin of the wing towards the base. This is illustrated by the wing of Cotwps (Fig. 496). In this genus veins III4+& and V]+2 coalesce at the mar- gin of the wing; veins Vs and VII, coalesce for nearly their entire !"■ in, i»4+s « VII, Fig. 497. — Wing of Rhyphus. length. The result of this coalescence is to cause the free part of vein V3 to appear like a cross-vein between cells V and the 1st cell V2. Veins VII2 and IX also coalesce at the margin of the wing. In a few genera of flies certain longitudinal veins are bent so as to form a sharp angle, and from this angle a spur is developed. Thus in Protoplasa there is a sharp angle near the base of vein III2+8 which bears a spur (Fig. 504, s) ; in Erax a similar spur is formed on vein III4 (Fig. 559, s) ; and in Pantarbes this spur on vein III4 is prolonged so as to form a complete cross-vein dividing cell 1 1 13 into two parts (Fig. 564)- TABLE FOR DETERMINING THE FAMILIES OF THE DIPTERA. A. Flies in which the abdomen is distinctly segmented, and the two legs of each thoracic segment are not widely separated. Habits various, but the adults do not live parasitically upon either birds or mammals. B. Antennae consisting of more than three segments. (Note that a style or bristle borne by the third segment is not counted as a segment.) DIPTERA. 423 C, Antennae consisting of more than five distinct segments, the segments beyond the second not consolidated; cell VIII of the wings but slightly narrowed at the margin of the wing, if at all ; palpi usually elongate, and composed of from three to live segments. D. Small moth-like flies, with the body and wings densely clothed with hairs and scales. Wings with from nine to eleven longitudinal veins, but with no cross-veins except sometimes near the base of the wings (Fig. 500). p. 428. PSYCHODIDiE. DD. Flies that do not resemble moths in appearance. E. Dorsum of thorax with a distinct V-shaped suture (Fig. 503). p. 429 TlPULIDiE. EE. Dorsum of thorax without a distinct V-shaped suture. F. Vein V of the wings three-branched; cell Va divided by a cross-vein (Fig. 527). p. 44S RhyphiDjE. FF. Vein V of the wings simple or two-branched ; cell V» not divided by a cross-vein. G. Wings with a network of fine lines near the outer and inner margins in addition to the veins (Fig. 506). p. 432 BLEPHAROCERlDiE. GG. Wings without a network of fine lines. H. The margin of the wings and each of the wing- veins fringed with scales (Fig. 512). p. 437. CULICIDjE. HH. The wing-veins with or without a fringe of hairs, but without a fringe of flat scales. I. Anal veins entirely wanting; vein V wanting or at most represented by a single unbranched fold (Fig. 522). p. 444 Cecidomyiid^e. II. Anal veins present or represented by folds ; vein V present or at least represented by a fold which is usually branched. J. Ocelli present. K. Antennae shorter than the thorax; legs comparatively short and stout ; coxae not un- usually long, p. 449 Bibionid^e. KK. Antennae usually longer than the thorax; legs slender, and with greatly elongate coxae (Fig. 518). p. 442 Mycetophilid^e. JJ. Ocelli absent. K. Antennae short, not clothed with long hairs, 424 THE STUDY OF INSECTS. and with most of the segments wider than long (Fig. 533) ; wings very broad (Fig. 534). p. 451 SlMULIIDiE. KK. Antennae either bushy, being densely clothed with long hairs or slender with nar- row segments ; wings narrow or moderately broad. L. Wing-veins well developed on all parts of the wing. M. Vein IIIi ending at or near the end of the second third of the costal margin. p. 449 ORPHNEPHILIDjE. MM. Vein IIIi ending on the outer margin of the wing (Fig. 509). p. 436. . Dixid^e. LL. Wing-veins much stouter near the costal margin of the wing than elsewhere (Fig. 517). p. 440 Chironomid^e. CC. Antennae either consisting of four or five distinct segments or consisting of five or more segments, with those beyond the second more or less closely consolidated so as to appear as a single segment consisting of several subsegments (Figs. 489, 490, 492, and 537) ; cell VIII closed by the coalescence of the tips of veins VII2 and IX, or greatly narrowed at the margin of the wing ; palpi rarely elongate, and composed of from one to three segments. D. Antennae consisting of four or five distinct segments, empodia wanting or bristle-like. E. Vein Ills not curved forward towards the costal margin of the wing (Fig. 559). p. 460 Asilid^? EE. Vein Ills curved forward towards the costal margin o' the wing (Fig. 561). p. 461 Midaid^e. DD. Antennae consisting of five or more segments, but with those beyond the second more or less closely consolidated ; empodia resembling pulvilli in form (Fig. 495). E. The branches of vein III crowded together near the costal margin of the wing, and the first cell V2 unusually short and broad (Fig. 545). p. 455 Stratiomyiid^e. EE. Venation of wings normal. F. The alulets large, p. 453 Tabanid.e. FF. The alulets small or wanting, p. 456. . Leptid^e. BB. Antennae consisting of not more than three segments ; the DIPTERA. 425 third segment either with or without a style or bristle, but not divided into subsegments. C. Antenna? consisting apparently of a single globular segment bearing along bristle; wings with some stout veins near the costal margin and other weaker ones extending across the wing unconnected by cross-veins (Fig. 581). p. 475.PHORID/E. CC. Flies that do not present the type of venation represented by Figure 581. D. Cells V and first V3 not separated (see Fig. 571 for an ex- ample of this type). £. Vein III with a knot-shaped swelling at the point of separation of veins III2 + 3 and III4 + 5; the cross-vein III-V at or near this swelling; no suture immediately above the antennae, p. 467 DOLICHOPODiD,E. EE. Vein III with or without a swelling at the point of separation of veins III2 + 3 and III4 + 5; the cross-vein III-V more remote from base of wing; a suture immedi- ately above the antennae, p. 479 Muscid^E. DD. Cells V and V2 separate. E. Vein III four-branched. F. Venation intricate, due to an unusual anastomosing of the veins (Fig. 555). p. 459 Nemistrinid^E. FF. Venation not of the type represented by Figure 555. G. Vertex of head distinctly hollowed out between the eyes (Fig. 557); eyes never contiguous, p. 460. ASILID.E. GG. Vertex of head not hollowed out between the eyes; eyes often contiguous in males. H. Alulets very large, p. 458 ACROCERIDJE. HH. Alulets small or rudimentary. I. Cell V3 present. J. Vein III5 ending before the apex of the wing (Fig. 562). p. 462 Apiocerid^e. JJ. Vein Ills not ending before the apex of the wing. K. Empodia pulvilliform, i.e„ with three mem- branous lobes beneath the tarsal claws (Fig. 495). p. 456 Leptid^e. KK. With only two membranous lobes beneath the tarsal claws, p. 464 Therevid/E. II. Cell V3 obliterated by the coalescence of veins V, and VIIi. 426 THE STUDY OF INSECTS. J. Third segment of antennae without bristle or style ; vein Vi ending at or before the apex of the wing (Fig. 568). p. 465 ScenopiniDjE. JJ. Third segment of antennae usually with bristle or style ; vein Vx ending beyond the apex of the wing. K. Vein VI I2 extending free to the margin of the wing or coalesced with vein IX for a short distance (Fig. 564). p. 463 Bombylid^e. KK. Vein Vila joining vein IX far from the margin of the wing, often extending towards the base of the wing (Fig. 569). p. 466. Empidid^e. EE. Vein III with not more than three branches. F. Wings lanceolate, and with no cross veins except at the base (Fig. 572). p. 469 Lonchopterid^e. FF. Wings not of the type represented by Figure 572. G. Flies with a very small head; with the thorax and abdomen inflated, giving the body a hunchback-like appearance, and with the alulets very large. The empodia pulvilliform, i.e., with three membranous lobes beneath the tarsal claws, p. 458 Acrocerid^e. GG. Head of ordinary size or very large ; form of thorax and abdomen various; alulets either large or small. The empodia not pulvilliform, i.e., only two membra- nous lobes beneath the tarsal claws. H. Vein Vila appearing as a cross-vein or curved back towards the base of the wing (Figs. 569, 588). I. Antennas with a terminal style or arista, p. 466. Empididte. II. Antennae with a dorsal arista. J. Proboscis rudimentary ; mouth-opening small ; palpi wanting, p. 477 CEstriDvE,. JJ. Proboscis not rudimentary ; palpi present. K. Head with a suture immediately above the antennae through which the ptilinum is pro- truded and withdrawn (Fig. 587). p. 479. MUSCID/E. KK. Head without such suture, p. 466. Empidid^e. HH. Vein Vila not coalesced with vein IX to such an DIPTERA. 427 extent as to cause the free part to appear like a cross-vein. I. Antenna with a terminal style or bristle. J. Antenna with a terminal bristle, p. 474. PLATYPEZIDiE. JJ. Antenna with a terminal style. K. Front with grooves or a depression beneath the antennae, p. 476 CoNOPiDiE. KK. Front convex beneath the antennae. p. 47° Syrphid^e. II. Antenna with dorsal bristle. J. Head extremely large, and with nearly the en- tire surface occupied by the eyes (Fig. 577). p. 473 Pipunculida:. JJ. Head not of the type represented by Figure 577- K. Wings with a vein-like thickening, the spu- rious vein, between veins III and V (Fig. 574). p. 470 Syrphidte. KK. Wings without a spurious vein. L. Front with grooves or a depression beneath the antennae, p 476 Conopid^e. LL. Front convex beneath the antennae. p. 470 SYRPHIDjE. AA. Flies in which the abdomen is indistinctly segmented, and the two legs of each segment are widely separated by the broad ster- num. The adults live parasitically upon birds, mammals, or the Honey-bee. B. Compound eyes present ; wings present or absent, p. 487. HlPPOBOSCIDiE. BB. Both compound eyes and wings absent. C. Halteres present; tarsal claws of ordinary form. Adults parasite upon bats. p. 489 Nycteribiid^e. CC. Halteres absent; last segment of tarsus with a pair of comb- like appendages, p. 489 Braulid^e. Suborder ORTHORRHAPHA (Or-thor'rha-pha). The Straight-seamed Flies. To this suborder belong those families of flies in which the pupa escapes from the larval skin through a T-shaped 428 THE STUDY OF INSECTS. opening, which is formed by a lengthwise split on the back near the head-end and a crosswise split at the front end of this (Fig. 498). In a few members of this suborder (i.e., some of the Cecidomyiidae) the pupa escapes FlG- *98- through a crosswise split between the seventh and eighth abdominal segments. The pupae are usually either naked or enclosed in the last larval skin, the puparium ; but the pupae of some of the gall-gnats, Cecidomyiidae, are enclosed in cocoons. The adult flies do not possess a frontal lunule. See footnote page 416. Family PsYCHODlDiE (Psy-chod'i-dae). The Moth-like Flies. There may be found frequently upon windows and on the lower surface of the foliage of trees small flies which have the body and wings densely clothed with hair and which resemble tiny moths in appear- ance. The wings are broad, and when at rest slope at the sides in a roof-like manner or are held horizontally in such a way as to give the FlG _A insect a triangular outline (Fig. 499). moth-iike fly. The moth-like appearance of these insects is sufficient to distinguish them from all other flies. The venation of the vn» Pig. 500.— Wing of a moth-like fly. DIP TEA' A. 429 wings (Fig. 500) is also vet}- peculiar. All of the longitu- dinal veins separate near the base of the wing except veins 1 1 Ia and 1 1 13 and veins V, and V,. In some forms veins III4 and III6 are distinct, as shown in the figure; in others hey coalesce completely, so that radius is only four-branched. In this case there is onlv a single vein between the two forked veins. The antennae are long and slender, and are clothed with whorls of hairs (Fig. 501). Those of the male are longer; and in the species figured the two basal segments are clothed with scales like those of the Lepidoptera. Scales of this form occur also on the wings, palpi, and legs of certain species. Only a few of the American species have been described ; these have been Fir,. 501. — Antennae of Psv- placed in the genus Psychoda ; the choda. m, antenna of male *■ and the second segment of the early Stages Of none Of them have same mnre enlarged ; /, an- * o tenna of female and the tip been observed. The larvae of some enlarged. European species inhabit cow-dung, and others live in water. They have a pair of spiracles at each end of the body. As regards the structure of their wings these flies are very distinct from all others. The pre-anal area, that part lying in front of vein VIII, presents an extremely generalized form. This is shown by the outline of the wing (a line drawn lengthwise of the wing through its centre will divide it into two similar parts), the small extent to which the veins coalesce, and the fact that the maximum number of veins is present. On the other hand, the anal area is so reduced as to be barely represented. The dotted line in the figure represents the position of what is left of the anal furrow (i.e., vein VIII). Family TlPULlDJE (Ti-pu'li-dae). The Crane-flies. The crane-flies are mosquito-like in form ; but they are usually very much larger than mosquitoes. The body is long and slender, the wings narrow, and the legs very 43Q THE STUDY OF INSECTS. long (Fig. 502). This family includes the larger members of that series of flies in which the antennae are thread-like ; but it also includes some species that are not larger than certain mosquitoes. The most distinctive feature of crane- flies is the presence of a transverse V-shaped suture on the dorsal side of the mesothorax (Fig. 503). Fig. 503 — Tho- rax of a crane- tiy showing- c. . the V-shaped Fig. 502.— A crane-fly. suture. The wings are Jong and narrow. In a few genera vein III is five-branched, and the branches separate near the middle of the wing (Fig. 504) ; but usually the number of 11 ix ^vnT~ VI1' Fig. 504.— Wing of Protoplasa filchii. (After Osten Sacken.) branches is reduced to three or four; and those that remain distinct separate near the apex of the wing (Fig. 505). Cell V2 is divided into two parts by a cross-vein ; the branches of vein VII like those of vein III separate near the distal end of the wing; and the margin of the wing is strengthened by an ambient vein. DIPTERA. 431 The structure of the ovipositor is also quite distinctive, being composed of two pairs of long, horny, pointed valves. These are fitted for depositing the eggs in the ground, or in other firm substances. The larvae of most species live in the ground ; and some of them destroy grass and grain by gnawing the young plants just below the surface of the soil. Those of other species live in various situation?, as in water, in decaying wood, in fungi, and even on the leaves of plants. The larvae xi ix VII> FlG. 505.— Wing of Tipula abdominalis. of this family have either a single pair of spiracles situated at the hind end of the body, or they have two pairs, one at each end of the body. The pupae are not enclosed in a puparium, and bear transverse rows of hairs, bristles, or spines, which enable them to work their way out from the earth when about to transform. Crane-flies often appear in great numbers, flying over meadows and pastures. But in most cases their power of flight does not seem to be well developed ; for they fly slowly, and only a short distance at a time. Some species, however, sustain themselves in the air for long periods. This is especially true of some of the smaller species ; which often collect in swarms at twilight, forming a small cloud, and dancing up and down like some of the midges. But even with these the flight is poor compared with that of the more specialized families, as the Syrphidae or the Muscidae. Their ability to walk is also poor; for they use their long legs awkwardly, as if they were in the way. This has sug- gested the rhyme : — " My six long legs, all here and there, Oppress my bosom with despair." 432 THE STUDY OF INSECTS. Not only are the legs of crane-flies poorly fitted for loco motion, but they are so feebly attached to the body that they are easily broken off ; however, the loss of a few legs does not seem to be a serious matter to one of these insects. Yet from what we know of the laws of development we are forced to believe that the peculiar form of the legs has been attained in order to fit them to perform better some impor- tant function. It may be that the great length of the legs is correlated with the unusual length of the abdomen and ovipositor, and enables the insect to oviposit in a better manner than would otherwise be possible. When about to lay her eggs, the female stands nearly upright and, bringing the abdomen at right angles to the surface of the earth, thrusts the ovipositor into the ground. After placing one or two eggs in the hole thus made, she moves forward a few steps and repeats the operation. Family BlepharoceridtE (Bleph-a-ro-cer'i-dae). The Net-winged Midges. The net-winged midges are extremely remarkable in- sects; for in certain respects the structure of the adults is very peculiar, and the larvae appear much more like Crusta- ceans than like Insects. The adults are mosquito-like in form ; but they differ from all other insects in having the wings marked by a net- work of fine lines which extend in various directions and are not influenced at all by the veins of the wing (Fig. 506); they are, however, quite constant in their position in the species that we have studied. When a wing is examined with a microscope, the fine lines are seen to be slender thickenings extending along the courses of slight folds in the wing. The significance of these folds is evident when a net-winged midge is observed in the act of issuing from its pupa-skin. When the wing is first pulled out of the wing-sheath of the pupa, that part of D1PTERA. 433 it which is crossed by the fine lines is plaited somewhat like a fan and folded over the other portion. By this means the wing, which is fully developed before the adult emerges, is packed within the wing-sheath of the pupa, which is much shorter and narrower than the wing. When the wing is 4+S VII, Fig. 506. — Wing of Blepharocera. finally unfolded, it does not become perfectly flat, but slight, alternating elevations and depressions remain, show- ing the positions of the former folds, a permanent record of the unique history of the wings of these insects. Ordinarily the wings of insects, while still in the wing- sheaths of the pupa, are neither longer nor wider than the wing-sheaths, but expand after the adult emerges from the pupa skin. Usually it takes considerable time for the wings to expand and become fit for flight ; and during this interval the insect is in an almost helpless condition. In certain caddice-flies that emerge from swiftly-flowing water, the time required for the expansion of the wings has been reduced to the minimum (see pp. 189, 190). In the net- winged midges, which also emerge from swiftly-flowing water, the difficulty is met by the wings reaching their full development before the adult leaves the pupa-skin. It is only necessary when the adult emerges from the water that it should unfold its wings to be ready for flight. The members of this family have three simple eyes. Each compound eye is divided into two parts: an upper half, in which the ocelli are very large ; and a lower half, in 29 434 THE STUDY OF INSECTS. which the ocelli are small. The antennae are thread-like, but are not furnished with whorls of long hairs (Fig. 507). The legs are very long. On the dorsum of the meso thorax there is on each side, beginning just in front of the base of the wing, a well-marked suture, like that of the crane-flies; but the two do not meet so as to form a continuous V-shaped suture as in the Tipulidae. In some species at least there are two kinds of females, which differ somewhat in the shape of the Fig. 507. head. These two forms also differ in habits, one being blood-sucking, the other feeding upon nectar. The adults may be found resting on the foliage of shrubs and trees on the margins of mountain-brooks, or dancing in the spray of waterfalls. The immature forms of these insects are even more wonderful than are the adults. The larvae live in water, in swiftly-flowing streams, where the water flows swiftest. We have observed the transformations of BlepJiarocera capitaia (Bleph-aroc'e-ra cap-i-ta'ta), which is abundant in some of the ravines near Ithaca, N. Y. The larvae of this species are readily seen on account of their black color, and are apt to attract attention on account of their strange form (Fig. 508, a). At first sight the body appears to consist of only seven segments, but careful examina- tion reveals the presence of smaller segments alternating with these. Each of the larger segments except the last bears a pair of conical, leg-like appen- dages. On the ventral side of the body (Fig. 508, b) each of the seven larger segments except the last bears a sucker, the cavity of which extends far into the body, and each Fig. 508. — Blfpharocera . <*, larva, dor- sal view ; b, larva, ventral view ; c, pupanum. DJPTERA. 435 of these segments except the first bears two tufts of tracheal gills ; but those of the last segment are united. The head, which forms the front end of the first of the seven larger divisions, bears a pair of slender antennas; each of these consists of a very short basal segment and two long segments; at the tip of the last of these there is a pair of minute appendages and a bristle. The suture between the head and the remaining part of the first division is best seen on the ventral side of the body. On the dorsal side a suture may be seen dividing the last division into two segments. The pupa-state is passed in the same place as the larval. Like the larvae the pupae are very conspicuous on account of their black color, and are apt to occur like the larvae closely clustered together. The pupa is not enclosed in the larval skin, and differs greatly in form from the larva. On the dorsal side the skin is hard, forming a convex scale over the body (Fig. 508, c) ; and the thorax bears a pair of breath- ing-organs; on the ventral side the skin is very delicate, soft, and transparent ; so that the developing legs and wings may be easily seen when the insect is removed from the rock. The pupae cling to the rock by means of six suckers, three on each side near the edge of the lower surface of the abdo- men ; and so firmly do they cling that it is difficult to re- move specimens without breaking them. We have watched the midges emerge from their pupa- skins and escape from the water. The pupae occurred in groups so as to form black patches on the rocks. Each one was resting with its head down stream. Each midge on emerging forced its way out through a transverse rent be- tween the thorax and abdomen. It then worked its body out slowly, and in spite of the swift current held it vertical. The water covering the patch of pupae varied from one fourth to one half inch in depth. In the shallower parts the adult had no trouble in working its way to the surface still clinging to the pupa-skin by its very long hind legs. 43° THE STUD Y OF INSECTS. While still anchored by its legs the midge rests on the sur- face of the water for one or two seconds and unfolds its wings; then freeing its legs it takes flight. The adults emerging from the deeper water were swept away by the current before they had a chance to take wing. The time required for a midge to work its way out of the pupa-skin varied from three to five minutes. Family DixiDyE (Dix'i-dse). The Dixa-midges. These midges closely resemble mosquitoes in size and form ; but they are easily distinguished by the venation of their wings (Fig. 509). Fig. 509. — Wing of Dixa. The wing-veins are not furnished with scales, and are distinct over the entire surface of the wing ; vein I is pro- longed into an ambient vein; vein II is well developed, but is short, ending in the margin of the wing near its middle, ana before the first fork of vein III ; vein III is four-branched ; vein V is two-branched ; cell V, is not divided by a cross- | vein ; and vein III, extends parallel to the mar- gin of the wing to a point on the outer end of the wing. The antennae (Fig. 510) are six- teen-jointed, and differ but slightly in the two sexes ; the legs are very long and slender ; and he caudal end of the abdomen of the male is pic. 51a enlarged. DIPTERA. 437 The family includes only a single genus, Dixa. We have found the adult midges common on rank her- bage, growing in a swampy place, in a shady forest. Family CULICID/E (Cu-lic'i-dae). The Mosquitoes. The form of mosquitoes is so well known that it would be unnecessary to characterize the Culicidae were it not that there are certain mosquito-like insects that are liable to be mistaken for members of this family. The mosquitoes are small flies, with the abdomen long and slender, the wings narrow, the antennae plumose in the males (Fig. 511), and usu- ally with a long, slender, but firm proboscis. The thorax lacks the transverse V-shaped suture characteristic of the crane-flies ; and vein V of the wings is only two-branched (Fig. 512). of mosquitoes is a fringe of scale-like hairs •/"• joiVij;.Vi»-i.r-<-f«V.i;f^ — e* — « 7*LnL' : i~ ~ ■■■' ' - --■ _. Fig. 512. — Wing of Culex. The larvae of mosquitoes, so far as they are known, are aquatic. But it is probable that some species breed in the ground, for mosquitoes occur in arid regions far from water. The transformations of those species with aquatic larvae are easily observed. The immature forms may be found in 438 THE STUDY OF INSECTS. pools of stagnant water, in watering-troughs, and in ex posed receptacles of rain-water. The long, slender eggs are laid side by side in a boat- shaped mass, on the surface of the water (Fig. 513). They Fig. 513. — A glass of water containing; eerers, larvae, and pupa? of mosquitoes. hatch in a few days, and the larvae escape from the lower ends into the water. The larvae are well known, and are commonly called " wigglers," a name suggested by their wriggling motion as they swim through the water. The larva (Fig. 514, a) has a large head and thorax and a slender abdomen. The next to the last abdominal segment bears a breathing-tube ; and when the larva is at rest it hangs head down- ward in the water, with the opening of this tube at the surface (Fig. 513). At the end of this tube there is a rosette of plate-like lobes (Fig. 515, a), which, floating on the surface of the water, keeps the larva in posi- tion when at rest. The larva grows rapidly, and after a few Fig. 514. — Mosquitoes. a, larva, i, pupa. DIPTERA. 439 molts changes into a club-shaped pupa, the head and thorax being greatly enlarged (5 14, b). With this transformation a remarkable change takes place in the re- spiratory system. There are now two breathing-tubes, and these are borne by the thorax. One of these tubes is repre- sented greatly enlarged by Figure 515, ^. At the tail-end of the body there is a pair •> l Fig. 515. — a, end of of leaf-like appendages, with which the ''rea'hm'f-ube.0i[ larvaj rr o » (,, breathing-tube of insect swims; for the pupae of mosqui- P°Pa- toes, and also of certain midges, differ from the pupas of other insects in being active. The pupa state lasts only a few days; then the skin splits down the back, and the winged mosquito carefully works itself out and cautiously balances itself on the cast skin, using it as a raft, until its wings are hardened so that it can fly away. In recent years it has been found that the transmission of several diseases is due to mosquitoes, different kinds of mosquitoes transmitting different diseases. Malaria is caused by a protozoan organism, Hcsmamceba, which de- stroys the red blood corpuscles of man. It has been dem- onstrated that when blood is taken by a mosquito of the genus Anopheles from a person suffering with malaria the Hcemamceba passes through certain stages of its life history within the body of the mosquito and finally reaches the salivary glands of the mosquito, from which the ma- larial germs are injected into persons bitten by the infected mosquito. And there is no reason to believe that man becomes infected with malaria in any other way. People have lived in extremely malarious regions and escaped taking the disease by merely spending the evenings and nights in mosquito-proof houses. It often happens that plagues of these pests are bred in receptacles of rain-water standing near dwellings ; such re- ceptacles should not be left open unnecessarily. When the breeding-places are ponds of limited extent the i'arva2 and 440 THE STUDY 'OF INSECTS. pupae can be destroyed by pouring a small quantity of kero- sene on the water ; this method of destroying them was first suggested by Mr. L. O. Howard. Family CHIRONOMID.E (Chir-o-nom'i-dae). The Midges. The members of this family are more or less mosquito- like in form. The abdomen is usually long and slender; the wings narrow; the legs long and delicate ; and the antennae, especially in the males, strongly plumose (Fig. 516). In fact many of these insects are commonly mistaken for mosquitoes; but only a few of them can bite, the Fig. 516. — Antennae of 1 1 • 1 1 chironomus. /, female ; greater number being harmless. The midges are most easily distin- guished from mosquitoes by the structure of the wings (Fig. 517). These are furnished with fewer and usually less ""'«!.■*£■- — '"■'■„, ^m^ vHIfM *■ ---_. .^ 'v Vllr. Fig. 517. — Wing of Chironomus. distinct veins; and the veins, although sometimes hairy, are not fringed with scale-like hairs. There is a marked contrast between the stouter veins near the costal border of the wing and those on the other parts of the wing, which seem to be fading out. The costal vein is not prolonged into an am- bient vein, beyond the apex of the wing. The name midge has been used in an indefinite way, some writers applying it to any minute fly. It is much better, however, to restrict it to members of this family DIP TEE A. 44 ' except where it has become firmly established as a part of a specific name. The Wheat-midge and the Clover-seed Midge are examples of names of this kind ; it would not be wise to attempt to change these names, although the insects they represent belong to the Gall-gnat family, and hence are not true midges. Midges often appear in large swarms, dancing in the air, especially towards the close of day. Professor Williston states that, over meadows in the Rocky Mountains, he has seen them rise at nightfall in most incredible numbers, pro- ducing a buzzing or humming noise like that of a distant waterfall, and audible for a considerable distance. The larvae are either aquatic or terrestrial ; they have two pairs of spiracles, one at each end of the body, or are furnished with tracheal gills. Some of the pupae are free and active, others are quiescent ; some of the latter remain partially enclosed in the split larval skin. Many of our species belong to the genus Chironomus (Chi-ron'o-mus). These are mosquito-like in form, but vary greatly in size, some being smaller than our common mos- quitoes, and others much larger. The head is small, the snout, comparatively short, and the antennae of the males very bushy. The larvae so far as they are known are aquatic. Many of them are blood-red in color ; and as they live in standing water they are sometimes found in vessels contain- ing rain-water, where they appear like bits of animated red thread. The pupae of this genus, like those of mosquitoes, are active. To the genus Ceratopogon (Cer-a-to-po'gon) belong the small midges commonly known as punkies. Of these there are many species, which vary greatly in size and color. The body and legs are not as slender as in the preceding genus, and consequently the insects appear much less mos- quito-like. Certain minute species are sometimes very abundant, and extremely annoying on account of their bites. We have found them exceeding troublesome in the Adiron- 442 THE STUDY OF INSECTS. dack Mountains. The larvae live under the bark of decaying branches, under fallen leaves, and in sap flowing from wounded trees. Family Mycetophilim: (My-cet-o-phil'i-dae). The Fungus-gnats. These flies are of medium or small size, and more or less mosquito-like in form. They are most easily recognized by the great length of the coxae (Fig. 518, c), and the fact that all the tibiae are furnished with spurs. They also differ from the closely-allied families in lacking, as a rule, whorls of hairs on the an- tennae of the males (Fig. 519), and in possessing ocelli. At first sight considerable varia- F,G' Sl8, 10.519- j.jon seems t0 exist in the venation of the wings as shown in the three wings represented in Figure 520 ; but in reality the variations are comparatively slight. Vein I extends along the margin of the wing to the end of vein III<+B. Vein II varies in length. Vein III pre- serves three branches in the more generalized form (Fig. 520, a); in some genera veins III, and II I2+3 coalesce from the apex of the wing backward for a greater or less distance so that the base of vein III2+3 appears like a cross vein (Fig. 520, b); this coalescence may be complete, in which case vein III is only two-branched (Fig. 520, c). Vein V is also two-branched. It should be observed that the cross-vein III— V extends more or less obliquely or even lengthwise of the wing; while the base of vein III«+6 may extend trans- versely, and then is liable to be mistaken for a cross-vein (Fig. 520, b, c). The flies are often found in great numbers on fungi and in damp places where there is decaying vegetable matter. They are active, and leap as well as fly. DIPT ERA. 443 i+j+) III. + I+3 The larvae are gregarious, and live in fungi and in decay- ing vegetable matter. The)- may be found in the fungi growing on logs and trees, in the vegeta- ble mould among dead leaves, under bark, and sometimes in cow-dung. They have eight pairs of spiracles. One spe- cies, Sciara mall (Sci'a-ra ma'li), feeds on ripe apples, es- pecially those that have been previously perforated by the Codlin-moth. In this family the larva has a distinct head. The pupa is not enclosed in the skin of the larva ; hur in ?nmp crpnera Fig. 520.— Wings of fungus-gnats. (The drawings are uul 111 sumc ^cucict after Winnertz; the lettering is original.) the transformations are undergone in a delicate cocoon. The larvae of some species of the genus Sciara often attract attention on account of a strange habit they have of sticking together in dense patches. Such assemblages of larvae are frequently found under the bark of trees. But what is more remarkable is the fact that when the larvae are about to change to pupae an assemblage of this kind will march over the surface of the ground, presenting the appear- ance of a serpent-like animal. Such a congregation is com- monly spoken of as a Sciara-army-worm. Examples have been described that were four or five inches wide and ten or twelve feet long, and in which the larvae were piled up from VIIj 444 THE STUDY OF INSECTS. four to six deep. The "larvae crawl over each other so that the column advances about an inch a minute. Family CECIDOMYIID^E (Cec-i-do-my-i'i-dae). The Gall-gnats. The gall-gnats are minute flies which are extremely delicate in structure. The body and wings are clothed with long hairs, which are easily rubbed off. The antennae are long, sometimes very long, and usually with a whorl of hairs on each seg- ment (Fig. 521); the legs are slender and quite long, but the coxae are not greatly elongate, and the tibiae are without spurs ; the wing-veins (Fig. 522) are greatly reduced in number; the anal veins being entirely wanting, and vein V wanting or merely Ftg. 521- — Antennae represented by a slight, unbranched fold. of gall-gnats. '", -p ., . r ., , , ., ,, e male; /. female, lo this family belong the smallest of enlarged more than ..... n . -~ . that of the male. the midge-like flies. On account of their minute size, the adult flies are not apt to attract the at- tention of the young student. But the larvae of many nu+s Fig. 522. — Wing of gall-gnat. species cause the growth of galls on plants ; some of which are sure to be found by any close observer. Other species arrest the growth of the plants they infest, and thus cause DIP TERA. 445 very serious injury; in this way the amount of a crop of grain is often greatly reduced. The larvae are small maggots, with nine pairs of spiracles. Many species are brightly colored, being red, pink, yellow, or orange. In almost every case a larva belonging to this family can be recog- nized as such by the presence of a horny piece on the lower side of the body, be- tween the second and third segments (Fig. Fig. 523.-Headend of . . . . , , larva showing the 523). lhis piece is called the breast-bone, breast-bone. Its homology and use have not been definitely determined. The different species vary as to the method of under- going their transformation ; in some the pupa is naked ; in others the pupa is enclosed in the dried skin of the larva; and in still others it is enclosed in a delicate cocoon. One of the most common and conspicuous of the galls made by gall-gnats is the Pine-cone Willow-gall (Fig. 524). This often occurs in great abundance on the tips of twigs of the Heart - leaved Willow {Salix cor data). The gnat that causes the growth of this gall is Cecidomyia strobiloidcs (Cec-i-do-my'i-a strob-i- loi'des). The gall is a deformed and enlarged bud ; the lengthening of the stem is checked by the injury caused by the larva ; but leaves continue to be devel- oped which results in the cone-shaped growth. The larva remains in the heart of the gall throughout the summer and winter, changing to a pupa early in the spring. The adult Fig. 524.— The Pine-cone Wil!ow-ga11. 44& THE STUDY OF INSECTS. emerges soon afterward, and lays its eggs in the newly- started buds of the willow. There is a guest gall-gnat, Cecidomyia albovittata (C. al- bo-vit-ta'ta), which breeds in large numbers between the leaves composing the Pine-cone Willow-gall. The larvae of this gnat do not seem to interfere in any way with the development of their host, there being abundant food in the gall both for the owner of the gall and for its numerous guests. The Clover-leaf Midge, Cecidomyia trifolii{C. tri-fo'li-i). — The leaflets of white clover are sometimes infested by white or orange-colored mag- gots which fold the two halves of the leaflet together. From one to twenty of these larvae may be found in a single leaflet. When f u 1 1- grown the larvae make cocoons, and undergo their transformations within the folded leaflet. In Figure 525 an infested leaf containing cocoons is represented natural size, also a larva and an adult gnat, greatly enlarged. The Clover-seed Midge, Cecidomyia leguminicola (C. le- gu-mi-nic'o-la), is a much more serious pest of clover. This infests both red and white clover. The larvae live in the heads of the clover and destroy the immature seed. When full-grown they drop to the ground, where they undergo their transformations. In some parts of this country it is impossible to raise clover-seed on account of this pest. The Hessian-fly, Cecidomyia destructor (C. de-struc'tor). — This is perhaps the most serious pest infesting wheat in this country. The larva lives at the base of a leaf between it and the main stalk. There are two or three broods of this insect in the course of the year. The larvae of the fall brood Fig. 523.— Cecidomyia trifolii. (From the Author's Report lor 1879.) DIP J ERA. 447 infest the young wheat-plants near the surface of the ground. When full-grown each changes to a pupa within a brown puparium, which resembles a flax-seed. Here they remain throughout the winter. In the spring the adult gnats emerge and lay their eggs in the sheaths of leaves some dis- tance above the ground. The infested plants are so weak- ened by the larva that they produce but little if any seed. The Wheat-midge, Diplosis tritici (Di-plo'sis trit'i-ci). — This gnat is also a very serious enemy of wheat. It deposits its eggs in the opening flowers of wheat. The larvae feed on the pollen and the milky juice of the immature seeds, causing them to shrivel up and become comparatively worthless. When full-grown the larvae drop to the ground, where the transformations are undergone near the surface. The adults appear in May or June. The Resin-gnat, Diplosis resinicola (D. res-i-nic'o-la). — - This species infests the branches of various species of pine. Fig. 526. -Di/.'osis resinicola. (From the Author's Report for 1879.) We have found it throughout the Atlantic region from New York to Florida. The larvae live together in considerable numbers within a lump of resin. They derive their nourish- ment from the abraded bark of the twig; and the resin exuding from the wound completely surrounds and protects 448 THE STUDY OF INSECTS. them. The transformations are undergone within the lump of resin. After the gnats emerge the empty pupa-skins pro- ject from the lump of resin as shown at the right in Figure 526. In this figure the gnat, a single wing, and a part of the antenna of each sex are represented, all greatly enlarged. Family Rhyphid,e (Rhyph'i-dae). The False Crane-flies. The false crane-flies are so called because they resemble the Tipulidae somewhat in the venation of the wings, the nil iir,+i i"4+j v:i. Fig. 527. — Wing of Rhyphus. three branches of vein V being preserved, and cell V, being divided by a cross-vein (Fig. 527). They lack, however, the V-shaped suture on the thorax that is characteristic of crane-flies ; and differ, also, in having ocelli, and in the structure of the antennae (Fig. 528). The wings are wider than is usual with crane-flies, and the branches of vein III separate nearer the base of the wing than in that family. The adults are mosquito-like insects with spotted wings, which often enter houses, where they are found on windows. We have also observed them in considerable numbers just at nightfall, feeding on sugar which had been placed on Fig. 52 DIPTERA. 449 trees to attract moths. They feed on over-ripe fruit and other vegetable substances. The larvae are found in pools and in decaying vegetable matter ; they have two pairs of spiracles, one at each end of the body. The pupae are free. Only four species of false crane-flies have been found in the United States ; these belong to the genus Rhyphus (Rhy'phus). Family ORPHNEPHILID.E (Orph-ne-phil'i-dae). The Solitary-midge. Only a single species of this family, OrpJinephila testacea (Orph-neph'i-la tes-ta'ce-a), is known to occur in North America. This is a small fly measuring about one eighth of an inch in length, with a wing-expanse of one third inch. The antennae are short, about as long as the head, and nearly of the same structure in both sexes ; the segments of the antennae except those at the base are slender and are clothed with a few short hairs. The ocelli are wanting. The compound eyes are large and meet in front in both sexes. The wing-veins are well developed on all parts of the wing ; vein II ends in the margin of the wing before the end of the basal third; vein III is two-branched, the first branch ending in the margin at the end of the second third of the wing and the other branch near the apex of the wing ; vein .* is two-branched, the branches separating at the end of the basal third of the wing and near the cross-vein III— V ; the fork of vein VII and the cross-vein V— VII are near the end of the basal fourth of the wing. The transformations of this insect are unknown. Family Bibioxid^e (Bib i-on'i-dae). The March-flies. In these flies the body is comparatively robust, and the legs shorter and stouter than in most of the families with 30 450 THE STUDY OF INSECTS. is much longer than wide. thread-like antenna; (Fig. 5-9). The abdomen, however. The antennae (Fig. 530) are shorter than the thorax, and composed of short, broad, and closely-pressed-together segments. Although the an- tennae are hairy, they are not furnished with whorls of long hairs in the males, as is the case in most of the preceding families. These insects resemble the fungus-gnats in having ocelli ; but they differ from them in the shortness of the antennae and in the fact that the coxae are not greatly elongate. In this family and the following one the eyes of the males are in many cases contiguous. The venation of the wings of the typical genus is represented by Figure 531. Fig. 529. — Bibio. Fig. 530. VII, Fig. 531.— Wing of Bibio. The adult flies are generally black and red, sometimes yellow. They are most common in early spring ; which has suggested the name March-flies ; but some occur later in the season. The larvae vary in habits ; some species feed on decay- ing vegetable matter, while others attack the roots of grow- ing plants, especially of grass. They have ten pairs of spiracles; which is an unusually large number, as but few insects have more than nine pairs. The pupae are usually free. DIP TEH A. 451 Family SiMULUD^E (Sim-u-li'i-dae). The Black- flies. The common name, black-flies, given to the members of this family is not distinctive, for there are many species in other families that are of this color ; but like many other names that are descriptive in form, it has come to have a specific meaning distinct from its original one. It is like the word blackberry ; some blackberries are white, and not all berries that are black are blackberries. In this family the body is short and stout (Fig. 532) ; the legs are short, and the tibiae are without spurs. The anten- nae, although composed of many seg- ments, are comparatively short, and taper towards the tip (Fig. 533) ; the segments of the antennae are short and closely pressed together ; they are clothed with fine hairs, but do not bear whorls of long hairs. There are no ocelli. In the males the compound eyes are contiguous, and are composed of two kinds of ocelli, those of one part of the eye being much larger than nil Fig. 532. Simuliunt, Fig. 533- Fig. 534. — Wing of Sitnuliutn. the others. The wings are broad, iridescent, and not clothed with hairs. The veins near the costal border are stout ; those on the other parts of the wing are very weak (Fig. 534). 452 THE STUDY OF IX SECTS. The females of many species suck blood and are well- known pests. Unlike mosquitoes and midges, the black-flies like heat and strong light. They are often seen in large numbers disporting themselves in the brightest sunshine. The larvae are aquatic; and usually live in swiftly-flowing streams, clinging to the surface of rocks in rapids or on the brinks of falls. They sometimes occur in such large num- bers as to form a moss-like coating over the rocks. There is a disk-like sucker fringed with little hooks at the caudal end of the body by means of which the larva clings to the rocks; and just back of the head there is a fleshy proleg which ends in a similar sucker fringed with hooks (Fig. 535). By means of these two organs the larva is able to walk with a looping gait similar to that of a measuring-worm. It also has the power of spinning silk from its mouth, which it uses in locomotion. The hooks on the caudal sucker and at the end of the proleg are well adapted . to clinging to a thread or to a film of silk Fig. 535 — Head *=> ^ of larva. spun upon the rock to which the larva is clinging. Respiration is accomplished by means of three much-branched tracheal gills which are pushed out from be- tween the last two abdominal segments. The head bears two large fan-shaped organs, which aid in procuring food. The food consists of microscopic plants and bits of tissue of larger plants. When full-grown the larva spins a boot-shaped cocoon within which the pupa state is passed (Fig. 536). This cocoon is firmly fast- ened to the rock upon which the larva has lived or to other cocoons, for they occur in dense masses, forming a carpet- like covering on the rocks. The pupa, like the larva, breathes by tracheal gills; but in this stage the tracheal gills are F|G 536_ Larva and co. borne by the prothorax. DIPTERA. 453 The adult fly, on emerging from the pupa-skin, rises to the surface of the water and takes flight at once. Soon after this, the eggs are laid. We have often watched the flies hovering over the brink of a fall where there was a thin sheet of swiftly-flowing water, and have seen them dart into the water and out again. At such times we have always found the surface of the rock more or less thickly coated with eggs, and have no doubt that an egg is fastened to the rock each time a fly darts into the water. The above account is based on observations made on the Innoxious Black-fly, Simulium innoxiuin (Si-mu'li-um in- nox'i-um), which is exceedingly common in the streams about Ithaca, N. Y. This species, fortunately, is not blood- thirsty, for, notwithstanding its great abundance in this locality, we have never known it to bite. The Southern Buffalo-gnat, Simulium pecnarum (S. pec- u-a'rum), of the Mississippi Valley is a terrible pest, which causes the death of many mules and other domestic animals. The popular name of this insect refers to a fancied resem- blance in the shape of the insect when viewed from one side to that of a buffalo. The Turkey-gnat, Simulium meridionale (S. me-rid-i-o- na'le), closely resembles the preceding in habits, infesting all kinds of domestic animals \ but as it appears at the time that turkeys are setting and causes great injury to this fowl, it is commonly known as the Turkey-gnat. The Adirondack Black-fly, Simulium molestum (S. mo- les'tum), is a scourge in the mountains of the Northeastern States. Family Tabanid^e (Ta-ban'i-dae). The Horse-flies. The horse-flies are well-known pests of stock, and are often extremely annoying to man. They appear in sum- mer, are common in woods, and are most abundant in the hottest weather. 454 THE STUDY OF INSECTS. In this family the third segment of the antenna is ringed (Figs. 537, 538) and is never furnished with a distinct style or bristle. The wing-veins (Fig. 539) are evenly distributed over the wing, as the branches of vein III are not crowded together as in the follow- ing family ; the costal vein extends completely around the wing; the alulets are large. The flight of these flies is very powerful ; they are able to outstrip the swiftest horse. The males feed on the nectar of flowers and on Fig. 538. Antenna of sweet sap. The mouth-parts of the Cn rysoj>s. female are fitted for piercing the skin and sucking the blood of men and quadrupeds; the Fig. 537. Antenna of Tabanus. ■VIIj + IX' VIIi Fig. 53Q. — Wingf of Tabanus. females, however, also feed on the sweets of plants when they cannot obtain blood. The larvae are carnivorous ; many live in the earth ; others live in water. They feed on various small animals; some upon snails, others upon the larvae of insects. In most cases they have a single pair of spiracles, which is situated at the hind end of the body; some have a pair of spiracles at each end of the body. The pupa is not enclosed in the skin of the larva. DIPTERA. 455 Fig. 540. — Tabanus at- ralus. Fig. 541.— ( h ryso/>s niger. The larger species, as well as some of moderate size, belong to the genus Tabanus (Ta-ba'nus), of which nearly one hundred American spe- cies are known. One of the most common of these is the Mourning Horse-fly, Tabanus atratus (T. a-tra'tus). This insect is of an uniform black color throughout, except that the body may have a bluish tinge (Fig. 540). To the genus CJirysops (Chry 'sops) belong the smaller and more common horse-flies with banded wings (Fig. 541). Nearly fifty North American species of this genus have been described. Family Stratiomyiid^ (Strat-i-o-my-i'i-dse). The Soldier-flics. The soldier-flies are so called on account of the bright- colored stripes with which some of the species are marked. In the more typical mem- bers of this family the abdo- men is broad and greatly flattened (Fig. 542), and the wings when at rest lie parallel upon each other over the ab- domen. But in some genera the abdomen is narrow and considerably elongate. The antennae vary greatly in form ; in some genera the third segment is long and con- sists of several quite distinct rings (Fig. 543) ; in others it is short with but few indistinctly-separated rings and with a bristle (Fig. 544), as in the true true short-horned flies. The most distinctive characteristic is the peculiar vena Fig. 542. St rat io- myia. Fig 543. FiG. 544. 456 THE STUD Y OF INSECTS. tion of the wings (Fig. 545). The branches of vein III are crowded together near the costal border of the wing ; and 11 mi nii+j ' — f *7* Fig. 545. — Wing of Stratiomyia. the first cell V, is unusually short and broad ; the branches of Vein V and vein VII, are comparatively weak. These flies are found on flowers and leaves, especially in the vicinity of water and in bogs and marshes. The larvae £\^s»iocera. ( After Williston> which are rare and occur in the far West. They are rather large and elongate, and are found upon flowers. DIPTERA. 463 The head is not hollowed out between the eyes ; the ocelli are present ; the antennae are furnished with a short, simple style. Vein III is usually four-branched, but some- times it is only three-branched ; all of the branches of vein III end before the apex of the wing (Fig. 562); cell V3 is present, but closed by the coalescence of veins Vs and VII, at the margin of the wing ; and cell Va is divided by a cross- vein. The empodia arc wanting. Family BOMBYLIID/E (Bom-by-li'i-dae). The Bee-flies. These flies are mostly of medium size, some are small, others are rather large. In some the body is short and broad and densely clothed with long, delicate hair (Fig. 563). Other species resemble the horse-flies somewhat in appearance, especially in the dark color or markings of the wings ; but FlG s^-—Bombyiius. these can be distinguished from the horse-flies by the form of the antennae and the venation of the wings. The antennae are usually short ; they are three-jointed ; the third segment is not ringed ; the style is sometimes present and sometimes wanting. The ocelli are present. The proboscis is sometimes very long and slender, and sometimes short and furnished with fleshy lips at the ex- tremity. Vein III of the wings (Fig. 564) is four-branched ; cell III3 is sometimes divided by a cross-vein ; cell V3 is obliter- ated by the coalescence of veins V3 and VII, ; in a few genera cell V, is also obliterated by the coalescence of veins V, and V2 ; cell VIII is narrowly open, or is closed at or near the border of the wing. The alulets are small or of moderate size. The adult flies feed on nectar, and are found hovering over blossoms, or resting on sunny paths, sticks or stones; they rarely alight on leaves. 4^4 THE STUDY OF INSECTS. The larvae are parasitic, infesting hymenopterous and lepidopterous larvae and pupae and the egg-sacs of Orthop- tera. The pupae are free. u.is + v, "ixvih Vj + vnt Fig. 564. — Wing of Pantnrbes capito. The family is a large one, including many genera and species. Family Therevid^: (The-rev'i-dae). The Stiletto-flies. With the flies of this family the head is transverse, being nearly as wide as the thorax ; and the abdomen is long and tapering, suggesting the name stiletto-flies. These flies are small or of medium size ; they are hairy or bristly. The antennae are three-jointed ; the third segment is simple, and usually bears a terminal style ; but this is sometimes want- ing. Three ocelli are present. The legs are slender and bristly; the empodia are wanting. Vein III of the wings (Fig. 565) is four-branched, and the last branch (vein III6) terminates beyond the apex of the wing ; the branches of vein V are all separate ; cell VIII is closed near the border of the wing; the 2d cell III and cell V are long. The adult flies are predaceous ; and conceal themselves among the leaves of low bushes or settle on the ground in sandy spots, waiting for other insects upon which they prey. The larvae are long and slender, and the body is appar- ently composed of nineteen segments. They are found in DIPTERA. 465 earth, fungi, and decaying wood. They feed on decaying animal and vegetable matter and are said to be predaceous also. The pupae are free. in, VUa+IX Fig. 565. — Wing of Thereva. The family is a comparatively small one, including but few genera and species. Family Scenopinid^e (Scen-o-pin'i-dae). The Window-flics. The window -flies are so-called because the best-known species are found almost exclusively on windows ; but the conclusion that these are the most common flies found on windows should not be drawn from this name ; for such is not the case. These flies are of medium size, our most common species measuring one-fourth inch in length. They are usually black, and are not clothed with bristles. The thorax is prominent, and the abdomen is flattened and somewhat bent down, so ^a^. that the body when viewed from the side f/T% presents a humpbacked appearance (Fig. 566). When at rest, the wings lie parallel, Scenopinus. one over the other, on the abdomen ; when in this position they are very inconspicuous. There are three ocelli. The antennae are three-jointed ; the first and second segments are short, the third is long and bears neither a style nor a bristle (Fig. 567). 31 466 THE STUD Y OF INSECTS. The venation of the wings is represented by Figure 568. Vein III is four-branched ; cells V, and V, arc both obliter- ated by the coalescence of the veins that bound them ; cell VIII is closed at a considerable distance before the margin; and the 2d cell III is much longer than cell V. The larva;, which are sometimes found in dwellings viu+ix Fig. 568.— Wing of Scenofiinus. under carpets or in furniture, are very slender, and are re- markable for the apparently large number of the segments of the body, each of the abdominal segments except the last being divided by a strong constriction/ They are also found in decaying wood, and are supposed to be carnivorous. The family is a very small one. The most common species is Scenopinus fenestralis (Sce-nop'i nus fen-es-tra'lis) Family EmpididtE (Em-pid'i-dae). The Dance-flies. The dance-flies are of medium or small size ; they are often seen in swarms under trees or near shrubs and about brooks, dancing and hunting. The family is a rather diffi« cult one to characterize owing to great variations in the form of the antennae and in the venation of the wings. The branches of vein VII coalesce with the adjacent veins (VII, with V3 and VII2 with IX) from the margin o* the wing towards the base for a considerable distance (Fig- 569). In most of the genera this coalescence is carried so far that the free parts of the branches of vein VII appear D1PTERA. 467 like cross-veins. The only other families of the suborder Orthorrhapha in which this occurs are the two following; and the venation of the wings in each of these is very differ- ent from that of the Empididae. The antennas are three-jointed ; the first and second nu+s v3 + VIIi Fig. 569. — Wing of Rhatuphomyia. segments are often very small, and then appear like a single segment ; the third segment may or may not bear a style or bristle. The mouth-parts are in many cases long, and ex- tend at right angles to the body or are bent back upon the breast. These flies are predaceous, like the robber-flies ; but they also frequent flowers. The larvae live in decaying vegetable matter, but are probably carnivorous. The pupae are free. The family is a large one, containing many genera and species. Family DOLICHOPODID^E (Dol-i-cho-pod'i-dae). The Long-legged Flies. These flies are of smalh or medium size and usually bright metallic green in color. The legs are much longer than is usual in the families belonging to the series of short-horned flies (Fig. 570). This suggested the name Do- lichopus (Do-lich/o-pus), which means long- footed, for the typical genus; and from this FlG the family name is derived. It should be Pus lobatus. 468 THE STUD Y OF INSECTS. remembered, however, that these flies are long-legged in comparison with the allied families, and not in comparison with crane-flies and midges. The members of this family are easily distinguished as such by the peculiar venation of the wings, the most char- acteristic features of which are the following (Fig. 571): cells V and 1st V, are not separated by a vein, the basal part of vein V3 being undeveloped ; veins III2+3 and III4+6 separate near the base of the wing, and the two veins form nil v, + VII, Fig. 571. — Wing of Psilophu* ciliatus. at the point of separation a more or less knot-shaped swell- ing; the cross-vein III-V is at or close by this swelling, so that cell III is very short. A somewhat similar venation occurs in some of the Muscidae ; but there the knot-shaped swelling on vein III is often wanting, and the cross-vein III-V is usually more remote from the base of the wing; and too the flies belonging to the Muscidae possess the suture above the antennae characteristic of the suborder Cy- clorrhapha. The members of this family have three ocelli ; the an- tennae are three-jointed ; the second segment of the antenna is sometimes rudimentary ; and the third segment bears a two-jointed arista. The adults are predaceous and hunt for smaller flies and DIPTERA. 469 other soft-bodied insects. They are usually found in damp places, covered with rank vegetation. Some species occur chiefly on the leaves of aquatic plants, and about dams and waterfalls ; and some are able to run over the surface of water. Others occur in dry places. The larvae live in earth or decomposing vegetable matter. They are long, slender, and cylindrical, and have two pairs of spiracles, one at each end of the body. In most cases the pupae are free ; but some form cocoons. The thorax of the pupa bears a pair of long breathing-tubes. The family is a large one ; more than two hundred North American species have been described already. Family Lonchopterid^e (Lon-chop-ter'i-dae). The Spear-winged Flies. These are minute flies, which measure from one twelfth to one sixth of an inch in length, and are usually brownish or yellowish. When at rest the wings are folded flat, one over the other, on the abdomen. The apex of the wing is pointed ; and the wing as a whole is shaped somewhat like the head of a spear. This suggested the family name. The venation of the wings is very characteristic, and is sufficient to distinguish these flies from all others. The V, + vii 1 Fig. 572.— Wing of Lonchoptera. cross-veins III-V and V-VII are oblique, and near the base of the wing (Fig. 572). Vein VII, is very short, and In the females vein extends towards the base of the wincr 47° THE STUDY OF INSECTS. VII, coalesces with vein Vs , as shown in the figure; but in the males the tip of vein YII, is free. The posterior lobe is wanting. Three ocelli are present. The antennae are three-jointed ; the third segment is globular, and bears a three-jointed style. These flies are common from spring till autumn, in damp grassy places. They frequent the shores of shady brooks, where the atmosphere is moist. But little is known as yet about their habits and tranformations. In the shape of the wings, the absence of cross-veins, except at the base of the wing, and the great reduction of the anal area of the wing the flies closely resemble the Psy- chodidae. Suborder CYCLORRHAPHA (Cy-clor'rha-pha). The Circular-seamed Flies. To this suborder belong those families of flies in which the pupa escapes from the larval skin through a round opening made by pushing off the head- end of it (Fig. 573). The pupa is always enclosed in a puparium. The adult flies possess a frontal lunule (see footnote page 461), and except in the Pu'Garfum~of ^rs^ ^our fam'nes a frontal suture, through which a Muscid. tjie ptilinum is pushed out, when the adult is about to emerge from the puparium (see page 419). Family Syrphid^E (Syr'phi-dse). The Syrphus- flies. The family Syrphidse includes many of our common flies; but the different species vary so much in form that no general description of their appearance can be given. Many of them mimic hymenopterous insects ; thus some species resemble bumblebees, others the honey-bee, and still others wasps; while some present but little resemblance to any of these. DIPTERA. 471 The most distinctive characteristic of the family is the presence of a thickening of the membrane of the wing, which appears like a longitudinal vein between veins III and V. This is termed the spurious vein, and is lacking in only a few members of the family ; it is represented in Figure 574 by a III, ,III3+3 JN4+S Fig. 574. — Wing- of Eristalis. band of stippling. Cell 1 1 IB is closed; and the 2d cell III and cell V are large. The antennae are three-jointed ; the third segment usually bears a dorsal bristle, but sometimes it is furnished with a thickened style. The face is not furnished with longitudinal furrows to receive the antennas as in the Muscidae. The frontal lunule is present, but the frontal suture is wanting. The adults frequent flowers and feed upon honey and pollen. Some fly with a loud humming sound like that of a bee ; others hover motionless except as to their wings for a time, and then dart away suddenly for a short distance, and then resume their hovering. The larvae vary greatly in form and habits. Some prey upon plant-lice, and are often found in the midst of colonies of these insects ; others feed on decaying vegetable matter, and live in rotten wood, in mud, and in water. Some are found in the nests of ants ; and some in the nests of bum- blebees and of wasps. Among the common representatives of this family there is one that so closely resembles a male honey-bee as to be 47 2 THE STUDY OF INSECTS. often mistaken for it. This is the Drone-fly. Eristalis tenax (E-ris'ta-lis te'nax). It is common about flowers. The larva lives in foul water, where it feeds on decaying vegeta- ble matter ; it is of the form known as " rat-tailed," which is described below. The larvae of the genus Volucella (Vol-u-cel'la) are pre- daceous, living in the nests of bumblebees and of wasps {Vespd), and feeding upon their larvae. Some of the species in the adult state very closely re- semble bumblebees. The larvae of the genus Micro- dfo«(Mic'ro-don) are hemispherical, Fig. n$.—Microdon, adult and *■ ' r larva- slug -like creatures (Fig. 575), which resemble mollusks more than ordinary maggots ; they are common in ants' nests. The larvae of several species that live in water as well as some that live in rotten wood are known as rat-tailed mag- gots on account of a long, tail-like appendage, with which the hind end of the body is furnished. This is a tube, like that of a diver, which enables the insect to obtain air when its body is submerged beneath several inches of water or de- caying matter. This tube being telescopic can be lengthened or shortened as the insect may need it; and at its tip there is a rosette of hairs, which, floating on the surface of the water, keeps the tip from being submerged. The larva has on the ventral side of its body several pairs of tubercles armed with spines, which serve as prolegs. Among the more common members of this family are the yellow-banded species belonging to the genus Syrphns (Syr'phus) (Fig. 576). The larvae of these live in colonies of Aphids, and do much good by destroying these pests. This family is a very large one ; nearly or J . . FK.576.-Syr- quite two thousand species being known. In P^us. his monograph of the species of America north of Mexico, DIPTERA. 473 Professor Williston describes about three hundred species irom this region.* Family PlPUNCULlD/E (Pip-un-cu'li-dae). The Big-eyed Flies. This family is represented in the United States by a single genus, Pipmiculus (Pi-pun'cu-lus). These are small flies, with very large heads composed almost en- tirely of eyes (Fig. 577). The head is nearly spherical, and broader than the thorax. The abdomen is somewhat elongate with the sides nearly parallel. The body is thinly clothed with hair or nearly naked. The wings are much longer than the abdomen, and when at rest they lie parallel to each other upon it. (Fig. 578) closely resembles that of some of the Conopidae. Vein III is three-branched. The last branch of Vein III and Fig. s77.—Pi/un- cuius. The venation VIIj + IX Fig. 578. — Wing of Pipunculus. the first branch of vein V approach each other at their tips. Vein V3 coalesces with vein VII, for nearly its entire length. Veins VII, and IX coalesce at their tips. Cells III and V are long. The flies hover in shady places. They are sometimes found on flowers, and may be swept from low plants ; our most common species measure about one eighth of an inch in length, not including the wings. The larvae so far as known are parasitic upon bugs. * Bulletin of the U. S. National Museum, No. 31. 474 THE STUDY OE INSECTS. Family Platypezid^E (Plat-y-pez'i-dae). The Flat-footed Flies. These flies resemble the House-fly somewhat in appear- ance but are very much smaller. They hover in the air in shady places, and alight frequently on the leaves of low plants, where they run about in circles with great rapidity. The head is hemispherical or spherical, and as broad as or broader than the thorax. The antennae are three-jointed, with a terminal bristle. The legs are short and stout, and the tarsi of the hinder pair are often very broad and flat (Fig. 579). The wings are rather large, and when at rest lie parallel upon the abdo- men ; the axillary excision is prominent, but the posterior lobe of the wing is small (Fig. 580) ; the alulets are minute. Vein III of the wings is three- branched ; veins V, and V2 either coalesce Fig. 579.— Leg of piaty- throughout or separate near the margin peza. a, forked hairs of c . . . . .... leg greatly enlarged. of the wing. Cell V, is sometimes divided Vlh+IX Fig. 580 —Wing of Platypeza. by a cross-vein, and sometimes not. Cells 2d III, V, and VIII are short. This family includes but few species, and these are usually rare. The larvae live in rotten mushrooms. DIPTEKA. 475 Family PH0RID.4L (Phor'i-dae). The Humpbacked Flies. These are minute, dark-colored, usually black flies, which can easily be recognized by their humpbacked form and the peculiar venation of the wings. Certain species are often found running about rapidly on windows, others on fallen leaves. Sometimes they are seen in swarms dancing up and down in the air. The head is small ; the thorax large and humped ; and the abdomen rather short. The antennae are apparently 111,+j in* -5 Fig. 581.— Wing of Phora. one- or two-jointed, the last segment with either a dorsal or a terminal bristle. The coxae are long ; the femora, espe- cially of the hind legs, which are rather long, are widened and flattened. The wings (Fig. 581) are large, and are fur- nished with two strong veins near the costal border, which extend but a short distance beyond the middle of the wing. From these strong veins from three to five weak ones extend across the wing. The larvae feed on decaying vegetable matter, dead insects, snails, etc., and some are believed to be parasitic upon other insects. 4;6 THE STUDY OF INSECTS. Family CONOPID^E (Co-nop'i-dae). The Thick-head Flics. With the members of this family the head is large, being broader than the thorax. The body is more or less elon- gate ; sometimes the abdomen has a long, slender pedicel like that of certain wasps. The body may be naked or thinly clothed with fine hair, but it is rarely bristly. The ocelli may be either present or absent. The an- tennae are prominent, and project forward ; they are three- jointed ; and the third segment bears either a dorsal bristle IIIi illb+j Vlh+TX Fig. 582. — Wing of Conors affinis. or a terminal style. Vein III of the wings (Fig. 582) is only three-branched. The last branch of vein III and the first branch of vein V end near together or coalesce at their tips. Cell V2 is divided by a cross-vein. Vein V3 coalesces with vein VII, for nearly its entire length. Veins VII, and IX coalesce at their tips, and sometimes for nearly the entire length of vein VII2. The adult flies are found on flowers. In some genera the abdomen is long, with a slender, wasp-like pedicel (Fig. 583). In others the abdomen is of the more usual FlG- form. The larvae are parasitic, chiefly upon bumblebees and wasps, but some species infest locusts. DIPT ERA. 477 Family CEstrid^e (CEs'tri-dae). The Bot-flies. This family includes flies that are large or of medium size; most of the species resemble bees in appearance; some, the honey-bee; others, bumblebees. In the vena- tion of the wings they closely resemble the Muscidae ; but the wings are usually furnished with fine transverse wrinkles. They are most easily distinguished from the Muscidae by the small size of the opening of the mouth and the rudi- mentary condition of the mouth-parts, the proboscis being rudimentary and the palpi usually wanting. The head is large, with the face broad. The antennae are small, three-jointed, more or less concealed in a suban- tennal cavity or grooves ; the last segment bears a dorsal bristle. Vein III of the wings is three-branched. Cell III6 is broadly open (Fig. 584), or is narrowed at the margin of \\u +JX Fig. 584. — Wing of Gastrophilus. the wing, or closed. The alulets are usually large, conceal- ing the halteres ; but sometimes they are small. The larvae are parasitic upon mammals. The best known species are the following : The Horse Bot-fly, Gastrophilus equi (Gas-troph'i-lus e'qui). — The adult fly closely resembles the honey-bee in 478 THE STUDY OF INSECTS. form except that the female (Fig. 585) has the end of the abdomen elongate and bent forward under the body. It is most often seen flying about horses, which have an instinctive fear of it. The eggs are attached to the hair, chiefly on the legs and shoulders of the horse. The larvae are licked off by the horse and swallowed with its food. When the larvae reach the stomach they fasten themselves to the inner coat of it, and remain there until full-grown. Then they pass from the animal with the dung, and crawl into some protected place, where they transform within a puparium. The Oxwarble, Hypoderma lineata (Hyp-o-der'ma lin- e-a'ta). — The larva of this species is the common pest that lives in the backs of cattle just beneath the skin. The adult lays its eggs on the backs of cattle ; and it has been supposed that the young larvae penetrate the skin, thus reaching the place where they are commonly found. But Dr. Cooper Curtice has recently shown that the larvae are licked off from the back by the cattle and swallowed. He found the larvae in large numbers in the walls of the oesophagus in November; later, about Christmas-time, they appeared sud- denly, and in large numbers under the skin of the back. The course of their migration from the oesophagus to the skin has not yet been traced. The greater part of the growth of the larva is made within the tumor beneath the skin. When full-grown it passes out through a hole in the skin and undergoes its transformations on the ground. Dr. Curtice has also shown that the most common oxwarble of this country is Hypoderma lineata and not Hypoderma bovis, as has been supposed. The Sheep Bot fly, GEstrus ovis (CEs'trus o'vis). — The eggs of this species are laid in the nostrils of sheep. The larvae pass up into the frontal sinuses and into the horns when they are present. Here they feed upon the mucus. They are very injurious to sheep, causing vertigo or the DIPTERA. 479 disease known as " staggers." When full-grown they pass out through the nostrils and undergo their transformations beneath the surface of the ground. Other species infest rabbits, squirrels, deer, and reindeer. One that lives beneath the skin of the neck of rabbits is very common in the South. Family MUSCID.E (Mus'ci-dae). The Muscids {Mils' cids). The form of the more typical members of this family i^ well shown by the common House-fly. But the family is a very large one and includes species that differ greatly in form. These differences are so great and so varied that some writers divide the family into nearly thirty families. It seems to us, however, to be better to consider these divisions of subfamily value. The following characters are presented by the family as a whole. The antennae (Fig. 586) are three-jointed ; the third seg- ment bears a dorsal bristle. The frontal suture is present" (Fig. 587). The proboscis is always present. Vein II of the wings may be present or absent ; vein III is three- branched ; cells V, and V3 are wanting; the branches of vein VII coalesce with the adjacent veins (VII, with V,, and VII, with IX) for nearly their entire length. The pulvilli are present, and the empodia are never pulvilliform. As this family includes more than one third of all the known Diptera, it usually happens that a large proportion of the flies in a collection belong to it. It seems necessary, therefore, to indicate some of the principal divisions of the Fig. 586. Fig. 587 480 THE STUDY OF INSECTS. family. The first of these is into two groups of subfamilies, and is based upon the size of the alulets. The division is not a satisfactory one ; and it is only given here because it is commonly employed by writers on the Diptera, and a more definite one has not yet been discovered. A. The alulets large; face with a depression or vertical grooves beneath the antennas; cell Ills closed or narrowly open, except in the Anthomyiinae, where it is widely open. p. 480. Calyptrate Muscid.