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ELEMENTARY ENTOMOLOGY 
 
 BY 
 
 E. DWIGHT SANDERSON 
 
 DEAN OF THE COLLEGE OF AGRICULTURE, WEST VIRGINIA UNIVERSITY 
 DIRECTOR WEST VIRGINIA AGRICULTURAL EXPERIMENT STATION 
 
 AND 
 
 C. F. JACKSON 
 
 PROFESSOR OF ZOOLOGY AND ENTOMOLOGY, NEW HAMPSHIRE COLLEGE 
 
 GINN AND COMPANY 
 
 BOSTON ■ NEW YORK • CHICAGO • LONDON 
 
COPYRIGHT, 1912, BY E. DWIGHT SANDERSON AND C. J. JACKSON 
 ALL RIGHTS RESERVED 
 
 8,2.7 
 
 TEfte atfttnaeum jgregft 
 
 GINN AND COMPANY • PRO- 
 PRIETORS • BOSTON • U.S.A. 
 
prp:face 
 
 During recent years there has been increasing demand for 
 short courses in elementary entomology. For several years past 
 the authors have been endeavoring to present such courses to 
 their students, but have encountered the difficulty that no textbook 
 was available which met their needs. This book is, therefore, the 
 authors' effort to furnish such a text for beginners, and if it is 
 found useful to them and to the increasing number of teachers 
 who are endeavoring to instruct them in the subject, the authors 
 will feel well repaid. The work is confessedly very largely a com- 
 pilation from the works of others (as, indeed, any such work must 
 be), and it is obvious that many errors and defects may have been 
 overlooked, although the authors have spared no pains to eliminate 
 them. To those who observe such shortcomings, or who may be 
 able to offer suggestions for the improvement of the book when 
 revised, the authors will be under great obligation. 
 
 It was originally intended to include several chapters treating of 
 the various insect pests affecting crops and domestic animals, but 
 it was found that such a work would be too cumbersome ; indeed, 
 it is usually not possible to cover both elementary and economic 
 entomology in a single course. The economic side of the subject 
 has, however, been made the dominant note in the following pages, 
 and the forms discussed are mostly those of economic importance. 
 There is a popular belief, often held by young agricultural stu- 
 dents, that the chief subject matter of a course in entomology 
 should be a discussion of the common injurious insects. Expe- 
 rience has shown that such an idea is fallacious, and that, from the 
 standpoint of practical utility as well as from that of general cul- 
 ture, a knowledge of the structure, habits, and classes of insects 
 in general is much the more important phase of entomology for 
 academic study. Economic entomology is important and should 
 
iv ELEMENTARY ENTOMOLOGY 
 
 not be neglected, but general entomology is the foundation upon 
 which it must be erected, and without a knowledge of the elements 
 of entomolog}^ a course in economic entomology will have but 
 little meaning to the average student, whereas if the more general 
 knowledge of the subject has been mastered, the study of the 
 various insect pests may be profitably pursued by the individual, 
 even if he has not been able to take a systematic course in that 
 phase of the subject. 
 
 Students should be encouraged to make free use of the standard 
 textbooks for reference and to aid in the identification of speci- 
 mens. Much interest may be added to the course by securing the 
 available entomological publications of the state agricultural experi- 
 ment stations (a list of which stations may be found in the 
 Appendix) and those of the Bureau of Entomology, United States 
 Department of Agriculture, Washington, D.C., many of which may 
 be had free of charge. 
 
 The work outlined in the study of life histories, in collecting, 
 and in the identification of insects is necessarily largely suggestive. 
 The amount and nature of such work must depend upon the time 
 available, the equipment, the time of year, and the local surround- 
 ings of the school, and must be determined by every teacher to 
 suit his own conditions. It should be emphasized, however, that 
 a maximum of laboratory and field work and a minimum of book 
 work will probably give the average student a better knowledge of 
 insect life than the opposite arrangement, as the subject is one in 
 which the student must secure his knowledge directly from the 
 material, if it is to have much real meaning to him. 
 
 The senior author is entirely responsible for the preparation of 
 Parts I and II, and the junior author for Part III, although they 
 have consulted together on all parts of the work. 
 
 Many of the half-tone illustrations are from photographs by 
 the senior author or from those of Dr. C. M, Weed, his prede- 
 cessor at the New Hampshire Agricultural Experiment Station, 
 while several new line drawings have been prepared for the work 
 by Alma Drayer Jackson and Iris L. Wood, for whose generous 
 aid the authors are greatly indebted. The remaining illustrations 
 
PREFACE V 
 
 have been drawn from various sources, as indicated in the titles, 
 but the authors are under particular obligations to the following 
 persons for the loan of cuts for electrotyping : Dr. L. O. Howard, 
 Chief of the Bureau of Entomolog)', United States Department 
 of Agriculture ; Professor F. L. Washburn, State Entomologist of 
 Minnesota; Dr. J. B. Smith, State Entomologist of New Jersey; 
 Dr. V. L. Kellogg, of- Leland Stanford Junior University ; Dr. 
 W. E. Britton, State Entomologist of Connecticut ; Dr. E. P. 
 Felt, State Entomologist of New York ; Professor G. W. Herrick, 
 of Cornell University ; Professor C. P. Gillette, Director of the 
 Colorado Agricultural Experiment Station ; P. Blakiston's Son 
 & Co., and D. Appleton and Company. 
 
 The authors are also greatly indebted to the following entomolo- 
 gists for reading portions of the manuscript and criticizing the keys 
 for the identification of insects, which criticisms have added greatly 
 to the accuracy and reliability of the work : Professor Herbert 
 Osborn, Dr. C. T. Brues, Mr. C. W. Johnson, Mr. Nathan Banks, 
 Dr. J. B. Smith, Dr. Harrison G. Dyar, and Dr. A. D, MacGillivray. 
 
 E. DWIGHT SANDERSON 
 C. F. JACKSON 
 
CONTENTS . 
 
 CHAPTER PAGE 
 
 I. IXTRODUCTION I 
 
 TART I. THE STRUCTURE AND GROWTH OF INSECTS 
 
 H. Insects and their Near Relatives 5 
 
 III. The Anatomy of Insects — External lo 
 
 IV. The Anatomy of Insects — Internal 28 
 
 V. The Growth and Transformations of Insects ... 45 
 
 PART II. THE CLASSES OF INSECTS 
 
 VI. The Classification of Insects 67 
 
 VII. Bristletails and Springtails (After A) 73 
 
 VIII. Cockroaches, Grasshoppers, Katydids, and Crickets 
 
 {Orthoptera) 76 
 
 IX. The Nerve-Winged Insects, Scorpion-Flies, Caddis- 
 Flies, May-Flies, Stone-Flies, and Dragon-Flies . 89 
 X. TheWhite Ants, Book-Lice, AND BiRD-LiCE(/^z:^r}'/'7'£'/?.4) 103 
 XL The True Bugs, Aphides, and Scale \'s,sf.ci:s{Hemiptera) 107 
 XII. The Beetles {Coleoptera) 136 
 
 XIII. The Butterflies and Moths {Lepidoptera) .... 172 
 
 XIV. The Flies, Mosquitoes, and Midges {Diptera) . . . 218 
 XV. The Saw-Flies, Ichneumons, Wasps, Bees, and Ants 
 
 {Hymenoptera) ' . . 243 
 
 PART III. LABORATORY EXERCISES 
 
 XVI. The External Anatomy of the Locust 275 
 
 XVII. A Comparison of the Different Types of Arthropoda 284 
 XVIII. A Comparison of Different Types of Insects; Struc- 
 ture OF THE Bee, Fly, and Beetle 287 
 
 XIX. The Internal Anatomy of the Locust 290 
 
 XX. The Mouth-Parts of Insects 294 
 
 XXI. The Life History of Insects 298 
 
 XXII. The Classification of Insects 302 
 
 XXIII. Methods of Collecting Insects 330 
 
 XXIV. Methods of Preserving and Studying Insects . . . 343 
 
 APPENDIX 359 
 
 INDEX AND GLOSSARY 363 
 
 vii 
 
ELEMENTARY ENTOMOLOGY 
 
 CHAITKR I 
 INTRODUCTION 
 
 A professor of entomology in one of the leading universities 
 has recently been quoted as saying that this is "the age of in- 
 sects." Doubtless most of us have been accustomed to consider it 
 "' the age of man," but although man's sway is dominant in all 
 parts of the earth, there is considerable evidence that, from a purely 
 biological standpoint, insects are the most characteristic form of 
 life of the present age, and the statement quoted challenges our 
 attention for more than a passing consideration. 
 
 That such a statement should be made by a well-known ento- 
 mologist, and should be widely quoted, is significant of the present 
 attitude of the public toward insect life, which has changed radi- 
 cally during the last generation. Not many years ago the entomol- 
 ogist, or " bug collector," was looked upon as a harmless individual 
 who amused himself with his hobby ; and as he was met with his 
 butterfly net, the passer-by might lift his eyebrows as if questioning 
 whether a grown man who would devote himself to such insignifi- 
 cant creatures was really quite normal. 
 
 To-day the public has come to appreciate that insect life plays a 
 most important part in the economy of our civilization. Some of 
 the problems which require the work of the trained entomologist are 
 worthy of the highest scientific training and best executive ability. 
 
 Insects and disease. The modern methods of sanitation for the 
 control of malarial fever and yellow fever involve the control of 
 mosquitoes, which transmit these diseases. More and more the 
 sanitary measures which are making the tropics habitable for the 
 more northern races of man are being made possible by a knowl- 
 edge of the relation of insect life to the transmission of disease. 
 Even the common house-fly, formerly considered a mere nuisance. 
 
2 ELEMENTARY ENTOMOLOGY 
 
 is now known to carry typhoid fever and probably various intestinal 
 disorders, to which a large part of our infant mortality is due ; 
 and it has been well said that, during the Cuban War, probably 
 more American soldiers were killed through the agency of flies 
 carrying typhoid germs than by Spanish bullets. 
 
 Injury to crops. In their economic relations the insects affect- 
 ing crops are by all odds of the most importance, many of them 
 causing a loss of several million dollars a year to the farmers of the 
 United States. The boll weevil destroys over $25,000,000 worth 
 of cotton in Texas and Louisiana alone, and 10 per cent of the 
 wheat crop of the entire country, valued at $60,000,000, is usually 
 destroyed by insect pests. It has been estimated by competent 
 authorities that 10 per cent of the total value of the farm products 
 of the United States is annually lost by the ravages of insect 
 pests, amounting to nearly $800,000,000 per annum. 
 
 Injury to domestic animals. Domestic animals are affected by 
 various insects, such as the warble, or ox-bot, and the screw worm, 
 — which affect cattle, — the sheep maggot, and many others, in- 
 cluding the ticks, which carry Texas fever and other diseases ; so 
 that the annual loss to live stock through insects is estimated at 
 $175,000,000 per year. 
 
 Injury to household and stored goods. Housekeepers, manufac- 
 turers, and wholesale dealers must take into consideration the insect 
 life which affects all sorts of vegetable and animal products, and the 
 aggregate loss due to the insect pests of household and stored goods 
 must in the aggregate be a considerable item in domestic economy 
 and mercantile business. 
 
 Productive insects. A few insects contribute directly to the 
 wealth of the w^orld : the silkworm produces over $200,000,000 
 worth of silk annually, and the product of the busy honey-bee 
 amounts to over $20,000,000 per year in the United States alone. 
 
 Beneficial insects. The direct relations of insects to mankind are 
 by no means the most important phases of their ecology. The role 
 of insects in the pollenization of fruits and flowers is fundamental 
 to the successful fruiting and perpetuation of a large proportion of 
 common plants. Again, a large number of insects prey upon or live 
 within the bodies of other insects, and constitute the most impor- 
 tant factor in the natural control of injurious species. Were it not 
 
INTRODUCTION 3 
 
 for these beneficial forms, which prevent the normal increase, many 
 of our common injurious insects would become so numerous as to 
 practically prohibit the growth of crops affected. 
 
 Value of study of insects. The strictly economic aspect of insect 
 life is not, however, the only phase worthy of our attention and 
 study. The apathy with which the study of entomology was for- 
 merly treated was unquestionably due to the general lack of interest 
 in biology until recent years. During the last generation it has been 
 more and more appreciated that man is but a child of nature, and 
 that he can learn much in the proper conduct of his affairs by a 
 study of the laws of life in general, whether of the uncivilized races 
 of mankind, of insects, or of microscopic bacteria or protozoa. Our 
 grandfathers hardly knew that bacteria existed '; to-day most of the 
 science of pathology, and much of the practice of medicine, is based 
 on an understanding of their life. It would seem, therefore, that 
 insect life should furnish a large field for the student of general 
 biolog}', and more and more biological problems of fundamental 
 importance are being worked out through studies of insects. 
 
 That this should be the case is extremely obvious when we 
 remember that there are over 300,000 known species of insects, 
 including over four fifths of the described species of animals, and 
 that at the rate at which they are being described, it has been esti- 
 mated that over a million species exist. The immense number of 
 insects, both of species and of individuals, is undoubtedly due to 
 their varied structure, which enables them to live under all possible 
 conditions. Thus the larv'ae of many different species are adapted 
 so that they live entirely in water, others bore in trees and plants, 
 some are subterranean, while still others inhabit the tissues of do- 
 mestic animals or of other insects. By the aid of their wings the 
 adults spread rapidly and are thus able to migrate when necessity 
 arises. Thus the insects possess such diversity of structure and 
 habit that they are able to live under all external conditions, and 
 on account of their immense numbers they have been able to adapt 
 themselves to a changing environment which would have entirely 
 obliterated classes or species few in number. 
 
 Not only are insects the most abundant form of animal life, but 
 they exhibit the highest degree of intelligence of any of the lower 
 or invertebrate animals. The wisdom of the ant and the industry 
 
4 ELEMENTARY ENTOMOLOGY 
 
 and domestic economy of the honey-bee are proverbial, and new 
 observations are constantly showing the wonderful intelligence, if 
 it may be so called, evinced by many insects hitherto but little 
 known. No class of animals is more fascinating or better rewards 
 the study of the nature lover, as may be slightly appreciated from 
 the perusal of the habits described in succeeding pages. 
 
 It may now be evident, in view of the immense preponderance 
 of species and individuals of insects in the animal kingdom, and 
 their important role in the economy of nature, that there is some 
 ground for describing the present as " the age of insects," though 
 the term is of course used from a purely biological standpoint. 
 
PART I. THE STRUCTURE AND 
 GROWTH OF INSECTS 
 
 CHAPTER II 
 
 INSECTS AND THEIR NEAR RELATIVES 
 
 If we are to study insects, it is necessary that we should have a 
 clear conception of just what an insect is and how insects may be 
 distinguished from other animals. Most of us recognize bees, flies, 
 beetles, and butterflies as insects, but other forms of insect life we 
 
 Fig. I. Earthworm 
 w, mouth ; c, girdle, or clitellum. (After Jordan and Heath) 
 
 should probably call "worms," and various insectlike animals are 
 commonly termed " insects." 
 
 The animal kingdom is divided intoJtwo^large^rpups_of animals, 
 — those having a backbone, the Vertebrates, and those without a 
 backbone, the Invertebrates. In the former are included all the 
 
 Fig. 2. Diagram to express the fundamental structure of an arthropod 
 
 a, antenna ; cil, alimentary canal ; b, brain ; d, dorsal vessel ; ex, exoskeleton ; /, limb ; 
 ;?, nerve chain ; s, subesophageal ganglion. (After Schmeil, from Folsom) 
 
 higher animals, such as the fishes, reptiles, birds, and mammals ; 
 while in the latter are included all the lower forms of life, vvhi^ 
 are usually smaller in size and soft-bodied, as the molluscs, echino- 
 derms, worms, insects, and their relatives. 
 
 ^^'" 5 
 
6 ELEMENTARY ENTOMOLOGY 
 
 The Invertebrata are divided into several branches, or phyla (sin- 
 gular, phylum), which divisions are based on fundamental differences 
 in the body structure of the animals in these groups. Of these 
 phyla there are two which have the body made up of a series of 
 segments and were at one time classed together as the Articiilata. 
 
 Fig. 3. A lobster; a typical crustacean 
 
 The first of these two phyla, the Vermes, or worms, has no jointed 
 appendages, while the second, the Arthropoda, is characterized by 
 having jointed appendages on either several or all segments of the 
 body, from which the term "Arthropoda," from artJiron (joint) 
 and pons (foot), is derived. The Arthropoda include the insects, 
 spiders, myriapods, and crustaceans, all of which are related by the 
 possession of these jointed appendages. The distinctions between 
 
INSECTS AND THEIR NEAR RELA'l'IVES 
 
 7 
 
 these four classes are based largely upon the manner in which 
 the different segments are grouped together to form compact and 
 distinct parts of the body, and b)- the number and position of the 
 appendages. 
 
 The Crustacea include the lobsters, crabs, crayfish, shrimps, bar- 
 nacles, sow-bugs, etc., and are primarily distinguisTied from all other 
 arthropods by_the_iactjhat they breathe by means of gills and live 
 either in the water or in damp places. The body is divided into 
 two main regions, the 
 anterior segments be- 
 ing usually covered b)- 
 a single large shell 
 forming the head-tho- 
 rax, or cephalothorax, 
 while the remaining 
 segments form the ab- 
 domen. Each segment 
 usually bears a jpair of 
 appendages. On the 
 head are found two 
 pairs of antennae, and 
 on the thorax and ab- 
 domen are numerous 
 appendages fitted for 
 walking or swimming. 
 
 The only crustacean commonly mistaken for an insect is the little 
 sow-bug, or pill-bug, found in greenhouses, under boards, or in 
 darhprpraces~7I^gr4y. These rarely do any damage and may be 
 readily distinguished from insects by the two pairs of antennae 
 and the numerous appendages. The gills are to be found under 
 plates on the lower side of the abdomen. 
 
 The Arachnida include the spiders, scorpions, ticks, and mites, 
 and are almost entirely terrestrial. The body is divided into the 
 cephalothorax and abdomen, as in the Crustacea, but there are^o 
 antennas and but four pairs of legs. Although ticliS-ajid mites are 
 not ins ects, yet they are so nearly related, and their injuries to plants 
 and animals are so similar to insect depredations, that they are com- 
 monl)' included in economic entomology. Spiders are, if anything, 
 
 Fig. 4. Sow-bug, or pill-bug [Poirellis laevis) 
 Enlarged. (After Jordan and Heath) 
 
8 
 
 ELEMENTARY ENTOMOLOGY 
 
 beneficial, though they feed on beneficial as well as on injurious 
 insects, while scorpions are found only in tropical countries and 
 
 are chiefly a nuisance on account 
 of their poisonous sting. 
 
 The Myriapoda include the myri- 
 apods and centipedes, commonly 
 called thousa mi-legs. Their body 
 consists of a distinct head and a 
 long abdomen, all of the segments 
 of which are similar, and each of 
 which bears a_j)air of legs, so that 
 they are readily distinguished from 
 all other arthropods. In many ways 
 the myriapods are more closely re- 
 lated to the insects than either of 
 the other classes mentioned above. A few species sometimes 
 injure vegetables or fruits lying on or in the ground, and these 
 are considered as within the 
 sphere of economic entomol- 
 ogy ; but for the most part 
 myriapods are harmless, al- 
 though the house centipede 
 
 Fig. 5. A spider ; a typical arachnid 
 
 Fig. 6. A myriapod 
 
 Fig. 7. A parasitic fly, showing 
 parts of a typical insect 
 
 ant^ antennae ; h, head ; /, thorax ; 
 abd, abdomen ; wg, wings ; /, legs 
 
 is a nuisance and is abhorred by the 
 housekeeper. Some of the tropical 
 myriapods reach relatively enormous 
 size, being several inches long, and 
 bear poison fangs in connection with 
 the mouth-parts. 
 
 The Insecta, or Hexapoda, include 
 the tme insects, which form the largest 
 group of animals as far as both the 
 number of different species and the 
 number of individuals are concerned. 
 About 300,000 different species have 
 already been described, while there is 
 probably a total of 1,000,000 species 
 in existence. The known species form 
 over four fifths of the total number of 
 
INSECTS AND THEIR NEAR RELATIVES 9 
 
 animals now described. The adult insects are readily recognized 
 from the other classes of arthropods, but many of the immature 
 forms, such as maggots, lack the typical characteristics of the 
 group. The segments of the body of an insect are grouped into 
 three distinct regions, — thejiead, the thorax, and the abdomen, 
 The liead bears a single pair of feelers, or antenn^, the mouth-parts, 
 and the conipound eye^s. The thorax bears three pairs of jointed 
 legs and in the adult stage usually two pairs of wings, though in 
 the flies there is but a single pair and in a few orders wings are 
 lacking. The abdomen is usually without appendages in the adult 
 state, although on caterpillars and other immature stages prolegs, 
 or false legs, which are not segmented, are often found. 
 
 Comparative Structure of the Classes of Arthropoda 
 
 
 Class 
 
 Parts of 
 
 Body 
 
 AnTENN/E 
 
 Eyes 
 
 Legs 
 
 in,>ge,/ 
 
 I 2 
 
 3 
 
 
 
 
 Insecta 
 
 Head, thorax, 
 
 abdomen 
 
 One pair 
 
 Compound 
 
 Six 
 
 JJ7/tgA-ss 
 Myriapoda 
 
 I 
 Head, 
 
 abdomen 
 
 One pair 
 
 Compound 
 
 One pair per 
 segment 
 
 Arachnida 
 
 Head-thorax, 
 
 abdomen 
 
 None 
 
 Simple 
 
 Eight 
 
 Aquatic 
 
 I 
 
 2 
 
 
 
 
 Crustacea 
 
 Head-thorax, 
 
 abdomen 
 
 Two pairs 
 
 Compound 
 
 Many 
 
 
CHAPTER III 
 
 ANATOMY OF INSECTS — EXTERNAL 
 
 Body structure. The extinct ancestors of the insects were 
 doubtless elongate, wormlike animals composed of a series of 
 cylindrical segments very similar in structure and with a pair of 
 jointed appendages attached to each segment. The mouth being 
 
 Fig. 8. Types of insect antennae 
 
 A, filiform, from grasshopper {Schisfoccrca amcrkana) ; i?, clubbed, or clavate, from teneb- 
 
 rionid beetle i^Nyctobaics pcnnsykaiilcus) ; C", pectinate, or feathered, from a moth ; Z*, aris- 
 
 tate, with dorsal plumose arista, from a fly ; E^ lamellate, from a May-beetle {Lac/mosiema 
 
 fiisca) ; F, moniliform, from a beetle 
 
 at the anterior end, the appendages near it were developed to 
 secure and tear up the food. Thus the mouth-parts were gradu- 
 ally evolved, and the segments bearing them grew closer together 
 until they coalesced and formed a single well-defined region, the 
 head. With the development of wings the appendages of the pos- 
 terior segments were useless and soon disappeared, and the legs 
 on the three segments immediately back of the head became 
 
ANATOMY OF INSECTS — EXTERNAL 
 
 II 
 
 further specialized as organs of locomotion. With the development 
 of the large muscles necessary for the propulsion of the wings and 
 legs, these three segments back of the head became sharply differ- 
 entiated from the rest, so that they now form a quite distinct 
 region, the thorax. The remaining posterior segments, called the 
 abdomoi, having lost most of their appendages, are quite similar 
 in form, with the exception of those at the extreme posterior end, 
 where the shape of the segments and of their appendages has 
 been modified in connection with the external sexual organs. The 
 insect is therefore divided into three well-defined parts, — the head, 
 the thorax, and the abdomen, — which are composed of more or 
 less visible segments. 
 
 The head. The embiyolog}^ 
 and nervous system of the head 
 show that it was originally com- 
 posed of six segments, almost 
 no traces of which are now 
 discernible except their append- 
 ages, of which four pairs are rec- 
 ognizable as homologous with 
 the thoracic legs and the ab- 
 dominal appendages of lower 
 forms. These appendages con- 
 sist of the feelers, or antennas, 
 and three pairs of mouth-parts. 
 The head also bears a pair of 
 compound eyes and often a variable number of simple eyes, or ocelli. 
 
 Antennae. The antennae are often called feelers, indicating their 
 principal function as sense organs, which will be discussed in con- 
 sidering the senses. The shape of the antennae is very different 
 in different groups of insects, as is also the number of segments, 
 both of which characters are of the greatest importance in dis- 
 tinguishing the various groups. In the case of the katydid the 
 threadlike antennas are much longer than the body, while in some 
 flies they are reduced to mere knobs with a single strong bristle. 
 The different shapes of the segments give rise to many different 
 characteristic types of antennae, some of the more important of 
 which are shown in Fig. 8. In many cases, notably in the moths 
 
 '^^J 
 
 Fig. 9. Head of drone bee, showing 
 compound and simple eyes 
 
 (After A. B. Comstock) 
 
12 
 
 ELEMENTARY ENTOMOLOGY 
 
 and mosquitoes, the antennae of the sexes are quite different, so 
 that the sexes are readily distinguishable. 
 
 Eyes. On either side of the antennae are found the large com- 
 pound eyes, often forming the larger part of the side of the head, 
 and sometimes, as in the dragon-fly and horse-fly, forming the 
 major portion of the head. . The compound eyes are usually oval 
 or circular in outline, and are called compound because, when 
 examined under a lens, they are seen to be composed of large 
 numbers of hexagonal areas, called facets. The number of these 
 facets varies from 50 in certain ants to 4000 in the house-fly and 
 
 -mx.p 
 
 lab 
 
 ^Ib.p 
 
 Fig. 10. Face of grasshopper 
 
 an/, antenna ; f/,iclypeus ; eye, compound eye ; /ad, labium ; //>r, labium ; /l>./, labial palpi ; 
 ""^ mx./, maxillary palpi ; oc, ocellus 
 
 27,000 in certain sphinx moths. Between the compound eyes, 
 on the front, or vertex, of the head, are two or three small oval 
 or circular simjple^ eyes^-Calied^^^-///. Caterpillars and other larvae 
 have no compound eyes, but on either side of the head have a 
 group of from four to six ocelli. In many flies and bees the com- 
 pound eyes of the male are larger and closer together than those 
 of the female, this being due, possibly, to the male's leading a 
 more active life. 
 
 Mouth-parts. The mouth-parts are of prime importance, both 
 from an economic and from a systematic standpoint. Upon their 
 structure depends the kind of insecticide which may be effectively 
 
ANATOMY OF INSECTS — EXTERNAL 
 
 13 
 
 used, and their structure is so constant and characteristic in different 
 groups as to furnish one of the best meansjaf classification. Most 
 of the orders possess 
 one of the two main 
 types of mouth-parts, 
 — those formed for 
 biting (mandibulate), 
 and those formed for 
 sucking (suctorial, or 
 haustellate). The bit- 
 ing type, as found in 
 the grasshopper, is the 
 more typical, and will 
 therefore be discussed 
 first. 
 
 The labr?nii, or up- 
 pei^Jip, is a simple 
 flap projecting over 
 the upper part of the 
 opening of the mouth 
 and cover in^gjlifr-Hian- 
 dibles. It is hingsd-On 
 the posterior margin, but otherwise is free and may be slightly 
 protruded 01^ retracted, to aid in bringing food to the mandibles. 
 
 Fig. II. Mouth-parts of grasshopper, typical biting 
 or mandibulate mouth-parts 
 
 //'r, labrum, or upper lip ; md, mandible ; wx, maxilla ; hil>, 
 
 labium, or lower lip ; /, palpus ; g, galea ; /, lacinia ; lig, 
 
 ligula ; hyp, hypopharyn.x 
 
 Fig. 12. Various forms of mandibles 
 
 A, grasshopper {Melanopbts) ; B, tiger beetle (Cicindcfulae) ; T, bee {Apis) ■' D, Onthopha- 
 gus ; E, lace-winged fly {Chrysopd) ; F-I, soldier termites. (After Hagen, from Folsom) 
 
 The majtdibles, or jaws, are composed of a single toothlike 
 piece and move in a transverse plane. The form of the mandibles 
 
14 
 
 PILEMKNTARY ENTOMOLOGY 
 
 is modified according to the food of the insect. Thus, in the grass- 
 hopper and similar insects feeding upon vegetation the mandibles 
 are short, with strong teeth at the tip and behind them a crushing 
 or grinding surface. In carnivorous and pre- 
 daciou§>insects the mandibles are usually 
 long, slender, and sharply toothed, adapted 
 for grasping the prey or tearing flesh. In 
 certain of the Neuroptera, as in the aphis- 
 lion (see page 92), the mandible has a 
 deep groove on the inner surface, through 
 which the juices of the plant-lice are sucked. 
 In soldier ants the mandibles are developed 
 as effective weapons, while in other forms 
 they are otherwise specialized according to 
 the food habits of the insect ; but they are 
 always essentially biting organs. 
 
 Beneath the mandibles are the maxillce, or 
 under jaws. The 
 maxillae are much 
 more complex, con- 
 sisting of a basal 
 portion (stipes) 
 which is hinged to 
 the head (by the 
 cardo) and which 
 the palpus, galea, 
 and lacinia. The palpus is composed 
 of four or five segments, resembles a 
 miniature antenna, and, like it, is a 
 sensory organ. The inner lobes, the 
 lacinia, are usually provided with teeth 
 or spines and aid the mandibles in hold- 
 ing and masticating the food. 
 
 The third pair of mouth-parts have 
 grown together on the median line so as 
 to form a single piece, known as the 
 labinni, or underlip. In the embryo this is composed of a pair of 
 appendages similar to the maxillae, and for this reason is sometimes 
 
 Fig. 13. Maxilla of a 
 ground beetle {Harpa- 
 lits i-ciliginosus), ventral 
 aspect 
 
 c, cardo ; g, galea ; /, la- 
 cinia ; /, palpus ; //, palpi- 
 fer; s, stipes ; sg, subgalea 
 (After Folsom) 
 
 bears three lobes, - 
 
 Fig. 14. Labium of a ground 
 
 beetle [Harpaliis caliginosits), 
 
 ventral aspect 
 
 g, united glossas, termed the glos- 
 sa ; ;«, mentum ; /, palpus ; fg^ 
 palpiger; /;•, paraglossa ; sm, sub- 
 mentum. The median portion of 
 the labium beyond the mentum is 
 termed the ligula. (After Folsom) 
 
ANATOMY OK INSECTS — EXTERNAL 
 
 15 
 
 termed the second tnaxillce. The labium forms the floor of the 
 mouth and assists the mandibles and maxillas with the food. It is 
 hinged to the head at its base (by the viejitjivi\, and projecting 
 from either side is a palpjis, similar in form and function to the 
 maxijlary palpi. Between the palpi are one or two pairs of lobes, 
 the ligiila. 
 
 ""Projecting into the cavity of the mouth from the inner sur- 
 face of the labium is the hypopharynx\ or tongue. This in the 
 
 Fig. 15. Mouth-parts of the squash-bug 
 
 lab^ labium, forming a sheath for the other parts ; 
 Ibr^ labrum, fitting into the lower part of the 
 suture of the labium ; nni, mandible ; w.v, max- 
 illa. Mandibles and maxillee pulled out of labium 
 
 Fig. 16. Side view of head 
 
 of butterfly, with part 
 
 of antennae {a) removed, 
 
 showing mouth-parts 
 
 w.v, maxillae ; /, labial palpus 
 
 grasshopper is a fleshy, tonguelike organ, but in some orders it 
 is quite differently developed. The salivary glands open near its 
 attachment. 
 
 Suctorial type of mouth-parts. The mandibulate mouth-parts 
 of the different orders are all of so similar a type as to be appar- 
 ently homologous. The suctorial mouth-parts consist of several 
 
i6 
 
 ELEMENTARY ENTOMOLOGY 
 
 very distinct types, entirely dissimilar in structure and origin, 
 resembling each other only in that they enable the insect to suck 
 or lap its food rather than to bite it. 
 
 Fig. 17. Cross section of proboscis of cotton-worm moth, showing concave inner 
 
 faces of maxillae locked together to form the sucking tube 
 
 (After Comstock) 
 
 ,. „, ' ''■ '' » 
 
 Fig. 18. Mouth-parts of female mosquito {Ciihx pipiens) 
 
 A, dorsal aspect; B, transverse section; C, tip of maxilla; Z), tip of labrum-epipharynx ; 
 
 (T, antenna ; c, compound eye ; //, hypopharynx ; /, labrum-epipharynx ; A, labium ; mx, 
 
 maxilla ; w, mandible ; /, maxillary palpus, (After Folsom and Dimock) 
 
ANATOMY OF INSECTS — EXTERNAL 
 
 17 
 
 Hemiptera. In the Hemiptera, or bugs, the labium forms a long, 
 jointed beak, or rostrum (Fig. 15). This rostrum is cylindrical in 
 section, and its evolution from the type of labium found in the grass- 
 hopper may be understood by conceiving the labium of the latter 
 to be greatly elongated and then curled up on either side until the 
 lateral margins meet 
 on the median line 
 above, forming a su- 
 ture, as seen in the 
 hemipterous beak. At 
 the base of this suture 
 is found a triangular la- 
 brum closing the base 
 of the tube. The man- 
 dibles and maxillae are 
 long, . bristlelike or 
 needlelike structures, 
 sharply pointed and 
 often bearing barbs at 
 the tip, and the max- 
 illae are locked to- 
 gether so as to form a 
 tube^ through which 
 the juices are sucked. 
 
 Lepidoptera. The 
 moths ^nd butterflies 
 possess a ver}' different 
 style of sucking tube, 
 or proboscis, which is 
 curled up under the head like a watch spring. This is composed 
 of the two maxillae, whose inner faces are concave and which lock 
 together so as to form a tube which opens into tlie moufh. All 
 the other mouth-parts are almost entirely absent in most forms, 
 except the labial palpi. It is evident that this type of mouth-part is 
 only adapted to sucking nectar from flowers and is never injurious 
 to vegetation, while often adapted for pollenizing flowers which the 
 moths frequent. The caterpillars of moths and butterflies have 
 biting mouth-parts similar to those of the grasshopper. 
 
 Fig. 19. Side view of head of a fly 
 «, antenna ; wa/, maxillary palpus ; Ar/', labellum 
 
i8 
 
 ELEMENTARY ENTOMOLOGY 
 
 Diptera. The flies have several types of mouth-parts, all essen- 
 tially suctorial. Those of the horse-fly and mosquito are good 
 examples of the piercing type (Figs. 15, 18, 20). Superficially they 
 resemble those of the Hemiptera, but the sheath of the beak is not 
 so strong and is quite open above, and there are six lancetlike or- 
 gans which in the horse-fly 
 are quite strongly devel- 
 oped. The esophagus is 
 controlled by sets of mus- 
 cles which make it an effec- 
 tive bulb for pumping up 
 the food. The common 
 house-flies and blow-flies 
 have mouth-parts (Fig. 1 9) 
 adapted for rasping or lap- 
 ping rather than for pierc- 
 ing, though the liquid food 
 is sucked up in much the 
 same way. The proboscis 
 consists principally of the 
 very complex labium, or 
 lower lip, which is very 
 much expanded at the tip 
 to form a pair of fleshy 
 lobes. When looked at 
 under the microscope, the 
 tip of the proboscis is 
 seen to contain a series 
 of grooves and transverse 
 horny ridges with sharp, 
 projecting edges. With 
 these rasplike projections the fly is enabled to scrape the surface 
 of the food and gradually loosen small particles, which are dissolved 
 or carried in the saliva to the mouth. 
 
 Hymenoptera. The mouth-parts of the Hymenoptera include 
 both biting and sucking types. The saw-flies and ants (Fig. 22) 
 have well-developed biting mouth-parts, which are used as such, 
 while in the wasps and bees the maxillae and labium form a tube 
 
 Fig. 20. Mouth-parts of horse-fly {Tahantis) 
 
 Upper figure showing mouth-parts separated, and 
 
 lower figure showing lancets dissected out. (After 
 
 J. B. Smith) 
 
ANATOMY OF INSECTS — EXTERNAL 
 
 19 
 
 around the greatly elongated tongue (hypopharynx) which is used 
 for lapping and sucking, though the mandibles are still functional 
 and are used in shaping wax and pollen. 
 
 It should be noted that in several of these orders having suctorial 
 mouth-parts in the adult stage the larvae have true biting mouth- 
 parts. Caterpillars of all the Lepidoptera and the larvae of many 
 
 Fig. 21. Mouth-parts of the honey-bee 
 
 a, antenna ; /, labellum ; g, glossa, or tongue ; bn, labrum ; Ip^ labial palpi ; m, mandible ; 
 )«.v, maxilla ; mxp, maxillary palpus ; pg, paraglossa 
 
 families of flies and Hymenoptera have biting mouth-parts and are 
 injurious to vegetation, while the adults may be entirely harmless. 
 This difference in the mouth-parts of the same insect in different 
 stages must be borne in mind in considering insecticides for them. 
 
20 
 
 ELEMENTARY ENTOMOLOGY 
 
 We have stated that the structure of insects often determines 
 the method of treating them. This may now be understood, for 
 
 it is evident that 
 ./ a poison such as 
 
 Paris green, ap- 
 phed to the food 
 of a sucking in- 
 sect, such as a 
 plant-louse, would 
 not be taken into 
 the mouth through 
 the sucking mouth- 
 parts, which ex- 
 tract only the juices 
 beneath the sur- 
 face, while it might 
 be entirely effect- 
 ive against an 
 insect with biting 
 mouth-parts, which 
 consumed the sur- 
 face covered by the 
 poison. A better 
 understanding of 
 these simple facts 
 of insect anatomy 
 would save Amer- 
 ican farmers thou- 
 sands of dollars 
 every year, now lost 
 through ignorance. 
 Thorax. The thorax is the middle region of the body, composed 
 of the three segments back of the head, which are called the ^ro- 
 tJiorax^ mesothoi-ax, and nietathorax respectively. As previously 
 indicated, the differentiation of the thorax has been incidental to 
 the development of the wings, and the structure of the thorax is 
 determined by the development and use of the organs of locomo- 
 tion. A pair of jointed legs is attached to each segment and 
 
 Fig. 22. Mouth-parts of an ant {Mymiica ntl>?-a) 
 
 A, seen from the lower side in siiti ; B and Z>, maxillae; 
 C, labium seen from the upper side, detached ; a, mandible ; 
 h^ maxilla ; f, mentum ; d, maxillary palp ; e, labial palp ; /, 
 glossa or tongue ; g, adductor muscle of mandible ; h, abductor 
 muscle of mandible ; /', labium ; k, gustatory organs ; /, duct 
 of salivary glands ; ;«, maxillary comb : «, gular apodeme. 
 (After Janet, from Wheeler) 
 
ANATOMY OF INSECTS — EXTERNAL 
 
 21 
 
 the mesothorax and 
 metathorax of most 
 adult insects bear a 
 pair of wings. The 
 prothorax is usually 
 smaller than the 
 two posterior seg- 
 ments, the relative 
 size of which de- 
 pends upon which 
 pair of wings is the 
 better developed. 
 The dorsal surface, 
 or back, of a tho- 
 racic segment is 
 called the tergmn, 
 or notinn, the ven- 
 tral or under sur- 
 face is the sternum, 
 and each side is 
 a plcurum. These 
 parts are further 
 divided by sutures 
 into distinct plates, 
 or sclcritcs, to which 
 the appendages are 
 articulated. The de- 
 velopment, shape, 
 size, and position of 
 these sclerites are 
 characters of such 
 uniformity that the 
 sclerites are used 
 in classifying in- 
 sects, in much the 
 same way as are 
 the bones of the 
 vertebrate animals. 
 
22 
 
 ELEMENTARY ENTOMOLOGY 
 
 i-Cla 
 
 Fig. 24. Typical insect leg 
 
 Cx, coxa ; C/a, claws ; Ji'it/, empodia ; /% femur ; Tar, tarsal 
 
 segments ; Tl>, tibia ; Tr, trochanter, (.\fter Snodgrass, 
 
 United States Department of .Agriculture) 
 
 Legs. The legs articulate with the sternum and pleurum and con- 
 sist of five parts, — the coxa , (ror/iajj tfj; fcitiu j:. tibia, and iarsj/s. 
 The hase of the coxa forms the joint of the leg to the bod^', which 
 
 is either of the ball- 
 and-socket or of the 
 hinge type. The tro- 
 chanter is a small, in- 
 termediate segment, 
 which in parasitic Hy- 
 menoptera is double. 
 The femur is the 
 largest segment in 
 the leg, and in grass- 
 hoppers and other 
 jumping insects is 
 strongly developed 
 by the muscles with- 
 in. The tibia is_ usu- 
 ally long and slender. The tarsus is usually composed of several 
 similar segments, five being the typical number. The last segment 
 usually be ars a ^ir of sharp claws in adult insects and a single 
 claw in larvae. Between the claws of most adult insects is a little 
 pad, called a pnlvillns, or cmpodinm, a suckerlike organ which 
 enables them to walk upon smooth surfaces and to cling to objects 
 when upside down. 
 
 Nearly all adult and most larval insects have three pairs of 
 thoracic legs, but many boring and parasitic larvae have lost them 
 entirely. The legs are often greatly modified according to the habits 
 of the insect, not only for locomotion, but for grasping, digging, and 
 other purposes. The legs of most beetles are typical of walking 
 insects. In jumping insects, like the grasshopper and flea beetles, 
 the hind femora ^re greatly developed. In diggingjnsects, such as 
 the mole cricket and cicada nymphs, the tibia "and tarsus of the fore- 
 legs are developed as shovels. The forelegs of many predacious 
 insects, such as the mantis, assassin bugs, and others, bear teeth 
 upon the opposing surfaces of the tibia and femur, which make 
 them efficient grasping organs. The legs of the bees are highly 
 developed : the forelegs bear a comb for cleaning the antennae, 
 
ANATOMY OF INSECTS — EXTERNAL 
 
 the metatarsi bear a series of spines used as a pollen comb, and 
 the metatibiae bear a fringe of hairs on the outer surface surround- 
 ing what is called the pollen basket, adapted for carr)dng pollen. 
 
 Fig. 25. Types of insect legs 
 
 A, grasshopper {ScMstocerca ama-icmia) ; B, a cicindelid beetle {Cichtdela b-guiiata) ; C. a 
 gyrinid beetle {Dincntcs vitlatiis) ; Z), ayoung mantis ; E, a mole cricket {G)yllotalpa borcalis) 
 
 In aquatic forms the legs are variously developed for swimming or 
 skimming over the surface. The males frequently have the fore- 
 legs developed for grasping the females, as in the suckerlike disks 
 on the fore tarsi of the predacious diving beetles {Dytiscidac). In 
 general, insects which are strong fliers and are usually on the wing 
 have weak legs. 
 
 Wings. Millions of years ago insects became the pioneers in 
 aerial navigation by the development of wings, which have un- 
 doubtedly been chiefly responsible for the enormous development 
 of insects as a class, living in 
 all latitudes and environments. 
 The largest existing insects are 
 certain tropical moths whose 
 wings expand nearly a foot, 
 but fossils from the coal age 
 show that immense phasmids 
 (nearly related to grasshoppers) 
 then existed, with a wing ex- 
 panse of over two feet. The 
 
 largest wings are not, however, always the most serviceable, and 
 the strongest fliers are usually of medium size. ThejwingS-PE£- 
 sent a variation of structure in almost every group, and, with the 
 
 .fiADlVS 
 
 Fig. 26. Hypothetical type of wing 
 venation 
 
 (Adapted from Comstock and Needham) 
 
24 
 
 ELEMENTARY ENTOMOLOGY 
 
 mouth-parts, form the most important basis for classification. Thus 
 most of the orders are distinguished by differences in the wings, as 
 indicated by their names, which usually end in -ptera (from pteron, 
 a wing), and many insects may be classified to the genus or even to 
 the species by the wings alone, this being particularly true of fossil 
 forms, in which the wings are often the only parts well preserved. 
 Most adult insects possesstwo pairs of wings, borne by the meso- 
 thorax and metathorax, but in some parasitic orders the wings have 
 been lost, and one order, the Thysanura, represents the primitive 
 insect without wings. In the flies (Diptera) only the mesothoracic 
 wings are developed^, and the metathoracic wings are represented by 
 clublike appendages, called Jialtcrcs, or balancers. The relative shape 
 
 and size of the two pairs vary 
 greatly, and frequently the 
 two wings of each side over- 
 lap or are held together by 
 various structures, so that 
 they act as a single organ. 
 The wings are strengthened 
 by numerous thickenings, 
 called veins, whose number 
 and position form the basis of 
 the classification of families, 
 genera, and species. It has 
 been shown by Professors Comstock and Needham that the prin- 
 cipal veins are homologous in all the orders of insects, and that 
 they have been derived from one original type, either by the disap- 
 pearance of certain veins, by their growing together, or by the 
 addition of supplementary veins. The typical longitudinal veins, as 
 shown in Fig. 26, are the casta, subcosta, radius, media, cubittis, 
 and anals. The costa (r) is unbranched and strengthens the 
 anterior margin of the wing. The subcosta {se) is typically two- 
 branched, though often single, and, where the costa is small or 
 wanting, appears to be the first, or anterior, vein. The radius (;-) is 
 typically five-branched, the base of the second principal branch, 
 from which the four posterior branches divide, being known as the 
 radial sector. The media («/) is typically four-branched, though 
 often but two or three branches are present. Cubitus (r^)Jias 
 
 Fig. 27. Wing of house-fly [Musca dotnesii- 
 
 ca), showing speciaUzation of wing venation 
 
 through reduction of veins 
 
 c, costa ; r, 
 
 radius ; m, media ; at, cubitus ; 
 anal. (After Comstock) 
 
ANATOMY OF INSECTS — EXTERNAL 
 
 25 
 
 usually two branches. The anal veins (a) are typically three in, 
 number, but often one or two are lost, and in other groups the 
 anal area is greatly expanded and they become many-branched. 
 Specialization by reduction in the number of veins is seen in the 
 wings of the flies, bees, and butterflies and moths, while special- 
 ization by addition is found in the wings of Orthoptera and the 
 neuropterous orders. 
 
 In several orders the front wings are modified to form wing- 
 covers for the hind wings and are not used in flight. Thus the 
 front wings of the beetles, called elytra, are hard and horny, those of 
 the grasshoppers are 
 leathery, and those 
 of the bugs are leath- 
 ery at the base, with 
 membranous tips. 
 
 In addition to be- 
 ing^qrgans of flight, 
 the wings sometimes 
 have other functions. 
 T-hus in crickets and 
 other Orthoptera the 
 wings bear sound- 
 producing structures, 
 and the honey-bee 
 maintains the temperature of its hive by the body heat derived 
 from the incessant motion of the wmgs. 
 
 Abdomen. The ten segments of the abdomen are the most dis- 
 tinct and simple of the body. The jointed appendages have been 
 almost entirely lost in adult insects, and the abdomen merely houses 
 the respiratory, digestive, and genital systems, the posterior seg- 
 ments being modified in connection with the external sexual organs. 
 In the lowest order, the Thysanura, rudimentary abdominal append- 
 ages still exist, and caterpillars and other larvae frequently bear 
 several pairs of fleshy, unsegmented prolegs, or false legs, bearing 
 a circlet of hooks at the tip. In several orders the "females bear an 
 ovipositor, or ^-gg guide, which has been developed from a speciali- 
 zation of the appendages of the seventh, eighth, and ninth seg- 
 ments. The females of many grasshoppers and crickets bear large 
 
 28. ^\ ing of May-fly, showing specialization of 
 wing venation by addition of wing veins 
 
 Lettering as in Fig. 27. (After Folsom) 
 
26 
 
 ELEMENTARY ENTOMOLOGY 
 
 ovipositors, with which they are enabled to insert their eggs in the 
 ground or in wood, but the greatest development of the ovipositor 
 is found among hymenopterous insects in which it is formed for 
 sawing, boring, or stinging. Another pair of jointed appendages, 
 
 Fig. 29. Ovipositor of periodical cicada 
 At rest at .A, and exserted at B 
 
 — C^ 
 
 called ccfci, are frequently found attached to the tenth abdominal 
 segment. They are quite variable in length, but in May-flies are 
 as long as the body and resemble very slender antennae projecting 
 backward from the abdomen. In most cases they are tactile organs, 
 
 but in the cockroach they assist in 
 smelling. 
 
 The nurnber of visible abdom- 
 inal segments varies from five .to 
 eleven in different orders, and fre- 
 quently the number is different on 
 the upper, or dorsal, and under,j3r 
 ventral, sides. The structure of- the 
 anal segments is usually different 
 in the sexes and furnishes impor- 
 tant characters for classificatioru - 
 
 Integument. Before studying 
 the internal anatomy, the skin, or 
 integument, of the insect should 
 be considered. This has become 
 hardened so that it forms a firm outer skeleton, to which the mus- 
 cles and internal organs are attached. Thus the parts of the insect 
 skin, as have been described, are analogous to the bony skeleton 
 
 Fig. 30. Section tlirough skin of a 
 beetle {Chrysobothris) 
 
 b, basement membrane ; c', primary cutic- 
 
 ula ; C-, secondary cuticula ; //, hypoder- 
 
 mis cell ; ;?, nucleus, (.'\fter Tower, from 
 
 Folsom) 
 
ANATOMY OF INSECTS — EXTERNAL 
 
 27 
 
 of higher animals in that th ey su pport the tissues of the body^ and 
 their structure is characteristic of the different groups. This ha_rd- 
 ening of the skin is found in all arthropods and is due to a sub- 
 stance, called cJiitin , which is formed by the lower layer of cells of 
 tliL' sl^in, the hypodermis, and which forms an impervious, hard 
 la\cr o\cr the body of the entire animal, though but slightly devel- 
 oped in the membranous joints between the segments. Chemically, 
 chitin is somewhat akin to silk, or to the spongin of the sponge skele- 
 ton. It is unaffected by ordinary acids and alkahes, though soluble 
 in sodic or potassic hypochlorite. The insolubility of chitin is of 
 impoi'tance in the consideration of insecticides, for there is hardly 
 anything that can be applied to any but the most soft-bodied insects 
 which will corrode the skin without injuring the foliage of the 
 plants upon which they feed. The surface of the chitinous skin 
 may be smooth or pitted, wrinkled, striated, granulated, or marked 
 in various characteristic ways. The chitin is not only developed 
 by the outer skin but is formed on the surface of the entire epider- 
 mis, including the lining of the anterior part of the alimentary tract 
 and the respiratory tubes, or trachea, as can be seen by the exam- 
 ination of a cast skin after an insect has molted. 
 
CHAPTER IV 
 
 ANATOMY OF INSECTS — INTERNAL 
 
 The general arrangement of the internal organs of an insect 
 may be understood by a study of transverse and longitudinal sec- 
 tions, as shown in Figs. 31 and 32. Attached to the inside of 
 
 Fig. 31. Ideal section through an insect 
 
 a, alimentan- canal ; //, heart ; «, nerve cord ; s, stigmata, or spiracles : /, tracheal tubes ; 
 /, legs; 7c, wings. (From Riverside Natural Historj) 
 
 the body wall are found layers of longitudinal and vertical mus- 
 cles which control the body movements. Through the center of 
 the body runs a large tube, the alimentary canal, or digestive tract. 
 
 m h 
 
 Fig. 32. Ideal longitudinal section of an insect, showing relative position of organs 
 
 a, alimentary canal ; /;, heart ; ;«, muscle bands ; ;;, ner\'e cord ; ;', reproductive organs. 
 
 (After Comstock) 
 
 Just beneath the back is a small, transparent tube, the dorsal blood 
 vessel, or heart. Along the median line, close to the ventral wall, 
 is a series of small white knots, or ganglia, connected by a double 
 
 28 
 
ANATOMY OF INSECTS — INTERNAL 
 
 29 
 
 cord, which form the nervous system. On either side of each seg- 
 ment is a small opening through the body wall, called a spiracle, 
 through which air is admitted to the breathing tubes, which branch 
 to all parts of the body and form the respiratory system. The re- 
 prdductive organs are found in the posterior segments of the abdo- 
 men and have a separate opening just below the anus. 
 
 The digestive system. The digestive tract, or alimentar}- canal, 
 consists of a more or less straight tube, occupying the larger part of 
 the center of the body and divided into parts with special functions, 
 whose development depends upon the food habits of the insect. 
 
 Pharynx. The food, after being torn to pieces and ground up 
 by the mouth-parts, is received into the pJiary}ix (often called the 
 
 Fig. -^Tj. Digestive and excretory system of a grasshopper 
 
 r, crop ; g, gizzard, or proventriculus concealed by caeca ; g.c^ gastric caeca ; /./, large intes- 
 tine ; ;«, mouth ; m.t, Malpighian tubes ; o, esophagus ; r, rectum ; s^ stomach ; s.g^ salivary 
 glands ; s.i, small intestine 
 
 mouth), lying within the head, and in which it is acted upon by the 
 saliva. In sucking insects the pharynx acts as a pumping organ, as 
 already described. The saliva is secreted by the salivary glands, 
 which lie along the esophagus in the thorax, whose ducts open at 
 the base of the tongue (hypophan-nx). The saliva acts on starch, 
 changing it into glucose as in the vertebrates ; in some carnivorous 
 insects it acts on the proteids and is sometimes used to poison the 
 prey ; in mosquitoes the poisonous saliva prevents the coagu- 
 lation_i]£_the_blood_ofanimals, though its original function may 
 
?o 
 
 ELEMENTARY ENTOMOLOGY 
 
 have been to act on the proteids of plant juices. In most cater- 
 pillars, of which the silkworm is the best example, and in many 
 other insect larvae, certain salivary glands have become specialized 
 so that their secretion hardens upon coming in contact with the air 
 and forms the silk of which their cocoons are spun. 
 
 Esophagus. The esophagus is a straight tube passing from the 
 pharynx to the crop or gizzard, or directly into the stomach. 
 
 Crop. The crop is practically a dilation of the posterior end of 
 the esophagus and in herbivorous insects forms the larger part 
 
 of the digestive tract. The food is 
 stored in the crop until the action 
 of the saliva has been completed, 
 changing the starches into glucose 
 sugar and the albuminoids into as- 
 similable, peptonelike substances. 
 In many insects which feed on 
 liquids, the storage capacity of the 
 crop is increased by a lateral 
 pocket, which in some cases forms 
 a separate sac communicating with 
 the crop by a short neck. The 
 walls of the crop contain a layer of 
 muscles which force the food back 
 into the gizzard when it is suffi- 
 ciently digested. 
 
 Gizzard. The gizzard [proven- 
 tnculns) is found best developed 
 in biting insects, such as grass- 
 hoppers and beetles, which feed 
 on coarse food, and is but slightly 
 developed or absent in many orders. It is termed "gizzard " because 
 it somewhat resembles the gizzard of a bird and was supposed to 
 function similarly. It is a small, very muscular organ, lined within 
 with strong chitinous teeth, or ridges, which strain the food, pre- 
 venting the passage of large particles into the true stomach. Some 
 have thought that these ridges aid in grinding the food, but this 
 seems doubtful. Usually a valve allows the food to be forced from 
 the gizzard back into the stomach, but prevents its return. 
 
 Fig. 34. Cockroach dissected to show 
 ahmentary canal and bands of muscles 
 
 alx, alimentary canal. (After Hatshek and 
 Cori, from Jordan and Kellogg) 
 
ANATOMY OF INSECTS — INTERNAL 
 
 Stomach. The stomach {vcntriciilus) is usually a simple tube 
 somewhat larger in diameter than the esophagus or intestine, but 
 of variable size and strength. As the food passes into the stomach 
 it is acted upon by the secretions of the ccccal tubes {gastric caca) 
 which are glandular pouches, or tubes, opening into the anterior 
 end of the stomach. Their number, size, and shape are quite vari- 
 able, and they secrete a weak acid which emulsifies fats and con- 
 verts albuminoids into peptones. The stomach is not lined with 
 chitin, as is the rest of the alimentary tract, but is glandular and 
 secretes a neutral or alkaline fluid which aids in the further diges- 
 tion of the food. The chief function of the stomach, however, is 
 to absorb the digested food and pass it into circulation. 
 
 Fig. 35. Digestive canal of a carabid beetle 
 
 /i, esophagus ; c, crop ; d, proventriculus ; /, stomach with its caeca ; g, posterior portion 
 of stomach ; //, intestine ; /, two pairs of Malpighian tubes ; k, rectum ; /, anal glands. ' 
 
 (After Dufour) 
 
 Intestine. The food passes from the stomach into the intestine 
 through a pyloric valve which prevents its passage backward. The 
 intestine is divided into three fairly distinct parts, the ileum, colon, 
 and recttnn. The length and size of these parts varies greatly ac- 
 cording to the food of the insect, the ileum often being considerably 
 coiled. In the ileum the digested food materials are absorbed and 
 passed into the blood circulation ; the colon, which is often absent, 
 contains undigested matter and waste products ; while the rectum 
 has thick, muscular walls and expels the feces through the anus, 
 which opens through the last segment of the abdomen. 
 
 Malpighian tubes. Opening into the intestine, just back of the 
 stomach, are several small, slender tubes, variable in number, in 
 which uric acid is found, and which are considered to be excretory 
 organs similar in function to the kidnevs of hig-her animals. 
 
32 
 
 ELEMENTARY ENTOMOLOGY 
 
 When arsenical insecticides are applied to the food of biting 
 
 insects, the arsenic must be in the most insoluble form, to avoid 
 
 burning the foliage, and it is therefore not dissolved until it 
 reaches the stomach, when, having been mixed 
 with the digestive juices mentioned, it becomes 
 sufificiently soluble to be absorbed by the walls 
 of the stomach and ileum. Some insects are 
 able to consume a large amount of poison before 
 an amount sufficient to kill them is dissolved 
 and absorbed. In such cases poisons are some- 
 times of no avail, because serious injury is 
 done before the pest is brought under control, 
 and other means must be employed. 
 
 In the young 
 stages of insects 
 the digestion, 
 and consequent 
 growth, is ex- 
 tremely rapid. 
 A caterpillar 
 will frequently 
 eat and digest 
 
 two or three times its own weight 
 
 in a day. Thus the silkworm, 
 
 when it hatches from the egg, 
 
 weighs but one twentieth of a 
 
 grain, but in 56 days, when full 
 
 grown, it has consumed 120 oak 
 
 leaves, weighing three fourths of 
 
 a pound, and half an ounce of 
 
 water, or 86,000 times its original 
 
 . r 1 • 1 r 1 • 'Pig. 37. Diagram to indicate the 
 
 weight, of which food 207 grains ^o^rse of the blood in the nymph of 
 
 have been assimilated, one fourth a dragon-fly 
 
 of a pound has been voided as a, aorta; /i, heart. The arrows show the 
 
 excrement, and five ounces have ''""''" ''"'^^li'^Tro^'X '"'" 
 evaporated as water. 
 
 Circulatory system. The /j/ood vessels of an insect are exceed- 
 ingly simple, consisting of a single dorsal tube, or heart, which 
 
 Fig. 36. Diagram 
 
 of a portion of the 
 
 heart of a dragon-fly 
 
 nymph 
 
 0, ostium ; f, valve. 
 The arrows indicate 
 the course of the blood. 
 (After Kolbe, from 
 Folsom) 
 
ANATOMY OF INSECTS — INTERNAL 
 
 33 
 
 extends the length of the body along the median line just beneath 
 the notum. In the abdomen of adult insects this tube is divided 
 into several chambers, each of which has a valve at either side, 
 allowing the blood to flow into it but preventing its escape. The 
 chambers are also separated by valves which allow the blood to 
 flow forward but prevent its backward passage. The abdominal 
 part of the tube, the heart proper, pulsates and drives the blood 
 toward the head, while the forward part is a simple blood vessel, 
 called the aorta, which usually divides in the head, where it ends 
 abruptly, allowing the blood to flow into the body cavity. Thus the 
 blood is admitted to the heart by the lateral valves, is forced forward 
 to the head, and thence flows in more or less defined currents 
 
 Y\G. 38. Portion of a trachea of a caterpillar, with its branches 
 (After Leydig, from Gegenbauer) 
 
 throughout the body, bathing all the organs. The pulsation of the 
 heart and the flow of the blood may be observed in many thin- 
 skinned larvae and nymphs. 
 
 The blood consists of a watery fluid, — the plasma, or serum, — 
 and the white corpuscles, or leucocytes. Usually colorless, it is 
 often yellowish or greenish. The blood has almost nothing to do 
 with the aeration of the tissues, that being done by the respiratory 
 system, as described below, its chief function being to nourish the 
 tissues with the food materials that it carries. 
 
 Respiratory system. Insects have no lungs, but breathe through 
 a system of tubes, called trachea, which extend to all parts of the 
 body, bringing fresh air to the tissues and carrying off the carbon 
 dioxide. On either side of two thoracic segments, and on all the 
 
.34 
 
 ELEMENTARY ENTOMOLOGY 
 
 abdominal segments but the last two or three are small openings 
 called spiracles, or stigmata, which are the external openings 
 through which air is admitted to the trachea. The spiracles are 
 guarded by hairs and other devices, to prevent the ingress of dust 
 and foreign matter, and each has a valve operated by a special muscle 
 which opens and closes it. From each spiracle a short tube extends 
 inward and opens into a main tracheal tube which extends along 
 the side of the body. There are commonly two of these main tubes, 
 
 or tracheal trunks, on either side of 
 the body, which give off three main 
 branches in each segment. The upper 
 branch goes to the dorsal muscles, the 
 middle one branches to the alimentary 
 canal and reproductive organs, and the 
 lower one supplies the nerve cord and 
 ventral muscles. These branches divide 
 and subdivide into the finest tubes, 
 which penetrate all the tissues, run- 
 ning between the muscle fibers ; some 
 authorities state that they may even en- 
 ter individual cells. They do not end 
 blindly, but anastomose so as to form 
 a capillary network, so that a contin- 
 uous circulation of air is possible. By 
 opening the spiracles the air enters 
 the tracheal system, and it is expelled 
 by muscles which cause a vertical con- 
 traction of the body walls and thus 
 force it out. The rhythmic expansion 
 and contraction of the body occurs at 
 a regular rate, dependent upon the 
 temperature and the activity of the insect, and resembles the 
 breathing of higher animals. Many insects are provided with 
 large air sacs which serve as air reservoirs. The trachea are 
 readily recognized by their striated appearance, which is due to 
 a thickening of the cuticle into a thread, which lies on the inner 
 surface in a compact spiral, like a compressed spiral spring, and 
 thus prevents the collapse of the tubes. 
 
 Fig. 39. Diagram of tracheal 
 system in body of a beetle 
 
 sp, spiracles ; ii\ trachea. (After 
 Kolbe) 
 
ANATOMY OF INSECTS — INTERNAL 
 
 In aquatic insects various respiratory devices have been developed. 
 Many of them (May-fly, dragon-fly, stone-fly, and mosquito nymphs) 
 bear tracheal gills which consist of a leaflike expansion, or a tuft of 
 thin filaments, into which the trachea extend and divide into a fine 
 network. The oxygen of the water passes through the gill mem- 
 brane into the air of the trachea, and thus the air of the tracheal 
 system is purified. No true gills, — that is, gills carrying blood 
 vessels, like those of fishes, — are found in insects. Other aquatic 
 insects carry a thin film of air with them, either by means of a 
 thick coating of fine hairs to which air bubbles 
 adhere, or beneath the wing-covers. The trachea 
 are sometimes prolonged into tubes which pro- 
 ject beyond the tip of the abdomen and extend 
 to the surface of the water or mud in which 
 these insects live. 
 
 From the above description it is evident that 
 insects possess the best-developed t)'pe of respir- 
 atory system, extending as it does to all the 
 tissues of the body, giving them a constant 
 supply of fresh air and carrying off the waste 
 gases. With an ample food supply this makes 
 possible a rapid oxidation of the tissues, and 
 undoubtedly is one of the chief reasons for the 
 wonderful muscular activity, working power, and 
 endurance of insects. 
 
 The structure of the respiratory system is of great practical im- 
 portance in combating insect pests. Many insects which cannot 
 be destroyed with arsenical poisons are killed by contact insecti- 
 cides in either a spray or a dust form. These contact insecticides 
 destroy the insect by entering or clogging the spiracles or trachea. 
 Oils are particularly valuable because they spread and pass readily 
 through the hairs which guard the spiracles. Soap solutions leave a 
 gummy deposit, when the water evaporates, which clogs the trachea. 
 Finely divided dusts, such as fine tobacco dust, pyrethrum, and 
 even air-slaked lime or road dust, will clog the spiracles of many 
 insects. Insects living in grain, stored products, and other inac- 
 cessible places are often destroyed by the use of poisonous gases, 
 such as carbon bisulphide and hydrocyanic acid gas, which quickly 
 
 Fig. 40. Diagram 
 
 of trachea in head 
 
 of cockroach 
 
 /, trachea, or air tubes. 
 Note branches to all 
 the mouth-parts and 
 the antennas. (After 
 Miall and Denny) 
 
36 
 
 ELEMENTARY ENTOMOLOGY 
 
 asphyxiate them through the well-developed tracheal system, though 
 occasionally the valves of the spiracles are so well developed that 
 an insect may keep them closed for a long time, so that fumiga- 
 tion, in order to be fatal, must be prolonged. 
 
 Muscular system. Insects are well provided with powerful mus- 
 cles, a caterpillar having some two thousand. The muscles are 
 yellowish in color, and the fibers are striated as in the voluntary 
 muscles of vertebrates. The simplest type of muscles is found in 
 larvae and in the abdominal segments of adult insects, where the 
 
 abc 
 
 Fig. 41. Muscles of cockroach, of ventral, dorsal, and lateral walls, respectively 
 
 a, alary muscle : (i/>c; abductor of coxa ; ai/c, adductor of cojcji ; /s, longitudinal sternal ; //, 
 
 longitudinal tergal ; //A, longitudinal thoracic ; os, oblique sternal ; ts, tergo-sternal ; /jl, 
 
 first tergo-sternal. (After Miall and Denny) 
 
 muscles of each segment are very similar, forming segmented 
 bands on the inside of the body wall. The longitudinal muscles 
 beneath the tergum and above the sternum are arranged so that, 
 when they contract, the body bends in that direction, and by their 
 rhythmic contraction the looping walk of the caterpillar is produced. 
 Oblique-sternal muscles bend the abdomen laterally, and vertical 
 muscles draw the tergum and sternum together in expiration. The 
 thorax of adult insects is filled with the strong muscles which 
 operate the wings and legs, and the muscles which operate the 
 mouth-parts occupy the back of the head. 
 
ANATOMY OF INSECTS — INTERNAL 
 
 Z7 
 
 The work performed by the muscles of insects appears prodigious 
 compared with that done by higher animals. Thus the weakest 
 insect can pull over twenty times its weight. A house-fly can 
 carry a match, to equal which a man would need to carry a timber 
 thirty-five feet long and as large around as his body. An earwig can 
 lift twelve times its weight, and a honey-bee, in flight, carries four 
 fifths of its weight. A small insect is relatively stronger than a large 
 one, and the relative strength of insects is largely accounted for by 
 their small size. This is due to the fact that the weight increases as 
 the cube of a single 
 dimension, while the 
 strength of a muscle 
 increases as the square 
 of its diameter. The 
 endurance and rapidity 
 of muscular action of 
 insects is no less mar- 
 velous. By determin- 
 ing the pitch of the 
 note made by the wing 
 vibrations of a gnat, 
 physicists have shown 
 that its wings may move 
 as much as fifteen thou- 
 sand times per minute. 
 The prolonged vibra- 
 tion of the honey-bee's 
 wings is another instance of remarkable muscular endurance. 
 
 Nervous system. The nervous system consists of a series of 
 small white ganglia which are connected by a double nerve cord 
 lying along the bottom of the body cavity. In the larvae there is 
 usually one ganglion to each segment, but in the adult insects 
 the ganglia are often fused together, those of the thorax and an- 
 terior abdominal segments having grown together, as well as those 
 toward the tip of the abdomen. In the head the ganglia have 
 grown together to form the brain, which lies just above the esoph- 
 agus and which is connected with the subesophageal ganglion by 
 a double nerve cord, one commissure of which passes on either side 
 
 Fig. 42. Nervous system of honey-bee, at a, and 
 
 of its larva, at b, showing the simple type of the 
 
 larva and the specialization in the adult due to 
 
 fusion of the ganglia 
 
38 
 
 ELEMENTARY ENTOMOLOGY 
 
 of the esophagus, thus forming a nerve collar. The brain gives 
 off nerves to the eyes, antennae, palpi, and other sensory organs 
 of the head, receiving the sensory stimuli and controlling the coor- 
 dinated muscular movements. In a general way the brain is the 
 seat of whatever "will" an insect may have. The subesophageal 
 ganglion coordinates the movements of the mouth-parts, as well 
 as some bodily movements. The thoracic and abdominal ganglia 
 give off nerves to all parts of their segments, the movements of 
 which they control. They are more or less independent, each 
 
 Fig. 43. Nervous system of head of cockroach 
 
 a, antennal nerv'e ; a^, anterior lateral ganglion of sympathetic system ; i, brain ; d, salivary 
 duct ; /, frontal ganglion ; /i, hypopharynx ; /, labrum ; //, labium ; m, mandibular nerve ; i/ix, 
 maxillary nerve ; «/, nerve to labrum ; n/i, nerve to labium ; 0, optic nerve ; oc, esophageal 
 commissure ; oe, esophagus ; /^, posterior lateral ganglion of sympathetic system ; r, 
 recurrent nerve of sympathetic system ; s, subesophageal ganglion. (After Hofer, from 
 
 Folsom) 
 
 forming a nerve center for its segment. Thus a decapitated 
 insect will walk or fly, and the abdomen of a grasshopper will 
 continue to breathe, these functions being controlled by the seg- 
 mental ganglia, though lacking coordination. In addition to the 
 main nervous system there is a sympathetic system, one part of 
 which runs along the upper part of the alimentary canal and con- 
 trols the digestive process, while a small ventral sympathetic nerve 
 gives off branches which control the spiracle muscles. 
 
 Dr. J. B. Smith, in his " Economic Entomology," gives an 
 interesting account of some experiments which show the relation 
 of the brain and ganglia to the body : 
 
ANATOMY OF INSECTS — INTERNAL 
 
 I found that if I cut off the abdomen completely, the fly would live for 
 twenty-four hours thereafter ; with practically no digestive system, and with 
 most of its heart gone. Turning the matter, I cut off the head, and found that 
 it would live without a head for just about as long a time as it would without 
 an abdomen. Of course death was bound to result from this mutilation in 
 time, but the interesting feature is that no apparent symptom of pain developed. 
 I found, however, that just as soon as I cut the large ganglion in the middle 
 of the thorax I terminated life. Whatever sentimental feeling there may be 
 in the matter of causing unnecessary pain, there is no reason to believe that 
 insects have any well-developed sensitiveness, as we understand that term. 
 The character of the insect nervous system is so entirely different from that 
 of our own that we are left without real guides in our interpretation of the 
 various sensitive structures. Man judges most things by himself, and where 
 this guide fails, he is at a loss and cannot be certain that he interprets what he 
 sees correctly. 
 
 The senses of insects. Sight. Attention has already been called 
 to the simple eyes, or ocelli, and the compound eyes. An ocellus 
 consists of a lens, vitreous 
 bod}', retina, and nerve, much 
 like the eye of vertebrates, 
 but its form is fixed, and as 
 there is therefore no power of 
 accommodation to the distance 
 between it and the object seen, 
 its power of vision must be 
 extremely limited. As far as 
 the ocelli are concerned, in- 
 sects must be very nearsighted, 
 for they are quite convex and 
 will only focus at one distance, 
 which must be short. Ex- 
 periments have shown that 
 light and darkness are distin- 
 guished by the ocelli, for if the Fig. 44. structure of median ocellus of 
 compound eyes of a grasshop- honey-bee, in sagittal section 
 
 per are covered with varnish, /', hypodermis ; /, lens ; «, nerve ; /, iris pig- 
 
 ,V ^^^ C^A ;*-,. „ ^,,4- ^C „ U^ ment; ;-, retinal cells; v, vitreous body. (After 
 
 It can find its way out of a box Redikorzew, f^m Folsom) 
 
 with a single opening. Prob- 
 ably the ocelli are of more service in this way than in forming 
 definite images, though insect larvas possess only ocelli. 
 
40 
 
 ELEMENTARY ENTOMOLOGY 
 
 I < 
 
 The surface of the compound eye is composed of numerous 
 hexagonal facets, each of which is the end of a single eye element 
 
 called an ommatidium, which is prac- 
 tically a separate and distinct eye. 
 Each ommatidium is composed of the 
 various optical elements necessary for 
 vision, but it receives impressions only 
 in a straight line, which form only a 
 very small part of the total field of the 
 insect's vision. This is due to the fact 
 that each ommatidium is surrounded 
 by black pigmented cells, which ab- 
 sorb or reflect the light, as shown in 
 Fig. 46, so that only those rays which 
 come in a straight line impress the 
 retina. Thus the whole view formed 
 by the images from all the ommatidia 
 as they reach the optic nerve must be 
 like that of a mosaic. 
 
 Insects are able to distinguish forms 
 at but relatively short distances, vary- 
 ing from two to five feet, and to 
 
 Fig. 45. Portion of compound 
 
 eye of fly {Calliphora vomitoria), 
 
 radial section 
 
 f, cornea ; /, iris pigment ; «, nerve 
 fibers ; iic^ nerve cells ; r, retinal pig- 
 ment ; t, trachea. (After Hickson, 
 from Folsom) 
 
 see distinctly only near-by objects. 
 Large eyes, as those of the dragon- 
 fly, give a wide field of vision, 
 and numerous facets would give a 
 greater distinctness of vision. In- 
 sects' eyes are well adapted to 
 detect motion, as a moving object 
 affects the facets in succession, and 
 motion is thus observed without 
 moving the eyes. They are able 
 to distinguish colors and often 
 respond quite definitely to them, 
 but their color sense seems to 
 have a different range from that 
 of man, as ants are sensible to the 
 ultra-violet rays. 
 
 Fig. 46. Illustrating mode of vision 
 in compound eye 
 
 " The light enters through the cornea. 
 The rays which strike the sides of each 
 tube or cone are absorbed by the black 
 pigment which surrounds the tube. Ac- 
 cordingly those rays of light only which 
 pass through the crystalline cones directly 
 (or are reflected from their sides), such 
 as a-a' , b-b', c-c', d-d', e-e', will ever affect 
 the nerves at a', b', </, d', e'." (After 
 Lubbock, from S. J. Hunter) 
 
ANATOMY OF INSECTS — INTERNAL 
 
 41 
 
 Touch. The sense of touch is very highly developed in many 
 insects, sensory tactile hairs commonly occurring over the whole 
 body, and the antennae, palpi, and 
 cerci being specially developed as 
 tactile organs. 
 
 Taste. Both observation and 
 experiment have shown that in- 
 sects have a well-developed sense 
 of taste, though it is often quite 
 different from that of man, as 
 they detect some substances but 
 fail to perceive others, and often 
 seem to relish substances wholly 
 repugnant to us. The sense of 
 taste is located in sensory hairs or microscopic pegs borne upon 
 the tongue (see Fig. 47), or hypopharynx, on the epiphar}''nx (a 
 
 Fig. 47. Tip of tongue of honey-bee 
 
 Showing labellum {Ll'l), guard hairs {Hi), 
 
 and ventral groove (-(■), from above and 
 
 below. (After Snodgrass, United States 
 
 Department of Agriculture) 
 
 Fig. 48. Nerve endings in tip of maxillary palpus of (a) Lociista viriJissima, 
 and in labial palpus of {h) Machilis polypoda. (Greatly magnified) 
 
 sh, sense hairs ; sc, sense cells ; be, blood cells. (After \'om Rath, from Kellogg) 
 
 sensor)^ portion of the roof of the pharynx similar to the palate of 
 higher animals), and on the maxillary and labial palpi. Probably the 
 sense of smell is used more than the taste organs in choosing food. 
 
42 
 
 ELEMENTARY ENTOMOLOGY 
 
 Fig. 49. Sensory cells 
 
 in antennas of aphides. 
 
 (Greatly magnified) 
 
 Smell. Most insects depend upon their sense of smell to find 
 
 their food and to discover the opposite sex. Thus beetles and flies 
 are drawn to carrion and^to decaying vegetation, 
 and in almost all cases it seems probable that 
 the food plant of an insect is distinguished by 
 smell rather than by sight. A confined female 
 Cecropia moth will often draw numerous males 
 from a considerable distance. Experiments 
 have shown that the antennae are the chief 
 organs of smell, though the maxillary palpi 
 and cerci detect certain 
 odors and enable certain 
 insects to smell when the 
 antennae are removed. 
 The olfactory function 
 of the antennae can be 
 
 very easily shown by taking an insect which 
 
 is definitely attracted to some substance by 
 
 smell and removing the antennae or covering 
 them with shellac, when 
 it will be found wholly 
 indifferent to what was 
 previously so attractive. 
 Vile-smelling substances 
 which are supposed to 
 
 repel insects are usually showing smelling pits on the 
 
 of no value, not affect- 
 ing the insect as they do 
 
 man. Some attempts have been made to utilize 
 the sense of smell in luring insects to destruc- 
 tion, but as yet with no very marked success, 
 though there is promise of possible control of 
 some pests in this way. 
 
 Hearing. There is no evidence that hearing 
 
 is generally developed in insects, but in many 
 
 groups we naturally infer its presence from the 
 
 fact that characteristic noises are produced, as the "singing" of 
 
 the cicada and katydid. These noises are produced in various 
 
 Fic. 50. Antenna of la- 
 mellicorn beetle 
 
 expanded terminal segments. 
 (After Jordan and Kellogg) 
 
 Fig. 51. Under sur- 
 face of right wing 
 of the male cricket. 
 (Enlarged) 
 
 /, rasp ; z, position of 
 scraper, only scraper of 
 the left wing used; j, 
 attachment of wing. (Af- 
 ter Linville and Kelly) 
 
ANATOMY OF INSECTS — INTERiNAL 
 
 4, 
 
 ways. Thus flies and bees buzz with their wings in rapid vibra- 
 tion, and the singing of the male cicada is produced by the rapid 
 vibration of a pair of membranes on the first abdominal segment. 
 Many beetles squeak by rubbing the wing-covers against some rasp- 
 like part of the body. But the grasshoppers and crickets are the 
 leaders inJJie_iiisectorcij£stra. Grasshoppers often produce noises 
 in flying by rubbing 
 
 7 
 
 the hind legs against 
 the wing-covers or 
 by rubbing together 
 the front and hind 
 wings. Katydids 
 and crickets have 
 the best-developed 
 musical apparatus, 
 having a scraper 
 on the base of one 
 wing-cover and a 
 vein ridged like a 
 file on the base of 
 the other, which, 
 when rubbed to- 
 gether, vibrate the 
 neighboring mem- 
 brane and produce 
 the strident song, 
 or the shrill chirp, 
 so characteristic of 
 these insects. 
 
 Fig. 52. 
 
 Ear of locust (Caloptonts italicin) 
 the inner side 
 
 seen from 
 
 T, tympanum : 77?, its border ; 0, 21, two bonelike processes ; 
 bi, pear-shaped vesicle ; ii, auditory nerve ; ga, terminal gan- 
 glion ; sf, stigma, or spiracle ; m, opening muscle, and wi, 
 closing muscle of same ; .1/, tensor muscle of the tympanic 
 membrane. (After Graber) 
 
 That these sounds are heard by their mates is shown by the 
 answering call of one to another, and to similar tones produced 
 artificially. In grasshoppers a large auditory organ, or " ear," is 
 found on either side of the first abdominal segment. It consists of 
 a surface membrane, or tympanum, stretched over a cavity, on the 
 inner surface of which rest two processes, analogous to the small 
 bones of the human ear, which carry the vibration to a delicate 
 vesicle which connects with an auditory nerve. Similar small 
 membranes are found on the fore-tibia of certain insects and are 
 
44 
 
 ELEMENTARY ENTOMOLOGY 
 
 considered probably auditory. In male mosquitoes, and probably in 
 some other forms, the antennae have an auditory function which 
 enables them to find the females, as is shown by their vibrating in 
 unison with a tone produced by a tuning fork of the same pitch 
 as that made by the female with her wings. 
 
 Fig. 53. Female mosquito 
 
 Showing auditory hairs {ak) on the 
 antennas. (After Jordan and Kellogg) 
 
 Fig. 54. Diagram of longitudinal section 
 through first and second antennal segments 
 of a mosquito {Mochlonyx culict'/ormis), male, 
 showing complex auditory organ composed 
 of fine, chitinous rods, nerve fibers, and nerve 
 cells. (Greatly magnified) 
 
 (After Child, from Kellogg) 
 
CHAPTER V 
 
 THE GROWTH AND TRANSFORMATIONS OF INSECTS 
 
 Stories of the lives of insects, or their " hfe histories," are 
 among the most interesting and marvelous to be found in the 
 realm of science, furnishing themes for poet, philosopher, and 
 scientist. 
 
 Egg. All begin life in the egg stage. The shape, size, number, 
 and position of the eggs are as different as are the many families 
 of insects, and cannot be described in general terms. Usually they 
 
 m, n o p q r s 
 
 Fig. 55. Eggs of different insects. (Enlarged) 
 
 a, Toririx ; b, Liparis ; r, a Noctuid ; (/, usual shape of those of a bark borer ; e, May-beetle 
 {Lachnostertid) ; /, midge (Chiro)iomus) ; g, Lyda ; h, fly {Miisca) ; /, honey-bee ; k^ gall-fly 
 {Rhodites rosae) ; /, lace-winged fly {Cluysopa) ; wz, pomace-fly {Drosophila) ; ;;, Peniatoma: 
 0, back-swimmer {IVefa) ; /, butterfly {Pieris crataegi) ; q, bedbug ; r, louse, fastened to a 
 hair; s, bot-fly {Hyfoderma). (After Judeich and Nitsche, from Packard) 
 
 are laid upon the food plant, or host, but occasionally their position 
 could not be accounted for were the habits of the young not known. 
 The number laid by a female may vary from one or two, as in the 
 case of some aphides, to many thousands, as in bees and termites, 
 but a fair average would probably be about one hundred. The size 
 varies inversely with the number produced, and the shape and struc- 
 ture are largely influenced by the environment in which the eggs are 
 laid. In a few cases the eggs hatch within the body of the female, 
 which thus gives birth to live young, as do the aphides. Those 
 eggs which hatch during the summer have an incubation period of 
 from a day or two, as do those of certain flies and mosquitoes, to 
 
 45 
 
46 
 
 ELEMENTARY ENTOMOLOGY 
 
 three or four weeks, while very many remain dormant over winter 
 and hatch when sufficient temperature occurs the next spring or 
 summer. 
 
 Transformations. Upon hatching from the egg the young grass- 
 hopper is of much the same general appearance as when full grown, 
 and is readily recognized as a grasshopper ; but if we did not 
 
 Fig. 56. Molting of the full-grown nymph of the periodical cicada, showing process 
 of emerging from the skin of the nymph, with the soft white adults below 
 
 The adults become black after hardening for a few hours 
 
 know that the little caterpillar, after completing its growth, finally 
 transforms into a butterfly, we should never suspect them to be 
 different stages of the same insect, and a lack of knowledge of 
 these transformations has caused many strange superstitions con- 
 cerning insects. 
 
 The transformation of the butterfly from the caterpillar is a 
 complete one, and is known as a complete metaviorpJiosis. The 
 
GROWTH AND TRANSFORMATIONS OF INSECTS 
 
 47 
 
 Fig. 57. Nymph of lubber grasshopper {Dictyophora 
 
 reticulata) ; similar to the adult (Fig. 105) in general 
 
 form, except in lacking wings 
 
 growth of the grasshopper, on the other hand, is gradual and 
 presents no striking changes, and is known as an incomplete 
 vietmnorphosis. 
 
 Growth. The hard, chitinous skin which ser\-es the insect as 
 an outer skeleton has already been described, and furnishes an obvi- 
 ous obstacle to its rapid growth. When the insect has grown to 
 
 the limit of this outer 
 shell, its predicament 
 is solved in the only 
 possible way, by the 
 skin splitting down the 
 middle of the back 
 and being sloughed 
 off, while the new skin 
 formed beneath the 
 old one allows further 
 growth. This process, 
 called molting, occurs 
 in all insects, as well 
 as among other Arthropods, the skin being usually shed some 
 four or five times during growth, though some species molt from 
 ten to twenty times. 
 
 Incomplete metamorphosis. Young insects which resemble the 
 adults, as those of the grasshopper, are termed nymphs. After the sec- 
 ond or third molt, small wing 
 pads appear on the back, 
 becoming much larger with 
 the fourth molt, and upon 
 
 the fifth molt the adult F^^- 58- A typical larva, the cotton bollworm 
 ... or corn-ear worm; totally unlike the adult 
 
 wmged msect emerges, to ^„,h in form 
 
 feed and reproduce. 
 
 Complete metamorphosis. The caterpillar, maggot, or grub bear- 
 ing no resemblance to its parents is called a larva. The larva 
 grows and molts several times, and although its new clothes are 
 sometimes of a different color, they are all cut on the same pattern, 
 and there is usually no marked change in shape or structure until 
 the larva is full grown. Upon reaching its growth the larva molts for 
 the last time and transforms into a pupa. The pupa is a dormant 
 
 ^^^1^^^^^ 
 
48 
 
 ELEMENTARY ENTOMOLOGY 
 
 Fig. 59. Cocoon of the rusty tussock moth, made of silk 
 with the hairs of the caterpillar intermingled. (Enlarged) 
 
 Stage, usually inactive and taking no food, resembling neither larva 
 nor adult, in which the tissues and organs of the larva are re- 
 constructed into 
 those necessary 
 for the winged 
 adult. In many 
 pupae the wings 
 and legs of the 
 adult are clearly 
 distinguishable, 
 closely folded 
 to the sides of 
 body, but in the 
 others the outer 
 skin of the pupa 
 
 is only a firm shell with bare outlines of the adult forming within. 
 
 Before the last molt many larvae burrow into the ground, where 
 
 they hollow out cells, sometimes 
 
 lined with silk or cement, or find 
 
 other suitable secluded places 
 
 in which to pupate. The cater- 
 pillars of moths and many other 
 
 larvae spin a firm casing of silk, 
 
 called a cocooji, in which they 
 
 pupate . B utterfly caterpillars lash 
 
 themselves to the food plant by 
 
 one or two thick strands of silk, 
 
 and the pupa, which is known 
 
 as a chrysalis, hangs suspended 
 
 by the tip of the abdomen with 
 
 no cocoon. In many cases in- 
 sects hibernate over winter in 
 
 the pupal stage, so that the time 
 
 of the pupal life varies from a 
 
 few days in summer to nine or 
 
 ten months, according to the 
 
 habit of the species. Finally, j,,^ ^o. Cocoons of tiger moth cater- 
 
 the pupal shell splits open and pillars on underside of loose bark 
 
GROWTH AND TRANSFORMATIONS OF INSECTS 49 
 
 the adult insect emerges, with wings soft and Hmp but expand- 
 ing and hardening in a few hours, when it is ready to seek food 
 and a mate. 
 
 Thus the stages of growth of those insects having a complete 
 metamorphosis are essentially different from those having the in- 
 complete t}'pe, as indicated in the following summary' : 
 
 Incomplete metamorphosis 
 Complete metamorphosis : 
 
 P'crcr 
 F"crcr 
 
 Nymph, Adult. 
 Larva, Pupa, Adult. 
 
 An insect never grows after it reaches the adult stage. The 
 little flies which appear on the window in early spring are not 
 "baby" flies and do not grow larger, but are entirely different 
 from other larger species 
 which supersede them 
 later in the season. 
 
 The life histories of 
 insects are as diverse as 
 are the species, no two 
 being quite alike. To 
 study and carefully deter- 
 mine the time, place, 
 and manner of the trans- 
 formations is one of the 
 most important duties 
 of the economic ento- 
 mologist, for by ascer- 
 taining them the means 
 of control of injurious 
 species are often dis- 
 covered. Many insects 
 may thus be controlled 
 by simply changing gen- 
 eral farm methods, such 
 as the rotation of crops. 
 
 Fig. 61. Chrysalis of black swallow-tailed butterfly 
 {Papilio polyxencs) 
 
 Showing attachment of tip of abdomen to mass of silk 
 
 threads which have become torn from around the 
 
 stem, and the silken loop which supports the thorax. 
 
 (Photograph by Weed) 
 
 the time of plowing, etc., which result in the prevention or mitiT «-* 
 gation of the pest ; or a knowledge of the feeding habits may in(%. ^. 
 cate the most promising means of attack, and successful methodO • 
 may be determined by subsequent experiments. ^ W* 
 
50 
 
 ELEMENTARY ENTOMOLOGY 
 
 A better appreciation of these general facts concerning insects' 
 growth will be secured by a more intimate study of the life of one 
 or two of each of the types of metamorphosis. 
 
 The life of a squash-bug (Anasa tristis). Incomplete metamor- 
 phosis. About the time that squash, cucumbers, and melon vines 
 begin to " run," there is found here and there a wilted leaf, which 
 examination shows to be due to the common grayish- or brownish- 
 black squash-bug which has just emerged from hibernation. If 
 search be made in the early morning, the bugs will usually be 
 
 found secreted under 
 clods of earth, or what- 
 ever rubbish may be 
 near the vines, from 
 which they emerge to 
 feed during the day, 
 flying about with a 
 characteristic buzz. 
 
 £j^^. For the next 
 month or-six weeks the 
 females deposit their 
 eggs, mostly on the un- 
 dersides of the leaves. 
 The eggs are oval, 
 about one sixteenth 
 inch long, attached on 
 one side, and laid in 
 irregular-shaped clus- 
 ters arranged in rows as shown in Fig. 63, from three or four to 
 forty eggs being found in a cluster. Newly laid eggs are a pale 
 yellow-brown, which grows darker a day or two before hatching, 
 so that the approximate development may be determined by the 
 color, which is the case with many insects' eggs. 
 
 Nymph. In about eleven days, the exact time varying from six 
 to fifteen days according to the temperature, a small, disk-shaped 
 piece of the shell is forced open toward one end of the Q.^g and 
 the little nymph emerges. The newborn buglet is brilliantly col- 
 ored and is quite conspicuous against the green leaves, the antennas 
 and legs being a bright crimson, the head and anterior thorax a 
 
 Fig. 62. The squash-bug, adult and nymphs of first, 
 third, and fifth stages. (About twice natural size) 
 
 (Photograph by Quaintance) 
 
GROWTH AND TRANSFORMATIONS OF INSECTS 
 
 51 
 
 lighter crimson, and the posterior thorax and abdomen a bright 
 green ; but in an hour the crimson darkens, and in a few hours 
 
 changes to a jet- 
 black. The young 
 bugs hatching from 
 a cluster of eggs 
 remain together in 
 a sort of family dur- 
 ing their infancy, 
 each inserting its 
 tiny beak in the 
 succulent leaf from 
 which it vigorously 
 «v- iHH^VSflllK sucks the juice. In 
 
 J^*^ about three days 
 Fig. 63. Egg masses of squash-bug. (Twice natural size) ^^^ abdomen bc- 
 (Photograph by R. I. Smith) ■,. , 1 i • 
 
 comes distended, m- 
 dicating the need of a larger suit of clothes to allow further 
 growth. The nymph now assumes a quiet position, the skin splits 
 down the middle of the back 
 along the thorax and anterior 
 abdomen, and gradually the little 
 bug pulls itself out of its baby 
 
 clothes, the time required for 
 this change of costume vary- 
 ing from a half-hour to several 
 hours. A few hours later the 
 skin, now much lighter in color, 
 has hardened, and the insect is 
 about one fifth inch long. The 
 nymph now becomes more active 
 and alert and continues to feed 
 some nine days before molting 
 again. In the third stage it is 
 considerably larger and flatter, 
 and darker in color. Eight days 
 later the third molt takes place, and the new clothes of the fourth 
 stage differ in having small but distinct wing pads extending back 
 
 Fig. 64. Squasii-bug 
 
 t7, mature female ; 6, side view of head, show- 
 ing beak ; c, abdominal segments of male ; 
 if, same of female, (a, twice natural size ; 
 />, c, d, more enlarged.) (After Chittenden, 
 United States Department of Agriculture) 
 
Fig. 65. Squash-bugs and nymphs at work on a young plant. (Natural size) 
 
 52 
 
GROWTH AND TRANSFORMATIONS OF INSECTS 
 
 from the thorax. In another week the skin is shed for a fourth 
 time, and the fifth stage is easily recognized as a full-grown nymph, 
 
 being one third inch long, and 
 the wing pads and thorax 
 being much enlarged. After 
 feeding for another nine days 
 it molts for the last time and 
 transforms to the winged adult, 
 the whole growth having re- 
 quired from four to five weeks. 
 Adult. The new adults be- 
 come numerous in August, but 
 neither mate nor lay any eggs 
 during that season, continuing 
 to feed until the first frosts of 
 autumn blacken the leaves, 
 when they rapidly disappear 
 into winter quarters.^ During 
 the middle of the day they fly 
 here and there in search of 
 suitable hibernating places, and 
 finally hide along the edges of 
 woodlands, or beneath leaves, 
 under logs, boards, or whatever 
 
 Fig. 66. First three stages of the nymphs 
 of the differential locust. (Much enlarged) 
 
 shelter may be adjacent to the garden, where they remain dormant 
 until called back to activity by the warm sunshine of late spring. 
 Life history of the differential locust (Melanoplus differentialis). 
 Incomplete metamorphosis. Through- 
 out the Mississippi Valley, from Illi- 
 nois southward, the differential locust 
 is one of the most common and de- 
 structive grasshoppers, and is an excel- 
 lent example of several of our more 
 abundant and injurious species whose 
 life histories and feeding habits are, in general, very similar. 
 
 Fig. 67. Egg mass of the 
 differential locust 
 
 1 The life history as given is for New England ; farther south the transforma- 
 tions take place earlier and more rapidly, and in the extreme south there may be 
 more than one generation. 
 
54 
 
 ELEMENTARY ENTOMOLOGY 
 
 Nymphs. The little grasshoppers hatch about the middle of May 
 (though we have observed hatching by the middle of March in 
 central Texas) and are of a dusky brown color marked with yellow. 
 The head and legs are the most prominent features of the young 
 nymph. During their subsequent growth they molt five times, at 
 intervals of from ten days to two weeks, the relative size and appear- 
 ance of the different stages being shown in Fig. 6"/ . Professor 
 H. A. Morgan, who made a careful study of an outbreak of this 
 
 species in Mississippi in 
 1900, has given an inter- 
 
 esting 
 
 growth 
 
 which 
 
 quoted 
 
 account of their 
 and habits, from 
 the followinof is 
 
 Growtli. The young on first 
 emerging from the eggs are 
 sordid white and after an airing 
 of an hour or two are darker, 
 assuming a color not unlike the 
 dark gray alluvial soil over 
 which they feed. There are 
 changes of color as the earlier 
 stages are assumed, but until 
 the close of the third stage these 
 changes are not readily percep- 
 tible in the field to the naked eye. 
 At the close of stage four the 
 greenish-yellow color becomes 
 prominent on many forms, and 
 in stage five the greenish-yellow and yellow ground colors predominate. The 
 vigorous feeding and rapid growth of the young in stages four and five, and 
 the prominence of the wing pads in stage five, cause the grasshoppers in 
 these conditions to appear almost as conspicuous as adults. 
 
 Habits. The habits of the young are interesting, and a knowledge of some 
 of them may be helpful in developing remedies. After hatching they remain 
 for several hours in close proximity to the egg pod from which they emerged. 
 With this period of faint-heartedness over they may venture out for a few yards 
 each day into the grass, weeds, or crop neighboring the egg area. Upon being 
 disturbed they invariably make the effort to hop in the direction of their so- 
 called nest. Nymphs emerging from eggs on a ditch bank, if forced into the 
 water will seldom make the effort to reach the other side, but will turn back to 
 the bank from which they were driven. As development takes place the extent 
 
 Fig. 68. Last two stages of nymphs of differ- 
 ential locust. (Enlarged) 
 
(;rowth and transformations of insects 
 
 55 
 
 of their peregrinations into the crop is easily traced by the shot-hole appearance 
 of the leaves upon which they feed. The tender leaves of cocklebur are 
 always preferred by the grasshoppers in the early stages. Young Bermuda grass 
 is also a favorite food, and succulent grasses of all kinds are freely eaten. In 
 the third, fourth, and fifth stages, as grass, weeds, and even shrubs disappear 
 along the ditch banks and bayous, the crops of corn and cotton adjacent 
 begin to show signs of vigorous 
 attack, and the march of destruc- 
 tion commences. ... A few hours 
 before molting the grasshoppers 
 tend to congregate and become 
 sluggish. Molting varies as to 
 time, and slightly as to manner, 
 with different stages. In the early 
 stages less time is required, and 
 the operation occurs on the ground 
 or upon low bunches of grass and 
 weeds. Every effort of the grass- 
 hoppers at this time seems to be 
 to avoid conspicuity, and in doing 
 so spare themselves, in a man- 
 ner, enmity of parasites. After the 
 molting of the first, second, and 
 third stages it is not long before 
 the young grasshoppers are suf- 
 ficiently hardened to begin feed- 
 ing again, but after the molt of the 
 fourth and fifth stages, particularly 
 the last molt, some time is required 
 to extend the wings and dry and 
 harden the body before feeding is 
 reassumed. The last molt usually 
 occurs on the upper and well- 
 exposed leaves of corn and other 
 plants upon which they may be 
 feeding, though it is not uncom- 
 mon for the grasshoppers to drop 
 to the ground during the maneu- 
 vers of the process. The reason for the selection of the more exposed places 
 for the last molt is obvious. The bodies are large, and rapid drying protects 
 them from fungous diseases which lurk in the more shaded and moist sections 
 during the months of June and July. The last prominent habit to which we 
 call attention is that of the fully grown grasshoppers to seek the shade offered 
 by the growing plants during the hottest part of the day. 
 
 Fig. 69. Nymph of last stage of differential 
 locust with cast skin, on tip of corn plant 
 
 (Authors' illustration, United .States Department 
 of -Agriculture) 
 
56 
 
 ELEMENTARY ENTOMOLOGY 
 
 Adults. The hoppers become full grown about the first of July. 
 The adult is about one and one half inches long, its wings expand 
 two and one half inches, and it is of a bright yellowish-green color. 
 
 Fig. 70. The differential locust. (Enlarged) 
 (Authors' illustration, United States Department of Agriculture) 
 
 The head and thorax are olive-brown, and the fore-wings are of 
 much the same color, without other markings than a brownish 
 shade at the base ; the hind-wings are tinged with green ; the 
 
 hind thighs are bright 
 yellow, especially below, 
 with four black marks ; 
 the hind shanks are yel- 
 low with black spines 
 and a ring of the same 
 color near the base. The 
 adults at once attack any 
 crops available, often 
 finishing the destruc- 
 tion of those injured 
 by them as nymphs, but 
 in a few days their ap- 
 petites seem to become 
 somewhat appeased and 
 they commence to mate 
 and to wander in search 
 of suitable places for 
 laying the eggs. 
 
 Egg laying. Rela- 
 tively few eggs are laid in cultivated ground, the favorite places 
 being neglected fields grown up in grass and weeds, the edges of 
 
 Fig. 71. Grasshopper ovipositing in a stump 
 (Photograph by Weed) 
 
GROWTH AND TRANSFORMATIONS OF INSECTS 57 
 
 cultivated fields, private roadways, banks of ditches and small 
 streams, and pasture lands. Alfalfa land is a favorite place for 
 
 oviposition, and alfalfa is often seriously 
 injured by this species. It is doubtless 
 due to these egg-laying habits, and to 
 the abundance of food on uncultivated 
 land, that this species always increases 
 enormously on land which has been 
 flooded and then lies idle for a year or 
 two. Most of the eggs are laid in Au- 
 gust and early September. Each female 
 deposits a single egg mass of about one 
 hundred eggs just beneath the surface 
 of the soil. During this season the fe- 
 males may frequently be found with their 
 abdomens thrust deep in the soil, as the 
 process of egg laying requires some time. 
 The eggs are 
 arranged in an 
 irregular yel- 
 low mass which 
 is coated with 
 a gluey sub- 
 stance, to which 
 the earth ad- 
 
 FlG. 72. Egg mass of the 
 tent caterpillar 
 
 (Photograph by Weed) 
 
 heres and which protects them from 
 changes of moisture and temperature. 
 Life history of the tent caterpillar 
 (Malacosoma americana). Complete meta- 
 morphosis. With the bursting of the leaf 
 buds in early spring the tips of the 
 branches of apple and wild cherry trees 
 are festooned by the small, tentlike webs 
 of the tent caterpillar. Usually the web is 
 formed on a small crotch, which gives it 
 the tent shape, and farther out on the twig 
 will be found the egg mass from which 
 
 Fig. 73. Web of young tent 
 caterpillars over the egg mass 
 
 (Photograph by Weed) 
 
 the little caterpillars hatched, just before the leaf buds opened. 
 
5« 
 
 ELEMENTARY ENTOMOLOGY 
 
 The egg mass is from one half to three fourths of an inch long 
 and forms a grayish-brown, knotlike band around the twig, closely 
 resembling the bark in color. Each mass contains from one hun- 
 dred fifty to two hundred fifty eggs, placed on end, packed closely 
 together, and covered with a layer of light brown, frothy glue, which 
 gives a tough, smooth, glistening surface to the whole mass. The 
 eggs are deposited by the female moths by early midsummer ; 
 
 when fresh the ^gg mass is 
 white, but in a few days the 
 color darkens. 
 
 Larva, or caterpillar. Dur- 
 ing late summer the little cater- 
 pillars are formed within the 
 eggs, but do not hatch until 
 the next spring. Often they 
 emerge before the leaf buds 
 have expanded sufficiently to 
 furnish any food, in which case 
 they satisfy their appetites with 
 the glutinous covering of the 
 ^gg mass, spinning over it a 
 thin web. Soon they are able 
 to bore into the swollen buds, 
 when a web is commenced at 
 the nearest crotch. Wild cherry 
 and apple, which are often 
 stripped of their foliage year 
 afteryear, are the favorite foods, 
 but all the common fruit trees 
 are more or less frequented, and sometimes the common shade trees 
 are attacked and occasionally one is defoliated. The family instinct 
 is very strong with the young caterpillars and all from one ^gg mass 
 cooperate in spinning the tent which furnishes them shelter at night 
 and during cold or wet weather. The tent is gradually enlarged by 
 new layers of silk, which cover the masses of excreta in the lower 
 layers, the caterpillars living between the outer layers. They com- 
 mence feeding soon after sunrise, but often retire to the nest during 
 the heat of the day, and always seek its shelter during cold days or 
 
 Fig. 74. Partly formed web of the tent 
 caterpillar 
 
 (Photograph by Weed) 
 
GROWTH AND TRANSFORMATIONS OF INSECTS 
 
 59 
 
 when the sky becomes clouded 
 and rain threatens. While 
 young they feed together, each 
 little caterpillar spinning a fine 
 strand of silk wherever it goes, 
 which forms a sort of trail for 
 the others. They become full 
 grown in six or seven weeks, 
 during which time they have 
 molted some four or, excep- 
 tionally, five times, at intervals 
 of eight or nine days, though 
 the length of time between 
 molts varies widely according 
 to the food supply and weather 
 conditions. After the fourth 
 molt the fifth stage occupies 
 about two weeks before the 
 caterpillar transforms to the 
 pupa. When full grown they 
 become extremely restless, wan- 
 der away from the nest, and are frequently encountered on walks 
 and roadsides, 
 and feed on al- 
 most any plant 
 found. They 
 are now about 
 two inches in 
 length, deep 
 black in color, 
 thinly covered 
 with yellowish 
 hairs, with a 
 white stripe 
 dowTi the mid- 
 dle of the back. 
 
 At the middle pi^. 76. Full-grown tent caterpillars on web. (Reduced) 
 of the side of (Photograph by Weed) 
 
 Fig. 7 5. Tent caterpillars about half grown 
 on web 
 
 (Photograph by Weed) 
 
6o 
 
 ELEMENTARY ENTOMOLOGY 
 
 each segment is an oval, pale blue spot with a broader, velvety black 
 spot adjoining it in front, giving somewhat the effect of an eyespot. 
 Cocoon ajtd pupa. Having found a suitable place under loose 
 bark, in a fence, in the grass or rubbish beneath the tree, or in the 
 shelter of some neighboring building, the caterpillar settles down 
 and proceeds to encase itself in a thin cocoon of tough white 
 
 silk. In forming the cocoon 
 the caterpillar rolls its head 
 from side to side, the silk being 
 drawn out from the lower lip 
 and hardening as soon as it 
 comes into contact with the 
 air. With wonderful contor- 
 tions it gradually shapes the 
 oval cocoon, the outer part of 
 which is composed of coarse, 
 loose white threads, with a 
 yellowish powder intermixed, 
 while the inner layer forms a 
 tougher, parchmentlike lining. 
 Frequently, when the caterpil- 
 lars are abundant and there is 
 desirable shelter near the nest, 
 several cocoons are formed en 
 masse. 
 
 Exhausted by its labors, the 
 caterpillar now becomes quiet, 
 the body shortens to about an 
 inch long, and, finally, the skin 
 
 Fig. 77. Web of tent caterpillars which 
 has been riddled by birds. (Reduced) 
 
 (Photograph by Weed) 
 
 splits down the back, is sloughed off into one end of the cocoon, 
 and the transformation to a brown, oval object, tho^ p?ipa, is accom- 
 plished. The pupa is about an inch long, and the surface markings 
 of the solid shell outline the legs and wings of the adult moth, but 
 otherwise there is no indication of any relationship to the larva or 
 to the adult, and, had we not seen it emerge from the larval skin, 
 it would be difificult to believe that it is the same animal. 
 
 Moth. In about three weeks the pupal shell splits open and the 
 adult moth works its way out of one end of the cocoon. Like all moths 
 
GROWTH AND TRANSFORMATIONS OF INSECTS 6 1 
 
 the adults are night flyers and are frequently attracted to lights. 
 They are stout-bodied, of a reddish-brown color, with two nearly 
 
 Fig. 78. Tent caterpillar from above and from side. (Slightly enlarged) 
 
 parallel white bands extending obliquely across the fore-wings. 
 The males are much smaller and may be distinguished by the more 
 
 Fig. 79. Cocoons of the tent caterpillar. (Natural size) 
 (After Lowe) 
 
 feathery antennae. The sexes soon mate and the females deposit the 
 eggs, which remain on the twigs over winter, as already described. 
 
Fig. So. Female tent caterpillar moth at rest on leaf. (Slightly enlarged) 
 
 (After Lowe) 
 
 4-^^ -i. *<--j-*vr^i*--K^Oii 
 
 Fig. Si. Mourning cloak butterfly depositing eggs 
 (After \\-eed) 
 
 62 
 
GROWTH AND TRANSFORMATIONS OF INSECTS 6^ 
 
 The life of the spiny elm caterpillar {Euvanessa antiopd). Com- 
 plete metamorphosis. What boy does not remember, when the first 
 warm days of spring hired him to a tramp in the woods, that a large, 
 dark purple, yellow-bordered butterfly, usually found sipping the sap 
 from a newly cut tree stump, was the first to greet him ? It is one 
 of our commonest butterflies, and we have translated its German 
 name of T^-aucrmantcl to "mourning cloak butterfly," though it is 
 also often known as the Antiopa 
 butterfly, from its specific name. It 
 is a most cosmopolitan insect, occur- 
 ring throughout North America as 
 far south as Mexico and Florida, and 
 is found over northern Europe and 
 in Asia. 
 
 Egg laying. Unlike most butter- 
 flies it hibernates over winter, which 
 accounts for its early and often some- 
 what battered appearance in spring.^ 
 When the leaves of the elm and poplar 
 are nearly expanded, the female may 
 be found laying her eggs upon the 
 twigs of elm, poplar, and willow. 
 Standing with wings spread, she de- 
 posits the eggs in clusters around the 
 twig, as shown in Fig. 8i, <7. In about 
 two weeks the small, blackish cater- 
 pillars emerge through round holes 
 eaten out of the upper surface of the 
 eggs, and crawl to the nearest leaf, 
 where they range themselves side by 
 side, with their heads toward the margin of the leaf. Feeding in 
 this position, they nibble the green surface of the leaf but leave 
 the network of veins untouched. 
 
 Laji'a, or caterpillar. They continue to feed side by side for 
 about a week, marching in processions from leaf to leaf as the food 
 supply is exhausted. Each little caterpillar spins a silken thread 
 
 1 We are indebted, for much of the hfe history, to the account given by 
 Dr. C. M. Weed in Bulletin 67, New Hampshire Agricultural Experiment Station. 
 
 Fig. 82. Eggs of the spiny elm 
 
 caterpillar, or mourning cloak 
 
 butterfly, on willow twig 
 
 (Photograph by Weed) 
 
64 
 
 ELEMENTARY ENTOMOLOGY 
 
 wherever it goes, 
 so that the many 
 threads soon make 
 a fine silken car- 
 pet, which serves 
 as a foothold. At 
 the end of a week 
 they molt ; the skin 
 of each caterpillar 
 splits down the 
 back, and it crawls 
 out with a new and 
 larger skin, which 
 has been' forming 
 beneath the old 
 one. The caterpil- 
 lars remain quiet 
 during molting, 
 but they soon be- 
 come active again 
 and feed with in- 
 creased voracity. 
 Ever}^ week for the 
 next three weeks 
 this molting proc- 
 ess is repeated, 
 the cast skins 
 decorating the de- 
 foliated twigs, as 
 shown in Fig. 84. 
 As they grow, the 
 caterpillars scatter 
 over the neighbor- 
 ing leaves, but still 
 remain in colonies. 
 Their appetites 
 
 Fig. 83. The spiny elm caterpillar, or mourning cloak seem tO increase 
 butterfly. (Slightly reduced) ^^ ^j^^^ g^^^,^ ^^^ 
 
 Partly grown caterpillars, chr\'salis, empty chrysalis, and adults. 
 (After Britton) 
 
GROWTH AND TRANSFORMATIONS OF INSECTS 65 
 
 Fig. 84. Twigs denuded by spiny elm cater- 
 pillars, bearing their cast skins. (Reduced) 
 
 they eat more of the leaf sub- 
 stance, devouring all but the 
 midrib and veins when half 
 grown, and, when larger, leave 
 only the midrib. The carpet- 
 like web which they spin also 
 becomes more evident as they 
 gi'ow older, often binding to- 
 gether the ends of near-by twigs, 
 especially where the caterpillars 
 rest after feeding. The full- 
 grown caterpillar is about two 
 inches long, with numerous 
 branched black spines. It is 
 blackish in color, with a row 
 of red spots down the back, 
 and with transverse rows of 
 minute white spots. 
 
 Pupa, or chrysalis. The 
 caterpillars are full grown in 
 
 (Photograph by Weed) 
 
 about four weeks. Dr. Weed, in his interesting account of this spe- 
 cies, describes its transformation as follows : 
 
 They then leave the tree or shrub on which 
 they have been feeding, and scatter about, seeking 
 some sheltered situation. Having found this, — 
 perhaps beneath a stump or along the underside 
 of a fence, — each caterpillar spins a web of silk 
 along the surface. It then entangles the hooked 
 claws of its hind legs (anal prolegs) in this silken 
 web and lets its body hang vertically with the head 
 end curved upward. It remains in this position 
 for some hours before the skin along the back just 
 behind the head splits apart, and is gradually 
 wriggled upward until it is finally all removed, 
 and there hangs in place of the caterpillar a 
 peculiar object having no definite form — that of 
 the chrysalis} 
 
 In this quiet chrvsalis the insect is apparently ^^*^- ^5- Mourning cloak 
 1 .. • ^ " ic ^ 1 •. •. butterfly emerging from 
 
 almost as mert as a mummv. If you touch it, it , ?■ 
 
 ■' chr)-salis 
 
 1 See Fig. S3. (Photograph by Weed) 
 
66 
 
 ELEMENTARY ENTOMOLOGY 
 
 will wriggle a little, but otherwise it hangs there mute and helpless. On the 
 inside, however, the tissues are being made over in such a wonderful way 
 that in about two weeks, from the mummy case into which the caterpillar 
 entered, there comes a beautiful butterfly. When it first breaks the mummy 
 shell its wings are very small, although its body, " feelers," and legs are well 
 developed. By means of the latter it clings to the empty chrysalis while the wings 
 expand. A butterfly in this position, with its wings nearly expanded, is shown 
 in Fig. 86, from a photograph taken from a living specimen. In the course of half 
 
 an hour the wings become fully de- 
 veloped, and the butterfly is likely 
 to crawl to some firmer support, 
 where it will rest an hour or so 
 before venturing on its first flight. 
 
 In New Hampshire there 
 seems to be but a single gen- 
 eration a year, the newly 
 emerged butterflies appear- 
 ing in July or August and dis- 
 appearing during August and 
 September, though they are 
 seen occasionally on warm 
 days in late fall. Under the 
 side of a log, beneath the 
 loose bark of a dead tree, in 
 woodpiles, and in similar sit- 
 uations the butterflies are to 
 be found during the winter 
 lying flat on the side, sus- 
 pended under a culvert, or 
 in a hollow tree. Apparently 
 they are dead, but if taken 
 into a warm room, they will 
 quickly revive and fly about, and if given a little sugar-water for 
 food, will live for some time. Often in summer they will drop on 
 one side, motionless, evidently feigning death, and if lying on a 
 background of dead leaves, are very difficult to see. 
 
 Fig. 86. Newly emerged mourning cloak 
 
 butterfly hanging to empty chrysalis while 
 
 its wings expand and harden 
 
 (Photograph by Weed) 
 
PART II. THE CLASSES OF INSECTS 
 
 CHAPTER \T 
 
 THE CLASSIFICATION OF INSECTS 
 
 Identity of insects. If a crop of potatoes is being destroyed by 
 the Colorado potato beetle, it is at once recognized as the cause 
 of the injury, and the method of control is known or may be ascer- 
 tained from books or bulletins. In many cases, however, insects 
 are found abundant upon a crop which is evidently being injured, 
 but the casual observer may not be able to determine just which 
 are responsible for the injury without devoting more time to the 
 matter than is available, or without more knowledge of the habits 
 of insects than he possesses. Thus, when a colony of plant-lice is 
 found ruining a crop, there are usually found with them various in- 
 sects which are either preying upon them, as do the ladybird beetles, 
 aphis-lions, and syrphus-fly larvae, or caring for them, as do the ants. 
 No one would consider the ants as producing the aphides, but it is 
 not at all uncommon for those unacquainted with the life history of 
 plant-lice to assert that they are produced by the ladybird beetles 
 or other insects which are found associated with them, which are 
 consequently destroyed when they should be protected. If the insect 
 is very evidently the cause of the injury, but of unknown iden- 
 tity, it is of the utmost importance to identify it, so that its habits 
 and the best means of control may be ascertained. A knowledge of 
 the different kinds of insects is thus seen to be not only a matter 
 of theoretical or biological knowledge, but of considerable practical 
 importance. 
 
 The classification of insects and the manner in which they may 
 be identified may be illustrated by a study of the ladybird beetles 
 already mentioned. Upon examining a ladybird beetle, we at once 
 recognize it as a beetle from the hard wing-covers, with the mem- 
 branous hind-wings folded beneath them, and die_bitingjTiouth^.arts. 
 
 67 
 
68 ELEMENTARY ENTOMOLOGY 
 
 Thus we ascertain that it belongs to one of the several divisions, 
 called orders, ^nto which all insects are divided known as tlie. 
 order Cole opt cm. Some nineteen orders of insects are now recog- 
 nized by entomologists, but only six or seven are of any economic 
 importance. Most of the orders are distinguished by the structure 
 of the wings, and the names of the orders usually end in the syl- 
 lable //rr<^, irom ptcjvji, meaning "a wing." A brief survey of the 
 beetles shows that the order Coleaplera consists of numerous fami- 
 lies, which are grouped together according to the number of seg- 
 ments in the hind tarsi. An examination of the hind tarsus of a 
 ladybird beetle reveals that it is composed of but three segnients, 
 which is characteristic of only one family, the CocciiielUdac,, the 
 family of the ladybird beetles. A brief account of this family indi- 
 cates that nearly all of its members are predacious upon plant- 
 lice or other small insects, and that the more common forms are 
 small yellow or red beetles with black spots, like the specimen in 
 hand. It is evident, therefore, that our ladybird beetle is feeding 
 upon the plant-lice and is in no way responsible for them, for a 
 similar study of the plant-lice would show that they belong to an 
 entirely different order (the Hemiptera), which has sucking mouth- 
 parts and an entirely different life history. We should also learn 
 from the account of the Coccinellidae that the little long-legged, 
 blackish, brilliantly marked larvae which accompany the ladybirds 
 are the young stage from which they develop, and that these larvae 
 also feed upon the plant-lice. Probably we should find several 
 different kinds of beetles, evidently all of the ladybird family, but 
 differing in size, shape, and coloration. Should we desire to speak 
 exactly of any one sort, we should be obliged to determine to what 
 genus of the family it belonged, and then to which of several 
 species in that genus. Usually the amateur will not be able to 
 identify an insect farther than to its family, but in the case of 
 common forms, especially those commonly injurious, the illustra- 
 tions or descriptions of the insect or its characteristic work as given 
 in textbooks, or the comparison of the specimen with those of 
 a named collection, if one is available, will make it possible to 
 definitely determine the species. 
 
 Scientific names. The name of the genus and species together 
 is commonly called the scientific name, and is in Latin and usually 
 
THE CLASSIFICATION OF INSECTS 69 
 
 printed in italics for its easy recognition. Scientific names are a 
 necessity, because the common name of an insect in one commu- 
 nity may often be applied to an entirely different species in some 
 other section, or different common names may be applied to the 
 same insect ; and they are written in Latin because that is under- 
 stood by scientists in all countries, and is common to them all, 
 which is true of no other language. The ladybird beetle in ques- 
 tion may have been of the species novemnotata, meaning nine- 
 spotted, and of the genus Coccinella, which is the typical genus of 
 the family. This name is written Coccinella novemnotata Herbst. 
 The name of the genus is always placed first and commenced with 
 a capital letter, the name of the species following and commencing 
 with a small letter. Botanists often commence the specific name 
 with a capital letter if it is named for some person or country, but 
 zoologists commence all specific names with small letters to dis- 
 tinguish them readily from the generic names. After the scientific 
 name proper is often placed the name, or an abbreviation of the 
 name, of the author who originally described the species (as Herbst, 
 in the above), for not infrequently different authors will use the 
 same name for different species, which often results in endless 
 confusion when the name of the author who has described each 
 species under the name is not given. Thus the generic and specific 
 names of a plant or animal are analogous to the Christian name 
 and surname of a man, except that in the case of the latter the 
 name applies to an individual, while in the former it applies to a 
 large number of individuals.- The scientific name also has a some- 
 what analogous significance and use. Thus, if we speak of Patrick 
 O'Connor or Napoleon Bonaparte, we at once think of the individ- 
 uals known to us by those names. But the name also tells us that 
 Patrick is of the O'Connor family, with their general characteris- 
 tics, and we know the O'Connors to be from the Emerald Isle, 
 which we know to be inhabited by people of the Caucasian race, 
 and, similarly, we know the Bonapartes to be Corsican. In the same 
 way the specific name of a plant or animal signifies its relationship 
 to those acquainted with the different sorts. Thus the specific 
 name novemnotata (or g-notata) at once signifies that this particular 
 species of beetle has nine spots and is a separate species from bi- 
 pnnetata, which has but two spots, while the generic name indicates 
 
70 ELEMENTARY ENTOMOLOGY 
 
 that it belongs to the genus Coccinella, to which this species and 
 many others belong, and which we recognize in this case as prob- 
 ably belonging to the family Coccincllidac, which we know to be a 
 family of predacious beetles of the order Colcoptcra. 
 
 Thus animals and plants are divided into the following succes- 
 sive groups : 
 
 Group Examples 
 Phylum {Arthropodci) 
 Class {Insecta) 
 
 Order {Coleoptcra) 
 
 Family {Coccinellidae) 
 Genus {Coccinclla) 
 
 Species {iioveninotatd) 
 
 Coccinclla novemnotata Herbst. 
 
 Species. The exact definition of a species has worried naturalists 
 since the time of Linnaeus and is still under dispute, so that no 
 exact definition will be attempted. It is evident that, inasmuch as 
 it applies to a large number of individuals, and as we know that 
 individuals vary exceedingly, it is largely a conception for our 
 convenience in designating forms of life. Inasmuch as we now 
 believe that all forms of life have had a common origin and have 
 been gradually evolved from one or at least a very few original 
 ancestors of all life during the millions of years of the earth's 
 history, and as we know that species of plants and animals are now 
 being formed, while others have disappeared from the earth, it is 
 evident that the species now being formed will be very similar to 
 each other and will be separated with great difficulty, if at all ; 
 whereas those species which have existed for a long period of time, 
 and whose nearly related species have disappeared, will be easily 
 recognizable and form very distinct species. In short, it may be 
 said that a species is aji aggregation of individuals of so similar 
 a structJirc that they might all have been derived from the same 
 parent, wJiicJi are more similar to each other tJian to any other in- 
 dividuals, and which, ivhen bred together, prodiice progeny of the 
 same degree of likctiess, which zvill also be fertile and produce their 
 kind. The number of individuals in a species and their distribution 
 
THE CLASSIFICATION OF INSECTS 71 
 
 over the earth depend upon its habits and food supply. Some 
 species are exceedingly limited in their distribution, — as, for in- 
 stance, the little butterfly Oencis semidca, which inhabits only the 
 highest peaks of the Wliite Mountains, — while others are quite 
 cosmopolitan, living in many distant parts of the world and with 
 quite different food habits, an example being the bollworm [Hcli- 
 otJiis obsolcta), which is found on every continent. Some species 
 are so rare that but one or two specimens have ever been taken, 
 while others occur in such countless myriads as to become the 
 •worst pests of crops. 
 
 Genus. As a species is composed of individuals of similar struc- 
 ture, so a genus is formed of a number of species having some 
 common characteristics which make them more nearly related to 
 each other than to any other species. In the same way genera are 
 grouped together into families, which have some common charac- 
 teristics distinguishing them from other families of genera, and 
 families are likewise grouped into orders. Frequently, various other 
 subdivisions are made for the purpose of bringing out certain re- 
 lationships, which are evident but which do not seem to warrant 
 definite rank. It should be observed that no standard exists as to 
 what structural characters are sufficient for establishing a species, 
 genus, or family, and that structures which will separate species in 
 one order are of sufficient importance to separate families in another 
 order, this all depending upon the constancy and relative importance 
 of the character. Thus, orders are commonly divided into sub- 
 orders, families into subfamilies, and genera into subgenera, while 
 we recognize varieties and races of individuals within a species, as, 
 for instance, the varieties and races of garden plants and domestic 
 animals. In each case the subgroup is composed of a portion of 
 the larger group, which has some common characters distinguish- 
 ing it from the other subgroups of the same rank. Such terms as 
 sections, divisions, tribes, and series are also used in the same sense. 
 
 Inasmuch as some three hundred thousand species of insects have 
 been described, it would evidently be impossible for any one person, 
 or any one library, to have all the descriptions which are scattered 
 throughout the scientific books and journals of all countries and 
 languages. Hence most entomologists acquire a general knowledge 
 of the larger groups and then make a special study of some one 
 
72 ELEMENTARY ENTOMOLOGY 
 
 family or small portion of a family, sending the insects of other 
 groups to specialists of those groups for determination, and thus 
 building up collections which they may use for the subsequent 
 determination of specimens by comparison. The common families, 
 and particularly those of economic importance, may usually be 
 recognized by the amateur, and the identification of the family will 
 usually indicate the possible economic importance of a given insect, 
 and may lead to its definite identification, if it is a common form. 
 In the following pages we have endeavored to give a very brief 
 account of the characteristics of the more common orders and 
 families of insects. Keys for their determination will be found 
 in Chapter XX, 
 
CHAPTER VII 
 
 BRISTLETAILS AND SPRINGTAILS (APTERA) 
 
 Characteristics. Wingless insects which have no metamorphosis. Mandi- 
 bles and maxillce retracted within the head, but used for biting and chewing 
 soft substances. True compound eyes rarely present ; a group of simple eyes 
 on each side of head in some genera. Abdomen sometimes furnished with 
 rudimentary jointed appendages. 
 
 This is a relatively unimportant order from the economic stand- 
 point, but is of interest from the fact that it includes the most 
 
 Fig. 87. Silver fish-moth [Lepisma saccharina). (Enlarged) 
 
 A household nuisance and a good example of the bristletails. (After Marlatt, United .States 
 Department x)f Agriculture) 
 
 primitive insects now in existence. The name Aptera is given on 
 account of the entire absence of wings, in consequence of which 
 
 73 
 
74 
 
 ELEMENTARY ENTOMOLOGY 
 
 - a 
 
 there is no metamorphosis. In some forms there are rudimentary 
 appendages on the underside of the abdomen, which are supposed 
 to be degenerated abdominal legs, though not now capable of being 
 
 used as such. The order is divided 
 into two distinct suborders, sometimes 
 considered separate orders. 
 
 Bristletails {Thysanurd). One of the 
 commonest bristletails is the little shiny 
 fish-moth, which annoys housekeepers 
 by getting into starched clothes, among 
 books, papers, etc. It is about half an 
 inch long, with long antennae and three 
 bristles extending half the length of 
 the body from the tip of the abdomen, 
 and is covered with silvery scales which 
 glisten as it darts around in a book- 
 case or drawer, reminding one of a 
 fish's scales flashing in the sunlight. 
 They are very soft-bodied little insects, 
 more abundant in warm climates, and 
 feed on starchy matter or soft paper. 
 In some species of bristletails the bris- 
 tles have been modified into forcep- 
 like appendages. Most bristletails are 
 much smaller 
 than the fish- 
 moth, and are 
 found beneath 
 stones, logs, and 
 loose bark, and 
 in similar situ- 
 ations ; and one genus {Machilis), found in 
 many parts of the world, has rudimentary 
 abdominal appendages, as shown in Fig. 88. 
 
 Springtails {Collembold). Every boy who has worked in a 
 northern maple-sugar " bush " knows the litde snow fleas, large 
 numbers of which jump around on the snow and have a propen- 
 sity for getting into the sap buckets. Other species are found on 
 
 Fig. 88. Underside of abdomen 
 of a female Machilis ?na>-iii>na, 
 to show rudimentary limbs {a) 
 of segments 2 to 9 ; c, cerci. 
 (Enlarged) 
 
 (After Oudemans, from Folsom) 
 
 Fig. 89. The pond-sur- 
 face springtail {^Stnyn- 
 ihunis aquatiais) with 
 spring extended. (Much 
 
 enlarged) 
 (After Schott, from Kellogg) 
 
BRISTLETAILS AND SPRINGTAILS 
 
 75 
 
 the surface of stagnant pools, in manure piles, in the decaying 
 hollows of trees, in gardens, hotbeds, window boxes, and, in general, 
 in moist places where decaying vegetation 
 is found. They are usually microscopic in 
 size, from one tenth to one twentieth of an 
 inch long, but have an exceedingly inter- 
 esting structure. Projecting forward from 
 the underside of the next to the last ab- 
 dominal segment is a long abdominal ap- 
 pendage, or spring, by the extension of 
 which the insect is enabled to shoot for- 
 ward as if shot from a catapult, jumping a 
 considerable distance. As the springtails 
 feed only on decaying vegetation, they are 
 never injurious, unless exceptional num- 
 bers render them a nuisance. Occasionally 
 such immense numbers of small spring- 
 tails are found in manure heaps or on the 
 surface of stagnant pools or ponds as to attract attention to them. 
 Many of these little springtails are prettily colored with patterns 
 composed of very minute scales. For this reason they are often 
 used as test objects for microscopes, the quality of the lens being 
 determined by its efficiency in revealing the very fine markings on 
 these tiny scales. 
 
 Fig. 90. Underside of the 
 American springtail {Lepido- 
 cyrtus atttericaniis) with the 
 spring folded underneath the 
 body. (Much enlarged) 
 
 (After Howard and Marlatt) 
 
CHAPTER VIII 
 
 COCKROACHES, GRASSHOPPERS, KATYDIDS, AND CRICKETS 
 (ORTHOPTERA) 
 
 Characteristics. Insects with four wings : the first pair, more or less leathery, 
 not used for flight, and forming wing-covers for the hind-wings ; the second 
 pair membranous, larger, with numerous veins, and folded like a fan. Mouth- 
 parts formed for biting. Metamorphosis, incomplete. 
 
 The members of this order are among the best known of any 
 of our common insects, possibly because many of them form the 
 
 Fig. 91. The German roach {Ectobia gennmiica) 
 
 n, first stage ; b, second stage ; c, third stage ; d, fourth stage ; e, adult ; /, adult female with 
 egg-case ; g, egg-case (enlarged) ; /;, adult with wings spread. {X\\ natural size except g.) 
 
 (From Riley) 
 
 main strength of the insect orchestra of a drowsy summer even- 
 ing, while others are among the most destructive pests. We have 
 already become fairly well acquainted with a common grasshopper 
 (pp. 53-56) which forms a good type of the order. The biting 
 mouth-parts, leathery fore-wings, and fanlike hind-wings make the 
 order easily distinguishable, and from the latter characteristic comes 
 the name " Orthoptera," from ortJws (straight) 2ivA pteron (wing), 
 referring to the straight-folded wings. 
 
 The order is divided into six families, which are readily distin- 
 guished as regards both structure and habits. 
 
 76 
 
ORTHOPTERA 
 
 n 
 
 Cockroaches, or running Orthoptera {Blattidae). The Croton bug, 
 or German cockroach, is a famihar pest in all eastern cities, 
 wherever kitchens, pantries, and living rooms are not kept scru- 
 pulously clean. The name "Croton bug," as well as that of 
 "water bug," comes from the fact that it was introduced into 
 New York City about the same time as the Croton water system, 
 with which it was associated in the popular mind. Roaches not 
 only make themselves a nuisance by getting into everything, but 
 
 Fig. 92. The oriental roach {Periplaneta orientalis). (Natural size) 
 
 a, female : b^ male ; 
 
 side view of female ; d^ half-grown nymph. (After Marlatt, United 
 States Department o'f Agriculture) 
 
 often do serious damage by gnawing the bindings of books, eating 
 off wall paper, etc. Our common native species are larger, almost 
 black, and live under stones and logs ; they are of no economic 
 importance. 
 
 The body of a roach is flattened, due to its habit of living in 
 narrow cracks and similar out-of-the-way places, and the legs are 
 long and enable it to run with remarkable swiftness for so awkward- 
 looking an insect. About two dozen eggs are laid together in a 
 single pod-shaped mass, which is covered with a brown cement, 
 making it look much like a large bean, and is left lying in a crack 
 or quite exposed. 
 
7« 
 
 ELEMENTARY ENTOMOLOGY 
 
 The mantids, or grasping Orthoptera (Mantidae). Mantids are 
 found commonly throughout the southern states, and form the only 
 
 Fig. 93. The common European praying mantis (Afantis religiosa). (Natural size, 
 
 from life) 
 
 a, adult mantid patiently waiting or " praying " for its prey ; b, busily engaged in eating a 
 live grasshopper. (After Slingerland) 
 
 family of Orthoptera which is strictly predacious, as they feed en- 
 tirely on other insects, and are therefore beneficial. They are curious- 
 looking insects and are called praying mantes, from the prayerlike 
 
ORTHOPTERA 
 
 79 
 
 attitude assumed by the forelegs, which really, however, are merely 
 held ready to quickly grasp any unwary insect prey which may 
 
 come within reach. 
 
 Early writers on natural history 
 had many curious fancies concern- 
 ing this insect, which are evinced by 
 the name of our most common spe- 
 cies, Alantis rcligiosa {mantis, "a 
 prophet"), the name undoubtedly 
 referring to the pious attitude. 
 
 Fig. 94. Egg mass of the praying 
 mantis. (Natural size) 
 
 (After Slingerland) 
 
 There are many local names 
 for them, such as rear-horses, 
 devil-horses, etc., while the 
 southern negroes know them 
 as mule killers and other sim- 
 ilar names, from the supersti- 
 tion that the brown saliva from 
 their mouths will kill a mule. 
 The eggs are laid in shingled 
 masses, attached to a twig or 
 weed, and are coated with a 
 hard, gummy covering. The 
 young, as well as the adults, 
 feed on insects and are ex- 
 tremely difficult to rear, as 
 they are rabid cannibals, eating 
 
 Fig. 95. Walking-stick resting on birch 
 
 twig, the leaves of which were attacked by 
 
 the birch-leaf skeletonizer 
 
 (After Weed) 
 
8o 
 
 ELEMENTARY ENTOMOLOGY 
 
 each other with avidity. The 
 adults have an extremely 
 long prothorax, with a small 
 transverse head, and long 
 legs. In many tropical 
 forms the wings are bright 
 gi'een and closely resemble 
 leaves, thoroughly protect- 
 ing the insect as it awaits 
 its prey. 
 
 Walking-sticks, or walk- 
 ing Orthoptera (Phasmidae). 
 The walking-sticks are aptly 
 described by their name ; 
 so closely do they resemble 
 the twig of a bush or tree 
 that they are found with 
 difficulty and usually quite 
 by accident. Only one spe- 
 cies occurs in the northern 
 states, which feeds upon 
 the foliage of forest trees 
 and is particularly common 
 on hazel and beech, the 
 body color varying from 
 
 greenish to brown according to the surroundings. In the tropics 
 
 are many phasmids of large size and having wings which closely 
 
 resemble leaves in both color and shape. 
 
 The large, oval eggs are dropped loose 
 
 upon the ground, where they pass the 
 
 winter and hatch the next summer. 
 The next three families all have the hind 
 
 legs adapted for jumping, and are com- 
 monly grouped together as the jumping 
 
 Orthoptera. Most^ of the forms in these 
 
 three families also have the ability to 
 
 produce sounds either by their legs or j,,^ ^^ ^^^^ ^^ ^^^ ^^jl^. 
 
 wings. ing-stick 
 
 Fig. 96. A pair of walking-sticks on a birch twi 
 (Photograph by Weed) 
 
ORTHOPTERA 
 
 8l 
 
 Fig. 98. 
 
 The red-legged locust. 
 (Natural size) 
 
 (After Riley) 
 
 The short-horned grasshoppers, or locusts (Acrididae). The word 
 "grasshopper" is an American term for the insects which in the 
 
 Old World are called locusts, as they 
 are termed in the Biblical account of 
 the Eg}^ptian plague of locusts. The 
 locusts include all of our more com- 
 mon grasshoppers, which have the 
 antennae shorter than the body, and 
 a short ovipositor. Man)- of them are 
 seriously injurious. Their structure 
 and life habits have alread}- been sufficiently discussed (Chaps. V, 
 XVI), so that we shall merely consider a few of the more common 
 and important forms. The 
 most common throughout 
 the East is the small red- 
 legged locust {Melanoplus 
 feniur-rubrtmi) and the 
 nearly related lesser migra- 
 tory locust {Mclanoplns at- 
 lantis), hardly distinguish- 
 able from each other by the 
 casual observer, both of 
 which are abundant in our pastures, and often do serious injury to 
 grass and garden crops. One of the most common forms east of 
 
 Fig. 99. Two-striped 
 I'ii'ittafiis). 
 
 grasshopper [Melanopliis 
 (Natural size) 
 
 (After Riley) 
 
 Fig. 100. The bird grasshopper, or American locust. (Natural size) 
 (After Riley) 
 
 the Rockies is the Carolina locust, which flies up along the roadside 
 and in waste places where it lives. It closely matches its surroundings 
 
82 
 
 ELEMENTARY ENTOMOLOGY 
 
 in color, but the hind-wings are black, with a broad yellow edge 
 quite conspicuous in flight. Throughout the Mississippi Valley 
 
 the differential locust 
 {Mclaiiopliis ■diffcr- 
 entialis) is one of 
 the most destructive 
 forms, being particu- 
 larly injurious after 
 floods, when it multi- 
 plies rapidly on the un- 
 cultivated land which 
 has been flooded. A 
 generation ago (i 874 
 -1877), the crops of 
 the western part of 
 the Mississippi Val- 
 ley were utterly de- 
 stroyed for several 
 or migratory locusts 
 
 Fig. ioi. Rocky Mountain locust laying eggs 
 
 a, females ovipositing, with earth cut away to show tip of 
 
 abdomen placing eggs at </, and completed egg mass at c ; 
 
 c, eggs. (After Riley) 
 
 years by the clouds of Rocky 
 {Mclanopbis sprctus) which 
 swooped down from the 
 tablelands of the northwest, 
 where they bred and mul- 
 tiplied. Accounts of the 
 numbers and voracity of 
 these locusts seem almost 
 incredible to-day, except to 
 those who have seen an 
 occasional outbreak in the 
 northwest, for with the set- 
 tling and development of 
 the western plateau they 
 have become less abundant, 
 and are now injurious only 
 in Minnesota, the Dakotas, 
 and Manitoba. In the mid- 
 dle and southern states the 
 large bird grasshopper, or 
 
 Mountain 
 
 The Carolina locust {Dissoste/ra 
 Carolina), female. (Slightly enlarged) 
 
 (After Lugger) 
 
ORTHOPTERA 
 
 S3 
 
 American Acridium {Schistocara avicricana), is common, but 
 rarely becomes numerous enough to be seriously injurious. It is 
 one of our largest species (nearly three inches long) and makes as 
 much commotion as a small bird as it flies up before one. In the 
 Gulf States, and on the plains of the southwest, occur our two larg- 
 est species, known as the lubber grasshopper and the clumsy locust, 
 so called from their clumsy movements. Both are short-winged 
 and unable to fly, but manage to travel considerable distances. 
 
 Fig. 103. The southern lubber grasshopper {Dictyophom reticulata). 
 (About natural size) 
 
 The long-horned grasshoppers (Locustidae). The katydids and 
 meadow grasshoppers form another family readily distinguished 
 by their slender antennas, which are much longer than the body 
 and give the group the name " long-horned," in contrast to the 
 short antennas of the grasshoppers, or locusts. The ovipositor of 
 the Jemale is also long and sword-shaped. Unfortunately, the 
 scientific name of this family, Locustidae, has the same root as the 
 true locjists, or grasshoppers, with which they should not be con- 
 fused on that account. The base of the wings of those males 
 which have well-developed wings is usually constructed for sound 
 producing, so that when the wings are rubbed together and set 
 vibrating, the characteristic note is made. The Japanese inclose 
 
84 
 
 ELEMENTARY ENTOMOLOGY 
 
 some of the best of these in- 
 sect songsters in small cages, 
 in much the same manner 
 as we do song birds. The 
 "ears," or auditory organs, 
 of the long-horned grass- 
 hoppers, instead of being in 
 the first abdominal segment, 
 as in the locusts, are situated 
 on the tibia of the forelegs. 
 The light green or red- 
 dish-brown meadow grass- 
 hoppers are common occu- 
 pants of our meadows, where 
 they may be heard calling 
 to each other at dusk. The 
 antennae are usually very 
 long, and often the ovipositor 
 is as long as the body, being 
 adapted for placing the eggs 
 in the stems and roots of 
 grasses, where they are usu- 
 ally laid. 
 
 The katydids are larger, of a bright green color, and with much 
 broader wings, which are frequently quite leaflike in both shape 
 and color. The kat\'dids feed mostly in trees, though some prefer 
 
 Fig. 104. A common katydid. (Natural size) 
 (Photograph by Weed) 
 
 -Fig. 105. A katydid {Microcentmm hmrifolium) and its eggs. (Natural size) 
 
 (After Riley) 
 
ORTHOPTERA 
 
 85 
 
 bushes and shrubs. The eggs are laid along the edge of a leaf or 
 along a stem, slightly shingled, as shown in Fig. 105, being 
 
 quite different 
 from those of 
 any similar in- 
 sects and thus 
 easily recogniz- 
 able. 
 
 In this fam- 
 ily there are 
 two groups of 
 wingless forms: 
 the cricketlike 
 grasshoppers, 
 which are to 
 be found under 
 stones and rub- 
 
 FiG. 106. The western cricket {Anabnis simplex), adult 
 female. (Natural size) 
 
 (After Gillette) 
 
 bish, particularly in woodlands, and the shield-backed grasshoppers, 
 which look ver}' much like crickets. One of them, known as the 
 western cricket iyAuabrns), which is about one and one half inches 
 long, often becomes so 
 abundant in the northwest- 
 ern states as to be ven,- de- 
 structive to crops. 
 
 The crickets {Gryllidae). 
 The common black or 
 brownish crickets, with 
 their familiar chirp, are well 
 known to ever)' one. The 
 wings are laid flat on the 
 back when at rest, instead 
 of meeting like a roof as 
 in the grasshoppers, the an- 
 tennae are long, and the 
 ovipositor is long, but cylindrical in section, being lance-shaped 
 rather than sword-shaped as in the grasshoppers. Our common 
 crickets usually feed upon ^•egetation, and very rarely become inju- 
 rious, though some are predacious and at times are uncompromising 
 
 Fig. 107. The black cricket, male and female 
 (After J. B. Smith) 
 
86 
 
 ELEMENTARY ENTOMOLOGY 
 
 cannibals. The egers are laid in the ground in the fall and hatch 
 
 the next summer. 
 
 Fig. io8. Female of GiyHiis asshnilis, with inner and outer 
 views of auditory membranes on front tibi^, at c and d 
 
 (After Marlatt, United States Department of Agriculture) 
 
 The males have the best-developed musical 
 
 apparatus of all 
 the orthopteran 
 orchestra. The 
 principal vein, 
 which extends 
 along the base of 
 the wing-cover, 
 is ridged like a 
 file, and on the 
 inner margin of 
 the wing-cover, 
 a short distance 
 from the base, 
 the edge is hard- 
 ened so that it 
 may be used as a 
 
 scraper, or rasp. Elevating his wings to an angle of forty-five degrees, 
 and arranging them so that the 
 scraper of one rests on the file 
 of the other, he moves them to 
 set the neighboring wing mem- 
 branes into vibration, thus pro- 
 ducing the shrill call or the 
 faint chirp, according to his 
 mood. 
 
 The tree crickets are quite 
 different from the common 
 black sorts and are arboreal, as 
 their name indicates. They are 
 of a creamy-white or light yel- 
 lowish color, often slightly 
 tinged with green, and the wings 
 are transparent. The antennas 
 are much longer than the body. 
 
 Fig. 
 
 109. A tree cricket {(Ecaiithns fasci- 
 atiis), male and female 
 
 (After Lugger) 
 
 which is about half an inch long, and the Ovipositor is well devel- 
 oped. The wings when at rest are usually held so as to form a long 
 
ORTHOPTERA 8/ 
 
 wedge tapering toward the head. The young tree crickets are 
 somewhat beneficial, as they feed upon plant-Hce, but the adults 
 do considerably more injury by slitting the 
 twigs of cane fruits, fruit trees, cotton, eto:, 
 in which their eggs are deposited, and beyond 
 which the twigs usually die. 
 
 One small group of crickets, called mole 
 crickets, are wingless and live in the ground, 
 burrowing here and there by means of the 
 front tibiae, which form shovels admirable for 
 that purpose. Mole crickets are more abun- 
 dant in the South and Southwest, where they 
 feed upon the roots of plants, but are very 
 rarely injurious. In Porto Rico, however, the 
 chaiiga is the most serious insect pest of the 
 island, annually doing one hundred thousand 
 dollars' worth of damage to the staple crops. 
 
 Fig. iio. Eggs of 
 
 the snowy tree cricket 
 
 [CEcaiit/iiis niveiis) 
 
 (7, blackberry cane, show- 
 ing egg punctures ; b, the 
 same split, to show the 
 arrangement of the eggs ; 
 c, egg very much en- 
 larged ; (/, its tip still more 
 enlarged, (.\fter Kiley) 
 
 Earwigs (Euplexopterd). 
 
 The earwigs are nearly re- 
 lated to the Orthoptera, 
 though they are often placed 
 in a separate order, Euplex- 
 
 optera, which means "well-folded wing," referring to the wing, 
 which is folded lengthwise, like that of the grasshopper, and 
 then crosswise. They are small insects, our common species 
 
 Fig. III. Changa {Scapteriscus didactylus Latr.) 
 
 A mole cricket which is the most serious insect pest 
 in Porto Rico, (.\fter Barrett) 
 
88 
 
 ELEMENTARY ENTOMOLOGY 
 
 being from one fourth to one half an inch long. The wing-covers 
 are short and thick like those of some beetles, and at the tip of 
 the abdomen is a pair of strong, forceplike appendages. Earwigs 
 
 Fig. 112. An earwig (Forjicula iaeniata). (Enlarged) 
 
 I, male ; 2, female ; 3, wing showing fanlike folds and joints where the 
 tip is folded on the base 
 
 are rare in the United States, except in the South, and are not 
 injurious. The common name "earwig" arises from an old super- 
 stition that they crawl into the ears of sleepers and kill them. In 
 the South they often fly into lights, and in Europe and subtropical 
 countries they sometimes become injurious. 
 
CHAPTER IX 
 
 THE NERVE-WINGED INSECTS, SCORPION-FLIES, CADDIS-FLIES, 
 MAY-FLIES, STONE-FLIES, AND DRAGON-FLIES 
 
 The earlier naturalists grouped all of the insects having four 
 membranous wings with numerous fine cross veins, or nervures, as 
 they were then called, into the order Neuroptera, or nerve-winged 
 insects, from ncitjvn (nerve) ?iX\d pteron (wing). Further study has 
 
 Fig. 113. The adult male dobson-fly and its larva, the hellgramite 
 (After Comstock) 
 
 shown that these insects are not so nearly related, and that they 
 should be divided into several distinct orders, to exhibit their true 
 relationship. Few of them have any economic importance, and 
 
 89 
 
90 
 
 ELEMENTARY ENTOMOLOGY 
 
 they may convenient!)- be considered together and termed ' ' neu- 
 ropteroid insects." 
 
 True Neuroptera. In the true Nciiroptera the wings are usually 
 of equal size, with numerous cross veins, the mandibles are well 
 developed, and the metamorphosis is complete. The larvae are 
 carnivorous, and the mandibles are usually long and pointed. One 
 of the best-known forms is the large hellgramite {Corydalns cor- 
 mita), whose larvae, known as dobsons, are the favorite bait of 
 the bass fisherman. The larv'ae live under stones in swift-flowing 
 
 Fig. 114. Cluster of eggs of the lace-winged fly {Ch>ysopa). (Greatly enlarged) 
 
 (After S. J. Hunter) 
 
 streams, where they feed on the young of various aquatic insects. 
 They are readily recognized by the leglike appendages and a large 
 tuft of tracheal gills on either side of each abdominal segment 
 (Fig. 113). It requires nearly three years for the larva to become 
 full grown, when it forms a cell beneath a stone, or some object 
 near the bank, and pupates, the adult appearing about a month 
 later. The adults are readily recognized, as they have a wing ex- 
 panse of from four to five and one half inches and the males have 
 remarkably long mandibles. On the rocks under which the larvae 
 live the eggs are laid in chalklike masses of from two to three 
 thousand. 
 
? o-t: 
 
 91 
 
92 
 
 ELEMENTARY ENTCJMOLOGY 
 
 The aphis-lions {CJuysopidac) 
 enemies of the noxious plant-Hce. 
 
 are among the most important 
 The lar\'as are small, dark-colored, 
 spindle-shaped insects, from 
 one fourth to one third of an 
 inch long, with large, pincer- 
 like jaws, much longer than the 
 head, with which they grasp 
 the aphides. On the inside 
 of each mandible is a deep 
 groove, against which the max- 
 illa fits, thus forming a tube 
 through which the juices of the 
 
 (Photograph by Weed) ^^^^ ^^^ SUckcd intO the mOUth. 
 
 When full grown, the larva spins a small, globular cocoon of 
 pure white silk, in which it pupates. Frequently the old cocoons 
 will be found with a small, circular lid which the adult has opened 
 
 A Myrmeleonid, 
 the ant-lion 
 
 the aduh of 
 
 Fig. 117. The ant-Uon 
 
 a, larva of Myrmclcon sp. (three times natural size) ; b, pit of ant-lion, Myrmeleon sp., and 
 
 below a pupal sand-cocoon from which the adult has just issued, the pupal skin remaining 
 
 (natural size). (After Kellogg) 
 
 in making its escape. The adults are about an inch long, of a deli- 
 cate pale green color, with brown antennas and finely veined wings, 
 which are held like a roof over the back, and which have given 
 them the name of "lace-winged flies." The eyes are a glistening 
 
THE NERVE-WINGED INSECTS 
 
 93 
 
 Fig. ii8. A scorpion 
 
 fly (Paiiorpa rttfesceiis) 
 
 (Twice natural size) 
 
 (After Kellogg) 
 
 gold, from which they are sometimes called golden-eyes. The larvae 
 feed not onlv upon plant-lice, but upon any soft-bodied insects which 
 they can overpower, or on soft insect eggs, and 
 will not infrequently attack their own species. 
 The adults seem fully aware of these canni- 
 balistic tastes, for they lay the little white eggs 
 on stalks about half an inch high, placing them 
 out of the reach of the larvae. 
 
 In the undisturbed dust beneath an old shed, 
 or beneath cliffs, or along warm banks, one 
 will frequently find the little funnel-shaped 
 pits of the ant-lions {Myrnielcojiidac), some- 
 times locally known as " doodle bugs." At 
 the bottom of the pit may be seen two out- 
 stretched jaws awaiting any unwary insect 
 which may slide down the crumbling sides. The larvae are not 
 unlike those of the aphis-lions in general appearance, but have a 
 larger abdomen and a small thorax and slender legs. The adults are 
 dusky-colored, with long, narrow, delicate wings. They are poor 
 fliers and are often attracted to lights (Fig. 1 16). 
 
 The scorpion-flies (order Mecopterd) are readily distinguished by 
 the long head, which is prolonged into a beak, at the end of which 
 are the biting mouth-parts. They receive their common name 
 " scorpion-flies " from 
 the terminal segment 
 of the males of the 
 most common forms, 
 which is enlarged and 
 bears clasping organs, 
 so that it looks like the 
 fang at the tip of the 
 body of a scorpion. They are entirely harmless, howe\'er, being car- 
 nivorous both as adults and as larvas. The adults are most commonly 
 found on foliage in shady places, though they not infrequently fly into 
 lights, while the larvae look much like caterpillars and live in the soil. 
 The caddis-flies (order Trichoptera) ^ have wings with but few cross 
 veins but more or less densely clothed with hairs, thus being related 
 
 ^ From t/in'x (a hair) ^nd pteroii (a wing). 
 
 Fig. 1 19. 
 
 Scorpion-fl)- larva {Paitorpa sp. 
 times natural size) 
 
 (After Felt, from Kellogg) 
 
 (Three 
 
94 
 
 ELEMENTARY ENTOMOLOGY 
 
 to both the neuropterous insects and the Lepidoptera. The mouth- 
 parts of the adults are quite rudimentary. The hind-wings are often 
 
 somewhat larger than the 
 fore-W'ings and are then 
 folded under them in repose, 
 the fore-wings being held 
 like a roof over the back. 
 The antennas are usually very 
 long and slender. The lar- 
 vae are aquatic and form an 
 important item of fish food. 
 Some of them build most 
 interesting little cases from 
 grains of gravel, small shells, 
 bits of twigs, pine needles, 
 or whatever rubbish may be 
 at hand, lined within with 
 silk, which they carr}' around 
 with them, the head and 
 thorax projecting out as they 
 move or feed. Every small pool or brook harbors some of these 
 interesting case bearers, which will hardly be distinguished except by 
 closely watching the bottom until they are seen in motion. Most of 
 these larvae are herbivorous, feeding on whatever vegetable matter 
 is available, and look like small 
 caterpillars. The caddis-worms of 
 one group construct silken nets 
 across small rapids, between stones, 
 or upon the brink of little water- 
 falls, which are doubtless of serv- 
 ice in catching the tiny insects 
 which float downstream, as the lar- 
 vae which make them are known 
 to be carnivorous. When ready to change to a pupa, the caddis- 
 worm closes up the entrance to its case, but leaves an opening for 
 the water to flow through so that the pupa can breathe, sometimes 
 making a simple grating of silk over the entrance. Upon trans- 
 forming to the adult the caddis-fly secures almost immediate use 
 
 Fig. I20. Caddis-fly larval cases. (Enlarged) 
 (After Furneaux) 
 
 Fig. 121. Adult caddis-fly (Goiiioiaii- 
 liiis dispcctiis Walk). (Enlarged) 
 
 (After Xeedham) 
 
THE NERVE-WINGED INSECTS 95 
 
 of its wings, as is highly necessary if it is not to be drowned. Most 
 insects require several minutes or even hours for the wings to ex- 
 pand and harden, but Professor Comstock observed a caddis-fly 
 which took flight immediately upon emergence from the water. 
 The adults are usually gra)'ish, brownish, or dusky in color, marked 
 with black or white, and are rarely observed except as they fly 
 into lights. 
 
 Pseudoneuroptera, with incomplete metamorphosis. All of the 
 three orders just considered have a complete metamorphosis and are 
 more or less closely related. The next three orders are all aquatic 
 and have an incomplete metamorphosis, for which reason they are 
 often grouped together as false Neuroptera {Psciuionciiroptcrd). 
 
 The May-flies {Ephemenda) ^ are \^ ell 
 named, for they are the most ephemeral 
 of insects. The wings are exceedingly 
 delicate and the fore-wings are much the 
 larger, the hind-wings sometimes being 
 entirely wanting. The mouth-parts of f ^^''^r " 
 
 the adults are exceedingl)- rudimentary, fe* i/iM^:/' /. , / 
 and they probably take no food. The Ml!'JAJLMm'it^ILJ:!ll 
 antennse are short, but at the end of ^"'^- '--■ ^'^^^^ ^ net-building 
 
 , , r 1 1 1 caddis-worm 
 
 the long, soft abdomen are two or three 
 
 , .... ,,., , (After Comstock) 
 
 long, many-jomted, threadlike append- 
 ages, the cerci, which are quite characteristic of the May-flies. On 
 warm nights of late spring and early summer the lights of towns 
 near rivers and lakes are often darkened by myriads of May-flies. 
 They are light brown or dusky colored, with wings expanding from 
 one to one and one half inches, and with cerci fully as long. The 
 nymphs live at the bottom of ponds, streams, and lakes, feeding on 
 small insects and vegetable matter in the ooze. Along either side of 
 the nymph's abdomen is a row of delicate, platelike, fringed tracheal 
 gills, through which it breathes, and at the tip of the abdomen are 
 three feathery appendages. The legs are strong and enable it both 
 to walk and to swim. The nymphs molt very frequently, there being 
 as many as twenty molts in some species. After about the ninth 
 molt the wing pads commence to appear on the back, and become 
 
 1 From cphemeros (lasting but a day). 
 
Fig. 123. May-flies {Ephemera varia Etn.) 
 
 /, 2, side and back views of nymph ; 3^ 4, side and back view of adult male {Siphlurus 
 alieniaius Say); j, 6, side and back view of nymph; 7, side view of adult male. (After 
 
 Needham) 
 
 96 
 
THE NERVE-WINGED INSECTS 
 
 97 
 
 Fig. 124. A stone-fly [Pteronarcys regalis). 
 reduced) 
 
 (After Newport, from Folsom) 
 
 (Slightly 
 
 larger with each successive molt, until the water nymph sheds its 
 skin for the last time, the gills and mouth-parts are left behind, and 
 
 the winged May- 
 fly comes forth. 
 After flying a 
 short distance it 
 alights and again 
 sheds its skin, a 
 thin layer coming 
 off from all parts 
 of the body, even 
 from the wings, 
 which process 
 must certainly be 
 the " exception 
 which proves the 
 rule, "for no other 
 insects ever molt 
 after becoming winged. The eggs are now deposited by the females 
 either on the surface of the water or on stones beneath the surface, 
 and in a few hours, or at most in a day or two, 
 the adults die. The nymphs live from one 
 to three years, according to the species, and 
 form an important item of the food of fishes, 
 but are otherwise of no economic importance. 
 The stone-flies (order Plecopterd) ^ are quite 
 similar to the May-flies in their general hab- 
 its, but quite unlike them in appearance. The 
 hind-wings are much larger than the fore- 
 wings and are folded beneath them in plaits 
 when at rest. The mouth-parts of the adults 
 are of the biting type, but are often poorly 
 developed. The antennae are rather long and 
 slender, and usually there are two many- 
 jointed cerci extending from the tip of the 
 abdomen. The nymphs live beneath stones 
 in swift-running streams and are from one 
 
 ^ Yrom plecos (plaited), and fteron (wing). (After Comstock) 
 
 Fig. 125. A stone-fly 
 nymph 
 
98 
 
 ELEMENTARY ENTOMOLOGY 
 
 half to one and one half inches long ; with their long legs, and anten- 
 nae and cerci projecting from either end, they have a very distinctive 
 appearance, as shown in Fig. 125. Behind each leg is a clump of 
 hairlike tracheal gills, very similar to those found on the dobson, 
 through which they breathe. They are a favorite food of fishes, 
 particularly of brook trout, and make excellent bait. When full 
 grown the nymphs crawl upon rocks or reeds and transform to the 
 
 adult stone-flies, the old skins 
 being frequently found in such 
 places. The adults are dull 
 grayish or brownish, the more 
 common forms being from one 
 to one and one half inches long, 
 and are usually found on foliage 
 in shady places along streams. 
 They probably take no food and 
 live only long enough to lay the 
 eggs. Some of the smaller spe- 
 cies, about one fourth of an inch 
 long, of a blackish color, are 
 often common on snow in early 
 spring, and frequent windows 
 at that time. 
 
 The dragon-flies and damsel- 
 flies (order Odonata) are readily 
 recognized by their long, nar- 
 row, powerful wings, which are 
 about equal in size and on the 
 front margin of which is a little 
 
 Fig. 126. 
 
 A damsel-fly (Lestes uiicata 
 Kirby), female 
 
 (After Needham) 
 
 notch and strong cross vein, called the nodus . The mouth-parts are 
 well developed and are of the biting type, both larvae and adults being 
 predacious upon other insects. The dragon-ffies and damsel-flies 
 are distinguishable both as adults and as nymphs. The adult damsel- 
 fly holds the wings vertically over the back when at rest, like a butter- 
 fly ; the fore and hind wings are similar in shape, and the nymphs 
 have three long, leaf like tracheal gills projecting from the tip of the 
 abdomen. The dragon-flies hold their wings horizontally when at 
 rest, the hind wings are usually much broader at the base, and the 
 
Fig. 127. Nymph of a damsel-fly 
 (Lestes sp.). (Twice natural size) 
 
 Showing the three leaflike tracheal 
 
 gills at the tip of the abdomen. (After 
 
 Kellogg) 
 
 Fig. 128. Early stages of nymph of a 
 dragon-fly (Aiiax jiniiits Dru.). (All en- 
 larged) 
 
 Showing changes of color pattern : A, newly 
 
 hatched ; B, one fourth grown ; C, one half 
 
 grown. (After Needham) 
 
 Fig. 129. A dragon-fly and its development 
 
 Nymphs feeding at / and j, showing extension of underlip or mask and the way prey is 
 
 grasped by it ; 2, mature nymph ready to molt ; 4, skin of nymph from which the adult (j) 
 
 has emerged. (After Brehm) 
 
 99 
 
lOO 
 
 ELEMENTARY ENTOMOLOGY 
 
 nymph has five converging, spinelike appendages at the tip of 
 the abdomen. The dragon-flies are among the swiftest fliers, dart- 
 ing here and there after small flies, and are impoitant enemies of 
 mosquitoes. They have received many local names, such as darning 
 needles, snake doctors, etc., with which are connected many curious 
 
 superstitions of sewing up people's 
 ears, bringing snakes to life, etc., of 
 which they are of course entirely in- 
 nocent. They are usually dark colored, 
 though often brilliantly marked with 
 metallic blue, green, and red. The 
 damsel-flies are more slender-bodied 
 and fly lazily about. The eggs are 
 laid in the water or fastened to aquatic 
 plants. From them hatch the little 
 long-legged nymphs which may be 
 found browsing in the ooze and mud 
 of any pond. Dark-colored, flat, and 
 spiny, they are hardly distinguishable 
 from the debris of the bottom. They 
 have a peculiar underlip, remarkably 
 extensile, with two .powerful hooks 
 at the tip, which, when thrown for- 
 ward from the head, grasps the un- 
 suspecting prey. When drawn in, 
 the labium covers the front of the 
 face and gives the nymph an exceed- 
 ingly comical appearance, with its 
 large, shrewd eyes on either side. 
 The nymphs of the damsel-flies 
 breathe through the tracheal gills at 
 
 Fig. 130. A, part of two rows of 
 respiratory folds from cuticular 
 lining of rectum of dragon-fly 
 nymph {^Esr/t/ni). The shaded 
 parts are abundantly supplied with 
 tracheal tubes, as shown at B, a 
 small part of one leaflet highly 
 magnified, showing many fine tra- 
 cheal branches 
 
 (Redrawn from Miall) 
 
 the tip of the abdomen, but the 
 dragon-fly nymphs have a peculiar way of drawing water into the 
 rectum, whose walls are very thin and lined with numerous tra- 
 chea, so that the air in the trachea is purified through the wall of 
 the rectum as if it were a tracheal gill. The water from the rectum 
 may be ejected forcibly, so as to drive the nymph suddenly for- 
 ward. When full grown the nymph crawls up on a reed or plant 
 
' WwoiS^ g ^.ii i i ' '"" ■' ' 
 
 Fu;. 131. Development of a dragon-fly [Leiicorhinia glacialis Hagen) 
 
 /, two nymphs on the bottom of the pond ; 2, the empty nymphal skin left clinging to a 
 branch after transformation ; 3, the adult female ; 4,5, back and side views of the adult male 
 
 (After Needham) 
 loi 
 
I02 
 
 ELEMENTARY ENTOMOLOGY 
 
 and molts for the last time, the adult quickly flying away and 
 leaving the cast skin, which is often found intact and gives an 
 excellent idea of the structure of the nymph, so remarkably unlike 
 the adult in both form and habit. 
 
 Fig. 132. Dragon-fly [Libelhda pulchella). (Slightly reduced) 
 A, last nymphal skin ; i?, adult. (After Folsom) 
 
 Summary of the Nerve-Winged Insects and their 
 Relatives 
 
 A. With complete metamorphosis : 
 
 Order Nenroptera. Wings equal ; numerous cross veins. 
 The dobsons {Sialidae). Larvae aquatic. 
 The aphis-lions {Chrysopidae). Feed on aphides, etc. 
 The ant-lions [Afyr/neleonidae). Larvae make pits in soil. 
 
 Order Mecoptera. Scorpion-flies. Elongate head, and tip of abdomen fang- 
 like. Larvae live underground. 
 
 Order Trichoptera. Caddis-flies. Wings with few cross veins and clothed 
 with hairs. Larvae live in water, many being case bearers. 
 
 B. With incomplete metamorphosis {Psendo/ieuroptera) : 
 
 Order Ephemerida. May-flies. Fore-wings much larger ; mouth-parts rudi- 
 mentary. Nyrrlphs aquatic. 
 
 Order Plecoptera. Stone-flies. Hind-wings larger and plaited beneath the 
 fore-wings when at rest. Nymphs aquatic. 
 
 Order Odonata. Dragon-flies and damsel-flies. Wings about equal in size, 
 with a nodus on the front margin. Nymphs aquatic. 
 
CHAPTER X 
 
 THE WHITE ANTS, BOOK-LICE, AND BIRD-LICE (PLATYPTERA) 
 
 Characteristics. Insects with two pairs of delicate, membranous wings equal 
 or the hind pair smaller, and with the principal veins few and simple, or entirely 
 wingless ; mouth-parts, mandibulate ; body, flattened ; prothorax, broad ; meta- 
 morphosis, incomplete. 
 
 The Platyptera (from platys, "flat," d.ri^ ptcron, "a wing," allud- 
 ing to the wings of the white ants, which lie flat on the back when 
 at rest) include three groups, which are often considered as separate 
 orders and are quite dis- 
 tinct in appearance and 
 habits, but may well be 
 placed in a single or- 
 der based upon the struc- 
 tural characters given 
 above. When present 
 the wings are never net- 
 veined, and the book-lice 
 and bird-lice are wing- 
 less. The body is usually 
 flattened and the pro- 
 thorax is usually well- 
 developed and distinct. 
 
 The white ants {Ter- 
 mitidae) are well-known 
 inhabitants of fallen logs 
 and decaying wood, and 
 are readily mistaken for 
 ants by the casual observer. The light yellowish color and the fact 
 that the abdomen is broadly joined to the thorax, with no toothed 
 constriction, as in the true ants, easily distinguish them. Though 
 entirely unrelated to the true ants, they have a very similar social 
 organization, with several distinct castes, of which only the so-called 
 
 103 
 
 '^IW'"' 
 
 Fir,. 
 
 a, queen : 
 
 White ants, or termites. (Enlarged) 
 
 male; r, worker; d, soldier. (.After Jordan 
 and Kellogg) 
 
I04 
 
 ELEMENTARY ENTOMOLOGY 
 
 kings and queens are winged. The wings are long and narrow, 
 somewhat leathery in texture, and are furnished with numerous 
 
 but somewhat indistinct 
 veins, are about equal in 
 size, and are laid flat on 
 the back when at rest. 
 They have well-devel- 
 oped biting mouth-parts, 
 the mandibles of the sol- 
 diers projecting well for- 
 ward of the huge head. 
 They are most abundant 
 in the tropics, where 
 they are serious pests of 
 all kinds of woodwork, 
 mining into foundations, 
 posts, furniture, and 
 whatever happens in 
 their way. The nests of 
 the tropical species are 
 often of large size, form- 
 ing mounds sometimes twelve feet high, or huge, roundish masses 
 several feet thick attached to trees. But one species ( Tcrvicsflavipcs) 
 
 Fig. 134. White ants' nest on trunk uf tree (at 
 arrow) in Cuba 
 
 (Photograph by Slingerland) 
 
 Fig. 135. Psociis liiieatiis. (Much enlarged) 
 (After J. B.Smith) 
 
 is common throughout the United States ; it is usually found in 
 old logs and stumps, but sometimes establishes its nests beneath 
 
THE WHITE ANTS, BOOK-LICE, AND BIRD-LICE 105 
 
 Fig. 136. A psocid (side 
 
 view), showing position of 
 
 wings at rest. (Thirteen 
 
 times natural size) 
 
 (After Kellogg) 
 
 buildings, whose wooden foundations are then attacked and often 
 
 so mined as to necessitate their removal. Such instances are more 
 
 common in the South, but even in the North porch timbers are 
 
 often attacked, and now and then the white ants invade a building 
 ^ and thoroughly tunnel the studding and even 
 
 the lathing. The workers of both sexes are 
 wingless, of a dirty white color, and busy 
 themselves in building their nests, caring for 
 the young termites, and securing food for 
 the whole colony. The soldiers are also of 
 both sexes, wingless, and resemble the work- 
 ers, except that the heads are of immense 
 size, being frequently as large as the rest of 
 the body, and bear very strong mandibles, 
 which form effective weapons. The kings 
 
 and queens are really merely fathers and mothers, for they produce 
 
 the colony but do not rule it. In early summer the kings (males) 
 
 and queens (females) swarm forth from the nest and, after a short 
 
 flight, shed their wings. Individual males 
 
 and females now mate and are ready to start 
 
 a new colony, but unless they are found and 
 
 established by some workers they perish, and 
 
 thus only few of them ever survive. If a 
 
 pair are fortunate enough to be discovered 
 
 by some workers, they are provided with 
 
 food and are imprisoned in a circular cell. 
 
 The queen now commences to develop eggs, 
 
 and her body enlarges enormously, finally 
 
 becoming nothing but a huge sack, often 
 
 six inches long, filled with eggs. She is fed 
 
 by the workers, who carry away the eggs and 
 
 rear the young, which resemble the adults in 
 
 general form. Thus -the domestic economy 
 
 of these colonies is hardly less interesting than that of the true ants. 
 Book-lice. In neglected libraries or in old books which have been 
 
 stored are to be found the tiny book-lice (Psocidae) which feed upon 
 
 the paper bindings. They are exceedingly wise-looking little insects 
 
 when examined with a lens, having all the appearance of being 
 
 Fig. 137. A wingless book- 
 louse (.-i/n'/i' J- sp.). (Greatly 
 enlarged) 
 
 (After Kellogg) 
 
io6 
 
 ELEMENTARY ENTOMOLOGY 
 
 adapted to their surroundings. Other members of this family, called 
 psocids, are winged and look much like large plant-lice. The wings 
 are of a dusky color, have a very characteristic venation, and are 
 held roof-shaped over the back. Psocids feed on lichens and decay- 
 ing wood and are fre- 
 quently found in large 
 masses on fences or 
 tree trunks, where they 
 are suspected of doing 
 mischief, but they are 
 entirely harmless and 
 need not be disturbed. 
 The biting bird-lice 
 (Mallophagd) are curious 
 looking, wingless para- 
 sites which infest the 
 feathers of poultry and 
 birds, while some infest 
 sheep and mammals. 
 They have biting mouth-parts and feed on feathers, hair, and bits 
 of skin, thus differing from the true lice (see p. 121), which have 
 sucking mouth-parts with which they extract the blood. The flat- 
 tened bodies and curiously shaped heads enable one to identify 
 them readily. A dust bath, with a frequent thorough cleansing of 
 the poultry house by spraying with kerosene and then whitewash- 
 ing, will usually prevent serious annoyance to poultry. 
 
 Fig. 138. Biting lice (A/a//o^Aaga). (Greatly enlarged) 
 
 a, turkey-louse {Goniodes siylifer Nitsch) (after Cuvier); 
 
 b, the biting dog-louse (Trichodectes latus Nitsch) (after 
 Denny). (From Osborn, United States Department of 
 
 Agriculture) 
 
CHAPTER XI 
 
 THE TRUE BUGS, APHIDES, AND SCALE INSECTS {HEMIPTERA) 
 
 Characteristics. Insects with four wings, except in the parasitic forms ; fore- 
 wings, thickened at the base, with membranous tips and overlapping on the 
 back in the Heteroptera, but entirely membranous and sloping at the sides of 
 the body in the suborder Homoptera ; mouth-parts, suctorial ; antennae, few- 
 jointed ; metamorphosis, incomplete. 
 
 Ordinarily all insects or small, insectlike animals are called 
 bugs by the uninitiated, but when the entomologist speaks of a 
 
 Fig. 139. Fore-wings of Heteroptera, showing thickened veins and arrangement 
 of veins in membranous tip characteristic of various families 
 
 /, Capsidae ; 2, Pyrrhocorldac ; s, I^ygaeidae ; 4, Coreidae ; j, A^abidac ; 6, Acantliidae 
 
 (After Comstock) 
 
 bug he refers to an insect of the order Hcmiptcra. The insects 
 of this order are readily recognized by the strong, pointed suck- 
 ing beak which extends from the head between the legs, and in 
 which are inclosed the other mouth-parts, as already described (see 
 p. 17). They develop with an incomplete metamorphosis, as has 
 been described for the squash-bug (p. 50), which is a good ex- 
 ample of one group. The name of the order, Haniptera, is de- 
 rived from herni (half) and pteron (wing), but is really applicable 
 to only one suborder, the Heteroptera. The name Heteroptera has 
 a similar significance, referring to the fore-wings, which ha\'e the 
 
 107 
 
io8 
 
 ELEMENTARY ENTOMOLOGY 
 
 Fig. 140. A winged pea aphis, illustrating the uni- 
 form translucent, membranous texture and vena- 
 tion of the wings of the Homoptera. (Much 
 enlarged) 
 
 basal half thickened and 
 the tips membranous 
 and overlapping, while 
 the hind-wings are en- 
 tirely membranous, so 
 that the wings are unlike 
 {hcicros), and the beak 
 arises from the front of 
 the head. In the other 
 principal suborder, the 
 Homoptera, the wings are 
 membranous throughout 
 and slope at the sides of 
 the body like a roof, both 
 pairs of wings being 
 alike {hornoios), and the 
 beak arises from the back of the head. A third suborder, the Para- 
 sita, are entirely wingless, degen- 
 erate forms which are parasitic 
 on man and other mammals. 
 
 Suborder Heteroptera 
 
 The aquatic bugs. Several 
 families of true bugs inhabit our 
 streams, ponds, and lakes. The 
 water-boatmen {Corisidac) are 
 from one fourth to one half an 
 inch long, and of a brownish 
 color, but appear like glistening 
 silver as they dive through the 
 water, carrying with them a thin 
 coatingof air which they breathe. 
 Their near relatives, the back- 
 swimmers {Notoncctidac), differ 
 in that they swim upside down 
 
 ,1 . , 1 1 . , 1 , Fig. 141. Back-swimmers {N'otoneda) 
 
 on their backs, which are shaped ^^ ^,^ ^^^ water-boatman {Corixa) B. 
 
 like the keel of a boat instead of (Slightly enlarged) 
 
 being fiat. The water-scorpions (After Linville and Kelly) 
 
THE TRUE BUGS 
 
 109 
 
 {Nepidac) are so called from the long tube extending from the tip 
 of the abdomen, which is thrust to the surface of the water for 
 breathing. They are elongate insects, with long legs, the front 
 
 Fig. 142. A water-scorpion [Rajiatra fitsca). (Enlarged) 
 (After Lugger) 
 
 pair being fitted for grasping their prey, and live on the stems of 
 plants, which they closely resemble. 
 
 The giant water-bugs {Belostoniidac) are probably better known 
 to most boys as electric-light bugs, 
 for with the advent of the arc light 
 they have become very numerous on 
 the streets on warm summer even- 
 ings. The largest are over two 
 inches long and can inflict a pain- 
 ful wound with their strong beaks, 
 which they use for preying upon 
 other insects and small fish. These 
 larger water-bugs, as well as the back 
 swimmers, often become a serious 
 pest where the artificial propagation of fish is attempted. Many of the 
 females fasten their eggs to their own backs with a waterproof glue. 
 
 Every one who has been fishing knows the water-striders {Hydro- 
 hatidac) which dart here and there over the surface and suddenly 
 
 Fig. 143. The undulating back- 
 swimmer {A^ohviecta uiiditlata). 
 (Twice natural size) 
 
 (After Weed) 
 
B 
 
 Fig. 144. A, the giant water-bug or electric-light bug {Belostoma aniericaiia) ; B, 
 
 the western water-bug {Serphus sp.), male, with eggs deposited on its back by 
 
 the female. (Natural size) 
 
 (After Kellogg) 
 
 Fig. 145. A water-strider [Hygrotrechits remigiis Say). (Enlarged) 
 (After Lugger) 
 

 Fig. 146. The masked bedbug hunter [Opsicoetus personatus Linn.), adult and 
 dust-covered nymphs. (Enlarged) 
 
 (After Brehm) 
 
 Fig. 147. The big bedbug or bloodsucking cone-nose {Co7iorhiniis sattgjiistiga). 
 
 (Enlarged) 
 
 a, /', last stages of nymphs ; c, d, adults. (After Marlatt, United States Department of 
 
 Agriculture) 
 II I 
 
I 12 
 
 ELEMENTARY ENTOMOLOGY 
 
 leap for some unwaty midge or other small insect. They usually 
 occur together in some numbers, and some kinds have been seen 
 on the ocean hundreds of miles from land. 
 
 All of the aquatic bugs are predacious upon other insects or upon 
 small aquatic animals or fish, and may therefore be either beneficial 
 or injurious, according to the nature of the food. 
 
 Fig. 14S. The wheel-bug (Prionidits cristatiis Linn.), eggs, nymphs, and adults 
 (After Glover, United States Department of Agriculture) 
 
 The predacious bugs. Several terrestrial families are predacious 
 and may be conveniently considered together. The assassin-bugs 
 {Rcduviidac) are well named in this respect. They feed on soft- 
 bodied insects, but unfortunately are not discriminating in their 
 choice, so that frequently beneficial insects are destroyed in large 
 numbers. They are more common in the South, where one of the 
 largest species is known as the wheel-bug {Arihis cristatiis) from 
 the large hump, like a cogwheel, on the back. In the North are 
 several species, commonly found around houses, one of which is 
 
THE TRUE BUGS 
 
 113 
 
 known as the masked bedbug hunter, from the habit of the nymph 
 of covering itself with dust and rubbish so as to be thoroughly con- 
 cealed as it waits in dusty corners for its prey. This species, with 
 
 Fig. 149. Thread-legged bug {Emesa longipes De G.) 
 
 (After Lugger) 
 
 another {Melanolcstcs picipcs), was the subject of considerable 
 newspaper notoriety a few years ago as the kissing bug, since it not 
 infrequently attacks the lips of people while they are asleep. The 
 
 Fig. 150. A damsel-bug (Coriscus subcoleoptents Kby. ) 
 (After Lugger) 
 
 thread-legged bugs {Evicsidac) are well described by their name, all 
 of the legs being long and threadlike. The forelegs are fitted for 
 grasping the prey, resembling those of the mantis, and the anten- 
 nae are bent so as to simulate forelegs. They are sometimes found 
 
114 
 
 ELEMENTARY ENTOMOLOGY 
 
 Fig. 151. Phymaia wolfii. 
 
 (7, b, side and back views ; f, front leg ; </, 
 
 beak. (After Riley, United .States Department 
 
 of Agriculture) 
 
 around barns and sheds, where they are said to rob spiders' webs 
 of their prey. The damsel-bugs {Nabidae) frequent flowers and 
 vegetation, feeding on any small insects they may conquer. The 
 blond damsel-bug {Coriscns ferns) is a light yellowish color, with 
 
 numerous brown dots, and is 
 often taken in sweeping grass 
 with a net. The other most 
 common species, the black 
 damsel-bug {Coriscns snbcole- 
 op trains), receives its specific 
 name from the fact that at first 
 glance it closely resembles a 
 beetle, the wings being mere 
 rudiments and the body shin- 
 ing black, with yellowish legs. 
 A single species {Phyviata tvolfii) of the ambush-bugs {P/iyinati- 
 dae) is found very commonly lurking in the flowers of the golden- 
 rod. It is yellowish or greenish in color, with a broad black band 
 across the abdomen, and the front legs are strongly developed for 
 grasping, so that it is able to overpower much larger insects. The 
 bedbug and its relatives the flower-bugs {AcaniJiidac) are also 
 predacious. The former is too well 
 known to need description, and an- 
 other similar wingless form attacks 
 swallows, bats, pigeons, etc. The 
 flower-bugs have well-developed wings 
 and lurk in blossoms, where they at- 
 tack small insects. 
 
 The stink-bugs, or shield-shaped 
 bugs (^Pentatomidae), are a large fam- 
 ily readily distinguished by their 
 shape, and, with two or three nearly 
 related but small and unimportant families, may be distinguished 
 from other terrestrial Heteroptera by having antennae of five seg- 
 ments instead of four. The term "stink-bug" is not definite, for 
 many other families have very characteristic " buggy " odors, but 
 as these insects frequently attack berries, which retain their odor, we 
 have become better acquainted with this disagreeable characteristic 
 
 Fig. 152. Bedbug. (Enlarged) 
 
 , nymph ; /', adult, with outstretched 
 beak 
 
THE TRUE BUGS 
 
 115 
 
 in their case, — hence the name. They have small heads with broad, 
 prominent shoulders, and the large, triangular scutellum occupies 
 
 Fig. 153. The green soldier-bug (A\'zara hllaris). (Enlarged) 
 
 a, adult ; /', beak ; r, eggs ; d, single egg ; e, young nymph ; /, last stage of nymph. 
 (After Chittenden, United States Department of Agriculture) 
 
 the center of the back between the wings, which are rounded at the 
 tip of the abdomen, giving the whole body a characteristic shield- 
 shaped appearance. From an economic stand- 
 point the family is divided, some species being 
 predacious upon other insects and others 
 being serious crop pests, while some have 
 both habits, as circumstances may offer food 
 of one kind or the other. The predacious 
 species are commonly known as soldier-bugs 
 and feed mostly upon caterpillars. The com- 
 mon green soldier-bug {Nezara hilaris) feeds 
 upon the larvae of the Colorado potato-beetle, 
 cotton-leaf caterpillars, and other injurious 
 forms, but unfortunately it not infrequently 
 attacks cotton bolls, ripening oranges, and 
 various fruits and vegetables, doing consider- 
 able injury by sucking the juices and causing 
 malformations. The spined soldier-bug {Po- 
 dis7is spinosiis) is a common enemy of leaf-eating caterpillars, such 
 as the tussock moths, gypsy and brown-tail moths, and of many 
 soft-bodied grubs, like those of the potato-beetle. Other species, 
 like the harlequin cabbage-bug {Miaxautia Jiistrionica), which is 
 
 Fiu. 154. Spined soldier- 
 bug {Podisiis spiiiosiis). 
 (Enlarged) 
 
 (After Lugger) 
 
ii6 
 
 ELEMENTARY ENTOMOLOGY 
 
 black with numerous red or orange markings and is one of the 
 most serious pests of cabbage throughout the South, feed wholly 
 on vegetation. Small green species {TJiyanta cnstator -axx^ Pcnta- 
 toma sayi) have done serious injuiy to grain and forage crops in 
 Texas and Colorado in recent years. The little Negro-bugs of a 
 nearly related family {Corimclacnidac) are jet-black and have the 
 
 / 
 
 T> 
 
 Fig. 155. The harlequin cabbage-bug 
 
 a, b, adults (natural size) ; c, side view of head with mandibular and maxillary setae out of 
 
 beak ; d, eggs with newly hatched young ; e, nymphs ; /, egg masses with one egg hatching 
 
 and newly hatched nymph on lower right mass 
 
 scutellum enlarged so that it covers nearly the whole abdomen 
 and gives the bug the appearance of a beetle, for which it is fre- 
 quently mistaken by a beginner. They infest various plants and 
 often injure berries by imparting their disagreeable odor, as do 
 the stink-bugs. 
 
 Plant-bugs. The remaining families of Heteroptera feed entirely 
 on vegetation and may for convenience be grouped together as 
 plant-bugs. They are all more or less elongate in form, with slender 
 legs, and antennae about half the length of the body. The families 
 
THE TRUE BUGS 
 
 117 
 
 Fig. 156. 
 
 Lace-bug [Corythuca aniiata Say), 
 adult, eggs, and nymph 
 
 (After Comstock, United States Department of 
 Agriculture) 
 
 are most readily distinguished by the venation of the front wings, 
 several of which are shown in Fig. 139, p. 107. 
 
 The lace-bugs {Tingiti- 
 dae) are found commonly 
 on the leaves of bass- 
 wood, hawthorn, and 
 quince, occasionally in- 
 juring the latter. " One 
 glance at the fine white 
 meshes that cover the 
 wings and spined thorax 
 is sufficient," says Pro- 
 fessor Comstock, "to dis- 
 tinguish them from all 
 other insects, for these are 
 the only ones that are clothed from head to foot in fine white 
 Brussels net." They are small insects, about the size of plant-lice, 
 and suck the juices of the 
 leaves. The eggs are cov- 
 ered with a sticky sub- 
 stance and look like fungi 
 on the undersurface of 
 the leaf. 
 
 The leaf -bugs (Capsidae) 
 form the largest family of 
 Heteroptera, having over 
 two hundred fifty species 
 in this country. One of 
 the most common species 
 is the tarnished plant-bug 
 {Lygus pj'atensis). This 
 is yellowish- or greenish- 
 brown in color, about 
 one fourth of an inch 
 long (Fig. 157), and at- 
 tacks a great variety of plants, being injurious to nursery trees, 
 sugar beets, strawberries, and various vegetables and flowering 
 plants, causing the tips of plants like the dahlia and potato to 
 
 Fig. 157. Tarnished plant-bug. (About four times 
 natural size) 
 
 (7, bj c, d, four stages of nymphs ; e, adult bug. (After 
 Forbes and Chittenden) 
 
ii8 
 
 ELEMENTARY ENTOMOLOGY 
 
 wither beyond the point where the httle bug has inserted its beak. 
 The four-hned leaf-bug {Poecilocapsiis lineatus) is yellowish or 
 
 P'iG. 158. The four-lined leaf-bug 
 
 «, adult (enlarged) ; b, adult (natural size) ; c, single egg (greatly enlarged) ; d, lengthwise 
 section of stem, showing eggs in position (enlarged). (After Slingerland) 
 
 greenish, with four black stripes (Fig. 158), and is often a serious 
 enemy of currants, laying its eggs in the stalks and thus killing 
 the tips. The cotton leaf-bug is found throughout the country on 
 
 Fig. 159. Cotton leaf-bug [Calocoris rapidiis) 
 
 a, mature bug ; b, young nymph ; c, fourth stage of nymph ; d, fifth stage of nymph 
 (Authors' illustration, United States Department of Agriculture) 
 
THE TRUE BUGS 
 
 119 
 
 various flowers and is sometimes an enemy of the sugar beet, but 
 in the South it is best known for causing the cotton squares to drop 
 and producing black spots and distortions of the bolls. It is dark 
 
 Fig. 160. A stilt-bug {Jalysus sphiosiis Say). (Enlarged) 
 (After Lugger) 
 
 brown, with a narrow yellow border, the prothorax being )ellow and 
 red with two black spots. Nearly related is the red-bug family [Py?-- 
 rJiocoridac), named after the red-bug, or cotton-stainer {Dysdcrcus 
 
 Fig. 161. The chinch-bug. (Much enlarged) 
 
 Adult at left ; a, l>, eggs ; c, newly hatched nymph : </, its tarsus : c, f. g, second, third, and 
 
 fourth stages of nymph ; //, leg of adult ; J, tarsus of same ; /, proboscis, or beak. Hair lines 
 
 indicate natural size. (After Webster and Riley) 
 
 snturclhis), an insect of a reddish color, with pale yellow stripes, 
 with habits very similar to the one last mentioned, staining the cot- 
 ton where it punctures the bolls. Though common, it is by no 
 means a serious pest of cotton, but is often injurious to ripening 
 
I20 
 
 ELEMENTARY ENTOMOLOGY 
 
 oranges. The family is a small one of relatively large, bright-colored 
 bugs, with few species in the North. The stilt-bugs {Bcrytidac) 
 are well named from their long, stiltlike legs. They resemble the 
 thread-legged bugs in this respect, but are much smaller, being 
 
 only about one third of 
 an inch long. Only two 
 species are known in the 
 United States ; these fre- 
 quent the undergrowth 
 of woodland and pas- 
 tures. The chinch-bug 
 is the best-known exam- 
 ple of one of the larg- 
 est families {Lygaeidae), 
 with nearly two hundred 
 species in this country. The chinch-bug is about one sixth of an 
 inch long, of a jet-black color, with the fore-wings white with a 
 distinct triangular black spot at the middle of the outer margin. 
 
 Fig. 1 6 
 
 The false chinch-bug {Xysiiis ericae Schill.) 
 (Much enlarged) 
 
 a, injured leaf; /', last stage of nymph ; c, adult. 
 (After Riley) 
 
 Fig. 163. a, the northern leaf-footed plant-bug [Leptoglossiis oppositus); b, the 
 banded leaf -footed plant-bug {Leptoglossiis p/iyiloptts). (Twice natural size) 
 
 (After Chittenden, United States Department of Agriculture) 
 
 The young stages are red but become gray or blackish as they 
 grow older. It is found in all parts of the United States, but has 
 been most seriously injurious in the Mississippi Valley. 
 
I'HK TRUK BUGS 
 
 121 
 
 The squash-bug and its relatives form another large family 
 {Coreidac) of some two hundred species, of which the common 
 squash-bug {Anasa tristis), which we have already considered 
 (p. 50), is the best-known example. In the middle and southern 
 states there are several nearly related species 
 which have the hind tibia flattened and ex- 
 panded somewhat like a leaf, and are known 
 as leaf-footed plant-bugs. The box-elder bug 
 {Lcptocoris trivittatiis) is a common species 
 throughout the Mississippi Valley and Great 
 Plains, where it is a serious enemy of the 
 box elder, which is planted largely for shade. 
 It is blackish, with three bright red lines on the 
 prothorax, and with fore-wings having edges 
 and veins of a dingy red. 
 
 Fig. 164. Box-elder 
 
 bug [Leptocon's iriv it- 
 tat us). (Twice natural 
 size) 
 
 (After Kellogg) 
 
 Suborder Parasita 
 
 As their name indicates, the members of 
 this suborder are parasites upon man and other 
 mammals, being commonly known as lice. They may well be called 
 the true lice, or sucking lice, to distinguish them from the bird-lice 
 {Mallophagd), plant- 
 lice {Aphididac), and 
 other insects com- 
 monly called lice. 
 They are small, soft- 
 bodied, wingless in- 
 sects, with a stout, 
 unsegmented beak, 
 either without eyes or 
 with only simple eyes, 
 and the tarsi bear but 
 a single claw, all of 
 these characters indi- 
 cating a degenerate 
 group. The head-louse infests the hair of man, and the body- 
 louse, or grayback, as soldiers term it, lives in and lays its eggs in 
 the seams of clothing. The general appearance, greatly enlarged, 
 
 Fig. 165. 
 
 Sucking lice affecting man. 
 enlarged) 
 
 (Cireatly 
 
 (?, crab-louse {PtJiiniis iiigitbialis Leach) ; /', head-louse 
 
 {Pediiidiis capitis De Ci.). (^7, after Denny ; b, after Packard ; 
 
 from Osbom, United States Department of Agriculture) 
 
122 
 
 ELEMENTARY ENTOMOLOGY 
 
 of these vermin is shown in Fig. 165. Similar species infest horses, 
 cattle, and other domestic animals, as well as many wild mammals. 
 
 Suborder Homoptera 
 
 The cicadas {Cicadidae). The common dog-day harvest-fly 
 (Fig. 166) is the best known example of this interesting family; 
 and although we seldom see it, we are made aware of its presence 
 on a hot summer day by the shrill calls answered back and forth 
 from the tree tops. It is black and green in color, more or less 
 powdered with white beneath. The most remarkable member of 
 
 Fig. 166. Dog-day harvest-fly {Cicada iibicen), female 
 (After Lugger) 
 
 the family is the periodical cicada, often improperly called the 
 seventeen-year locust, from its habit of appearing in immense 
 numbers every seventeen years. It is of course entirely unrelated 
 to the true locusts, or grasshoppers. The adults lay their eggs in 
 the twigs of trees, often seriously injuring young fruit trees, as the 
 twigs or stems die beyond the point of the egg puncture. The 
 nymphs drop to the ground upon hatching and, burrowing into 
 the earth, feed upon the roots of trees for sixteen years. The 
 seventeenth year they emerge in immense numbers within a few 
 days, crawl up the trunks of trees, fences, buildings, etc., and trans- 
 form to the adults, which are blackish, with orange markings on 
 the wings. For the next few weeks the air is filled with their 
 shrill cries, and soon many affected trees turn brown as a result of 
 
Fig. 167. Periodical cicada 
 
 <7, adult; l>, young nymph (enlarged); c, cast skin of full-grown nymph; d, side view of 
 
 female to show beak, c, and ovipositor, /. (Natural size except i>.) (After Marlatt and Riley, 
 
 United States Department of Agriculture) 
 
 Fig. 168. Buffalo tree-hopper and twig of apple tree showing eggs and adult 
 
 Adult (enlarged) at left ; a, adult (natural size) ; i, recent egg punctures ; <r, bark reversed 
 
 with eggs in position; d, single row of eggs (enlarged); e, wounds of two or three years' 
 
 standing on older limbs, (.^fter Marlatt, United States Department of Agriculture) 
 
 123 
 
124 
 
 ELEMENTARY ENTOMOLOGY 
 
 Fig. 169. The bittersweet tree-hopper {Enchoiopa 
 
 binotata Say). Adult (side and bacii views) and egg 
 
 mass. (Much enlarged) 
 
 (.•\fter Lugger) 
 
 their egg laying. The different broods have been carefully mapped, 
 
 so that it is possible to foretell the appearance in any given locality 
 
 where the insect occurs. ^ 
 
 Plant-hoppers. The next three families may be grouped together 
 
 under the term "plant-hoppers," as they jump off suddenly when 
 
 disturbed. They are 
 small insects, usually 
 not over one fourth 
 of an inch long, and 
 suck the sap from the 
 leaves and stems of 
 their food plants. The 
 tree-hoppers {Alcin- 
 bracidac) have been 
 called the ' ' brownie 
 insects," for their bi- 
 zarre shapes are often 
 
 comically grotesque. The prothorax is prolonged back over the 
 
 abdomen and is often produced forward or up- 
 ward into horns or crests, as shown in Fig. 169. 
 
 One of the most common species is the buffalo 
 
 tree-hopper {Ceresa bnbalns), which lays its eggs 
 
 in the stems of weeds and young fruit trees, 
 
 causing large knotty scars on the twigs. Another 
 
 small brown species {Enchcnopa binotata) is 
 
 common on the bittersweet vine, the projecting 
 
 prothorax looking exactly like a thorn on the 
 
 stem. Few species of this family are sufificiently 
 
 numerous to do serious damage. 
 
 - Here and there on weeds, grass, and tree 
 
 foliage will be found a little mass of froth, within 
 
 which may be found a small nymph, which is 
 
 busily pumping the sap out of the plant, thus 
 
 causing the froth which was formerly supposed 
 
 to be voided by tree frogs and was termed ' ' frog 
 
 spittle," — hence the insects of this family 
 
 Fu;. 170. Mass of spit- 
 tle produced by the 
 nymph of a frog-hop- 
 per, or spittle-insect 
 
 1 See Bulletin No. 7/, Bureau of Entomology, United States Department of 
 Agriculture, for a very complete and interesting account. 
 
THE TRUE BUGS 
 
 125 
 
 (Ccrcopidac) arc called "frog-hoppers " or "spittle-insects." Within 
 this frothy mass the little n)'mph molts and grows and finally 
 forms a little clear space about its bod)-, around which the foam dries, 
 forming a little chamber within which it transforms to the adult. 
 Though very commonh' in evidence, few of this family are injurious. 
 The leaf-hoppers {Jassidae) are among the most abundant of the 
 Homoptera. Take a net and sweep back and forth in any meadow 
 and you will secure hundreds of 
 them, Professor Herbert Osborn 
 having estimated that frequently 
 over a million live on an acre of 
 grassland. They are more slender 
 than the two preceding families, 
 from an eighth to a fourth of an 
 inch long, and of a brownish, 
 green, or red color, the green and 
 red often being arranged in stripes, 
 giving a very striking coloration. 
 The grape leaf-hopper ( Typhlo- 
 cyba comes), commonly called the 
 grape thrips (although it is not a 
 true thrips), is one. of the most 
 serious enemies of the vine. In 
 late summer the foliage will often 
 be brown as a result of their work, 
 and a slight jar will cause them 
 to fly off in clouds. They are 
 small yellowish hoppers, scarcely 
 an eighth of an inch long and 
 strikingly marked with red and black. A yellowish-green species, 
 the rose leaf-hopper {Einpoasca jvsac), often does considerable 
 injur}^ to rose foliage, and a similar one, the apple leaf-hopper 
 {Einpoasca iiiali), is found on the apple and frequently becomes a 
 serious pest in the nursery. The presence of these leaf-hoppers 
 is always indicated by the numerous white cast skins of the nymphs 
 clinging to the undersides of the leaves. Leaf-hoppers fly to lights 
 in large numbers. The}' hibernate as adults, and the eggs are 
 usually laid just beneath the surface of the leaf of the food plant. 
 
 Fig. 171. Aphrophora ^-iiotata Say, 
 a common frog-hopper 
 
 (.A.fter Lugger) 
 
Fig. 172. Three cotton leaf-hoppers, commonly called "sharpshooters." 
 (Much enlarged) 
 
 a, Aitlacizes irroraia : b, Oncomctopia iimlata : c, Oncometopia lateralis. (Authors' illustra- 
 tion, United States Department of Agriculture) 
 
 Fig. 173. Grape leaf-hoppers. (Much enlarged) 
 
 a and b are female and male of typical comes variety ; c represents the v'ltis variety ; </, newly 
 
 hatched nymph ; <?, last stage nymph ; /, injured leaf ; g, cast skins. (After Marlatt, United 
 
 States Department of Agriculture) 
 
 126 
 
THE TRUE BUGS I 27 
 
 The psyllas, or jumping plant-lice (Psyllidae), look much like 
 miniature cicadas, but are more nearly related to the true plant-lice, 
 exuding sweet hone}'-de\v like the plant-lice but differing from them 
 in being very agile in the adult stage, giving a quick jump with their 
 strong hind legs and flying off at the slightest disturbance, whereas 
 the true plant-lice are exceedingly sluggish. The best-known example 
 is the pear psylla {Psylla pyricola), the adult of which (Fig. 174, a) 
 is not over a tenth of an inch long but which occurs in such enormous 
 numbers that it sometimes entirely ruins large pear orchards by 
 sucking the sap from the foliage. It has been most injurious in 
 the Middle Atlantic States. It exudes a large amount of honey-dew, 
 
 Fig. 174. The pear psylla. (Greatly enlarged, in different proportions) 
 rt, adult ; /'. full-grown nymph from above ; r, egg. (After -Slingerland) 
 
 which covers the foliage and bark, on which grows a sooty black 
 fungus which is a good indication of the presence of the pest. 
 
 The plant-lice, or aphides (Aphididae), are the most abundant and 
 possibly the most destructive family of all the Hemiptera. Florists 
 commonly call them green-flies, which term may refer to several 
 species. Usually they are not over a tenth of an inch long, and 
 the wingless forms are more or less pear-shaped, with long legs 
 and antennae, and the common forms have two tubes projecting 
 from the abdomen, called honey-tubes. The vast amount of 
 injur)^ done by them is chiefly due to their remarkably rapid power 
 of reproduction. During the summer the females will give birth 
 to from fifty to seventy-five young during a week or two, which 
 will become full grown in from one to two weeks. All of these 
 
128 
 
 ELEMENTARY ENTOMOLOGY 
 
 prove to be females, there usually being no males during the 
 summer, and each gives birth to a similar number of young, the 
 egg stage being passed within the body of the female and the young 
 
 being born alive. Thus 
 generation after gener- 
 ation is produced, and a 
 simple arithmetical cal- 
 culation will show that 
 the resulting progeny 
 must soon become suf- 
 ficiently numerous to 
 entirely destroy the veg- 
 etation from which the 
 myriad little beaks are 
 pumping out the sap. 
 In the fall true males and females usually appear, and eggs are 
 laid which hatch in the early spring. Most species are wingless 
 until the food supply commences to get short, when the next gen- 
 eration develops wings and migrates to new food plants. Many 
 species have winged generations in the spring and fall, which 
 
 Fig. 175. Wingless female pea aphis and newly 
 born young. (Enlarged) 
 
 Fig. 176. Apple aphis, last stage nymphs of winged females on undersurface of 
 
 apple leaf 
 
 migrate to and from the summer food plants to others upon which 
 they feed in fall and spring, and upon which the winter eggs are 
 deposited. Many plant-lice exude an abundance of a sweet liquid 
 
THE TRUE P3UGS 
 
 129 
 
 Fig. 177. Aphis 
 
 eggs on twig. 
 
 (Natural size) 
 
 (Aiter Weed) 
 
 called honey-dew, and are constantly attended by ants, which 
 eagerly devour it. In the case of several species the ants care for 
 them almost as if they were their domestic animals, 
 and very commonly ants are responsible for carrying 
 the aphides from one plant to another as the food 
 supply becomes exhausted, as in the case of the melon 
 aphis and the strawberry root-louse. Among the more 
 common species are the common green apple aphis 
 {Aphis pomi), the cabbage aphis, the pea aphis, which 
 often destroys entire crops of garden peas in the At- 
 lantic states, the green bug {Toxoptcra grajitiuinn), 
 which has recently been so 
 injurious to grain crops in 
 the southwest, the melon 
 aphis, the rose aphis, the 
 chrysanthemum aphis, 
 and a host of others. The 
 foliage of almost every 
 plant is attacked by one 
 or more species, and many of the most in- 
 jurious attack the roots, as the corn root- 
 aphis {Aphis maidi-radicis), which is one 
 of the most serious corn pests in the Miss- 
 issippi Valley. The grape phylloxera, an 
 American species attacking the roots of 
 the grape, was imported into Europe and 
 soon became the worst enemy of the vine 
 in France, where it has caused the loss 
 of millions of dollars. Several species 
 exude a cottony mass of wax over the 
 body, so that they appear like a mold. 
 Among these the woolly apple aphis is 
 often seen on the leaves and on wounds 
 and scars on the bark of apple trees, and 
 a similar species covers the twigs of alder 
 as if they were wound with cotton. 
 
 The scale insects (Coccidae). Some of the worst insect pests of 
 the fruit orchard belong to the scale insects, which are so peculiar 
 
 Fig. 178. Tip of dock stem 
 covered with black aphides 
 
Fig. 179. Melon aphis. (Greatly enlarged) 
 
 a, winged female ; a' , enlarged antenna of same ; ab, dark female (side view), sucking juice 
 
 from leaf ; b^ young nymph ; c, last stage of nymph of winged form ; d, wingless female. 
 
 (After Chittenden, United States Department of Agriculture) 
 
 Fig. 180. Mealy-bug (Dactylopius longifiUs), female and winged male. (Enlarged) 
 
 (After Comstock, United States Department of Agriculture) 
 
 130 
 
THE TRUE BUGS 
 
 131 
 
 in form that they would not be readily recognized as insects, were 
 their complicated life histories not known. Three quite distinct 
 
 Fig. 181. The cochineal insect 
 (7, on cactus; ^, male; c, female (enlarged). (From Riverside Natural History) 
 
 groups may be readily distinguished. The mealy-bugs are fre- 
 quently found on greenhouse plants, and are so named from their 
 mealy covering of wax and the numerous white, waxy filaments 
 
 Fig. 1S2. The peach lecanium, or terrapin scale 
 
 Adults at left (much enlarged and natural size) ; young at center and unfertilized female at 
 right (much enlarged). (After Howard, United States Department of Agriculture) 
 
 which are given off from their bodies. They are from an eighth to 
 a quarter of an inch long, and move about slowly over the plant, 
 retaining their les^s througrhout life. The soft scales include those 
 
I ^2 
 
 ELEMENTARY ENTOMOLOGY 
 
 of the genus Lccaniuvi and their 
 near relatives, and are known as 
 Lecaniums. They are usually of 
 a brownish color, quite strongly 
 convex (often ridged), and are 
 soft and easily crushed, — hence 
 the name. The upper surface 
 of the female gradually hardens, 
 and upon ma- 
 
 FlG. 183. The hemispherical scale 
 {Lecaniuni hemisphaericum Targ.) 
 
 a, scales on olive (natural size); />, three 
 female scales (considerably enlarged); c, 
 female scale lifted from leaf, showing mass 
 of eggs (enlarged). (After Marlatt, United 
 States Department of Agriculture) 
 
 eggs 
 neath it. 
 
 turity she dies 
 and the old skin 
 forms the scale 
 which covers the 
 laid be- 
 The 
 
 Lecaniums occur upon various greenhouse plants 
 such as crotons, upon the peach and plum, 
 and upon citrous fniits. The 
 cottony maple scale is a 
 species common on maple 
 shade trees and gives off 
 a mass of cottony wax in 
 which the eggs are laid. 
 
 The armored scales are 
 much smaller, flat, circular, 
 
 Fig. 185. The oyster- 
 shell scale on poplar twig 
 (Photograph by Weed) 
 
 Fig. 184. The col- 
 or elongate in outline, and tony maple scale 
 
 1 J ^ (Enlarged) 
 
 mclude our most common 
 
 ^ ^ , , . , (After Comstock) 
 
 species. Upon hatching, the 
 young scale insect crawls about for an hour or 
 two and then settles down, inserts its beak in 
 the leaf or bark, and henceforth the females 
 remain in the same place. Soon waxy fila- 
 ments commence to exude from the body, 
 which mat down into a small scale covering 
 the insect. When the skin is molted, it is 
 added to the center or one end of the scale, 
 which is gradually enlarged and assumes a 
 characteristic shape. With the first molts the 
 
THE TRUE BUGS 
 
 133 
 
 female loses her legs and eyes, and the body becomes a mere mass 
 of yellowish protoplasm with long, threadlike mouth-parts and a 
 characteristic fringe of plates 
 and hairs at the tip of the abdo- 
 men, by which the species is 
 principally distinguished. They 
 are named armored scales be- 
 cause the scales of this group 
 are mere coverings and form no 
 part of the insect. The scales 
 of the males are much smaller 
 than those of the females, and 
 after the second molt the male 
 goes into a true pupa stage 
 (otherwise the Hemiptera have 
 incomplete metamorphosis), the 
 legs, wings, and antennae being 
 outlined, and with the next molt 
 the adult male emerges from the scale and flies, to fertilize the fe- 
 male. The adult males of all the Coccidae have but a single pair of 
 
 Fig. 186. Female San Jose scale, mature 
 
 female insect removed from beneath it. 
 
 (Greatly enlarged) 
 
 (After Alwood) 
 
 Fig. 187. n, winged male San Jose scale (much enlarged); A, young scale insect 
 (enlarged 125 times) 
 
 (After Alwood) 
 
 wings, like the flies {Diptera), and bear long antennae and usually 
 one or two long processes from the tip of the abdomen. They are 
 very small whitish or yellowish insects, and usually fly at night, so 
 
134 
 
 ELEMENTARY ENTOMOLOGY 
 
 that they are rarely seen unless reared from the scales. Among the 
 most common of the armored scales are the oyster-shell bark-louse (so 
 called on account of the resemblance of the brown scale to an oyster 
 
 Fig. i88. Peach twigs infested with San Jose scale. (Much enlarged) 
 
 At left, large mature female and small young scales are clustered in a groove of the 
 
 twig. At right is shown a large female scale with the scale proper raised, showing the 
 
 insect beneath. (After Britton) 
 
 shell), which is common on apple and several shade trees ; the San 
 Jose scale, possibly the most serious pest of fruit trees ; the rose scale, 
 common on roses, raspberries, and blackberry canes ; and the various 
 fiat scales found on palms and other greenhouse and house plants. 
 
THE TRUE BUGS 
 Summary of the Hemiptera 
 
 I. Suborder Hctcropiera. Wings unlike. 
 I . Aquatic bugs. 
 
 The water-boatmen [Corisidae). 
 The back-swimmers {Notonectidae). 
 The water-scorpions {Xepidae). 
 The giant water-bugs (Belosto)nidae). 
 The water-striders {Hydrobatidae). 
 
 2. Predacious bugs. 
 
 The assassin-bugs {Reduviidae). 
 
 The long-legged bugs [E/nesidae). 
 
 The damsel-bugs [A'cTbidae). 
 
 The ambush-bugs {Phymatidae). 
 
 The bedbugs {Acanthidae). 
 
 The stink-bugs, or shield-shaped bugs {Pe/ifiifotfiidae). 
 
 3. Plant bugs. 
 
 The stink-bugs, or shield-shaped bugs {Pentato>/iidae). 
 
 The lace-bugs (Tingitidae). 
 
 The leaf-bugs {Capsidae). 
 
 The red-bugs {Pyrr/iocoridae). 
 
 The stilt-bugs {Berytidae). 
 
 The chinch-bugs {Lygeidae). 
 
 The squash-bugs (Coreidae). 
 
 II. Suborder Parasita. Wingless parasites of animals. 
 
 III. Sxxhorder Ho7nopfera. Wings alike, translucent. 
 
 1. The. cicdidz.?, (Cicadidae). 
 
 2. The plant-hoppers. 
 
 The tree-hoppers {Menibracidae). 
 
 The frog-hoppers, or spittle insects {Cercopidae). 
 
 The leaf-hoppers {Jassidae). 
 
 3. The psyllas, or jumping plant-lice {Psyllidae). 
 
 4. The plant-lice {Aphididae). 
 
 5. The scale insects (Coccidae). 
 
 135 
 
CHAPTER XII 
 
 THE BEETLES (COLEOPTERA) 
 
 Characteristics. Fore-wings, horny or leathery, forming wing-covers (elytra), 
 which meet in a straight line down the back ; hind-wings, membranous, tips 
 folded back under the wing-covers when at rest ; mandibulate mouth-parts ; 
 metamorphosis, complete. 
 
 The hard wing-covers of this order are so characteristic that a 
 beetle is commonly recognized as such, and they have given the 
 
 Fig. 189. A water-scavenger beetle with wing-covers and wings expanded 
 as when in flight. (Natural size) 
 
 (After Folsom) 
 
 order its scientific name, from coleos (a sheath) and pteron (a 
 wing). The beetles form one of the largest orders, with over twelve 
 thousand species in America north of Mexico, belonging to some 
 eighty families, only the most common of which will be mentioned. 
 They have a complete metamorphosis, the larvae being commonly 
 called grubs, and the pupae are usually found either in the ground 
 
 136 
 
THE BEETLES 
 
 137 
 
 or in the foodstuff of the larvae. Both larvae and adults have biting 
 mouth-parts, similar to those of the grasshopper, the structure vary- 
 ing with the food habits of the species. 
 
 The families of beetles are divided into several groups, based 
 largely on the structure of the tarsi and antennae, which aid the 
 student in their identification. The order is primarily divided into 
 the typical beetles {Coleoptcni gcnuina), in which the head is nor- 
 mal, and the snout-beetles {RJiynchopJwra), in which the head is 
 prolonged into a snout, or beak, at the tip of 
 which are the biting mouth-parts. 
 
 The Typical Beetles {Cqleoptera 
 GENU IX a) 
 
 Four principal sections of the families of 
 typical beetles are distinguished by the num- 
 ber of segments in the tarsi. 
 
 L BEETLES WITH FIVE-JOINTED TARSI 
 [PENTAMERA) 
 
 The first section is distinguished by all of 
 the tarsi being composed of five segments, 
 and is divided into four tribes according to 
 the structure of the antennae. 
 
 " TJie Carnivorous Beetles {Adephagd) 
 
 The carnivorous, or predacious, beetles 
 include several families, all of which feed 
 upon other insects and are therefore bene- 
 ficial. The antennae are threadlike, with dis- 
 tinct, cylindrical segments. 
 
 Fig. 190. A tiger-beetle 
 {Cicindela limbata). (Hair 
 line shows natural size) 
 
 (After Bruner) 
 
 The tiger-beetles (Cicindelidae). Along sandy paths, roadsides, rail- 
 road embankments, and in similar open, sunny spots, the tiger- 
 beetles fly up and dart swiftly ahead as one approaches. They 
 are swift runners and stalk their prey on foot. Most of our com- 
 mon species are either a brilliant, metallic green or a brownish- 
 bronze, banded or spotted with yellow. The larvae live in little 
 burrows in the ground, the head appearing at the opening so that 
 the eyes command the surroundings, and any unwar)' passing insect 
 may be seized with the strong jaws. Toward the tip of the abdomen 
 
ivS 
 
 ELEMENTARY ENTOMOLOGY 
 
 •«^vt.. 
 
 is a decided hump, and surmounting it are strong, curved spines 
 which serve as an anchor, so that a captured insect cannot drag the 
 
 lar\^a from its burrow. The vo- 
 racity of these beetles makes the 
 name "tiger-beetle" fitting, but un- 
 fortunately they are of little bene- 
 fit to the farmer, as they do not 
 frequent cultivated fields, and though they de- 
 stroy many insects, but few of them are of any 
 economic importance. The brilliant green species 
 are favorites of collectors, and one must be some- 
 thing of a sportsman to secure many of them, so 
 readily do they fly. Like many other active insects 
 they may often be easily caught towards sundown. 
 Ground-beetles. Upon turning over a stone 
 or a log, one frequently sees small, flat, black 
 beetles scurrying away, which belong to the fam- 
 ily of ground-beetles (Carabidac). Their name is 
 Fig. iqi. A tiger" ^ o \ 
 
 beetle and its lar- indicative of their habits, as their long legs fit 
 
 va in its burrow. _ 
 
 (Natural size) 
 
 (After Linville and 
 
 Kelly) 
 
 them for chas- 
 ing rapidly over 
 the ground in 
 pursuit of small 
 insects, though 
 some of them 
 ascend trees in 
 search of cater- 
 pillars. This is 
 a large family, 
 which has some 
 twelve hundred 
 
 '^^ Fig. 192. A ground-beetle [Calosoma sp.) feeding on a 
 
 country, and as cutworm ; below, a species of Ca7-abus 
 
 both larvae and (After Brehm) 
 
THE BEETLES 
 
 139 
 
 adults feed on many of our most noxious insects, ground-beetles 
 must rank among the farmer's best friends. The larvae live in the 
 ground, or in places similar to those of the adults, and are also pre- 
 dacious. The larvae are elongate, the body tapering slightly at either 
 end, with the strong jaws projecting in front and two bristly append- 
 ages at the tip of the abdomen. Our largest common species is the 
 searcher {Caloscwm scrutator), whose wing-covers are a beautiful 
 green or violet, mar- 
 gined with reddish, and 
 whose body is marked 
 with blue, gold, green, 
 and copper. It fre- 
 quently ascends trees in 
 search of caterpillars, 
 and, with nearly related 
 species, often does good 
 work in destroying large 
 numbers of them when 
 they become overabun- 
 dant. A European spe- 
 cies of this genus has 
 recently been imported 
 into Massachusetts to 
 prey upon the gypsy- 
 moth caterpillars. A 
 medium-sized species 
 with yellowish-red head 
 and thorax and bright 
 
 blue wing-covers {Lcbia (After Howard, United States Department of Agriculture) 
 
 graiiciis) (Fig. 195) has 
 
 made a name for itself as an enemy of the eggs and larv^ of the 
 Colorado potato-beetle. Our most common species are from one 
 fourth to one half an inch long, either shining black or with 
 greenish, bluish, or coppery reflections, and veiy frequently fly to 
 lights in considerable numbers. Their larvae feed on soft-bodied 
 insects which go into the ground to pupate, such as the plum 
 curculio and others, while the larger ones are among the most 
 important enemies of cutworms and various caterpillars. 
 
 Fig. 193. European ground-beetle {Calosoma 
 
 sycGphattia) imported to prey on the gypsy 
 
 and brown-tail moths 
 
I40 
 
 ELEMENTARY ENTOMOLOGY 
 
 The predacious diving-beetles (Dytisci- 
 dae) are to be found in any pond, where 
 they may be seen suspended at the sur- 
 face of the water with the tip of the abdo- 
 men thrust up so that air may be drawn 
 in under the elytra, or diving here and 
 there after their prey, which consists of 
 any insects that they can overpower, small 
 aquatic animals, and occasionally small 
 fish. The largest species are about an 
 inch long, while the commoner ones are 
 one half or three fourths as large and are 
 brownish-black, often marked with dull 
 yellow. The hind legs are long, flattened, 
 and fringed with hairs, 
 forming admirable swim- 
 ming organs. The larvae are elongate, spindle- 
 shaped grubs, with strong, ferocious-looking jaws, 
 with which they grasp and suck out the juices of 
 their prey, which has given them the name of 
 water-tigers. 
 
 Whirligig-beetles. Every pool is the home of 
 a school of the well-known whirligig-beetles {Gyri- 
 nidac), which chase each other over the surface, 
 where they feed on small insects which fall into 
 the water. They are usually much smaller than the last-named 
 family, are oval in shape, much flattened, of a jet-black color, and 
 
 Fig. 194. A ground-beetle 
 
 (Calosoiiia calichiin). (Natural 
 size) 
 
 Fig. 195. Lebia 
 grandis, an im- 
 portant enemy of 
 the potato-beetle 
 (Enlarged) 
 
 Fig. 196. A common ground-beetle {Harpahis caliginosus). (Enlarged) 
 A, its larva; B, head of larva, showing mouth-parts. (After Riley) 
 
THE BEETLES 
 
 141 
 
 are readily recognizable by the front margin of the head extending 
 across the eyes so that there seems to be a pair of eyes on both 
 the upper and the under surface. 
 
 The Club-Homed Beetles {Clavieoi-Jiia) 
 
 The antennae of the beetles of this tribe are either 
 '^ gradually or abruptly thickened toward the tip so as 
 
 to form a club. The 
 common families 
 either live as scav- 
 engers or feed on 
 stored products, 
 but there is a large 
 series of small fam- 
 ilies with the most 
 varied habits, al- 
 though not many 
 include species of 
 serious economic 
 importance. 
 
 The water-scavenger beetles (Hydrophilidae) closely resemble the 
 predacious diving-beetles, but are more convex above and more 
 flattened below, have more highly polished wing-covers, and have 
 
 Fig. 197. A predacious diving-beetle (Dytiscus sp.). 
 (Natural size) 
 
 (r, larva, or "water-tiger"; h, pupa; c, adult. (After Kellogg) 
 
 Fig. 198. Whirligig-beetles {Uyr/in.!\u ]. 1 Xaiural sizci 
 (.\fter Linville and Kelly) 
 
 antennae that are decidedly clubbed, though often concealed beneath 
 the head. They feed on decaying animal and plant tissues, though 
 they not uncommonly catch small insects, and the larvae feed 
 
14: 
 
 ELEMENTARY ENTOMOLOGY 
 
 entirely on insects, snails, tadpoles, etc. Both middle and hind 
 legs are developed for swimming and are used alternately. 
 
 'ucA/k^.:^~-^:^^=l^ 
 
 
 Fig. 199. Water-scavenger beetles [Ilydrophilits sp.), larva, and peculiar 
 egg mass on leaf 
 
 (After Brehm) 
 
 Carrion-beetles (Silphidae). Wherever a dead animal has. been 
 left exposed, the carrion- or burying-beetles may be found feeding 
 
 upon' it. The more com- 
 mon carrion-beetles of the 
 genus SilpJia are of a 
 broad, oval shape, much 
 flattened, with small heads, 
 and feed beneath the car- 
 rion. The burying-beetles 
 {Xccropliorus) are much 
 larger, from an inch to an 
 inch and a half long, with 
 thick, stout, rectangular 
 bodies, and with large 
 , ,,, , , heads. The common spe- 
 
 A burying-beetle [Aecrophonis sp.). , , , • , 
 
 (Slightly enlarged) cies are blackish, marked 
 
 (After Linviiie and Kelly) with dull red. Their name 
 
 Fig. 200. 
 
THE BEETLES 
 
 143 
 
 Fig. 201. A carrion-beetle 
 (Silpka iiovaboraceiisis) and 
 (One and one half times 
 natural size) 
 
 (After Kellogg) 
 
 larv; 
 
 is derived from their habit of excavating beneath dead animals, 
 which they gradually drop beneath the surface and then cover 
 with soil. Both adults and larvae feed on decomposing animals 
 and are among the chief natural agents for their sanitary disposal, 
 though some species are predacious and others feed on decaying 
 
 fungi. The larvae are black, flattened, 
 with the segments sharply marked, and 
 are found with the adults. 
 
 The rove-beetles (Staphylinidae). The 
 rove-beetles are readily recognized by 
 the very short wing-covers, usually not 
 o\'er a third of the length of the abdo- 
 men. Most species are very small, but 
 the more common ones are from half an 
 inch to an inch long, with narrow, parallel- 
 sided bodies. They run about swiftly and 
 when disturbed curl up the abdomen as 
 if to sting. The larger common species are found with the SilpJiidac 
 feeding on carrion or decaying organic matter, being commonly 
 found in dump heaps, while the smaller 
 species feed on pollen, fungi, or small 
 insects. 
 
 Cucujidae. The saw-toothed grain-beetle 
 {Silvamis siirinaniensis), which is one of 
 our commonest grain pests, is a good ex- 
 ample of the small family Citcujidac. It 
 is a small, flat beetle, an eighth of an 
 inch long, and readily distinguished 
 from other small grain insects by the ser- 
 rated edges of the thorax. It feeds also on all sorts of fruits, seeds, 
 and dry pantry stores, as do the little whitish larvae. The other com- 
 mon species are much-flattened beetles which live beneath bark and 
 feed upon small insects and fungi. One of these {Cticnjtis clavipes) 
 is a bright red, with eyes and antennae black and tibiae and tarsi 
 dark, and is readily recognized by the thin body. 
 
 Larder-beetles. Every housewife knows that she must be on the 
 lookout for the small carpet-beetle, often called the buffalo-moth 
 {AiitJircnus scropJinlai-ia), and for the larder-beetle {Dcrmestes 
 
 Fig. 202. 
 
 A rove-beetle and 
 
 its larva 
 
144 
 
 ELEMENTARY ENTOMOLOGY 
 
 lardarius), in stored meats or feathers. These are typical represent- 
 atives of a small family, Dcrmestidac, of oval, plump beetles, the 
 largest being about one third of an inch long. They are usually 
 grayish, brownish, or blackish, marked with colors due to minute 
 scales with which the body is covered. All of this family feed on 
 
 Fig. 203. The saw-toothed grain-beetle. (Much enlarged) 
 a, adult; /', pupa; <-, larva. (After Chittenden, United States Department of Agriculture) 
 
 dried animal substances, and some of the smaller species are par- 
 ticularly noxious to the entomologist, as they are the worst pests 
 which he has to combat in his collection cases. 
 
 TJic Saxv-Horncd Beetles {Serrieornia) 
 
 The tribe of saw-horned beetles includes several families of quite 
 different habits, which are very loosely related by all having serrated 
 antennae, the segments of the antennae being prolonged inward so 
 as to give the whole antenna a saw-toothed or serrate appearance. 
 
 Click-beetles. Every boy knows the long click-beetles, or snap- 
 ping beetles {Elateridae), which, when placed on their backs, will 
 flop up in the air with a decided click, or snap. They are flat, 
 elongate beetles, the commoner forms being about three fourths 
 of an inch long and of a dull brown color. The head is small and 
 the posterior angles of the thorax are much prolonged, giving it 
 
Fig. 204. The carpet-beetle, or buffalo-moth. (Enlarged) 
 a, larva ; /', pupa in lar\-al skin ; f, pupa from below ; d, adult. (After Kiley) 
 
 Fig. 205. The larder-beetle. (Enlarged) 
 a, lar\-a ; /', pupa ; <■, adult beetle, (.\fter Howard, United States Department of .Agriculture) 
 
 14s 
 
146 
 
 ELEMENTARY ENTOMOLOGY 
 
 a characteristic shield shape. The larvae are known as wire-worms 
 
 and are among the worst pests of corn and small grains. Some 
 
 wire-worms live under bark and in 
 decaying wood, the adult of one of 
 these being the common eyed elater 
 {Alans ociilatjis), a large species an 
 inch and a half long, blackish, flecked 
 with gray, with two large, velvet-black, 
 white-rimmed eyespots on the thorax, 
 which give it a very wise appearance. 
 The metallic wood-borers {Bupres- 
 tidae) have much the same general 
 shape as the click-beetles, but the 
 tips of the elytra are more pointed, 
 the beetles are 
 unable to spring, 
 and their colors 
 are metallic. The 
 adults are medi- 
 um-sized beetles, 
 often found on 
 flowers or bark, 
 
 and do no harm as adults. The larvae are 
 
 flat, whitish grubs with small, brown heads 
 
 Fig. 206. The eyed elater (Ahn/ 
 ocitlatus.) (Slightly enlarged) 
 
 (After Linville and Kelly) 
 
 Fig. 207. a, beetle of wheat wire-worm [Agriotes 7na>icHs) ; /', beetle of Drasterius 
 elegans ; c, larva of same. (Much enlarged) 
 
 (After Forbes) 
 
THE BEETLES 
 
 147 
 
 and with the prothorax greatly widened, giving them the name 
 "flat-headed borers," which is also often applied to the family. 
 
 They are to be found beneath 
 bark, making irregular cham- 
 bers in the sapwood and in the 
 inside of the bark. Some feed 
 only on dead or dying tim- 
 ber, while others, like the 
 flat-headed apple-borer, attack 
 healthy trees and often cause 
 their destruction. One of the 
 common smaller species is the 
 red-necked blackberry-borer. 
 It is a third of an inch long, 
 with black wing-covers, dark 
 bronze head, and coppery 
 bronze prothorax. The larva bores in the sapwood of the rasp- 
 berry and blackberry, causing a gall-lik^ swelling, and when full 
 grown bores into the pith, 
 where it pupates. m^ 
 
 The fireflies {Lampyri- 
 dae) which twinkle in the 
 dusk of a warm summer 
 evening are not realh' 
 flies, but beetles, though 
 their bodies and wing- 
 covers are much softer 
 in texture than those of most beetles 
 
 Fic. ::oS. Flat-headed apple-tree borer. 
 (Twice natural size) 
 
 a, \zT\a ; I', beetle ; c, head of male ; </, pupa 
 
 (After Chittenden, United States Department 
 
 of Agriculture) 
 
 ".. 209. A firefly beetle (P/toihius pyralis) 
 a, lar\-a; /', pupa in cell; c, adult. (.After Kiley) 
 
 Fig. 210. Soldier-beetle (Ckattli- 
 ognaihus petmsylvanicus) 
 
 a, larva ; ^, its head enlarged ; c, 
 adult. (After Riley) 
 
 Most of the fireflies are 
 medium-sized beetles, about half an 
 inch long, of dull colors, with the pro- 
 thorax expanded so as to cover the 
 head. They are nocturnal in habit, 
 the phosphorescent glow being pro- 
 duced by the underside of the ter- 
 minal abdominal segments. Many of 
 the females are wingless and are also 
 phosphorescent, being known as glow- 
 worms. The larvae are predacious. 
 
148 
 
 ELEMENTARY ENTOMOLOGY 
 
 Another group of this family, known as soldier-beetles, fly by day 
 and are commonly found feeding on pollen, which they carry from 
 flower to flower, thus aiding pollination. The common species are 
 yellowish with black markings and with a prominent head. The 
 larvae are predacious and are among the important enemies of the 
 larvae of the codling moth and plum curculio. 
 
 The Leaf-Homed Beetles {LanielUeornid) 
 
 The tribe of leaf-horned beetles includes two families in which 
 the terminal segments of the antennae are greatly expanded and 
 flattened, like plates or leaves, forming a club. 
 
 The stag-beetles (Lucanidae). There are some fifteen species of 
 stag-beetles in this country, which receive their name from the 
 
 % 
 
 ^ 
 
 p 
 
 \ 
 J 
 
 \ 
 
 r 
 
 '^ 
 
 ^ 
 
 Fig. 211. Stag-beetles. (Natural size) 
 At the left, Lucamis clcfltas, male ; at the right, Lucmuis damn, male. (After J. B. Smith) 
 
 enormous jaws of some of the males, which are branched so as to 
 have a fancied resemblance to the antlers of a stag. They are 
 large brown or black beetles, from an inch to an inch and a half 
 long, and the large mandibles have given them the name of "pinch- 
 ing-bugs." The beetles feed on sap and decaying wood, and the 
 larvae, which are much like white grubs, are found in decaying 
 trunks and stumps. A shining black species, bearing a short horn 
 
THE BEETLES 
 
 149 
 
 bent forward on the head, is frequently found beneath the bark 
 of stumps and in rotting wood, and has been termed the horned 
 
 passalus (Passa/z/s cornntns). 
 
 Scarabaeidae. With over five hun- 
 dred species in this country, the Scar- 
 abaeidae form one of the largest and 
 most important families of beetles. 
 They are thick-bodied beetles of the 
 May-beetle, or June-bug, type, strong 
 but clumsy, and many have the an- 
 terior tibiae broadly flattened for dig- 
 ging. They may be divided into two 
 main groups, the scavengers and the 
 leaf-chafers. The larvae of all of the 
 species are commonly called white 
 grubs, for although they vary greatly 
 in size and structure, they all have the 
 same general appearance of the white grub, with its large yellow 
 or brown head with strong mandibles, long legs, thick, whitish 
 
 Fig. 212. Passalus coniniiis. 
 (Slightly enlarged) 
 
 (After J. B. Smith) 
 
 Fig 213 Scarab beetle {Ateuchus vanolosics) rolling egg balls of dung, and 
 Egyptian sculptures of Sacred Scarab 
 
 (After Brehm) 
 
I50 
 
 ELEMENTARY ENTOMOLOGY 
 
 body, curved, wrinkled, more or less clothed with hairs, and with 
 the tip segment of the abdomen enlarged. Of the scavengers, the 
 
 tumble-bugs are well known, as they 
 are often seen rolling balls of manure 
 along the roadside, which are finally 
 buried and in which the eggs are 
 laid. The fat grub feeds within this 
 ball until ready to pupate. The fa- 
 mous sacred scarabaeid was held in 
 high veneration by the ancient Egyp- 
 tians, who placed it in their tombs 
 and carved it on sarcophagi, stones, 
 and gems. With the first spring 
 days one encounters swarms of little 
 brown, black-spotted beetles which 
 fill the air. They belong to numer- 
 ous species of the genus ApJwdiiis, the larvae of which develop in 
 manure and are often found in the dung of horses and cattle in 
 pastures. Some of the scavengers make burrows in the soil under 
 
 Fig. 214. A dung-beetle [Apho- 
 
 dius granariits Linn.). (Greatly 
 
 enlarged) 
 
 (After Forbes) 
 
 Fig. 215. May-beetle [Lachnostenia sp.), showing larva (or white 
 pupa, and adult. (Natural size) 
 
 (After Linville and Kelly) 
 
 jrub), 
 
THE BEETLES 
 
 151 
 
 droppings, which they carry in for food for the larvae which Hve 
 in the burrows, while others, known as skin-beetles, feed on dried 
 or decomposing animal matter, frequenting the refuse of tanneries 
 and eating the hoofs and hair of dead animals. Thus the scaven- 
 gers may be considered as somewhat beneficial, but the leaf -chafers 
 include many of our worst pests. The June-bugs, or May-beetles, 
 
 Fig. 216. The rose-chafer 
 
 a, adult; b, larva; c, d, mouth-parts of same; c, pupa; /, injured leaves and blossoms of 
 
 grape, with beetles at work, a, I', e, much enlarged ; c, d, more enlarged ; /, slightly reduced. 
 
 (After Marlatt, United States Department of Agriculture) 
 
 are among the best-known representatives of this group. They 
 are stout, brown, or blackish beetles nearly an inch long, which fly 
 in and buzz around the lights in early summer. There are some 
 sixty species belonging to this genus {Lachnostcrna), the larvae of 
 which are the typical white grubs which attack the roots of grass, 
 corn, and garden crops. These beetles feed at night on various 
 shade and fruit trees, ragging the foliage as if it had been torn. 
 The rose-chafer is another well-known species, which destroys the 
 
1^2 
 
 ELEMENTARY ENTOMOLOGY 
 
 flowers and leaves of roses and grapes. It is a pale yellowish 
 beetle, three eighths of an inch long, somewhat hairy, with long, 
 pale red legs. All of the leaf-chafers have long, spiny legs, whose 
 use they do not seem to have mastered, for thev are ridiculously 
 
 Fig. 217. The rhinoceros beetle (Dimisies tityrus). (Natural size) 
 (After Kellogg) 
 
 awkward in walking. The largest beede of this country is the rhi- 
 noceros beetle {Dynastcs tityrus), which is two and one half inches 
 long, greenish-gray with black spots, and is named from the large 
 horn on the head, which meets a median horn extending from the 
 
 prothorax. It occurs in the South and 
 West, and in the W'est Indies there is a 
 similar species six inches long. Their 
 larvae live in the roots of decaying trees. 
 Another series of species are known as 
 flower-beetles, from their habit of feeding 
 on pollen, which they carry from flower to 
 flower. A common species of this sort is 
 the yellowish-brown bumble flower-beetle 
 {EnpJioria inda). It is half an inch long, 
 quite hairy, and flies from flower to flower 
 with a loud buzzing like that of a bumble- 
 bee. Occasionally these beetles assemble 
 on ripening peaches or other soft fruits, or lap up the sap from a 
 wounded tree. A bright-green species {Alloi-hina nitida), two 
 thirds of an inch long, is very common in the South, where it is 
 often called the green June-bug, and frequently attacks ripening 
 fruits, 
 often injure lawns 
 
 Fig. 218. The bumble flower- 
 beetle (£■///// (?;7rf htJa). (Twice 
 natural size) 
 
 (After Chittenden, United States 
 Department of Agriculture) 
 
 The larvae are white gmbs which live in grasslands and 
 
THE BEETLES 
 
 153 
 
 II. BEETLES WITH FOUR-JOINTED TARSI {TETRAMERA) 
 
 The tarsi of the famihes of this section are apparently composed 
 of but four segments, the fourth being very small and closely joined 
 to the last, or fifth, segment, and concealed by 
 the third segment, which is deeply bilobed. This 
 section is often called the Phytophaga, as all of 
 the families attack vegetation. 
 
 The leaf-beetles (Chrysomelidae) are one of the 
 largest and most injurious families, there being 
 some six hundred species in this country, a large, 
 number of which injure cultivated crops, while 
 those which normally feed on various weeds often 
 change their food habits and become crop pests. 
 The Colorado potato-beetle {Leptinotarsa decem- 
 liiicata) is one of the best-known species, and is 
 fairly typical of the family, except that it is much 
 larger than the average. The little black, red-and- 
 yellow-spotted asparagus-beetles which, with their 
 dark grayish, sluglike larvae, eat into young aspar- 
 agus, are well known throughout the East, as are 
 the twelve-spotted asparagus-beetles, which are red with twelve 
 black spots. 
 
 Fig. 219. Tarsus 
 of phytophagous 
 beetle, showing 
 indistinct fourth 
 segment 
 
 (After Comstock, 
 from Hunter) 
 
 Fig. 220. The common asparagus-beetle, — eggs, larva, and adult. ( Much enlarged) 
 
 (After Britten) 
 
154 
 
 ELEMENTARY ENTOMOLOGY 
 
 From North Carolina and Ohio to Maine the elm leaf-beetle 
 {Galeriicclla Intcola) is the worst insect pest of elm foliage, both 
 
 Fig. 221. The Colorado potato-beetle. (Enlarged) 
 
 «, beetle ; b, eggs ; <-, young larva ; </, full-grown larva. (After Chittenden, United States 
 I^epartment of Agriculture) 
 
 adults and larvae skeletonizing the leaves and so defoliating trees 
 that, where injured annually, many are killed. The beetles are 
 one fourth of an inch long, yellowish-brown, with black stripes at 
 
THE BEETLES 
 
 155 
 
 the outer margin of the wings, and the full-grown larvae are half 
 an inch long, orange-yellow, with numerous black tubercles. The 
 
 Fig. 222. The elm leaf-beetle 
 
 /, cluster of eggs; i a, single egg; 2, newly hatched larva; j, full-grown larva; 4^ pupa; 
 
 J, overwintered beetle ; 6, newly transformed beetle ; 7, leaf showing work of grubs and a few 
 
 holes eaten by beetles ; 5, leaf nearly skeletonized by larvae ; g, leaf showing holes eaten by 
 
 beetles. (All enlarged except 7, 5, q, which are slightly reduced.) (After Felt) 
 
156 
 
 ELEMENTARY ENTOMOLOGY 
 
 Fig. 223. Striped 
 cucumber-beetle 
 
 Striped cucumber-beetle {Diahrotica vittatd) is about 
 the same size, bright yellow with black stripes, and 
 is one of the worst pests of young cucumber and 
 melon vines. The larvae are long, slender whitish 
 grubs which feed on the roots. The twelve-spotted 
 Diabrotica is green with twelve black spots, with 
 similar food habits in the adult stage, but in the 
 South the larvae do serious injury to the roots of 
 corn, while the larva of another pale green species, 
 
 Fig. 224. A, potato flea-beetle ; /?, egg-plant flea-beetle. 
 (Both greatly enlarged) 
 
 (After Chittenden, United States Department of Agriculture) 
 
 known as the west- 
 ern corn rootworm, 
 is one of the worst 
 pests of corn in 
 the northern Miss- 
 issippi Valley. A 
 large group of small 
 species, with strong 
 hind legs which en- 
 able them to give 
 remarkable jumps, 
 are known as flea- 
 beetles. The potato 
 flea-beetle {Epitrix fnscitla) and nearly related species are com- 
 monly abundant on young potato and tomato plants, and on egg- 
 plants, the leaves of which are 
 . . __ riddled as if they had been hit 
 
 -'j^-''C a'"^^^!^"'^^ f ^^^^'^ ^^^ ^^''^ shot. The larvae are 
 
 small, slender white grubs, which 
 feed on the roots of various weeds 
 of the same botanical family, and 
 are rarely seen. All the garden 
 1 l"^^ri_ WiJLI^/ crops, as well as tobacco and corn, 
 
 1 ^i^m \^^/ 7. are attacked by one or more spe- 
 
 cies of these flea-beetles. The lar- 
 vae of a few species of this family 
 are leaf miners, the leaves of the 
 locust being commonly affected by 
 large, brown, blisterlike mines due 
 
 Fig. 2: 
 
 5. Striped turnip flea-beetle 
 (Greatly enlarged) 
 
 «, lar\'a : b, adult. (From Riley, United 
 States Department of Agriculture) 
 
THE BEETLES 
 
 157 
 
 to the larvae of the locust-beetle (Odontota dorsalis). On morning- 
 glory and sweet-potato vines are found some striking little beetles, 
 
 Fig. 226. The leaf-mining locust-beetle {Odontota dorsalis). 
 (Five times natural size) 
 
 a, beetle ; /', larva ; r, pupa, (.\fter Chittenden, United States Department of Agriculture) 
 
 called tortoise-beetles, from their tortoiselike shape, several of 
 which are a brilliant gold or silver color. The larvae feed on these 
 
 Fig. 227. The golden tortoise-beetle [Coptocycla bicolor Fab.) ; 
 egg at right. (Enlarged) 
 
 rt, b, larvas •, c, pupa ; d, beetle. (After Riley) 
 
 plants, and are curious little creatures, canying a mass of excre- 
 ment over the back, which has given them the name "peddlers." 
 
158 
 
 ELEMENTARY ENTOMOLOGY 
 
 The pea-weevil family (Bruchidae) includes the small weevils 
 which commonly infest peas, beans, and Other seeds. They are of 
 much the same general shape as some of the leaf-beetles, but the 
 
 head is prolonged into 
 a blunt snout, and the 
 wing-covers are square 
 at the tip, leaving the 
 tip of the abdomen ex- 
 posed. They are from 
 one eighth to one fourth 
 of an inch long, brown- 
 ish or ashen gray in 
 color, with whitish scales 
 or hairs on the wing- 
 covers, forming various 
 markings. Both beetles and larvas feed on seeds of leguminous 
 plants, of which they are the most serious insect pests. 
 
 The long-horned beetles (Cerambycidae) are easily recognized by 
 the long antennae, which are rarely shorter than the body and 
 often are twice as long. They are large, stout, cylindrical-bodied 
 
 Fig. 228. The pea-weevil. (Enlarged) 
 
 a, adult beetle ; /', lan-a ; c, pupa. (After Chittenden, 
 United States Department of Agriculture) 
 
 a c 
 
 Fig. 229. The common bean-weevil. (All enlarged) 
 a, beetle ; b, larva ; r, pupa. (After Chittenden, United States Department of Agriculture) 
 
 beetles, usually strikingly colored and patterned, attracting imme- 
 diate attention. The larvae are cylindrical white grubs which bore 
 in the heartwood of trees and are termed round-headed borers, in 
 contrast to the flattened forms of the Bnprestidae. The family is a 
 
Fig. 230. The round-headed apple-tree borer, — larvee, adults, and exit hole. 
 
 (Natural size) 
 
 (After Rumsey and Brooks) 
 
 Fig. 231. Work of the round-headed apple-tree borer. (Natural size) 
 
 rt, puncture in which egg is laid ; b^ same in section ; r, hole from which beetle has emerged ; 
 /, same in section ; g, pupa in its cell. (After Riley) 
 
 159 
 
i6o 
 
 ELEMENTARY ENTOMOLOGY 
 
 large one and includes many serious pests, such as the round- 
 headed apple-tree borer and others with similar habits. Three com- 
 mon blackish species, brilliantly striped 
 with yellow (Fig. 234), are known as 
 locust-borer, hickory-borer, and sugar- 
 maple-borer, after their respective food 
 plants, which are frequently killed from 
 the work of their larvae. Among our 
 largest beetles are the prionids, the larvae 
 of which infest the roots of various fruit 
 and shade trees and herbaceous plants. 
 The broad-necked prionus is from one 
 to two inches long, pitchy black, with the 
 thin margin of the prothorax toothed, as 
 shown in 
 Fie 
 
 232. 
 The oak- 
 
 FiG. 232. The giant root-borer 
 (Prioiiiis laticollis) 
 
 (After Riley) 
 
 pruner is 
 a slender, brown species, about three 
 fourths of an inch long, which lays 
 
 Fig. 234. Thehickorv-borer {Cylleiu 
 pictiis Dru.). {Enlarged) 
 
 (After Webster) 
 
 Fig. 233. The oak-pruner {Elaphi- 
 dion pai-alUliim) 
 
 a, larva ; /', pupa in its burrow ; c, beetle ; 
 k, k, cut ends of twig. (After Riley) 
 
 its eggs in the twigs of oak, maple, 
 and various fruit trees. The larvae 
 hollotv out the interior of the twigs 
 which are broken off by the winds, 
 and in these they pupate. One of 
 our largest species is the common 
 sawyer, a large gray beetle one 
 and one fourth inches long, with 
 very long antennae, whose larvae 
 bore into the heart of felled pine 
 and other softwood trees, making 
 large holes half an inch in diameter. 
 The raspberry cane-borer {Obcrea 
 
THE BEETLES 
 
 l6l 
 
 hiniacitlata) is a black beetle half an inch long, with yellow pro- 
 thorax bearing two black spots. Its larva mines raspberry' and 
 blackberry canes. The red milkweed-beetles {Tetraopes tctra- 
 ophthalnius) are always common on the flowers of the milkweed, 
 and the larva bore in the roots and stems. 
 
 III. BEETLES WITH THREE-JOINTED TARSI [TRIMERA) 
 
 The ladybird-beetles (Cocdnellidae) form the only family of the 
 section Trwiera, in which the tarsi have but three segments, and 
 
 Fig. 235. The convergent ladybird-beetle [Hippodamia convergens) 
 a, adult ; /', pupa ; <-, larva, (.\fter Chittenden) 
 
 the head is usually concealed beneath the prothorax. Their small 
 size (few being over one fourth of an inch long), their broad, oval, or 
 hemispherical shape, 
 and their characteris- 
 tic markings, consist- 
 ing of "polka-dot" 
 black spots on a yellow 
 or red background, 
 or red or yellow spots 
 on black, make them 
 readily recognizable, 
 though now and then 
 certain of the leaf- 
 beetles, which have a 
 
 1 , , Fk;. 2^6. The spotted ladybird-beetle (Mes^/lia 
 
 general resemblance, ^ ^ ,■ , " 
 
 are mistaken for them. , , au ,^(, nu.. a ttv^c. . 
 
 a, larva ; d, pupa : c, adult. (.After Chittenden, United States 
 Nearly all of this Department of .\griculture) 
 
l62 
 
 ELEMENTARY ENTOMOLOGY 
 
 Fig. 2 
 
 J/. The nine-spotted ladybird-beetle {Cccci- 
 nella novetnnotata), — adult and larva 
 
 (After Chittenden) 
 
 family feed on plant-lice, scales, and other soft-bodied insects, 
 both as adults and as lan^ae, and may be found wherever their 
 prey becomes abundant. In general the common yellow or red, 
 
 black-spotted species 
 
 feed on plant-lice, 
 
 while the smaller black 
 
 species, marked with 
 
 red or yellowish spots, 
 
 feed on scales. So 
 
 I igiM.^^^^^ 4 iULM^ common are the ladv- 
 
 ^^^^^> /i A^> birds among colonies 
 
 ^ ^--et*-^ C ^^f of plant-lice that they 
 
 are frequently mis- 
 taken as the parents 
 of the aphides, and 
 the misguided grower 
 carefully picks them off and destroys them, thinking he is elimi- 
 nating the cause of the aphid infestation, whereas he is really 
 destroying nature's most efficient agents for its alleviation. The 
 eggs are laid in little yellow masses on the leaves or bark where- 
 ever food is abundant. The lan-^ are commonly about one fourth 
 of an inch long, strongly tapering at either 
 end,' with long legs, and often marked 
 with spiny processes. They run here and 
 there in search of food, feed voracioush- 
 on any unlucky plant-lice or insects' eggs 
 which fall in their path, and, when full 
 grown, attach themselves to bark, leaves, 
 or fences by the tip of the abdomen and 
 there pupate, the cast lar\^al skin often 
 remaining over the pupa. The beetles 
 hibernate over winter. The nine-spotted 
 ladybird {Coccinella g-notata) is one of the larger common }"ellow 
 species, with nine black spots, and the little two-spotted ladybird 
 {Adalia bipiinctata) is smaller, slightly broader, and frequently 
 associated with the former species. The twice-stabbed ladybird 
 {Chiloconis biviilnerns) is black with a red spot on each wing-co\'er. 
 Its spiny larv'a is black, and, with the adult, feeds upon scale 
 
 Fig. 238. The twire-stabbed 
 
 ladybird-beetle {Chi/oconts 
 
 biviilnerits Muls.) and laiA'a. 
 
 (Enlarged) 
 
 (.A.fter Riley) 
 
THE BEETLES 
 
 163 
 
 insects, often checking their increase notice- 
 ably. Recently a very similar species, the 
 Asiatic ladybird, was imported from China to 
 prey upon the San Jose scale, but has not be- 
 come established in this country. Several very 
 small, black species of the genus Microweisea, 
 with their little black larvae, are also among 
 the most effective enemies of scale insects. 
 One of the most remarkable cases of the 
 utilization of a beneficial insect was the intro- 
 duction into California of the Australian lady- 
 bird {Vedalia cardinalis), which in a few years 
 was able to almost entirely subdue the cottony 
 cushion-scale, which was destroying the orange 
 trees. Unfortunately, there are some sinners 
 among the ladybirds, for there are one or two 
 large, hemispherical, black-spotted, yellow spe- 
 cies of the genus Epilachna, which defoliate 
 Fig. 239. Pup^ of the cucumbers, melons, and beans. 
 
 twice-stabbed ladybird- 
 beetle, in cast larval 
 skins 
 
 IV. BEETLES WITH DIF- 
 FERENT-JOINTED TARSI 
 {HETEROMERA) 
 
 The section Hctcroin- 
 era is distinguished by 
 having the front and mid- 
 dle feet with five tarsal 
 segments, while the hind 
 feet have but four ; hence 
 the name "different- 
 jointed." A number of 
 small, obscure families 
 are included in this sec- 
 tion, only two being of 
 sufficient importance to 
 warrant consideration. 
 
 Fig. 240. Australian ladybird-beetle (JVovius 
 
 cardinalis), the enemy of the white scale. 
 
 (Natural size) 
 
 a, ladybird lan'ae feeding on adult female and egg sac ; 
 
 /', pupa ; c, adult ladybird ; d, orange twig, showing 
 
 scales and ladybirds. (After Marlatt, United States 
 
 Department of Agriculture) 
 
Fig. 241. Mkroweisea misella, a small black ladybird-beetle which 
 feeds on scales. (All greatly enlarged) 
 
 (?, beetle ; /', larva ; c, pupa ; d, blossom end of pear, shovvino; San Jose scales upon which 
 
 the beetles and their larvae are feeding, and pupae in the calyx. (After Howard and Marlatt, 
 
 United States Department of Agriculture) 
 
 Fig. 242. The squash ladybird-beetle 
 
 (7, larva ; b, pupa ; f, adult beetle (three times natural size) ; </, egg (four times natural size) ; 
 e, surface of egg (highly magnified). (After Chittenden, United States Department of 
 
 Agriculture) 
 164 
 
THE BEETLES 
 
 i6^ 
 
 The darkling beetles (Tenehrionidae) live mostly under bark and 
 stones, are dull black, and have much the same gejieral appearance 
 as the ground beetles. They are much more abundant on the 
 
 QQ::cca^oc::c:c>._ 
 
 Fig. 243. The meal-worm ( Tenehrio molitor) 
 
 (7. lana : /■, pupa; c, female beetle ; </, egg with surrounding case ; f, antenna. (.\n excepts 
 about twice natural size ; <-, greatly enlarged.) (.After Chittenden, United -States Department 
 
 of Agriculture) 
 
 Pacific coast and in the Rockies, relatively few forms being found 
 in the East. A common species of the typical genus is the meal- 
 worm beetle {Tenebrio molitor) which infests grain-rooms, stores, 
 
 / 
 
 Fig. 244. The striped blister-beetle 
 
 (7, female beetle : h, eggs ; c, triungulin lar\-a : d, second or carabid stage of larva ; e, same 
 
 as/ doubled up as in pod ; /, scarabaeoid stage ; ^c- coarctate lar\'a. (All except e enlarged.) 
 
 (After Riley and Chittenden, United States Department of Agriculture) 
 
1 66 
 
 ELEMENTARY ENTOMOLOGY 
 
 Fig. 245. The black blister 
 beetle. (Enlarged) 
 
 pantries, and wherever meal is stored. The larvae are elongate, 
 brown, and horny, veiy much resembling wire-worms, and are 
 kept by bird fanciers for feeding song 
 birds in winter. The beetle is from one 
 half to three fourths of an inch long, dark 
 brown, with square prothorax and ridged 
 wing-covers. 
 
 The blister-beetles (Meloidae) are so 
 called because their juices cause a blis- 
 tering of the human skin, and when 
 dried and powdered they were formerly 
 much used by phy- 
 sicians for blister- 
 ing. They are soft- 
 bodied beetles with 
 
 (After Chittenden, United States ^^g head prominent 
 Department of Agriculture) ^ 
 
 and attached to the 
 
 thorax by a very distinct neck. The elytra 
 
 are flexible and rounded posteriorly, so 
 
 that usually they do not cover the tip 
 
 of the abdomen, 
 while in some forms 
 the wing-covers are 
 quite short and the 
 wings are lacking. 
 Our common spe- 
 cies are about half 
 
 an inch long, dull gray or blackish, often 
 marked with yellow stripes, while others 
 are of a brilliant metallic bronze, green, 
 or blue. The adults often appear in im- 
 mense swarms and ruin garden crops. 
 The striped blister-beetle {Epicaiita vit- 
 tata) was a common pest of potatoes 
 before the advent of the Colorado beetle, 
 and is known as the "old-fashioned potato- 
 bug." The larvae have a very complicated 
 metamorphosis, owing to their peculiar 
 
 Fu;. 246. The ash-gray 
 blister-beetle. (Twice nat- 
 ural size) 
 
 (After Chittenden, United 
 States Department of Agri- 
 culture) 
 
 Fig. 247. The white-pine 
 vi&t\\\(Pissodes st7vbi). (En- 
 larged and natural size) 
 
 (After Hopkins, United States 
 Department of Agriculture) 
 
'JHE BEETLES 
 
 167 
 
 habits. Some of them are parasitic in the nests of bees, while tlie 
 more common forms hve on the eggs of grasshoppers, which they 
 devour in large numbers, and are quite bene- 
 ficial in spite of the bad habits which they 
 later acquire as adults. 
 
 The Snout-Beetles {Rhynchophora) 
 
 In this suborder the head is prolonged 
 into a long snout, giving the names "snout- 
 beetles " "bill-bugs," "weevils," and "cur- 
 culios " to many of the common forms. 
 The body is 
 
 Fig. 248. The straw- 
 berry weevil. (Greatly 
 enlarged) 
 
 (After Riley) 
 
 strongly com- 
 pact, usually 
 well rounded 
 above, and is 
 more or less covered with scales. 
 The antennae arise from either 
 side of the snout, are bent for- 
 ward, or "elbowed," and end in 
 a club. The larvae are soft, foot- 
 less, wrinkled, whitish grubs, with 
 brown head, often thinly covered 
 with short, bristly hair, and live 
 mostly in fruits, nuts, or seeds, 
 or under bark, though a few live 
 on vegetation externally. All of 
 the families attack plants and are 
 therefore more or less injurious. 
 
 Fig. 250. 
 
 Head and mouth-parts of the 
 boll weevil larva 
 
 Fig. 249. The cotton-boll weevil. 
 (Enlarged) 
 
 some of our most troublesome 
 pests being found in this series. 
 Though there are common ex- 
 amples of several other families, 
 only three families are suffi- 
 ciently numerous to warrant 
 mention. 
 
 The curculios (Curculionidae) 
 are the most typical as well as the 
 largest family of the suborder. 
 
1 68 
 
 ELEMENTARY ENTOxMOLOGY 
 
 with over six hundred species. With her long snout the female 
 drills into fruits and stems and drops an egg in the bottom of the 
 
 excavation. Here the larva 
 feeds within the food plant, 
 well protected against attack. 
 In the northeastern states a 
 brownish beetle, about one 
 fourth of an inch long, with a 
 white spot on each wing-cover, 
 known as the white-pine weevil 
 {Pissodcs strobi), lays its eggs 
 in the axis terminal of pines, 
 which the larva tunnels out and 
 kills, completely spoiling the 
 The plum curculio 
 
 Fig. 251. Larva of the cotton-boll weevil 
 in opened square. (Natural size) 
 
 shape of the tree, 
 is the well-known little Turk which 
 makes the crescent-shaped punctures 
 on plums, peaches, cherries, and apples, 
 and whose grubs feed within. A 
 small blackish weevil, the strawberry 
 weevil {AntJiononius signatus), lays 
 its eggs in the 
 
 Fig. 252. The chestnut weevil 
 
 (Bala?iimis proboscideus Fab.). 
 
 (Natural size) 
 
 Fig. 253. A corn bill-bug 
 
 {SpAeitopkonis ochreus). 
 
 (Twice natural size) 
 
 (After Webster) 
 
 Strawberry buds, 
 which it then 
 cuts off, and the larvae feed on the develop- 
 ing flowers, often causing serious loss. The 
 cotton-boll weevil {Anthonovuis graudis) is 
 probably the most import^mt species from 
 an economic standpoint, causing a loss of 
 over twenty-five million dollars annually. 
 The most striking of all the weevils are 
 the acorn and chestnut weevils, with snouts 
 much longer than the body, enabling them 
 to drill through the chestnut bur and de- 
 posit the egg within the nut, in which the 
 larva develops. Almost all of our common 
 nuts are attacked by some species of these 
 weevils, which often are a serious nuisance. 
 
THE BEETLES 
 
 169 
 
 The bill-bugs {Calandridae) are from one fourth to one half of an 
 inch long, black, brown, or dark gray, with hard elytra, ridged and 
 
 Fig. 254. The gxciw^ry weexW (Cala/iJfa gni/iarhi). (Enlarged) 
 
 a, beetle ; /', lan-a ; 
 
 pupa; (/. the adult rice weevil {Calandra o>y~<^)- (After Chittenden, 
 United States Department of Agriculture) 
 
 sculptured. They attack corn, timothy, and other grasses, particu- 
 larly the coarse swamp grasses and sedges. The fat white larvse 
 
 «^ led 
 
 Fig. 255. The fruit-tree bark-beetle {Scolyttis ntgulosits) 
 
 a, adult ; li, same in profile ; c, pupa ; </, larva (about ten times natural size). (After 
 Chittenden, United States Department of Agriculture) 
 
 live in the crowns and stems of the plants. More important are 
 the small granary and rice weevils {Calandra gran aria and oryza), 
 
I/O 
 
 ELEMENTARY ENTOMOLOGY 
 
 small, slender, brown weevils, one eighth of an inch long, which 
 are the most abundant pests of granaries. 
 
 The engraver-beetles {Scolytidae), or bark-beetles, live on the 
 inner bark and sapwood of forest and fruit trees, the larvae of 
 each brood tunneling out their little burrows in characteristic 
 
 patterns, giving them the name 
 of "engravers." They are small 
 brown or blackish beetles, often 
 microscopic, rarely over one eighth 
 - and never over one fourth of an 
 inch long, and with the head very 
 slightly produced, so that they are 
 not readily recognized as snout- 
 beetles. They have stout, cylin- 
 drical bodies, obliquely or squarely 
 truncate at the tip. The larvae are 
 little white grubs, with brown 
 heads and strong jaws, which 
 riddle the inner bark of the food 
 plant and pupate in the burrows. 
 When the adults emerge, they make 
 numerous small holes through the 
 bark, which habit has given them 
 the name of " shot-hole borers." 
 This family includes the most de- 
 structive of all our forest insects, 
 the losses due to them being es- 
 timated at over one hundred million 
 dollars per annum. Almost every 
 tree has species which commonly 
 attack it in different sections of 
 the country, some infesting only 
 sick or dead timber, while others 
 attack the healthy trees and sweep them off over large areas, the 
 trees dying and giving rise to forest fires. The fruit-tree bark- 
 beetle {ScolytTis riigulosus) is a well-known example, infesting our 
 common fruit trees. 
 
 Fig. 256. Typical worK of a scolytid, 
 the fruit-tree bark-beetle, showing 
 the main galleries, the side or larval 
 galleries, and the pupal cells. (Slightly 
 enlarged) 
 
 (After Ratzeburg) 
 
THE BEETLES 
 
 171 
 
 Synopsis of Families of Beetles 
 
 Suborder Typical beetles (Coleopiera geiiuina) 
 Section i. With five-jointed tarsi {Pentamera) 
 Tribe i. Carnivorous beetles (A dep/iaga) 
 
 Tiger-beetles (Cici?idelidae) 
 
 Ground-beetles {Carabidae) 
 
 Predacious diving-beetles {Dy/iscidae) 
 
 Whirligig-beetles ( Gyrinidae) 
 Tribe 2. The club-horned beetles (Cla%iicornid) 
 
 Water-scavenger beetles {Hydrophilidae) 
 
 Carrion-beetles {Silphidae) 
 
 Rove-beetles (Sfaphyll/iidae) 
 
 Cucuj id-beetles ( Citcujidae) 
 
 Dermestid-beetles {Dennestidae) 
 Tribe 3. The saw-horned beetles [Serricornid) 
 
 Click-beetles (Elateridae) 
 
 Metallic wood-borers [Bupresildae) 
 
 Fireflies {Lampyridae) 
 Tribe 4. The leaf-horned beetles {Lainellicontia) 
 
 Stag-beetles {Lucanidae) 
 
 Scarabaeid beetles [Scambcieldae) 
 
 Section 2. With four-jointed tarsi {Tetramerd) 
 Leaf-beetles ( Ch/yso/nelidae) 
 Pea-weevils {Bnichidae) 
 Long-horned beetles (Cerambycidae) 
 
 Section 3. With three-jointed tarsi (Triinera) 
 Ladybird-beetles ( Coccinellidae) 
 
 Section 4. With different-jointed tarsi (Heicrovierd) 
 Darkling-beedes ( Tenebrionidae) 
 Blister-beetles [Meloidae) 
 
 Suborder Snout-beetles {RliyncIiopJiord) 
 
 The curculios [Cmrulio/iidae) 
 
 The bill-bugs (Calmidridae) 
 
 The engraver-beetles, or bark-beetles (Scolytidae) 
 
CHAPTER XIII 
 
 THE BUTTERFLIES AND MOTHS (LEPIDOPTERA) 
 
 Characteristics. Insects with four wings, which are membranous and cov- 
 ered with overlapping scales ; mouth-parts, suctorial ; metamorphosis, complete. 
 
 If the wing of a butterfly or a moth is rubbed, the color is quickly 
 removed as a sort of powder, leaving the transparent membranous 
 wing. If this powder is examined with a microscope, it will be seen 
 to be composed of small, finely ridged scales, which are arranged 
 
 on the wings in overlapping 
 rows and give it the charac- 
 teristic color pattern. Thus 
 we get the name of the order, 
 from lepis (a scale) and pteron (a 
 wing). These scales strengthen 
 the wings and are also found 
 on the body and on other ap- 
 pendages. The mouth-parts of 
 the adults consist of a long, 
 tubelike proboscis, which is 
 coiled under the head when 
 not in use, looking, in some of 
 the larger moths, much like a 
 watch spring. It is composed 
 of the two maxillae, the inner 
 faces of which are grooved and 
 locked together so as to form 
 a tube, through which the nectar of flowers is sucked. The man- 
 dibles are entirely wanting. The two brushlike organs on either 
 side of the proboscis are the labial palpi, the balance of the labium 
 being poorly developed. 
 
 The larvae of butterflies and moths are known as caterpillars. 
 They are quite variable in shape, but our common forms are readily 
 recognizable as belonging to this order. They are usually cylindrical, 
 
 172 
 
 Fig. 257. Portion of wing of monarch 
 butterfly, with some scales removed to 
 show insertion-pits and their regular ar- 
 rangement. (Greatly magnified) 
 
 (After Kellogg) 
 
THE BUTTERFLIES AND MOTHS 
 
 173 
 
 \ 
 
 \ 
 
 X'^Sj" 
 
 <^ 
 
 -^ 
 
 Fig. 258. 
 
 with a well-developed head bearing biting mouth-parts and small 
 ocelli on either side. The thorax bears three pairs of jointed legs, 
 which terminate in a single claw, and the back of the prothorax 
 
 forms a hard shield, 
 thepronotum. Theab- 
 dominal segments are 
 very similar and bear 
 from one to five pairs 
 of short, fleshy, unseg- 
 mented false legs, or 
 prolegs, which termi- 
 nate in a circle of small 
 hooks, one pair of 
 which is always borne 
 by the anal segment. 
 The caterpilMrs of 
 many moths pupate in 
 little cells, which they 
 hollow out in the 
 ground, but most of 
 them spin silken co- 
 coons, within which they pupate. Some are thin, flimsy affairs, while 
 others, like those of the silkworm, contain a large amount of silk 
 and are very firmly built, forming 
 a warm home for the hibernating 
 pupae. Butterfly larvae spin no co- 
 coons, and the pupae, or chrysalids, 
 hang pendent from the food plant 
 or some near-by object, to which they 
 are lashed by a strand of silk around 
 the body. 
 
 The order is one of the largest, 
 including over sixty-six hundred spe- 
 cies in this country, and contains 
 many of our most serious pests, while 
 
 very few of its members are beneficial. The families are largely 
 distinguished by the wing venation, which is difficult to see, so that 
 it is exceedingly hard to arrange them in any natural and easily 
 
 Luna moth, showing pectinate, or feath- 
 ered, form of moth antennae 
 
 (After S. J. Hunter) 
 
 Fig. 259. A skipper (^Fjidanuis ba- 
 i/iy!liis], showing recurved tips of 
 antennas 
 
 (After S. J. fiunter) 
 
174 
 
 ELEMENTARY ENTOMOLOGY 
 
 recognizable groups. The caterpillars of the different families may 
 be recognized, to a certain extent, by their habits and general 
 appearance. The butterflies and moths form two main divisions 
 of the order, which are readily distinguished. 
 
 Butterflies 
 
 The butterflies are day fliers, and when at rest the wings are held 
 in a vertical position over the back. The antennae are threadlike 
 and are distinctly enlarged at the tip. 
 
 The butterflies are much less numerous than the moths, both 
 in families and in species, and include relatively few species 
 
 of any considerable 
 economic importance. 
 Two main groups of 
 butterflies are recog- 
 nized, — the skippers 
 (Hesperina) and the 
 true butterflies {Pa- 
 pilionina). 
 
 SKIPPERS 
 
 The skippers are 
 
 Fig. 260. Hop-merchant butterfly, showing form of \\ A ^r fKoV 
 
 ki 1 1 , r 1 ^^ n- SO caiieQ irom tneir 
 
 nobbed antennas of butterflies 
 
 peculiar habit of dart- 
 ing suddenly from 
 place to place. The wings are held vertically over the back when 
 at rest, though often the hind-wings are held horizontally. The 
 antennae are enlarged at the tip, which usually forms a more or 
 less recurved hook. They have stout bodies, which resemble 
 moths more than butterflies. Some are blackish or dark, somber 
 brown, often flecked with grayish or white, while others are tawny 
 yellow with a blackish discal patch. The latter usually have the 
 fore-wings much more pointed, and have thick bodies. The larvae 
 of our common forms have a characteristic appearance (Fig, 261), 
 with large heads and strongly constricted necks. They feed on 
 foliage, usually concealing themselves within a folded leaf, which 
 is tied together with silk and within which they spin a loose cocoon 
 
 (Photograph by Fiske) 
 
THE BUTTERFLIES AND MOTHS 
 
 175 
 
 of silk before pupating. Very few of this group are of any economic 
 importance, though one larva occasionally attacks the calla lily, 
 
 Fig. 261. The tityrus skipper {^Epargyreus titvnts), — adult, larva, and leaf-cocoon. 
 
 (Natural size) 
 (After Linville and Kelly) 
 
 and another sometimes injures corn in the Gulf States, perforating 
 the leaves with numerous holes before they unfold. The skippers 
 may be considered as intermediate be- 
 tween the moths and the true butterflies. 
 
 TRUE BUTTERFLIES 
 
 The true butterflies include four well- 
 defined families. 
 
 The swallowtails (Papilionidae) include 
 our common black-and-yellow species, 
 which have the hind-wings prolonged 
 into characteristic tails. The only species 
 of any economic importance is the celery, 
 or parsley, cateipillar {Papilio polyxenes) 
 known swallowtail, jet-black with the outer edge of the wings 
 marked with two rows of yellow spots, and a peculiar eyespot on 
 
 Fig. 262. The manataaqua 
 skipper (Pamphila mana- 
 taaqtia), male. (Natural size) 
 
 (After Fiske) 
 
 The adult is our best- 
 
Fig. 263. The black swallowtail butterfly [Papilio folyxenes). (Slightly reduced) 
 
 a, egg; /', caterpillar; c, front view of head with osmateria protruded; </, chrysalis; <?,/, 
 adult. (After Webster) 
 
 176 
 
THE BUTTERFLIES AND MOTHS 
 
 177 
 
 the inner margin of each hind-wing. Between the rows of yellow 
 spots on the hind-wings are bluish scales, which are particularly 
 
 Fig. 264. The blue swallowtail butterfly (Laeiiias p/ii/enor). (Reduced one fifth) 
 (Photograph by Fiske) 
 
 prominent in the females. The caterpillar is green, banded with 
 black and spotted with yellow, and feeds on celery, parsley, 
 parsnips, and nearly related plants. Like other caterpillars of this 
 
 Fig. 265. Caterpillar 
 of the troilus butter- 
 fly {Pupil 10 t7viins) 
 
 (Photograph by \\'eed) 
 
 Fig. 266. The tiger swallowtail butterfly 
 {Papilio glaiiciis tuniiis). (Reduced) 
 
 (Photograph by Weed) 
 
178 
 
 ELEMENTARY ENTOMOLOGY. 
 
 Fig. 267. Three common pierid butterflies 
 
 (7, native cabbage butterfly {Foiitia napi oleracca), 
 
 male; /', imported cabbage butterfly {Pontia rapae), 
 
 female ; c, the common sulphur butterfly {Emymiis 
 
 philodke), female. (Photograph by Fiske) 
 
 family it has a pair of pecu- 
 liar, orange-colored, mem- 
 branous horns, which are 
 protruded from between 
 the segments close to the 
 head and which give off 
 quite a disagreeable odor. 
 Evidently these are defen- 
 sive organs, for they appear 
 only when the caterpillar 
 is disturbed. This family 
 includes our largest and 
 most brilliant butterflies. 
 The spring and summer 
 broods of some species are 
 so differently colored that 
 they might be taken for 
 distinct species. 
 
 Pieridae. The family 
 Picridac includes the yel- 
 low butterflies (sometimes 
 called puddle butterflies, 
 from their habit of swarm- 
 ing around puddles) and 
 the common white cabbage 
 butterfly, which is almost 
 the only form of economic 
 importance in the family. 
 The larvae are slender 
 
 green caterpillars, clothed with short, fine hairs, 
 and are often finely striped, resembling the 
 cabbage worms. The larvae of the common 
 clouded sulphur {E?irymus philodice) feed on 
 clovers and leguminous plants, but are rarely 
 numerous enough to be injurious. 
 
 The gossamer- winged butterflies (Lycaenidae), 
 so called on account of their delicate struc- 
 ture, include the little blue and copper-colored 
 
 Fig. ::6S. The common 
 
 blue butterfly {Lycaena 
 
 pseudargiolns Boisd.), 
 
 underside of female 
 
 (After Fiske) 
 
THE BUTTERFLIES AND MOTHS 
 
 179 
 
 Fk;. 269. The bronze copper 
 
 butterfly {Chrysopha>iiis thoe 
 
 Boisd.), female 
 
 (After Fiske) 
 
 butterflies which flit along the road- 
 sides in spring. Others are blackish 
 or bluish above, often with two or 
 more fine, threadlike tails extending 
 from the hind-wings, and are marked 
 with fine, hairlike streaks on the under- 
 surface, which has given them the 
 name of " hair streaks." The larvae 
 are quite different from other cater- 
 pillars, being flat, elliptical in outline 
 (with the head retracted), and quite 
 sluglike in appearance. Very few of them 
 are ever injurious, the worst offender being 
 the cotton-square borer {Uranotcs melli- 
 nns), which bores into cotton squares and 
 occasionally attacks beans and cowpeas by 
 eating into the pods. 
 
 The four-footed butterflies (Nymphalidae) 
 include most of our common larger forms, 
 and are so called on account of the great 
 reduction of the fore-legs ; this makes 
 them of no service in walking, and the 
 legs are folded on the breast. The common monarch, or milk- 
 weed, butterfly (Anosia 
 plexippns), whose green, 
 black-ringed caterpillars 
 feed upon the foliage of 
 the milkweed, is a good 
 example of the family. 
 The spiny elm caterpil- 
 lar, already described (see 
 p. 63), also belongs here. 
 The dark, reddish-brown 
 butterflies of the hop mer- 
 chant {Polygonia comma) 
 are of interest, for when 
 they fold their ragged- 
 edged wings and alight 
 
 Fig. 270. The acadian hair- 
 streak (Thecla acadica Edw.), 
 underside of female 
 
 (Photograph by Fiske) 
 
 Fig. 
 
 71. The cotton square-borer {L'ranotes 
 melliniii). (All somewhat enlarged) 
 
 a, dorsal view of butterfly ; b, butterfly with wings 
 
 closed; c, larva (side view) ; J, pupa. (After Howard, 
 
 United States Department of Agriculture) 
 
Fig. 273. The viceroy butterfly (Ba- 
 
 Fig. 272. The monarch butterfly (Anoiia silarchia archippus) and its chrysalis. 
 plexippus) on thistle. (Reduced) (Reduced) 
 
 (Photograph by Weed) (Photograph by Weed) 
 
 Fig. 274. Caterpillar and chrysalis of the monarch butterfly 
 (Photograph by Weed) 
 
 180 
 
Fig. 276. The myrina butuill)- {Ar- 
 gynnis myrina Cramer), male 
 
 (After Fiske) 
 
 Fig. 275. Caterpillar of the viceroy 
 butterfly. (Reduced) 
 
 (Photograph by Weed) 
 
 L// ' "<-►■; 
 
 Fig. 277. Harris's butterfly {McUtaea 
 harrisii Scud.), undersurface, male 
 
 (Photograph by Fiske) 
 
 Fig. 278. The tharos butterfly {Phy- 
 
 ciodes tharos Dru.), female, upper 
 
 and under surfaces 
 
 (After Fiske) 
 
 Fig. 279. The American tortoise butterfly [Vanessa milberti Godart), upper and 
 
 under surfaces 
 
 (After.Fiske) 
 
 iSi 
 
I«2 
 
 ELEMENTARY ENTOMOLOGY 
 
 Fig. 2^ 
 
 Hunter's butterfl\- (jyi-aiiu 
 Fab.), male 
 
 (After Fiske) 
 
 I III lit era 
 
 among dead leaves, as they frequently do when pursued in 
 
 woodland, the underwings so closely resemble the leaves as to 
 
 make them quite indis- 
 tinguishable. A bright, 
 silvery comma is seen 
 on the underside of 
 each hind-wing, which 
 gives the specific name. 
 The larvae are red- 
 dish or yellowish, with 
 black head and black- 
 j branched spines ; they 
 feed on elm and net- 
 tles, though they are 
 better known as pests 
 of the hop-vine. 
 The dull, grayish-brown butterflies, with numerous eyespots on 
 
 the borders of their wings, which flit through our woodlands 
 
 like changing shadows, are known 
 
 as meadow-browns, or satyrs, and 
 
 also belong to this large family. 
 
 The larvae of the more common 
 
 species feed on grass, and may be 
 
 recognized by the caudal segment 
 
 being bifurcated. 
 
 The fritillaries, or argynnids, are 
 
 another group of common butter- 
 flies included in this family. They 
 
 are usually of medium size, of a 
 
 golden-brown color, marked with 
 
 rows of black spots above and with 
 
 bright, silvery spots on the under- 
 
 surface. There are several species 
 
 which are very difficult to distin- 
 guish, and whose caterpillars feed 
 
 on violets. One of the smaller fk, ^gi. Hunter's butterfly at rest, 
 species, very similar to the larger showing underwing and chrysalis 
 forms, is illustrated in Fig. 276, (Photograph by weed) 
 
THE BUTTERFLIES AND MOTHS 
 
 183 
 
 Moths 
 
 The moths fly by night, are readily attracted to Hghts, and 
 are often called millers. When at rest the wings are folded 
 
 upon or around the 
 abdomen. The an- 
 tennas are thread- 
 like or feathered, 
 but are never en- 
 larged at the tip. 
 
 In striking con- 
 trast to the butter- 
 flies, most of our 
 moths are little in 
 evidence, but al- 
 most all of their 
 caterpillars are in- 
 jurious and require 
 incessant fighting 
 to control them. 
 No attempt will be made to indicate the natural relationships 
 of the families, which will be grouped and described in such a way 
 as to best aid in their recogni- 
 tion. Several of the more un- 
 common families have been 
 purposely omitted from the 
 discussion. 
 
 Three large, nearly related 
 families of small moths are 
 commonly grouped together as 
 Microlepidoptera, on account of 
 their relatively small size in 
 contrast to the remaining fam- 
 ilies. The laro^er moths and the 
 
 Fig. 282. The white-banded purple butterfly {Linieiiitis 
 arthemis Dru.), male 
 
 (After Fiske) 
 
 Fig. 283. The canthus butterfly 'T c\cd 
 
 brown [Xeoiivinpha caitthiis Boisd. and 
 
 Lee), undersurface 
 
 (After Fiske) 
 
 butterflies are termed Macrolepidoptera. This grouping together 
 of the larger and smaller moths is a classification for the conven- 
 ience of the collector and is not based on any specific difference 
 of structure. 
 
1 84 
 
 ELEMENTARY ENTOMOLOGY 
 
 MICROLEPIDOPTERA 
 
 The tineids (Tineidae) are our smallest moths and may be dis- 
 tinguished by the long, narrow wings having a broad fringe 
 of hair, particularly on the hind-wings, which are often very 
 
 Fig. 284. A tineid leaf-miner of the oak {[Jthocolletis hamaihyadella) 
 
 a, I), larva, flat and round forms ; c, pupa ; d, moth ; c, oak leaf showing mines, with cocoons 
 sxf,f. (After Comstock) 
 
 narrow, with a fringe several times as broad. Many of the larvae 
 are leaf-miners, feeding between the surfaces of leaves, in which 
 
 they tunnel out mines 
 whose shape is charac- 
 teristic of the species; 
 some are linear, others 
 serpentine, some are 
 trumpet-shaped, while 
 others are irregular 
 blotches. These little 
 larvae are usually white, 
 and are very much 
 flattened, with small, 
 wedge-shaped heads, 
 
 Fig. 285. The apple leaf-miner. (Greatly enlarged) 
 
 a, moth ; b^ moth at rest ; c, larva ; d, pupa. (After Quain- 
 tance, United States Department of Agriculture) 
 
THE BUTTERFLIES AND MOTHS 
 
 185 
 
 with only rudiments of legs, and with the abdomen constricted 
 between the segments. Many of them hibernate in the fallen 
 
 Fig. 286. The cigar case-bearer. (Much enlarged) 
 
 a, female moth ; /', side view of pupa ; r, larva ; d, egg ; e, wing venation ; /, upper view of 
 cigar-shaped case with three-lobed opening at tip ; g^ side view of same ; li, the case as it 
 appears in the spring ; /, the fall and winter case. (After Hammar, United States Depart- 
 ment of Agriculture) 
 
 leaves, in which they pupate and transform the next summer. A 
 well-known example is the apple-leaf trumpet miner {TiscJieria 
 malifoliella), whose brown, trumpet-shaped mines are common in 
 apple leaves and 
 often cause con- 
 siderable damage. 
 Some of the cat- 
 erpillars of this 
 family make little 
 cases of silk, in 
 which they reside 
 and which are 
 carried over the 
 abdomen as they 
 feed on the foli- 
 age, much like 
 the shell of a 
 
 snail. Common examples are the pistol-case bearer and the cigar- 
 case bearer, which are common on apple foliage and are so named 
 
 F"iG. 287. The case-making clothes moth {Tinea 
 pellioitella). (Enlarged) 
 
 ix, adult ; /', lar\-a ; c, larva in case. (After Riley) 
 
1 86 
 
 ELEMENTARY ENTOMOLOGY 
 
 Fig. 288. The angumois grain-moth [Sitotroga cerealella 
 01.). (Enlarged) 
 
 rt, eggs ; b, larva at work ; f, larva ; d, pupa ; ^, /", moth. (After 
 Chittenden, United States Department of Agriculture) 
 
 from the shapes of the cases. Nearly related to them are the little 
 clothes moths, the plague of every housekeeper, which feed on 
 
 woolens, furs, etc. 
 There are several 
 species : one makes 
 a case of bits of 
 food fastened to- 
 gether with silk, 
 another builds a 
 tube, and a third 
 feeds unprotected. 
 The more common 
 forms are of a 
 brown color and 
 may be distin- 
 guished from other 
 small moths which 
 frequent the house 
 by the broad fringe to the wings already mentioned. Another mem- 
 ber of this family which is a serious pest of stored corn in the 
 South is the angumois grain-moth 
 {GclecJiia cerealella), whose larvae 
 live in the kernels of corn and annu- 
 ally destroy millions of dollars' worth. 
 The leaf -rollers {Tortricidae). Here 
 and there on various shrubs and 
 plants will be found leaves which 
 have been rolled up and fastened 
 together with silk by a little cater- 
 pillar living within. Most of this is 
 done by the leaf-rollers, which are 
 the most characteristic of the family 
 Tortricidae, though by no means all 
 leaf-rollers belong to this group. The 
 oblique-banded leaf -roller {ArcJiips 
 rosaceana) is found commonly on 
 roses and various fruit trees, occa- 
 sionally becoming injurious, while its 
 
 ■Bfrf ^<^ 
 
 Fig. 289. The oblique-banded leaf- 
 roller {Archips rosaceana). (Slightly 
 enlarged) 
 
 a, egg-mass ; l>, larva ; r, pupa ; d, female 
 moth ; c, male moth 
 
THE BUTTERFLIES AND MOTHS 
 
 187 
 
 near relative, the cherry-tree leaf-roller (A. ccrasivorana), festoons 
 the branches of the wild and cultivated cherries with its large nests 
 of leaves fastened together with silk, in which a whole brood of 
 the yellow larvae live and transform. Another 
 group of this family includes the well-known 
 codling moth (Cydia povwnclla), the worst pest 
 of the apple grower, and the eye-spotted bud 
 moth [Tnictoccra occllana), which bores in the 
 young buds 
 of the apple, 
 as well as nu- 
 merous other 
 larvae which 
 bore in the 
 buds, termi- 
 nal twigs, 
 fruits, and 
 seeds of va- 
 rious trees 
 and plants. 
 
 The pyralids. The third family, Pymlidae, 
 includes some half dozen families of quite di- 
 verse appearance and habits, among which are 
 the larger "micros," some of the largest having 
 a wing expanse of one and one half inches and 
 being larger than the smaller forms of the 
 macrolepidoptera. Many of the caterpillars be- 
 longing to this group attack low-growing vegeta- 
 tion, the garden 
 web-worm {Lo- 
 xostege siniila- 
 lis) being one 
 which now and 
 then becomes a 
 pest in various 
 parts of the country, attacking gar- 
 
 1 1,1 Fig. 2Q2. Codling-moth larva in its 
 
 den crops, sugar beets and young ,,i,,ter cocoon under a bit of bark 
 cotton, and corn. The full-grown (Enlarged and natural size) 
 
 Fig. 291. The codling moth. (Enlarged) 
 (After Slingerland) 
 
 Fig. 290. Web and 
 empty pupal skins 
 of the cherry leaf- 
 roller [Archips cerasi- 
 vorana). (Reduced) 
 
 (Photograph by W'eed) 
 
1 88 
 
 ELEMENTARY ENTOMOLOGY 
 
 caterpillars are slightly over an inch long, yellowish or yellowish- 
 green, marked with numerous shining black tubercles or warts, 
 
 and may be recog- 
 nized by the fine 
 web which they spin 
 over the food. The 
 moths are of a 
 yellowish-buff color, 
 with darker mark- 
 ings (see Fig. 293). 
 The melon caterpil- 
 lar and the pickle- 
 worm ( DiapJiania 
 hvalinata and iiiti- 
 dalis) are serious crop 
 pests in the Gulf 
 States, though they 
 occur farther north and in the West. The caterpillars are about 
 an inch long, yellowish or greenish-yellow, and feed on the foliage, 
 flowers, and fruit. Among the typical pyralids is the clover-hay 
 
 Fig. 293. The garden web-worm (Loxostet^'c siniilalis) 
 
 a, male moth : b, larva, lateral view : c, larva, dorsal view ; </, 
 anal segment ; c, abdominal segment, lateral view ; /, pupa ; 
 g, cremaster. a,l'.c,f, somewhat enlarged; d,c,g, more en- 
 larged. (After Riley and Chittenden, United States Depart- 
 ment of Agriculture) 
 
 Fig. 294. The meal snout-moth (Pyralis farhialis Linn.). (Twice natural size) 
 
 a, adult moth ; b, larva ; c, pupa in cocoon. (After Chittenden, United States Department 
 
 of Agriculture) 
 
 worm {Pyralis costalis), which is abundant in stacks or mows of old 
 clover hay, upon which it feeds and which is spoiled by being cov- 
 ered with its silken webs and excrement. The moth is of a lilac 
 
THE BUTTERFLIES AND MOTHS 
 
 189 
 
 color, with golden bands and fringes, and expands four fifths of 
 an inch. The meal snout-moth {Pyralis farinalis) also sometimes 
 feeds on clover hay, though it is more commonly a pest of meal and 
 flour, in which it spins silken tubes wherever it feeds. A thorough 
 
 Fig. 295. The Indian-meal moth (F/odia interpunctella). (Enlarged) 
 
 (7, moth; /', pupa; r, /, caterpillar; d, head; e, first abdominal segment of same. (After 
 Chittenden, United States Department of Agriculture) 
 
 cleaning out of barns and grain rooms will usually prevent trouble 
 from both of these pests. 
 
 The subfamily PJiycitinac includes another pair of pests of grain 
 products, — the Indian-meal moth {Plodia interpu7ictelld), whose 
 white larvcC spin 
 silken tubes in 
 meal, dried fruits, 
 and other stores 
 which they infest, 
 and the Mediter- 
 ranean flour-moth, 
 which has similar 
 habits and has be- 
 come a very serious 
 pest of flour mills, 
 clogging up the 
 machinery with its 
 strong silken webs and necessitating frequent fumigation. The' only 
 common representative of another family is the bee-moth, whose 
 larvae feed upon the wax of honeycombs, in which they make 
 
 Mediteranean flour-moth [Epheslia 
 kuefnticUa) 
 
 n, 6, moth ; c, larva; d, pupa (enlarged); c, abdominal segment 
 
 of larva (more enlarged). (After Chittenden, United States 
 
 Department of Agriculture) 
 
190 
 
 ELEMENTARY ENTOMOLOGY 
 
 silk-lined galleries, destroying the combs. They attack weak colo- 
 nies of bees, which they frequently destroy, and are one of the 
 worst enemies of the apiary. The moth has purplish-brown fore- 
 wings and brown 
 or faded yellow 
 hind- wings. 
 
 The close-wings 
 {C?'a)nbijiac) are 
 so called because 
 their wings are 
 wrapped closely 
 about them when 
 at rest. They are 
 also called snout- 
 moths. They are 
 the small brown- 
 ish or silvery- 
 white moths which 
 fiy up before us 
 in pastures and 
 
 are scarcely distinguishable from the grass stems on which they 
 alight. The larvae feed on the roots and stalks of grasses, living 
 in little tubes constructed of bits of earth and vegetation fastened 
 together with silk. Several spe- 
 cies are sometimes quite injurious 
 to young corn planted on land 
 where they have been abundant, 
 the most common being known 
 as the corn-root web- worm. 
 
 Two other families of this group 
 are known as plume-moths {Ptero- 
 phoridae and Orneodidae), as the 
 wings are split into parts looking 
 like a small fan of feathers. The 
 larvae of one species occasionally 
 webs up the terminals of young grape shoots, and another species 
 is sometimes common on sweet-potato vines, but they are rarely 
 of economic importance. 
 
 Fig. 297. A crambid moth [Crainbin 7<u!i;ivai^clliis) 
 
 a, larva ; /', overground, and c, underground, tube and cocoon ; 
 
 if, e, /. moths with wings open and at rest ; g, egg much enlarged. 
 
 (After Riley) 
 
 Vic. 
 
 29S. 
 moth 
 
 A California plume- 
 (Natural size) 
 
 (After Kellogg) 
 
THE BUTTERFLIES AND MOTHS 
 
 191 
 
 MACRO LEPIDOPTERA 
 
 Among the larger moths are two famihes whose larvae bore into 
 solid wood, though they are by no means nearly related. 
 
 The carpenter-moths (Cossidae) are medium-sized to large moths 
 with spindle-shaped bodies and strong, narrow wings, thus closely 
 
 
 
 Fig. 299. The leopard moth. (Natural size) 
 
 a, female moth ; 3, male moth ; c, larva in burrow ; d, pupal skin from which moth has 
 emerged. (From Insect Life, United States Department of Agriculture) 
 
 resembling the sphinx moths. The caterpillars are all wood borers, 
 living from two to four years in the roots or trunks of trees. When 
 full grown they are from two to three inches long, usually whitish, 
 more or less black-spotted, with black heads bearing strong jaws. 
 The female moth of a common species, which lives in the locust, 
 has a wing expanse of three inches and is of a pepper-and-salt 
 color. A recently imported European species is the leopard moth 
 
192 
 
 ELEMENTARY ENTOMOLOGY 
 
 {Zaizera pyrina), which is seriously damaging the shade trees 
 of Eastern cities to which it has spread. It is white, spotted with 
 numerous black spots. 
 
 The clear-winged moths (Sesiidae). The caterpillars of the clear- 
 winged moths also bore into the trunks and roots of trees and the 
 stalks of smaller plants. The wings of the moths are quite narrow 
 and are free from scales except along the margins and over the 
 
 Fig. 300. Peach-tree-borer moths. (Natural size) , 
 
 The upper one and one at right are females, the other two are males. (After Slingerland) 
 
 veins, leaving them quite transparent. The antennae are long, and 
 the body is long and slender, the abdomen being commonly banded 
 with yellow and terminating in a tuft of scales. Unlike most moths 
 they are found frequenting flowers in the daytime, and may very 
 readily be mistaken for wasps, which they seem to mimic. The 
 best-known example of the family is the peach-tree-borer {Sanni- 
 noidea cxitiosa), whose white larvae bore into the lower trunks and 
 roots, being probably the worst insect enemy of the peach tree. 
 The males are black with narrow yellow bands on the abdomen, 
 
THE BUTTERFLIES AND MOTHS 
 
 193 
 
 and with quite transparent wings, while the females are much 
 larger, having fore-wings of a blackish brown and entirely covered 
 with scales, and a black abdomen with a broad orange band about 
 the middle. Other injurious species of clearwings, smaller and 
 more wasplike than the peach-borer, are the currant-borer {Scs/a 
 tip7diformis), the raspberry root-borer {Bcnibccia niarginata)^ and 
 the well-known squash-vine borer {Mclittia ccto) whose whitish 
 larvae bore through the vines of squash and other cucurbits, often 
 mining the crops. Not all clear-winged moths belong to this family, 
 
 Fig. 301. The squash-borer (Melittia saiyrinifo7-i7iis Hbn.)- (Enlarged 
 
 one third) 
 
 rt, male moth ; b, female with wings closed ; c, eggs on squash stem ; </, larva ; 
 ^, pupa ; /, cocoon 
 
 for a few of the sphinx moths (which, however, are much larger) 
 and one or two other families have species with wings almost 
 wholly free from scales. 
 
 The prominents (Notodontidae) are dull-colored, medium-sized 
 moths, with a wing expanse of from one and one fourth to two 
 inches, many of whose larvae bear strong humps or prominences 
 which may have given rise to the common name of the family. 
 The moths quite closely resemble the owlet moths, from which they 
 can be distinguished only by an examination of the wing venation. 
 The handmaid moths are of a reddish-brown color, with the fore- 
 wings crossed with several darker brown lines, whose larvae have 
 the peculiar habit of raising the head and tail and standing quite 
 
194 
 
 ELEMENTARY ENTOMOLOGY 
 
 motionless when disturbed, as shown in the ihustration (Fig. 302) 
 
 of the common yellow-necked apple caterpillar {D at ana luiuistra), 
 
 the specific name of which has 
 given the group the common 
 name of "handmaids." It is 
 common on apple trees in late 
 summer, the colonies of cater- 
 pillars stripping the foliage 
 back from the tips of the twigs, 
 and may be readily recognized 
 by the black head, yellow neck, 
 and black-and-yellow striped 
 body. Nearly related species 
 of blackish caterpillars covered 
 with gray hairs often defoliate 
 the hickory. The red-humped 
 apple caterpillar (ScJiiziira con- 
 cinna) is associated with the 
 above species on the apple 
 and has very similar habits. It 
 is of a yellowish-brown color, 
 pale along the sides, which 
 
 are marked with fine black lines ; the head is red, the fourth 
 
 segment bears a prominent red hump, and along the back there 
 
 are many short 
 
 spines. Several of 
 
 the caterpillars of 
 
 this family have 
 
 irregular humps and 
 
 prominences along 
 
 the back and are 
 
 of a green color, so 
 
 that as they feed 
 
 on the edge of a 
 
 leaf they are not 
 
 easily distinguished p^^ ^^^ ^^^^ red-humped apple caterpillar feeding in 
 from the ragged characteristic position. (Natural size) 
 
 leaf edge. Most of (After Britton) 
 
 Fu;. ^02. The yellow-necked apple cater- 
 pillar {^Datana ministra). (Larvae natural 
 size and moth slightly enlarged) 
 
THE BUTTERFLIES AND MOTHS 
 
 195 
 
 Fig. 304. Antlered maple worms {Hetero- 
 
 campa giitii'itta), shcrwnng variation in 
 
 color markings. (Slightly enlarged) 
 
 our commonest species feed 
 on shade and forest trees, but 
 rarely do widespread damage. 
 An exception to this is the case 
 of the antlered maple worm 
 {Heterocampa gutivitta), which 
 stripped thousands of acres of 
 maple and beech along the 
 mountain sides from central 
 Maine southwest to the Adiron- 
 dacks in the summers of 1908 
 and 1909. These caterpillars 
 arc bright green with a saddle- 
 shaped mark of purple, and when just hatched from the eggs have 
 small, branched antlers just back of 
 the head. The eggs of this family 
 are laid on the foliage of the food 
 plant, and the larvae descend to the 
 ground to pupate, the pupae usually 
 remaining in the soil over winter. 
 
 The measuring-worms (family 
 Geometridae) are the caterpillars of a 
 large family ; they have but one or 
 two pairs of abdominal prolegs, so 
 that as the middle of the body is 
 unsupported they are unable to walk 
 like ordinary caterpillars, but loop 
 along in a characteristic fashion, which has given them the com- 
 mon name of " inch-worms " or 
 " measuring worms." Many of 
 them will stand with the body 
 stretched out stiff and motion- 
 less, so that they are readily 
 mistaken for broken twigs and 
 are probably passed over by 
 
 ,, , , , ,, , birds seeking food. Although 
 
 Moth of the red-humped ° . . '^ 
 
 oak caterpillar there are no absolutely distinc- 
 
 (After Weed) tivc characters by which the 
 
 Fig. 305. Red-humped oak cater- 
 pillars {Symnierista albifrons) on 
 oak leaf. (Reduced) 
 

 
 
 .i 
 
 k^' ' 
 
 
 
 ^ 
 
 Hy 
 
 Fig. 307. Caterpillar of Nerice bidentata feeding on leaf, showing resemblance 
 of contour to edge of leaf 
 
 (After Packard) 
 
 Fig. 308. The chain-dotted geometer feeding on sweet-fern. (Slightly reduced) 
 
 196 
 
THE BUTTERFLIES AND MOTHS 
 
 197 
 
 moths may be readily recognized, their slender bodies, small heads, 
 and broad wings, which are usually noticeably thin and frail, give 
 them a characteristic appearance. They frequent forests and edges 
 of woodlands, and though a few are orchard pests, and others 
 affect the bush fruits, 
 nearly all of the cater- 
 pillars feed upon the 
 foliage of forest or 
 shade trees, and but 
 few frequent low-grow- 
 ing vegetation. The 
 moths vary from less 
 than an inch to over 
 two inches in wing 
 expanse, but are mostl)- 
 of medium size. The 
 wings remain spread 
 when at rest. Possibly 
 the best-known exam- 
 ples are the canker- 
 worms, which attack 
 the foliage of fruit and 
 shade trees in early 
 spring and drop down 
 from the trees on their 
 silken threads. The 
 females of the canker- 
 worms and some nearly 
 related species are wing- 
 less and look much 
 more like fat spiders 
 than moths. The chain- 
 dotted geometer {Ciu- 
 gilia catenarid) is a snow-white moth marked with zigzag lines 
 and dots of black. Its larvae feed on various low-growing shrubs 
 and trees and sometimes appear in great numbers, as was the case 
 in New Hampshire in 1906, when many acres of sweet fern and 
 scrub birches were stripped. The larvae are of a bright straw yellow. 
 
 Fig. 309. The chain-dotted geometer {Cingilia 
 
 catenaria) ; larva ; larva spinning cocoon ; pupa in 
 
 cocoon ; moth. (Slightly enlarged) 
 
^^^^^^^K)^^^^k 
 
 ^_ '» ^^^iB^ "^B 
 
 
 
 
 O ^^^3^^ 
 
 ^^^B ^^S^K.^^^' .^^^^^^^ 
 
 "/ 
 
 fl^^V^V^^^K^"^ 
 
 mJ^^/^^^1^^^^^^^^ 
 
 T 
 
 i:r <' 
 
THE BUTTERFLIES AND MOTHS 
 
 199 
 
 ^^a^ 
 
 marked with six black lines 
 and with a black dt)t on the 
 side of each segment. The 
 currant span-worm {Diastictis 
 ribraria) is a yellow, black- 
 spotted looper, which often 
 appears in such numbers on cur- 
 rant and gooseberry bushes as 
 to defoliate them very quickly. 
 
 The moths are pale yellow, 
 marked with irregular, dusky 
 spots. Most of the moths of 
 the subfamily Geovictriiiae are 
 of a green color with the wings 
 barred more or less distinctly 
 with whitish lines. The larvae 
 of one of these, the raspberry 
 geometer {SyncJilora glau- 
 caria), feeds on the fruit and 
 foliage of the raspberry, cover- 
 ing itself with bits of vegetable 
 matter, thus masking itself 
 beneath what is apparently a 
 little heap of rubbish. 
 
 The owlet-moths {Noctuidae) 
 are b)- far the largest family of 
 the order, including some 
 twenty-one hundred species, 
 three times as many as there 
 are North American species of 
 birds," and form the great bulk 
 of the moths commonly taken 
 by collectors. As their name 
 indicates, they fly by night (as do all other moths, 
 for that matter) and are frequently attracted to lights, 
 being the common " millers " of popular parlance. 
 The)- are not readily distinguished from nearly 
 related families, nor are the species recognizable 
 
 Fig. 311 
 moth and eg 
 winged male 
 cankerworm. 
 
 Adult female 
 
 gg mass and 
 
 of the fall 
 
 Natural size) 
 
 (After Dritton) 
 
 P"iG.3i2. Canker- 
 worms in charac- 
 teristic attitudes. 
 (Natural size) 
 
 (After Bailey) 
 
200 
 
 ELEMENTARY ENTOMOLOGY 
 
 ■i?*^*^ 
 
 
 .^' 
 
 ^. *^ 
 
 
 y^^*^ 
 
 ^ - --^ws 
 
 ^ y 
 
 ^'wL ■ "t 
 
 tv- ^m r 
 
 w ^ 
 
 ■t^ "'— JT 
 
 %h 
 
 %.**^ 
 
 E^J 
 
 c. 
 
 
 ^ 
 
 \ 
 
 
 
 ■^ 
 
 
 - ' ■ 
 
 Fig. 313. Drasteria erechtea, female 
 
 except by an expert, though many 
 of their caterpillars are the worst 
 pests of the farm and garden and 
 are well known as such to the 
 farmer. The moths are mostly 
 somber gray or brown, with a 
 wing expanse of from one to 
 three inches (averaging about one 
 and one half inches), and with 
 stout bodies. The fore-wings are 
 rather narrow, short, and stout, crossed by darker or lighter wavy 
 lines, and with one or two darker or lighter spots toward the 
 center. The hind-wings are usually plain, and when at rest are 
 concealed by the fore-wings, which 
 cover them, either flat on the back 
 or slightly roof-shaped. Some of 
 the caterpillars are hairy like the 
 " woolly bears," but most of them 
 are smooth, dull-colored " worms," 
 obscurely striped, as are the com- 
 mon cutworms. Almost all of the 
 larvae feed on low-growing vegeta- 
 tion and pupate in the ground. 
 Among the moths most often observed are those of the northern 
 grass worm {Drasteria erechtea). They are the common moths 
 with drab-gray fore-wings, crossed with two dark bands, which fly 
 up as one crosses a meadow or pasture. The larvae are green, 
 
 narrowly striped, and 
 are semiloopers, some- 
 what resembling the 
 measuring worms in 
 their gait. They feed on 
 clover, but rarely become 
 injurious. The common 
 cutworms which attack 
 garden and field crops 
 Fig. 314 <5. Army-worms. (Natural size) throughout the country 
 
 (After Weed) are the larvae of numerous 
 
 Fig. 314 a. Moth of the army-worm 
 {Leitcania icnipiincta). (Natural size) 
 
 (After Riley) 
 
Fig. 315. The cotton bollworm, or corn-ear worm [Hcliothis cbsoleta). 
 (Natural size) 
 
 rt, adult moth ; b, dark full-grown larva ; c, light full-grown lar\'a ; </, pupa. (.After Howard, 
 United States Department of Agriculture) 
 
 / 
 
 Fig. 316. The cotton-boll cutworm {Prodenia oriiithogalli Guen.). (Enlarged) 
 
 «, dark form of male moth ; b^ pale form of female moth ; c, pale form of lar\a ; </, dark 
 
 form of same ; c^ lateral view of abdominal segments of dark form ; /, of pale form. (.After 
 
 Chittenden, United States Department of Agriculture) 
 
 201 
 
202 
 
 ELEMENTARY ENTOMOLOGY 
 
 Fig. 317. The dark-sided cutworm 
 {Agrotis 7nesso7-ia) 
 
 (After Riley) 
 
 species of moths of this family, be- 
 longing to several genera. The 
 army-worm lyLeiicania iinipiiiicta) 
 is another caterpillar which or- 
 dinarily feeds unnoticed on rank 
 grasses, but occasionally becomes 
 very numerous and advances in 
 armies, destroying all crops in its 
 line of march. The fall army- worm 
 {Laphygvia frngipci-da) has very 
 similar habits, but is more common 
 in the South and West. Two 
 of the most serious cotton pests are 
 the leaf worm {Alctia argil I a ci a) 
 and the bollworm {Hcliothis obso- 
 leta), although the latter also attacks the ears of corn, tobacco, and 
 green tomatoes throughout the Middle States. A common pest of 
 
 cabbage and lettuce is 
 the cabbage looper {A u- 
 tographa bj'assicac), a 
 bright green worm with 
 whitish lines, which 
 bores into cabbages 
 much like the common 
 caterpillars of the cab- 
 bage butterfly. It is 
 known as a looper on 
 account of the way in 
 which it "humps" 
 along, much like a 
 measuring worm, be- 
 cause two pairs of 
 the usual abdominal 
 
 prolegs are lacking. 
 Fig. 318. The cabbasre looper ^ r i i 
 
 Some of the larger 
 
 a, male moth ; b, egg shown from above and from side ; . r 1 • r -i 
 
 c, full-grown larva in natural position, feeding ; d, pupa in SpCClCS 01 iniS lamuy, 
 
 cocoon. (7, c, d, one third larger than natural size ; /', more with 3. wino" expanSC 
 
 enlarged. (After Howard and Chittenden, United States ^ . ^ , 
 
 Department of Agriculture) Ot trom tWO tO three 
 
THE BUTTERFLIES ANT) MOTHS 
 
 203 
 
 inches, of the genus Catocala, have mottled gray fore-wings which 
 very closely resemble the bark of trees, upon which they rest during 
 
 the day. The hind- 
 wings are black, bril- 
 liantly banded with red 
 or yellow. They are 
 much fancied by col- 
 lectors and are taken 
 by luring them with 
 sugar water or similar 
 lures, smeared on the 
 trees. 
 
 The tussock-moths 
 (Liparidae). The cater- 
 pillars of the tussock- 
 moths are strikingly 
 clothed with tufts of bright-colored hairs, or tussocks, which has 
 given them their popular name. The moths are medium sized, 
 usually of a dull brown or gray color. The males have feathered 
 
 Fig. 
 
 519. Catocala nit ran ia and its larva 
 (After J. B. Smith) 
 
 Fig. 320. The white-marked tussock-moth. (Natural size) 
 «, wingless females depositing eggs on cocoons ; b, male moths ; c, full-grown female larva 
 
204 
 
 ELEMENTARY ENTOMOLOGY 
 
 '^ 
 
 :r> 
 
 antennae. The females of our common species, of which the 
 white-marked tussock-moth i^Hcincrocampa leucostigma) is a good 
 example, are wingless and look more like hairy grubs or fat 
 spiders than moths. These wingless females pair as soon as they 
 emerge from the cocoons, and then lay their eggs upon them and 
 die. The eggs of this species are usually found on the trunks of 
 trees, and are covered with a white substance looking like frosting. 
 
 The caterpillar is 
 ' about one and one 
 
 half inches long, with 
 a pair of black pencils 
 of hairs projecting a 
 half inch forward on 
 either side of the head, 
 and a single pencil of 
 similar length extend- 
 ing from the tip of 
 the abdomen. The 
 head and a small 
 glandular dot on the 
 center of the sixth 
 and seventh abdom- 
 «. - «.T7«> ' • inal segments are 
 
 ^^E Vf bright red, the body 
 
 ^^■^K -^ is yellow banded with 
 
 ^^^^^ black, and the first 
 
 four abdominal seg- 
 ments bear brushlike 
 tufts of white hairs. 
 This species often becomes a serious pest of shade and fruit trees, 
 while nearly related species are common but not so injurious. To this 
 family belong the gypsy moth {Porthctria dispar) and the brown- 
 tail moth {Ejiproctis chryson'hoed), both of which have been 
 imported from Europe into New England, where they have done 
 enormous damage to trees of all kinds. The male gypsy moth is 
 tawny brown, with black markings, while the female is much larger, 
 and is white, with wavy blackish lines across the wings. The 
 female is unable to use her wings for flight, and lays her eggs on 
 
 
 ■h 
 
 Fig. 321. Male and female gypsy moths 
 size) 
 
 (Natural 
 
 (After Forbush and Fernald) 
 
THE BUTTERFLIES AND MOTHS 
 
 205 
 
 Fig. 322. Gypsy-moth caterpillars. (Natural size) 
 (After Britton) 
 
 the bark near the cocoon. The caterpillar is two and one half 
 inches long when full grown, of a dark, sooty color, somewhat 
 hair)', and with a double row of five 
 pairs of blue and six pairs of red tuber- 
 cles down the middle of the back, 
 which distinguish it from all other com- 
 mon caterpillars. The brown-tail moths 
 are pure white, with a brown tuft of 
 hairs at the tip of the abdomen, more 
 prominent in the female. Both sexes 
 are strong flyers and are carried readily 
 by the wind. The eggs are laid in a 
 mass on the foliage and are covered 
 with brown hairs from the tip of the 
 female's abdomen. They hatch early 
 in August, and after feeding two or 
 three weeks the little caterpillars draw p,^^ .,._ ^nre brown-tail moth, 
 
 the leaves together at the tips of the male and female. (Natural size) 
 
206 
 
 ELEMENTARY ENl'OMOLOGY 
 
 Fig. 324. The brown-tail-moth caterpillar, 
 from side and back. (Natural size) 
 
 branches with strands of silk and in them spin Httle silken cells, 
 the whole forming a strong web, within which they pass the winter 
 
 and emerge to complete their 
 growth in the spring. The 
 caterpillars defoliate fruit and 
 shade trees, but never attack 
 conifers, as do the partly grown 
 gypsy-moth caterj3illars. They 
 are one and one half inches 
 long, of a dark brown color 
 marked with patches of orange, 
 and covered with numerous 
 long, barbed hairs. On the 
 side of each segment is a 
 characteristic white dash, and the little red spots characteristic of 
 this family are found on the center of the sixth and seventh abdom- 
 inal segments. The tubercles along the back and sides are thickly 
 covered with short brown hairs, the 
 masses having a velvety appearance. 
 These are the nettling hairs, which, 
 when they alight on the skin, produce 
 an eruption very similar to that caused 
 by poison ivy, and which is so painful 
 and annoying that, where the cater- 
 pillars become abundant, they render 
 life miserable for the inhabitants dur- 
 ing early summer. As the nests of 
 this pest have been imported on pear 
 seedlings by nurserymen in almost 
 every state during the past two years, 
 it will be remarkable if it is not soon 
 found outside of New England, and 
 should be constantly watched for, so 
 that it may be brought under control at 
 once before it spreads. This family is 
 a small one, and has almost no species 
 
 r • • , • 1 • tit;- 321;. Winter web of the 
 
 of economic importance m this country brown-tail-moth caterpillars 
 other than those mentioned. (Reduced) 
 
THE BUTTERFLIES AND MOTHS 
 
 207 
 
 Fig. 326. The salt-marsh caterpillar (Estigt/iLiic acraL-a), one of the 
 " woolly bears " 
 
 The tiger-moths (Arctiidae) are well named, for many of them 
 are conspicuously striped or spotted with orange, red, or black. 
 Among the larvae are the well- 
 known hairy "woolly bears," 
 which crawl across the walks 
 in late fall and early spring, 
 faithful harbingers of winter 
 and summer. The moths are 
 frequently attracted to lights, 
 when their brilliant colors al- 
 ways command attention. On 
 some of the larvae the hairs 
 are massed into brushes much 
 like those of the tussock-moths, 
 as is the case with the com- 
 mon harlequin milkweed cater- 
 pillar {Cj'cnia eglc), which is 
 
 Fig. 327. The hickory tiger-moth [Hale- 
 sidoia caryae) and its larva 
 
 clothed with tufts of orange, black, 
 and white hairs, and is the most 
 
 Fig. 728. The common red-and-black , -n ,1 ^^^ 
 
 caterpillar of the Isabella tiger-moth COmmon caterpillar on the milk- 
 
 {Pyrrharctia isabeiid) wccd. Our most common species 
 
 (After comstock) is possibly the Isabella tiger-moth 
 
208 
 
 ELEMENTARY ENTOMOLOGY 
 
 {Pyrrharctia isabclla), whose hairy larva is reddish-brown in the 
 middle and black at either end. It does but litde harm, but is the 
 
 species commonly 
 seen on walks in 
 fall and spring, so 
 that it is well 
 known. The fall 
 web-worm is the 
 common caterpil- 
 lar which covers 
 our fruit trees 
 with its unsightly 
 webs in late sum- 
 mer. The moths 
 are pure white or 
 spotted with black. 
 The caterpillars 
 vary from yellow- 
 ish to blackish, 
 with darker lines 
 and spots, and are 
 covered with long 
 hairs. Most of 
 the caterpillars of 
 this family feed on 
 low-growing vege- 
 tation and weeds ; 
 several now and 
 then become over- 
 abundant and at- 
 tack garden crops. 
 
 Fig. 329. The fall web-worm. (All slightly enlarged) 
 
 (7, light form of full grown larva; /', dark form of same ; r, pupa ; 
 d, spotted form of moth. (After Howard, United States Depart- 
 ment of Agriculture) 
 
 The hawk-moths {Sphingidae) are sometimes called humming- 
 bird moths, for the larger species are fully as large as a humming 
 bird, with three to five inches wing expanse, and are frequently 
 found hovering over petunias and similar flowers on warm summer 
 evenings. They are easily recognized from their long, spindle- 
 shaped bodies, strong, narrow wings, and thick, prismatic antennae, 
 which are often curved back at the tip, forming a slight hook. The 
 
THE BUTTERFLIES AND MOTHS 
 
 209 
 
 proboscis is very long, in some species being twice as long as the 
 body, and is coiled up under the head like a watch spring. Many 
 of the caterpillars are known as hornworms, from the strong horn 
 on top of the last segment, which is quite characteristic of the 
 family, though in some cases it is replaced by a bright, glassy 
 eyespot. "When at rest," says Dr. J. B. Smith, "some of them 
 have the habit of elevating the front part of the body and curling 
 the head under a little, giving them a fancied resemblance to a 
 
 spJiinx, and from 
 this the scientific 
 name has been 
 derived." A well- 
 known example 
 of this family is 
 the large green 
 tobacco or toma- 
 to worm {Phlege- 
 thontiiis q?nnq?ic- 
 viacnlata),\N\\\ch. 
 rags the foliage 
 of these plants, 
 and is the tobac- 
 co grower's worst 
 enemy. It has 
 slanting white 
 stripes along its 
 sides, and, when 
 fully grown, is 
 
 about three inches long ; then it goes underground and transforms 
 to a mahogany brown pupa from one and one half inches to two 
 inches long, bearing a peculiar handlelike process bent back from 
 the head, which has given it the names of " jug-handle grub " and 
 " hornblower." The pupae remain in the soil over winter, and the 
 moths emerge the next spring, there being two broods a season in 
 the North and three or four in the South. The adults are among 
 our most handsome moths, the wings expanding from three to five 
 inches, ashen-gray in color, the fore-wings crossed by irregular 
 darker lines with a white spot near the center, and the hind-wings 
 
 Fig. 330. LarvcC of achemon sphinx 
 
 Above, young larva with head extended and with caudal horn (en- 
 larged); below, full-grown larva with head partly drawn in (natural size) 
 
Fig. 331. Typical sphinx moths [Deilcphila lineata P'ab. above and F/ioliis 
 
 achemon below) 
 
 (After Lugger) 
 
 Fig. 332. Southern tobacco-worm moth. (Natural size) 
 (After Britton) 
 
THE BUTTERFLIES AND MOTHS 
 
 21 I 
 
 banded with black and white, while along the sides of the abdomen 
 are five large yellow spots. The grapevine hog caterpillar (A>/i- 
 pelophaga viyi'on) is typical of a series of species in which the 
 caudal horn of the larva is lost and replaced by an eyespot ; the 
 first two thoracic segments are much smaller and, with the head. 
 
 Fig. 333. Southern tobacco-worm. (Natural size) 
 (After Britton) 
 
 are retracted into the metathorax. This has given some one the 
 idea that they resemble fat porkers, — hence the name " hog cater- 
 pillars." This larva is common on the grape and woodbine and is 
 about two inches long, with a row of seven reddish or lilac spots set 
 on a yellow background along the middle of the back, and a white 
 
 stripe down each side, below 
 which are seven oblique stripes. 
 It is quite variable in color 
 and is very commonly infested 
 with braconid parasites (see 
 page 251), whose cocoons are 
 frequently found covering the 
 caterpillars. Some of the 
 smaller moths of this family 
 have the wings nearly bare 
 of scales, like the clear-winged 
 moths, and, like them, fly around flowers during the day. The larger 
 ones are often called humming-bird hawk-moths, while the smaller 
 
 F'iG. 334. A clear-winged sphinx moth, or 
 bee-moth {He maris ihysbe) 
 
212 
 
 ELEMENTARY ENTOMOLOGY 
 
 ones look quite like large bumblebees. They are readily recognized as 
 belonging to this family by the form of the body, wings, and antennae. 
 The saturnians (superfamily Saturnoided) include some forty-two 
 species of our largest silkworm moths, divided into four families, 
 which need not here be distinguished. The large, brilliantly colored 
 larvae are readily reared, and from the cocoons are secured the 
 handsome moths which are the pride of every collector. The males 
 of this group are easily distinguished from the females by their 
 broadly feathered antennae. The most important economic species 
 
 Fig. 335. Life history of silk moth [Bcnibyx mori) : adult ; caterpillars of different 
 ages; silken cocoons ; pupa; eggs. (Natural size) 
 
 (After Jordan and Heath) 
 
 of the group is the silkworm [Bonibyx mori), which is reared in 
 Europe and Asia for its silk, furnishing all the silk of the world. 
 It has been frequently introduced into this country, but, although it 
 can be grown here, its commercial culture has never proved suc- 
 cessful. It is one of the smaller moths of the group, expanding one 
 and one half inches, the wings being of a cream color, with two 
 or three brownish lines across the fore -wings. The larvae are of a 
 creamy white color and feed on the leaves of the mulberry. Another 
 small species which often defoliates our maples is the green-striped 
 maple-worm {Anisota riibicuiida). The caterpillars are one and one 
 half inches long, yellowish-green, striped with eight lighter lines 
 
THE BUTTERFLIES AND MOTHS 
 
 213 
 
 alternating with seven darker, almost blackish 
 lines, with two prominent black horns on the 
 thorax and a double row of short, thick spines 
 along either side of the body. The moths are 
 pale yellow banded with rose color, and are fre- 
 quently taken at lights. Nearly related species, 
 whose larvas are brownish with orange markings 
 and similar black spines, attack the oak foliage. 
 The lo moth {A?itoincris to) is one of the larger 
 forms, with a wing expanse of nearly three 
 inches, the fore-wings of the males being a 
 brilliant yellow color and those of the female a 
 dark purplish, both having a large eyespot on the 
 center of the hind-wings. The full-grown larva 
 is about two inches long, yellowish-green, with a 
 broad brown or reddish stripe, edged with white, 
 along either side, thickly covered with black- 
 tipped, branched spines which are decidedly 
 
 ftrl^e'd^Ipfe^wZ" Prisonous. The polyphemus moth (7>/..r /./j- 
 
 {Anisoia rtihicitnJa) pheiHits) is ouc of our largest and handsomest 
 species, expanding from four to five inches. 
 
 It is of a yellowish or brownish color, with a dusky band, 
 
 edged without with pink along the margins of both wings, and 
 
 with a prominent e)-espot at the middle of each wing, those on 
 
 the hind-wings 
 
 being bordered 
 
 by a large bluish 
 
 patch. The lar- 
 vas feed on oak 
 
 and various fruit 
 
 and shade trees ; 
 
 they are three 
 
 inches or more 
 
 in length, of 
 
 a bright green 
 
 color, with an 
 
 oblique yellow Fig. 337. The lo moth, female. (Natural size) 
 
 line on the side (After Lugger) 
 
Fig. 338. lo moth caterpillar Fig. 339. ']\'Ica polvphemits caterpillar 
 
 Fig. 340. Telea polyphemiis moth and cocoon. (Reduced) 
 
 (After Lugger) 
 214 
 
THE BUTTERFLIES AND MOTHS 
 
 215 
 
 of each abdominal segment, and with numerous small orange- 
 colored tubercles with metallic reflections. The cocoon is oval, 
 
 usually wrapped in a leaf, 
 and is attached to the 
 twigs of trees and shrubs. 
 The luna moth {Ac tin 
 hma) is a brilliant green 
 species with long tails pro- 
 jecting from the hind- 
 wings ; it is frequently 
 attracted to lights on warm 
 evenings of early summer. 
 Each wing bears a small 
 eyespot, and the anterior 
 margin of the fore-wings 
 is purplish. The larvae 
 feed on the leaves of wal- 
 nut, hickory, and forest 
 trees. Possibly our most 
 common species is the 
 cecropia moth {Saniia 
 cecropia) whose long 
 brown cocoons are fre- 
 quently found on fruit and 
 shade trees. The moths 
 are a dusky, reddish brown, 
 and may be readily recog- 
 nized from Fig. 34 1 . The 
 caterpillar is three or four 
 inches long, of a bright 
 green color, with six prom- 
 inent tubercles on the 
 thoracic segments, — the 
 first four coral-red and 
 the hinder two yellow, — 
 and with smaller, similar yellow tubercles on the back of the abdom- 
 inal segments. They feed commonly on fruit and shade trees, but 
 are never numerous enough to do much damage. The cocoons of a 
 
 Fig. 341. The cecropia moth {Samia cecropia), 
 larva, cocoon, and moth at rest. (All reduced) 
 
 (Photograph by A\'eed) 
 
2l6 
 
 ELEMENTARY ENTOxMOLOGY 
 
 Fig. 342. The promethea moth [Callosamia prornethia). 
 (Reduced) 
 
 (Photograph from hfe by Weed) 
 
 Fig. 343. Pendent 
 cocoons of prome- 
 thea moth. (Greatly 
 reduced) 
 
 nearly related species {Callosarnia prometJiid) hang pendent from 
 the twigs of wild-cherr)^, ash, willow, and other trees. Although 
 many attempts have 
 been made to manu- 
 facture the silk in 
 the cocoons of these 
 native species, they 
 have so far been un- 
 successful. 
 
 Our common tent 
 caterpillar, which is 
 fully described on 
 page 57, is a repre- 
 sentative of a family 
 of this group {Lasi- 
 ocampidae), though 
 much smaller in size 
 than the preceding, 
 having a wing ex- 
 panse of one and Fig. 344. Luna moth [Adia Itma). (Reduced) 
 one half inches. (Photograph from life by weed) 
 
THE BUTTERFLIES AND MOTHS 217 
 
 Fig. 345. Caterpillar of the imperial moth (Basilona imperialis). (Natural size) 
 
 Summary of the Lepidoptera 
 
 Butterflies. Day flyers. Antennae clubbed. Wings held vertically. 
 Skippers {Hcsperina). Antennae hooked. 
 True butterflies (^Papilioitind). 
 
 Swallowtail butterflies {Papilio/iidae). 
 
 White and yellow butterflies {Pieridae), 
 
 Gossamer-winged butterflies {Lycaenidae). 
 
 Four-footed butterflies {Xynnphalidae). 
 MoTH.s. Night flyers. Antennae not clubbed. Wings held flat. 
 Microlepidoptera. 
 
 Family ( Tineidae). Leaf -miners, clothes moths, etc. 
 
 Family (Tortricidae). Leaf -rollers, bud-borers, etc. 
 
 Family {Pyralidae). Leaf-folders, meal-worms, close-wings, bee-moth, 
 etc. 
 Macrolepidoptera (in part). 
 
 Carpenter-moths (Cossidae). Larvae wood borers. 
 
 Clear-winged moths {Sesiidae). Larvae wood borers. 
 
 Prominents (Notodontidae). 
 
 Measuring-worms (family Geoniefrhiac). 
 
 Owlet-moths {Noctuidae). 
 
 Tussock-moths [Lipai-idae). 
 
 Tiger-moths [Arctiidae). 
 
 H awk-moths [Sp/u'/ij^'idae). 
 
 Saturnians (superfamily Saturnoidea). Silkworm moths. Tent- 
 caterpillar moths. 
 
CHAPTER XIV 
 
 FLIES, MOSQUITOES, AND MIDGES (DIPTERA) 
 
 Characteristics. Insects with one pair of wings borne by the mesothorax; 
 the hind-wings represented by a pair of knobbed threads, called halteres ; 
 mouth-parts, suctorial ; metamorphosis, complete. 
 
 Ordinarily all sorts of small insects with membranous wings are 
 indiscriminately called ^Z/cj-, and the term " fly " has been used to 
 form part of a compound name for insects of several different 
 
 orders, such as May- 
 fly, sawfly, gallfly, 
 butterfly, etc., but," 
 considered from the 
 entomological stand- 
 point, a fly is a two- 
 winged insect of the 
 order Diptcra. With 
 this in mind, it is al- 
 ways easy to distin- 
 guish flies, as no 
 other order has a 
 single pair of wings 
 (except the male scale insects), and the name of the order becomes 
 significant, being derived from dis (two) and ptcron (wing). The 
 hind-wings are replaced by a pair of odd, club-shaped organs, 
 called balancers, or halteres, which seem to be concerned with main- 
 taining the equilibrium of the insect and are, of course, peculiar 
 to this order. A few of the parasitic families are wingless. The 
 mouth-parts have already been referred to (see page i8) and 
 are fitted for sucking the juices of plants and animals, though in 
 some there are strong, lancelike mouth-parts fitted for piercing, 
 while in others a large, fleshy proboscis, fitted for rasping and 
 lapping, is developed. 
 
 218 
 
 Fig. 346. The house-fly. (Enlarged) 
 
 a, larva, or maggot; b, puparium ; c, adult. (After Howard 
 United States Department of Agriculture) 
 
FLIES, MOSQUITOES, AND MIDGES 
 
 219 
 
 The transformations are always complete. The most common 
 larvae are termed "maggots," and are headless and foodess, white, or 
 light-colored, tapering to a point at the head, usually with a horny, 
 rasplike feeding organ retruded within the head, though many 
 absorb nutriment from the surrounding food through the skin. In 
 other larvae the head and mouth-parts are well developed, while 
 some, like the mosquito wrigglers, lead a most active life. The 
 pupas are usually 
 naked or inclosed in 
 the last larval skin, 
 though a few make 
 cocoons. Instead of 
 being molted, the 
 last larval skin of 
 most common flies 
 becomes hard and 
 distended, and the 
 pupa separates with- 
 in it, so that the lar- 
 val skin practically 
 forms a cocoon for 
 the pupa and is 
 known as a pupa- 
 rium, which looks 
 much like a large 
 brown or black seed. 
 
 The Diptera is 
 one of the largest 
 orders, with over 
 five thousand species in this country (a great majority of which 
 may be classed as injurious), and includes many serious crop pests 
 and most of the insects which carry disease. The different fami- 
 lies are distinguished by the structure of the antennae and of the 
 wing veins, and are divided into two suborders, the typical Dip- 
 tera {Diptera gennina), including all the common families, and 
 the Pnpipara, including three small families of parasitic species, 
 mostly wingless. 
 
 Fig. 347. A crane-fly [Tipiila hebes Loew) 
 
 a, larva, or meadow-maggot ; b, pupa ; c, adult male fly. 
 (After Weed) 
 
220 
 
 ELEMENTARY ENTOMOLOGY 
 
 -gjfc 
 
 I. Typical Diptera {Diptera genuina) 
 
 Disregarding characters of the puparium which are not readily 
 observable, the typical Diptera are divided into two series of fami- 
 lies, based upon the length of the antennae, known as the Long- 
 horned Diptera, which have 
 more than five antennal 
 segments, and the Short- 
 horned Diptera, having not 
 more than five segments. 
 
 LONG-HORNED DIPTERA 
 
 {XEIMATOCERA) 
 
 The crane-flies (Tipulidae) 
 
 are easily recognized by 
 their long, slender bodies, 
 narrow wings, and exceed- 
 ingly long, fragile legs, 
 which characteristics have 
 given them the name 
 " granddaddy-long-legs, " a 
 name more correctly ap- 
 plied to the harvestmen, 
 which are round-bodied 
 spiders with very long legs. 
 The maggots of crane-flies, 
 sometimes called leather- 
 jackets, or meadow-mag- 
 gots, are dirty white, with 
 a tough skin, and feed 
 upon the roots of plants, 
 decaying vegetable matter, 
 and fungi. They are fre- 
 quently found in the decay- 
 ing wood and mold in the 
 crotch of an old tree or in 
 a stump, while several species which feed on their roots sometimes 
 become abundant enough to do considerable damage to grasses and 
 grains. The adults are among our largest flies, the common species 
 
 Fig. 348. Life history of a mosquito 
 {Cii/ex sp.). (Much enlarged) 
 
 On the surface of the water, a small raft of eggs 
 
 in the water, several long, slender larvae (wrigglers) 
 
 and one large-headed pupa (tumbler) ; above 
 
 water, an adult. (From life, after Kellogg) 
 
 the 
 
FLIES, MOSQUITOES, AND MIDGES 
 
 221 
 
 having a wing expanse of from one and one half to two inches. 
 The giant crane-fiy {Holoriisia mbigmosd), of Cahfornia, is the 
 
 Fig. 349. Anopheles mosquito and malaria 
 
 a, larva; b, pupa; c, adult; d, the blast introduced into the blood by the mosquito ; e to J, 
 stages through which the plasmodium passes in the red blood corpuscle ; i, the spores 
 which enter new blood corpuscles ; /, ;«, the microgamete ; a, 0, the macrogamete ; /, 
 flagellae forming ; ^, union of a flagellum with macrogamete ; r, fusion of nuclei ; s, the 
 vermicule ; i to y, formation of the zygote in the mosquito stomach, the fully developed 
 zygote, J, rupturing to produce blasts. (After J. B. Smith) 
 
 largest species of the order, being two inches long and the legs 
 spreading some four inches. What advantage the crane-flies derive 
 from their size is a question, as they are very awkward and fragile. 
 
222 
 
 ELEMENTARY ENTOMOLOGY 
 
 The mosquitoes (Culicidae) are so well known as to need no 
 description, but there are many mosquitolike flies which might 
 
 easily be confused with 
 them. They have the 
 mouth-parts developed 
 into a strong proboscis 
 fitted for piercing, and 
 the antennae of the males 
 are strongly plumose (see 
 Fig. 53) ; but the most 
 distinctive character consists of a fringe of scales along the margin 
 of the wing and also along the wing-veins, which can be readily 
 seen with a lens. The eggs are laid in small masses on the surface 
 
 Fig. 350. Resting positions of Anopheles and 
 Cnlex mosquitoes. (Slightly enlarged) 
 
 (After Grassi) 
 
 Fig. 351. The yellow-fever mosquito {Stegomyia calopus). (Enlarged) 
 (After Howard, United States Department of Agriculture) 
 
 of quiet or slow-moving water, and hatch in from one to four days. 
 The larvae are the well-known wrigglers of ponds and ditches, with 
 their characteristic long, squirming bodies, thick head end, and 
 
FLIES, MOSQUITOES, AND MIDGES 
 
 223 
 
 forked abdomen. They breathe through the respiratory tube pro- 
 jecting upward from the abdomen, which is thrust through the 
 surface of the water as the wriggler rests at the surface. The 
 wrigglers feed on bits of organic matter and microorganisms. 
 The pupa has the head and thorax very remarkably enlarged, and 
 there are two breathing tubes which project from the back of the 
 
 Mil ^''^v-^fl 
 
 ■ k . S. "<J5?^ ^^. .^^"^Mbi^ ■ 
 
 
 >■ -^ . 
 
 Hk^ -:>^ ' 
 
 &:^ 
 
 ^^^^Ife^^Hii^riflBjfe ^9 ^^■i^^l^'Sk^K 
 
 IBhB 
 
 Fig. 
 
 35- 
 
 AVing of a mosquito (Miiuso/na titillaiis Walk.) enlarged, showing 
 scales on veins, and a portion of same further enlarged 
 
 (After Felt) 
 
 thorax. The pupa stage lasts from one to three days, the whole life 
 from t^g to adult requiring from eight days to two or three weeks. 
 Not only are mosquitoes exceedingly annoying, rendering some 
 sections almost uninhabitable, but it has been shown -that malarial 
 fever is transmitted only by mosquitoes of the genus Anopheles, 
 and that the dreaded yellow fever is similarly carried only by species 
 of the genus Stegomyia, which has resulted in an entire change in 
 the methods of controlling these diseases. Ver)^ much can be 
 
224 
 
 ELEMENTARY ENTOMOLOGY 
 
 done toward the riddance of mosquitoes in thickly settled com- 
 munities by destroying their breeding places by draining or filling 
 the pools and by oiling the surface of small ponds, rain barrels, etc. 
 True midges (Chironomidae). Many of these look much like 
 mosquitoes, the males having the plumose antennae and being of 
 about the same size, but the wing-veins are simpler and fewer in 
 
 Fig. 353. A midge [C/i/iv/io»/it.\ sp.). {(ireatly enlarged) 
 a, adult male ; /', pupa ; c, larva, (.-^fter Felt) 
 
 number, and lack the scales. Most of the larvae are aquatic, being of 
 very long, threadlike worms which live in the slime and decaying 
 vegetation at the bottom of pools and streams, where they feed on 
 vegetable matter. Many are a bright red in color and have been 
 called blood-worms. The minute punkies, or " no-see-ums," are 
 among the worst enemies of the hunter and fisherman, and one 
 must have a thick skin to withstand their bloodthirsty attacks. 
 
Fig. 354. A punkie, or "no-see-um" (Ceruto/o^ou £7eii/f en /i/s). (Greatly enlarged) 
 
 a, adult ; /', head of same ; c, lar\a ; d, head of same ; e, pupa. (After Pratt, United States 
 Department of Agriculture) 
 
 Fig. 355. (7, a net-winged midge (Z^^d- 
 lioicphala elcgaiititliis), female (two 
 and one half times natural length); b,c, 
 upper and under sides of larva of B. 
 comstockii (five times natural length) 
 
 (After Kellogg) 
 
 225 
 
226 
 
 ELEMENTARY ENTOMOLOGY 
 
 They are grayish-black, not over one twenty-fifth of an inch long, 
 
 and the larvae develop in the water in stumps and logs and under 
 
 damp, dead bark. 
 
 The net-winged midges (Blepharoceridae) are so called on account 
 
 of the peculiar network of small veins crossing the main wing- 
 veins around the margin of 
 the wing, which are peculiar to 
 this family. The small, black 
 larvae live in masses on the 
 rocks in swift- running moun- 
 tain streams, and seem to have 
 but seven segments strongly 
 constricted at each joint. 
 
 The Dixa-midges (Dixidae) 
 include but a single genus, 
 whose larvae are also aquatic. 
 Both of the last families com- 
 prise only a few uncommon 
 species, and lack the whorls 
 of hairs of the male antennae. 
 The black-flies (Simuliidae). Another pest of mountain lovers is 
 
 the black fly, the females of which are most bloodthirsty and often 
 
 Fig. 356. A black fly (Simiiliitm vemisttifii 
 (Four times natural size) 
 
 (7, larva ; b^ pupa ; ^, adult. (After Weed) 
 
 Fig. 357. The fickle midge (Sciara iiiconstaiis), a fungus-gnat sometimes trouble- 
 some in greenhouses. (Much enlarged) 
 
 a, male ; b, genital organs of same ; c, female ; d, enlarged antennal segments of same ; 
 
 e, maxillary palpus of same ; /, tip of abdomen of same from side ; g^ pupa ; h, larva. (After 
 
 Chittenden, United States Department of Agriculture) 
 
FLIES, MOSQUITOES, AND MIDGES 
 
 227 
 
 appear in immense numbers. The larvae are found attached to 
 rocks in shallow, swift-flowing streams, where they feed on various 
 minute plants and bits of vegetation. The adult flies are about one 
 fifth of an inch long, stout-bodied, blackish, with short legs and an- 
 tennae, though the antennae have many distinct segments. Recent 
 experiments made in the White Mountains indicate that it may be 
 possible to eradicate the larvae in mountain resort regions by oiling 
 the streams with Phinotas oil. The southern buffalo gnat is a 
 serious pest of domestic animals in the South, such immense 
 swarms sometimes appearing as to cause their death. 
 
 Fig. 358. The pine-cone willow gall caused by a cecidomyiid, cut open at 
 right to show maggots within 
 
 (After Washburn) 
 
 Fungus-gnats. Wherever there is decaying vegetable matter 
 or damp fungi, as in decaying wood, under damp bark, in decom- 
 posing leaves, etc., there are found small, white or pink maggots, 
 which develop into the graceful little fungus-gnats {Mycetophilidac). 
 The larvae often stick together in large patches, and sometimes 
 form long processions of wriggling maggots. One species feeds on 
 injured apples, while another has been shown to cause a form of 
 potato scab, and one is a serious pest of mushrooms, but most of the 
 larvae are entirely harmless. The flies are mosquitolike in general 
 form, but the antennae are bare and the coxae are unusually long. 
 
228 
 
 ELEMENTARY ENTOMOLOGY 
 
 Fig. 359. Pear midge [Di- 
 plosh pyrivora). (Enlarged) 
 
 (After Riley) 
 
 Gall-gnats. The smallest and most deli- 
 cate of the gnatlike flies are the gall-gnats 
 {Cecidomyiidae). The adults are rarely 
 over one eighth of an inch long, with long 
 antennae clothed with short hairs, and with 
 the wing-veins greatly reduced in number. 
 They will be rarely noticed by the begin- 
 ner, but the work of the larv^ is often 
 much in evidence, owing to their feeding 
 within the stems and leaves of plants and 
 giving rise to galls. Frequently a green, 
 cone-shaped gall is found on the tips of 
 willow twigs, known as the pine-cone 
 willow-gall, which is caused by one of 
 these larvae {Cccidomyia strobiloides). 
 The larvae of the clover-seed midge live in 
 the heads of clover and destroy the seed 
 so that in many sections it is often impossible to mature it. The 
 best-known exam- 
 ple of the family, 
 an d our worst wheat 
 pest, is the Hessian 
 fly, so called be- 
 cause it was sup- 
 posedly introduced 
 in straw brought 
 over to Long Is- 
 land by the Hes- 
 sian troops during 
 the Revolutionary 
 War. The mag- 
 gots bore into the 
 crown and stalks 
 of wheat, weaken- 
 ing the plant and 
 seriously curtailing 
 production where 
 they are abundant. 
 
 Fig. 360. The Hessian fly, adult male. (Much enlarged) 
 (After Marlatt, United States Department of Agriculture) 
 
FLIES, MOSQUITOES, AND MIDGES 
 
 229 
 
 Fig. 361. Horse-fly {Tahanus atratics) 
 n, lan'a ; fi, pupa ; c, adult, (.\fter Riley) 
 
 SHORf-HORNEl) FLIES {BRACHYCEKA) 
 
 In this section the antennae are composed of from three to five 
 segments, the famihes being divided into three groups according 
 
 to the structure of the 
 \ V/ / antennae, and being fur- 
 
 ther distinguished by 
 w^^ ^^-"•••""?=gr r^^^)^ .^=r:^^^grr^^^^ the wing-vcnation. 
 
 .3 X. , — ..-^jMBirfiii* . . . ^ ev In the first group the 
 
 third segment of the an- 
 tenna is clearly ringed, 
 showing that it is made 
 up of several segments 
 grown together. 
 
 Horse-flies. The best- 
 known family of this 
 group is that of the 
 horse-flies {Tabaiiidae). 
 They are well-known 
 pests of live stock and often become annoying to man. The adults 
 have short, broad heads, large eyes, thick bodies, short, oval abdo- 
 mens, and strong, powerful wings, which enable them to outstrip the 
 swiftest horse. They 
 are often most trouble- 
 some along wooded 
 roads, where they will 
 attack a horse in 
 swarms and, with their 
 loud buzzing, render 
 the animal frantic. 
 The larvae are long, 
 pointed maggots which 
 live mostly in water in 
 swampy places and 
 along the edges of 
 streams and ponds, 
 and are carnivorous. In the swamp lands of southern Texas and 
 Louisiana the large horse-flies appear in such swarms as to make 
 life for cattle almost impossible, and along our coasts wherever 
 
 Fig. 362. A "green-head" {Tabanus liiieohx Fab.) 
 (Much enlarged) 
 
 (After Lugger) 
 
2^^0 
 
 ELEMENTARY ENTOMOLOGY 
 
 there is marshland the well-known green heads annoy bathers as 
 well as animals. Our largest horse-fly is an inch long, with a 
 two-inch wing expanse, and of a dull black color, while other 
 common, smaller species are brown, with the wings banded with 
 black. Only the females are bloodsuckers, the males feeding on 
 the pollen of flowers. 
 
 The soldier-flies (Stratiomyidae) somewhat resemble the smaller 
 horse-flies, and are so named on account of the bright yellow or green 
 stripes across the abdomen. The antennae are somewhat longer 
 
 Fig. 363. Stratiomyia discalis. (Greatly enlarged) 
 (After Lugger) 
 
 and the wing venation is quite characteristic. The adults are found 
 on flowers near water, and the larvae are carnivorous or feed on 
 decaying vegetable matter, living in water, earth, or decaying wood. 
 
 In the second group are found two families having four or five 
 distinct antennal segments, — the robber-flies {Asilidac) and the 
 nearly related Midas-flies {Midaidac), which have very similar 
 habits. 
 
 The robber-flies (Asilidae). They are well named, being large, 
 hairy, ferocious-looking flies, which are strong, swift flyers. They 
 may often be seen resting quietly on a dead twig, which they closely 
 resemble in color ; suddenly they will dart off and in mid-air will 
 snatch a fly or any insect which they can overpower, in much the 
 
FLIES, MOSQUITOES, AND MIDGES 
 
 2^1 
 
 Fig. 364. A robber-fly [Stenopogon inqninattis), and 
 
 another {Dasylis soceata) resembling a bumble-bee. 
 
 (Natural size) 
 
 (After Kellogg) 
 
 same manner as does a dragon-fly. The most common species are 
 of a sober gray color, marked with white, yellow, or black, with a 
 long, tapering abdomen, long, narrow wings, large, keen eyes, and 
 a strong proboscis, with which they suck the juices of their prey. 
 
 Other species are 
 thickly clothed 
 with black and 
 yellow hairs, so 
 that they closely 
 resemble bumble- 
 bees. The lar\'se 
 are mostly pre- 
 dacious and live 
 in the ground or 
 in decaying wood, 
 where they feed 
 on the larvae of 
 beetles and on 
 
 decaying vegetable matter. The robber-flies can hardly be con- 
 sidered beneficial, as they rarely feed on noxious insects to any 
 extent, and often destroy bees. 
 
 In the third group is a considerable series of important families, 
 in which the first two segments of the antennae are small and the 
 third is large and clublike and bears a single, 
 conspicuous bristle, called an arista. 
 
 The bee-flies {Bomhyliidae) are medium-sized, 
 oval-shaped flies, with a thick covering of 
 yellow hairs, giving them a resemblance to 
 bees which is increased by their habit of hover- 
 ing over flowers, upon the nectar of which the 
 flies feed by means of their long tongues. 
 Some of them frequent orchards and aid in 
 carrying the pollen from flower to flower by 
 means of the body hairs, to which it adheres. 
 The lar\^ae live in the ground and are very beneficial, being para- 
 sitic upon cutworms, army- worms, and grasshopper eggs. 
 
 The long-legged flies (Dolichopodidae) should be mentioned, for 
 they are of such a striking metallic green, or blue, as to attract 
 
 Fig. 365. A bee-fly 
 {Bombylius sp.). (En- 
 larged) 
 
 (After Weed) 
 
232 
 
 ELEMENTARY ENTOMOLOGY 
 
 attention as they flit over rank-growing foliage in damp places. The 
 adults feed on small flies, and the larvae live underground, being 
 
 either predacious or feeding on 
 decaying vegetable matter. 
 
 The wasp-flies {Conopidae) 
 should also be mentioned, on 
 account of their close rell%ai- 
 blance to wasps, with ^wich 
 they may readily b^confused at 
 first glance, and which they 
 undoubtedly mimic. They are 
 narrow-waisted, the tip of the 
 abdomen is like that of a wasp, 
 and they are often banded and 
 colored to heighten the likeness. 
 The head is robust, which has 
 given them the common name 
 of " thick-headed flies." The 
 bodies of 
 
 Fig. 366. 
 
 A long-legged 
 ditiiis sipho) 
 
 (After Lugger) 
 
 fly [Psilopo- 
 
 larvae are parasitic within the 
 
 wasps, bumble-bees, and grasshoppers, on 
 
 which the eggs are laid. The adults feed on 
 
 nectar and pollen of flowers, over which they 
 
 may be found hovering. 
 
 The flower-flies (Syrphidae) are medium- 
 to-large-sized, bright-colored flies which feed 
 
 upon nectar and pollen of flowers, over 
 which they may be seen 
 to hover, almost motion- 
 less, for several seconds 
 and then to dart off and 
 as quickly return. These 
 
 flies may be readily recognized by a thicken- 
 ing which looks like a vein extending across 
 the middle of the wing. Our more common 
 species of the genus Syrp/uis have the abdo- 
 men marked with alternate bands of black and 
 yellow, and have greenish, bronze, or yellowish 
 bodies. They lay their small, oval, white eggs 
 
 Fig. 367. A wasplike 
 
 fly [P/iysocephala njfitiis). 
 
 (One and one half times 
 
 natural size) 
 
 (After Kellogg) 
 
 Fig. 368. The bee- 
 fly [Eristaiis ienax). 
 (Natural size) 
 
FLIES, MOSQUITOES, AND MIDGES 
 
 233 
 
 Fig. 369. Rat-tailed maggot, larva of 
 a syrphid fly similar to Fig. 368. (Twice 
 natural size) 
 
 (After Kellogg) 
 
 among colonies of plant-lice, around which the flies may be seen 
 hovering, and the maggots devour the aphides greedily, being 
 among their most important natural enemies. Some of the larger 
 species are thickly covered with yellow and black hairs, thus closely 
 resembling bumble-bees, in whose nests their larvae reside. A 
 
 common species which is 
 often found on windows in 
 fall is known as the drone-fly, 
 from its close resemblance 
 to a honey-bee drone. Its lar- 
 xa. lives in foul water and 
 excrement, and is typical of 
 a group which is often found 
 in privies and similar filth. 
 The larva is maggotlike in 
 shape but has a long, extensile tube, through which it breathes, 
 projecting from the tip of the abdomen to the surface of the food- 
 material, which has given it the name of " rat-tailed maggot." 
 None of the family seems to be injurious, and those larvae which 
 feed on plant-lice are exceed- 
 ingly beneficial. 
 
 Bot-flies (Oestridae) . Another 
 family in which the flies are well 
 covered with hairs, so as to 
 closely resemble bees, is that of 
 the bot-flies, whose maggots are 
 among the worst insect parasites 
 of domestic animals. The adults 
 have very rudimentary mouth- 
 parts, so that they probably take 
 no food. The eggs are usually 
 laid on the hair of various animals, from which they are licked off 
 and pass into the alimentary tract, though others lay them upon 
 the lips or in the nostrils of the host. Among the more common 
 are the horse bot-fly, which gives rise to the bots in the stomach 
 of the horse, the ox-warble fly, whose maggots pass from the 
 stomach through the tissues of cattle and finally emerge through 
 holes in the skin, causing " grubby " hides, and the sheep bot-fly, 
 
 Fig. 370. A syrphus-fly ( ]'olucena erecta) 
 which resembles a bumble-bee and is an 
 inquiline in bumble-bees' nests (after 
 S. J. Hunter); and a typical syrphus-fly 
 {^Syn-phits ribesii) 
 
2 34 
 
 ELEMENTARY ENTOMOLOGY 
 
 whose maggots work in the nasal sinuses of sheep, causing " grub- 
 in-the-head, " which often results in fatal vertigo, or "staggers." 
 
 Other species affect various wild 
 mammals, one inhabiting rabbits 
 being particularly common in the 
 South. When full grown, the bots 
 pass out with the excreta, or drop 
 to the ground, in which they 
 pupate. 
 
 The muscids. The last group 
 of the typical flies is much the 
 largest and is now held by most 
 students of this order to represent 
 from twenty to thirty families, so 
 that it may be considered as a 
 superfamily. They are all com- 
 monly called muscids (superfamily 
 Muscina) and the house-fly is the 
 best-known example. No attempt 
 will be made to give the technical 
 distinctions by which the different families or subfamilies may be 
 distinguished, for the knowledge of an expert is required for their 
 recognition ; but the different groups will be considered according 
 
 Fig. 371. 
 
 The ox bot-fly {Hypoden 
 liiieata) 
 
 (After Marlatt, United States Department 
 of Agriculture) 
 
 Fig. 372. The horse bot-fly [Gastrophiliis eqiti), male ; abdomen of female at left; 
 egg attached to hair at right. (Much enlarged) ^ 
 
 (After Lugger) 
 
FLIES, MOSQUITOES, AND MIDGES 
 
 235 
 
 Fig. 373. Bots in stomach of a horse ; some removed to show point of attachment 
 (After Osbom, United States Department of Agriculture) 
 
 to their habits. All are alike in having three-segmented antennae 
 bearing a strong bristle near the base, the modifications of which aid 
 in distinguishing the groups. The larvas are typical white or light- 
 colored maggots 
 livingwithin their 
 food, and the pu- 
 paria are usually 
 formed on or in 
 the soil. 
 
 The discovery 
 in recent years 
 that the common 
 house-fly and also 
 many of its near 
 relatives are re- 
 sponsible for the 
 spread of typhoid 
 fever, intestinal 
 diseases of in- 
 fants, and possibly other infectious diseases has given new interest 
 to the study of the common flies heretofore considered mere 
 
 Fig. 374. Stable-fiy {Sto/No.xys calcit7-aiis), adult, larva, and 
 puparium. (Enlarged) 
 
 (.\fter Howard, United States Department of Agriculture) 
 
236 ELEMENTARY ENTOMOLOGY 
 
 nuisances. Very similar and almost indistinguishable from the 
 house-fly is the common stable-fly, so annoying to cattle. The mouth- 
 parts of the females are fitted for piercing. Just before a storm 
 these flies frequently come into houses and annoy us, from which 
 comes the saying that flies bite before a storm. Like those of the 
 housefly, the larvae live in fresh horse manure. The little horn-flies 
 often annoy cattle by assembling on their flanks and clustering at 
 the base of the horns. The maggots develop in cow manure. 
 
 The flesh-flies (Sarcophagidae) are so called because many of them 
 lay their eggs on the bodies of dead animals or in open wounds. 
 
 Fig. 375. The horn-fly. (Enlarged) 
 (7, egg ; 1^, fly ; c and d, head and mouth-parts. (After J. B. Smith) 
 
 though some of the larvse live in dung and decaying vegetable 
 matter. The common flesh-fly {Sarcophaga sarraccnia) looks like 
 a very large house-fly and gives birth to live maggots (the eggs 
 hatching in the body of the female), which are deposited on fresh 
 meat or in open wounds. The blow-flies and blue-bottle flies are 
 about the size of house-flies, with the abdomen steely-blue or green- 
 ish, and lay their eggs on meat, cheese, or other provisions, which 
 are said to be " blown." The eggs hatch in a day ; the maggots feed 
 on the juices of decaying meat and become full grown in a few 
 days. The common blue-bottle or green-bottle fly {Liicilia cacsar) 
 also lays its eggs on cow dung. The screw-worm fly {CJirysoniyia 
 macellaria) is a bright, metallic green, about one third of an inch 
 
FLIES, MOSQUITOES, AND MIDGES 
 
 long, with four black stripes on the thorax. It is one of the most 
 serious pests of cattle in the South and West, laying its eggs in 
 wounds or sores in which the maggots develop, causing very serious 
 festering sores. Sometimes it oviposits in human nostrils, the 
 work of the larvae not infrequently resulting fatally. 
 
 Fig. 376. The screw-worm fly {Liccilia inacellaria) 
 (7, b, c, larva and details of same ; d, pupa ; f, adult ; /, head from side. (After J. B. Smith) 
 
 The tachina-flies (Tachinidae) are found frequenting flowers ; they 
 somewhat resemble the last group, but are commonly recognized 
 by the numerous stout bristles and hairs with which they are clothed. 
 The adults are mostly of a modest gray color, with thorax streaked 
 with blackish-brown or gray, though some have yellow-banded or 
 red abdomens. The eggs are 
 laid on the bodies of caterpillars 
 or on foliage on which they are 
 feeding, and the maggots are 
 parasitic within them. Any one 
 who has tried rearing moths 
 from their caterpillars will have 
 encountered these flies, for often 
 a score or more will inhabit a 
 large caterpillar. When full 
 
 grown the puparia are formed within the caterpillar or pupa, which 
 never transforms. Some European species w^hich are parasitic on 
 the gypsy moth have been imported into Massachusetts with the 
 hope that they may aid in controlling that pest in this country. 
 
 Fig. 377. A parasitic tachina-fly 
 and its puparium 
 
 (After Weed) 
 
2 38 
 
 ELEMENTARY ENTOMOLOGY 
 
 The tachina-flies are among our most beneficial insects, their white 
 eggs being commonly found on the necks of caterpillars and 
 
 grasshoppers, the flies 
 appearing in large num- 
 bers whenever there is 
 an outbreak of such 
 caterpillars as the army- 
 worm. 
 
 Root-maggot flies 
 (Anthomyiidae) are an- 
 other group of trouble- 
 some flies belonging to 
 this series, many of whose 
 larvae are serious pests 
 of the roots of vegeta- 
 bles. The flies somewhat 
 resemble house-flies, but 
 are smaller and slighter 
 in build. The cabbage- 
 maggot and onion-maggot are well-known examples of these inju- 
 rious larvae, and wherever small flies are seen hovering around 
 these or other root crops, such as radishes, turnips, beets, etc., 
 
 Fig. 378. The cabbage-maggot. (Enlarged) 
 
 a, larva ; /', pupa ; c, adult ; d, head ; c, antenna. 
 (After Riley) 
 
 Fig. 379. The apple-maggot 
 
 a, adult ; b, larva, or maggot ; c, funnel of spiracle on head ; </, puparium ; c, portion of 
 
 apple showing injury by maggots, {a, b, d, enlarged; c, reduced.) (After Quaintance, United 
 
 States Department of Agriculture) 
 
FLIES, MOSQUrrOKS, AND MIDGES 
 
 239 
 
 they may well be regarded with suspicion. One species occasionally 
 attacks the roots of corn, and another, the beet leaf-miner, makes 
 tortuous mines in beet leaves. 
 
 The fruit-flies (Trypetidae) burrow in the flesh of fruits and in 
 the stems of plants. The common round gall on the golden-rod is 
 caused by the maggot of one of this group, most of which are 
 medium-sized flies, often metallic in color and usually with strik- 
 ingly banded or mottled wings. In New England the common 
 apple-maggot {RJiagolctis fovioncUa), or "railroad worm," which 
 
 Fk;. 3S0. A pomace-fly [Dro.sophila ainpelophila). (Enlarged) 
 
 (7, adult ; b, antenna of same ; c^ base of tibia and first tarsal segment ; d, c, puparium 
 
 from side and above ; /, larva ; g, anal spiracles of same. (After Howard, United States 
 
 Department of Agriculture) 
 
 bores through the flesh of the apples, is a well-known example, the 
 adult being black and white with black-banded wings. In Mexico 
 a similar species infests the orange and is occasionally imported 
 into this country. The little pomace-flies {Drosophila sp.), small, 
 yellowish flies about one eighth of an inch long, are common about 
 cider mills and wherever there is decaying fruit, in which their 
 maggots develop. 
 
 II. PUPIPARA 
 
 This suborder includes three parasitic families, with but few 
 species, so named on account of the peculiar mode of reproduction. 
 The eggs and larvae are developed within the body of the female 
 and are given birth when mature and all ready to pupate. 
 
240 
 
 ELEMENTARY ENTOMOLOGY 
 
 Some of the louse-flies {Hippoboscidac) are winged, though some 
 of them cast off or bite off their wings, and are frequently found 
 on birds of prey, while others are common on various birds and 
 
 mammals. The bodies are 
 very much flattened, the 
 head is joined to the thorax 
 broadly, the antennae con- 
 sist of a single segment, 
 and the wing-venation is 
 very simple. The best- 
 known example of the 
 wingless forms is the com- 
 mon sheep-tick {Mclopha- 
 gus ovimis), which should 
 be carefully distinguished from the true ticks 
 (belonging to the Arachnida), and which is the 
 only troublesome member of the family. 
 
 A nearly related family {Nycteribiidae), look- 
 ing like small spiders, are known as bat-ticks 
 and are even more degenerate in structure. The 
 third family {Braulidac) consists of a single spe- 
 cies, the bee-louse, a minute insect about one six- 
 teenth of an inch long, which is found clinging 
 
 to the thorax of queen and drone bees 
 
 Fig. 381. A louse-fly (Olfersia sp.). (Enlarged) 
 
 Fig. 382. Sheep-tick 
 {Melophagus ovinus) 
 
 Fleas (Siphonaptera) 
 
 The fleas may be considered in con- 
 nection with the flies, for they were 
 formerly thought to be wingless Dip- 
 tera, but are now classed as a distinct 
 order. The name of the order is de- 
 rived from two Greek words, sipJwn (a 
 tube) and aptcros (wingless), referring 
 to the tubelike mouth-parts and the 
 lack of wings. The fleas have an oval 
 body which is very strongly compressed laterally, enabling them to 
 pass through narrow cracks. They are usually of a brown color, 
 with small heads bearing sucking or piercing mouth-parts, and 
 
 Fig. 383. Bee-louse [Braula 
 caeca) and its larva. (Greatly- 
 enlarged) 
 
FLIES, MOSQUITOES, AND MIDGES 
 
 241 
 
 have the merest rudiments of wing-pads. The posterior legs are 
 strongly developed, so that the}- are able to jump a considerable 
 distance. In the adult stage they live upon various warm-blooded 
 animals, sucking their blood. The eggs are scattered about in the 
 sleeping places of domestic animals and in the cracks of floors. 
 The larvae are wormlike creatures, with a distinct head, but without 
 legs. They ha\'e biting mouth-parts, and feed upon particles of 
 decaying animal and vegetable matter always abundant in the 
 places in which they live. The full-grown larva spins a cocoon in 
 which the pupal stage is passed. In view of these habits, in addition 
 to cleansing domestic animals it is also necessary to thoroughly 
 clean the sleeping places of cats and dogs, to scrub the floors, 
 and to treat large cracks, in which rubbish may accumulate, with 
 gasoline, kerosene, or a similar contact insecticide. In temperate 
 climates the common species which lives upon dogs and cats is 
 the only one often troublesome to human beings ; in the tropics 
 fleas are much more abundant, and attack man as well as the 
 domestic animals. 
 
 Fig. 384. Cat and dog flea {Ctenocephalus canis). (Much enlarged) 
 
 a, egg ; b, lan-a in cocoon ; c, pupa ; d, adult ; c, mouth-parts from side ; /, antenna ; g, 
 labium from below. (After Howard, United States Department of Agriculture) 
 
242 ELEMENTARY ENTOMOLOGY 
 
 Summary of the Diptera 
 
 Suborder I. Typical 'D\-piQra.{Dipte)-(i ge/iuina). 
 
 Section i. Antennae with over five segments. Long-horned Diptera 
 (^Neinatoceni). 
 Aquatic larvae. 
 
 Families. Mosquitoes {Citlicidae). 
 
 Midges {CJiiroiioviidae^ etc.). 
 Black-flies (Simuliidae). 
 Nonaquatic larvae. 
 
 Families. Crane-flies {Tipulidae). 
 
 Fungus-gnats {Mycefop/iilidae). 
 Gall-gnats {Cecidotnyiidae). 
 Section 2. Antennae with five or less segments. Short-horned Diptera 
 {Brachycerd). 
 Third antennal segment ringed. 
 Families. Horse-flies (Tabamdae). 
 
 Soldier-flies iStratioinyidae). 
 Antennae with four or five segments. 
 Families. Robber-flies {Asilidae). 
 Midas-flies (JMidaidae). 
 Antennae with three segments ; with an arista on third segment. 
 Families. Bee-flies {Boiiibyliidae). 
 Flower-flies {Syrphidae). 
 Wasp-flies [Coiiopidac). 
 Bot-flies {Oestridae). 
 Superfamily. Muscids {Muscina). 
 
 House-flies, etc. {Musctdae). 
 Flesh-flies {Sarcophagidae). 
 Root-maggot flies i^Anthoniyiidae). 
 Tachina-flies ( TacJiinidae). 
 Fruit-flies ( Trypetidae). 
 Suborder H. Pupipara. 
 
 Families. Louse-flies {Hippobosctdae). 
 Bat-ticks {Nycteribiidae). 
 Bee-lice {Bniulidae). 
 
CHAPTER XV 
 
 THE SAW-FLIES, ICHNEUMONS, WASPS, BEES, AND ANTS 
 (HYMENOPTERA) 
 
 Characteristics. Insects with four membranous wings, with few cross-veins, 
 the hind-wings smaller than the fore-wings ; mouth-parts, formed for both biting 
 and sucking, or lapping ; abdomen of the females, usually bearing an ovipositor 
 or sting ; metamorphosis, complete. 
 
 The insects of this order are mostly beneficial, though a few 
 families are injurious to crops. Probably no other invertebrate ani- 
 mals, and very few vertebrates, have as highly developed instincts 
 as many of the insects of this order, the social ants, bees, and 
 wasps having always been the objects of the greatest popular and 
 biological interest on account of their high intelligence, if it may 
 be so termed. 
 
 The wings are membranous, with but few veins, are frequently 
 clothed with short hairs, and are held together by a row of hooks 
 on the anterior margin of the hind-wings, which grasp a fold of 
 the hind-margin of the fore-wings, so that the two wings move to- 
 gether as one. The name of the order is derived from Jiymen (a 
 membrane) and pteron (a wing). The mandibles are always well 
 developed and used for biting. In the ants, bees, and wasps the 
 maxillae are more or less developed as a sheath surrounding the 
 labium, which is prolonged into a tongue, so that these mouth- 
 parts are adapted for sucking or lapping the liquid food. 
 
 Most of the larvae are footless and maggotlike, living within the 
 food, where the eggs are placed by the adults, but the larvae of the 
 first two families bear both true legs and several pairs of abdominal 
 prolegs, and resemble caterpillars in both form and habits. Many 
 species spin a cocoon before pupating, and the newly formed pupae 
 are white, with the legs, wings, and antennae pressed close to the 
 body. 
 
 The different families fall into several natural groups recogniz- 
 able by their structure and habits. 
 
 243 
 
244 
 
 ELEMENTARY ENTOMOLOGY 
 
 Suborder I. The Boring Hvmenoptera {Terebrantia) 
 
 In the first suborder the females bear a well-developed ovipositor, 
 with which the eggs are inserted into the food plant or host insect, 
 and the trochanters of the hind-legs consist of two segments. 
 
 1. PLANT-EATING HVMENOPTERA 
 
 The first two families are distinguishable by the base of the ab- 
 domen being broadly joined to the thorax, with no constriction at 
 this point. 
 
 The saw-flies {Tenthredinidae) are so called on account of the saw- 
 like ovipositor. It is toothed at the tip, having a structure which 
 enables the females to insert their eggs beneath the surface of leaves 
 
 5 
 
 The American rose-slug { Kit de Ion via rosae) 
 
 «, adult saw-fly ; b^ mature larva ; r, work of larva on rose leaf ; </, piece of rose leaf showing 
 location of egg near margin ; e, egg. (a, b, c, and e enlarged, d, natural size.) (After Chitten- 
 den, United States Department of Agriculture) 
 
 or in the stems of plants. They are medium-sized insects from one 
 fourth to one half of an inch long, usually blackish or yellow-and- 
 black in color, with the wings folded over the back when at rest. 
 The larvae resemble small caterpillars, but usually have a larger 
 
HYMENOPTERA 
 
 245 
 
 number of prolegs on the abdomen, and lack the hard shield usually 
 
 found on the prothorax 
 of lepidopterous cater- 
 pillars. Most of them 
 feed on foliage, and many- 
 are quite injurious. Sev- 
 eral species are soft- 
 bodied and covered with 
 a viscid, slimy matter, 
 which has given them 
 the name of "slugs." 
 Among the more com- 
 mon species are the 
 yellow-and-green currant 
 worms {Nematus ribc- 
 sii), which devour the 
 foliage of currants and 
 gooseberries, the rose- 
 slug {Monostcgia rosac), 
 which strips off the sur- 
 face of rose leaves, leaving them brown as if scorched, and the 
 
 pear-slug {Eiiocampa cc- 
 
 rasi), which injures pear 
 
 and cherry foliage in the 
 
 same manner. Other spe- 
 cies often defoliate straw- 
 berry and raspberry bushes, 
 
 and there are numerous 
 
 species which may be 
 
 found on various shade 
 
 and forest trees, one of 
 
 the most injurious being 
 
 the larch saw-fly {Ly- 
 
 gaeoncmatjts crichsonii) , 
 
 which has defoliated and 
 
 thus destroyed large areas 
 
 of larch in New England 
 
 and Canada. 
 
 Fig. 3S6. The pear-slug 
 
 a, adult saw-fly, female ; /', lan^a with slime removed ; 
 
 c, same in normal state ; d, leaves with larva (natural 
 
 size), {a, b, c, much enlarged.) (After Marlatt, United 
 
 States Department of Agriculture) 
 
 Fig. 387. Pear-slug, illustrating method of ovi- 
 position and emergence of larva. (Enlarged) 
 
 <7, cutting of cell beneath epidermis of leaf, showing 
 the tip of the ovipositor ; i, the cell after the egg 
 has been deposited ; c, same after the escape of the 
 larva. (After Marlatt, United States Department of 
 .Agriculture) 
 
246 
 
 ELEMENTARY ENTOMOLOGY 
 
 Horn- tails {Siricidae). The ovipositor of the horn-tails is cylin- 
 drical, more like a borer, and, as it projects from the abdomen, has 
 given the family its name. The eggs are laid within the stems of 
 grasses and various plants, such as berry canes and alder, while 
 some of the larger species deposit them in the solid wood of various 
 shade and forest trees, usually when the tree is beginning to die. 
 
 Fig. 388. The pigeon tremex, or horn-tail ( Tremex columba) 
 
 a, larva with young larva of Thalessa fastened to its side ; b^ its head ; c, d, female and male 
 pupae ; r, female. (After Riley) 
 
 The larvae feed within these plants, tunneling out burrows, and 
 are difficult to combat. Fortunately but few are of considerable 
 economic importance. 
 
 2. GALL-INHABITING HYMENOPTERA 
 
 Gall-flies (Cynipidae). The gall-flies lay their eggs in the leaves 
 and stems of plants, and the injury done by the developing larvae 
 causes the formation of a characteristic gall by the plant tissues 
 surrounding them. The adults are small insects resembling wasps, 
 
HYMENOPTERA 
 
 !47 
 
 and the abdomen is joined to tiie thorax by a slender petiole, or 
 
 stalk, as in the fam- 
 ilies named below, 
 from which they 
 are distinguished by 
 lacking the dark 
 spot, or stigma, 
 toward the end of 
 the anterior margin 
 of the fore-wings. 
 They have short, 
 thick bodies, and 
 the abdomen is com- 
 monly compressed, 
 so that the segments 
 appear to be more 
 or less telescoped. 
 The mossy rose-gall 
 [Rhociites rosae), 
 which forms a large, 
 
 Fig. 389. Mossy rose-gall [Ix/ioditc-s ?vsae) 
 (After Comstock) 
 
 mosslike gall on the stems of roses, and the 
 spongy oak-apple {AmpJiibolips spongifica), 
 which looks like a puff-ball on the leaves and 
 stems of oaks, are well-known examples. The 
 adult flies may be easily reared by removing 
 the galls from the plants when fully matured 
 and placing them in any suitable receptacles. 
 Only a few species are of economic importance 
 on cultivated crops, among which may be men- 
 tioned the pithy blackberry-gall {Diastrophus 
 nebuIos7is), an irregular swelling two to three 
 inches long on blackberry stems, inside which 
 will be found numerous larvae, 
 
 3. PARASITIC HYMENOPTERA 
 
 Most of the small, slender, wasplike hymen- 
 optera, which are distinguishable from the true 
 wasps by the two-segmented trochanters of the 
 
 Fig. 390. Spongy oak- 
 apple {Arnphibolips 
 spongifica) 
 
 (Photograph by Weed) 
 
'A8 
 
 ELEMENTARY ENTOMOLOGY 
 
 hind legs, are parasitic upon the eggs or larvae of other insects, 
 and belong to a group of families which are the most important 
 of parasitic insects. The technical differences 
 between the more common families are based 
 
 i^f: 
 
 Fig. 391. A gall-fly (dV 
 nips querciissaliratix), 
 which produces the 
 jumping galls formed 
 on oak leaves. (Much 
 enlarged) 
 
 (After Kellogg) 
 
 Fig. 392. Long-tailed ophion [Ophion 
 iiiacriinnii). (Much enlarged) 
 
 (After Riley) 
 
 upon the wing-venation, and need not be discussed, but the gen- 
 eral habits are somewhat similar. The female lays her eggs either 
 
 Fig. 393. Pivipla cotiquisitor. (Twice natural size) 
 a, female ; b, female in act of ovipositing in cocoon of tent caterpillar. (After Fiske) 
 
HYMENOPTERA 
 
 249 
 
 upon or within a larva or an egg, the larger forms laying but a 
 single egg on a larva, while the smaller species may deposit a con- 
 siderable number within a large caterpillar. The young larva at 
 once enters the body of the host and feeds upon its blood, not 
 interfering with the principal tis- 
 sues and organs, so that the host 
 goes on growing and furnishing 
 food to the parasite. Finally, 
 however, the parasite so depletes 
 the vitality of the host that it 
 dies, though often not until it 
 has transformed to a pupa. The 
 parasitic larva then spins its co- 
 coon, usually either within or upon 
 the dead host, and in due time 
 the adult parasite emerges and 
 continues the good work. To a 
 
 Fig. 394. Long-tailed ichneumon-fly {Thalessa lunator). (Natural size) 
 
 The parts of the long ovipositor normally lie together as a single organ ; the figure at the left 
 shows the manner of inserting the ovipositor in wood. (After Comstock) 
 
 certain extent many parasites are peculiar to certain host insects, 
 though many of them attack various larvae or caterpillars having 
 similar habits. Frequently many of our worst insect pests are 
 brought under control by the beneficent work of these little parasites, 
 
250 
 
 ELEMENTARY ENTOMOLOGY 
 
 and we are just commencing to learn how to utilize them in com- 
 bating imported insects. Thus the state of Massachusetts and 
 the United States Bureau of Entomology are now carrying on ex- 
 tensive experiments in the importation of the parasites of the 
 gypsy and brown-tail moths, which are very largely effective in 
 holding those insects in control in Europe. The various parasites 
 which attack the eggs and caterpillars at different stages of growth 
 have been imported ; they are reared in this country until suf- 
 ficiently numerous, and are then liberated in sections badly affected 
 by the caterpillars, with the hope that they will ultimately become 
 numerous enough to hold their hosts in check. 
 
 Ichneumon-flies (Ichneumonidae). Any one who has attempted to 
 rear any of our large moths, such as the cecropia or polyphemus 
 
 moths (see page 215), will have be- 
 come acquainted with the Ophion flies, 
 which commonly parasitize them. 
 They are light brown or golden in 
 color, about three fourths of an inch 
 long, and the abdomen is compressed 
 laterally, so that the back is ridged. 
 A single egg is laid on the caterpillar, 
 which lives to pupate. The OpJiion 
 larva spins a tough brown cocoon 
 within the pupal shell and emerges 
 from it the next spring. They belong 
 to the large family of ichneumon-flies, 
 which includes most of the larger par- 
 asites, though some of this family are 
 quite small. The Pimpla flies are nearly the same size, but are 
 black in color and have the abdomen more broadly joined to the 
 thorax. They are effective parasites of many of our most common 
 caterpillars, such as the tent caterpillar, tussock-moth caterpillars, 
 the cotton-worm, and others. 
 
 Braconid-flies (Braconidae). Wherever plant-lice are abundant 
 there will be found some empty brown skins, globular in form and 
 with a small round hole in each. Other individuals will be brown, 
 swollen, and dying as a result of the parasitism of little braconid, 
 flies which are developing within them. When mature the parasite 
 
 Fig. 395. Limnet'ia fugitiva, £ 
 
 parasite of the tent caterpillar 
 
 (Twice natural size) 
 
 (After Fiske) 
 
HYMENOPTERA 
 
 251 
 
 leaves the swollen skin of the aphis through a round hole. Often 
 whole colonies of aphides will be found to have been thus parasi- 
 tized. One little species {LysipJilcbus tritici) has been principally 
 responsible for subjugating the green-bug, or southern grain aphis, 
 
 P'iG. 396. Lysiphlebiis tritici, male, the wasplike parasite 
 of the green-bug. (Very much enlarged) 
 
 (After S. J. Hunter) 
 
 which has been so destructive to grain in the southwest ; this par- 
 asite also attacks many other commonly injurious aphides. Larvae of 
 the large green tobacco or tomato worm {PJilegethojituis qtiinqtte- 
 maailata (Fig. 333) 
 are frequently found 
 covered with what 
 appear to be small 
 silken eggs. These 
 are the cocoons of 
 little braconids of 
 the genus Apantcles 
 
 which have devel- y\g. 397. Lysiphlebus parasite in act of depositing 
 oped within the cat- eggs in the body of a grain aphis. (Much enlarged) 
 erpillar's body. Not (After Webster, United States Department of Agriculture) 
 
2^2 
 
 ELEMENTARY ENTOMOLOGY 
 
 infrequently such caterpillars are ruthlessly destroyed on the sup- 
 position that these are the eggs of the caterpillars, whereas they 
 are its worst enemies and should always be protected. The bra- 
 
 conids are small, wasplike flies, from one 
 sixteenth to one eighth of an inch long, 
 of brown or yellow-and-black colors. 
 
 Fig. 398. Dead green- 
 bugs, showing holes from 
 which parasites emerge. 
 (Much enlarged) 
 
 The upper figure shows the lid 
 still attached, and the lower 
 shows the parasite emerging. 
 (After Webster, United States 
 Department of Agriculture) 
 
 Fig. 399. Wheat-louse parasite (Apkidius 
 g^-anariaphis Cook) and parasitized aphid 
 from which a parasite has emerged. (Much 
 enlarged) 
 
 (Copied from J. B. Smith) 
 
 Fig. 400. Sphinx caterpillar with cocoons of braconid parasites 
 
HYMENOPTERA 
 
 253 
 
 The chalcis-flies (Chalcididae) are even smaller, and are usually 
 blackish with strongly metallic reflections of bronze or green, and 
 are readily recognized by the stout bodies and the almost entire ab- 
 sence of wing veins. Some of them are parasitic on various cater- 
 pillars. One species i^Ptcronialiis pupanim) attacks the common 
 
 Fig. 401. rteromalus piiparitm, a chalcis-fly which parasitizes the cabbage-worm 
 and many other injurious insects. (Greatly enlarged, hair line shows natural size) 
 
 (?, male ; /', female. (After Chittenden, United States Department of Agriculture) 
 
 cabbage-butterfly caterpillars, from one of whose chrysalids several 
 hundred of the parasitic flies may often be reared, and in some sec- 
 tions entirely prevents the increase of this troublesome garden pest. 
 Many of the species are parasitic in the eggs of insects, while others 
 are the most effective parasites of scale insects. Unfortunately one 
 or two species are injurious to crops, the best-known example being 
 the joint- worm of wheat 
 {Is o soma tritici), whose 
 larva works in the lower 
 stems, causing gall-like 
 swellings of the joints 
 and weakening them so 
 that the grain is blown 
 over, much the same as 
 when affected by the Hes- 
 sian fly. 
 
 Smallest of all the par- 
 asites are the little proc- 
 totrypids {Proctotrypidae), 
 the largest of which are 
 
 Fig. 402 
 
 A chalcis parasite (Chhvpachys coloti) 
 of the fruit-tree bark beetle 
 
254 
 
 ELEMENTARY ENTOMOLOGY 
 
 not over one twenty-fifth of an inch long, and the smallest not 
 over one fifth that size. Most of them inhabit the eggs of insects, 
 though some are secondary parasites ; that is, they are parasitic 
 on larger parasites, and to this degree are sometimes injurious. 
 
 Fig. 403. The fig insect {Blastophaga grosso7-inn), whose introduction has made 
 Smyrna fig culture possible in California. (Enlarged) 
 
 a, adult female ; b, head of same from below ; c^ from side ; d, male fertilizing female ; e, 
 female igfeuing from gall ; /, adult male, (.\fter Westwood, from Howard) 
 
 Suborder H. The Stinging Hvmenoptera {Aculeata) 
 
 In the second suborder the female bears a well-developed sting 
 at the tip of the abdomen, which is effectively used as an organ of 
 offense. The trochanters of the hind-legs have but a single seg- 
 ment in all of the ants, wasps, and bees which form this suborder. 
 
 1. THE ANTS {FORMICINA) 
 
 A long chapter might well be devoted to these well-known in- 
 sects, for many interesting volumes have been written by some of 
 our greatest naturalists concerning their remarkable intelligence 
 and the highly developed organization of their society.^ Every one 
 recognizes an ant, but the so-called white ants, or termites ( Tenni- 
 tidae, order Platyptcrd), and the velvet ants {JMiitillidac) may be 
 distinguished from them by the fact that the first segment of the 
 
 1 See the most interesting monograph of Dr. W. M. Wheeler, "Ants," Colum- 
 bia Biological Series. 
 
HYMENOPTERA 
 
 255 
 
 Fig. 404. 
 
 Wheat straw-worm, spring 
 tion. (Much enlarged) 
 
 a, b, lar\'ae ; /, female, (.\fter Riley, United States 
 Department of Agriculture) 
 
 abdomen of true ants forms a sort of knot or tooth between the 
 
 thorax and abdomen. The males and females are winged and mate 
 
 in their nuptial flight, 
 which may often be ob- 
 served on a warm summer 
 day, when the air will be 
 filled with them. After 
 this the males soon die, 
 but the females bite off 
 their wings and either 
 found a new colony or are 
 taken in by some workers. 
 The workers, or neuters, 
 are wingless, undeveloped 
 females. They may upon 
 necessity lay eggs, but 
 these give rise to males 
 only. The workers do all 
 
 the work of the colony, caring for the eggs and larvae, which they 
 
 feed and bring up with all the nicety 
 
 of the best-ordered nursery. The true 
 
 females, or so-called queens, merely 
 
 lay the eggs, having no control over 
 
 the colony, which is managed on the 
 
 most socialistic lines by the workers. 
 
 There are frequently many different 
 
 sizes and forms of workers, each of 
 
 which has a particular sort of work. 
 
 Thus the large-headed, strong-jawed 
 
 individuals are naturally the soldiers, 
 
 while others look after the larvae and 
 
 eggs. Ants feed on various animal 
 
 substances, being very fond of dead 
 
 insects and sweets of all kinds. It is 
 
 the latter taste which leads many 
 
 species to take such care of the little „ a . .. j- u-j 
 
 ^ Fig. 405. Ants attending aphids. 
 
 green plant-lice (see page 127), which (Slightly enlarged) 
 
 give off the sweet honey-dew of which (Photograph by weed) 
 
256 
 
 ELEMENTARY ENTOMOLOGY 
 
 they are so fond. Wherever aphides which produce honey-dew 
 are abundant, the ants will be found watching over them, warding 
 off parasites and often transporting them from plant to plant when 
 food becomes scarce. Now and then an ant may be seen to tap 
 an aphis with its antennae, when a drop of the honey-dew will be 
 exuded and greedily lapped up. So well do they herd them that 
 the aphides have been aptly called the ants' little green cattle. The 
 relation of some ants to plant-lice is most remarkable, as in the 
 case of the little brown ant {Lasiiis nigcr amcricaiuis) which cares 
 for the eggs of the corn root-aphis in its 
 a b ,<? J j-^gg|- Q^gj. y^i]-i|-gj- 2,x\^ then carries the 
 
 aphides to the roots of weeds and grasses 
 and then to corn roots in the spring. It is 
 this relation of the ants to aphides which 
 makes many species of decided economic 
 importance to the farmer and necessitates 
 his destroying them as far as possible. 
 There are several families of ants, but 
 most of our common forms are included 
 in two large families. 
 
 The typical ants (Camponotidae) have but 
 one segment to the petiole of the abdomen, 
 and have no sting. The large, black car- 
 penter-ant {Ca7nponot2is pennsylvaniciis), 
 which tunnels out dead or dying trees, 
 logs, and timbers, is a well-known example 
 of one of our larger species, and the little 
 brown ants of the genus Lasiiis make their 
 nests along roadways and in pastures and meadows, and include the 
 species which care for the corn root-aphis and other injurious 
 plant-lice. Some of the species make large mounds for their 
 homes, and others are slaveholders, capturing the ants of other 
 colonies and maintaining them in servitude. 
 
 Stinging ants. In the Myt-inicidae the petiole of the abdomen 
 is composed of two segments, and most of the females bear a sting. 
 The little red ant {Mojtomoritim pharaonis) which often infests our 
 pantries is well knoWn, but fortunately has no sting. The so-called 
 agricultural-ants of the southwest belong to this group. Their 
 
 Fig. 406. Lateral aspects 
 of abdomens of three fam- 
 ilies of ants 
 
 I, Camponotidae ; 2, Poncri- 
 dae ; j, Mynnicidae ; a, tho- 
 rax ; i, first abdominal seg- 
 ment ; c, second abdominal 
 segment ; (/, third abdominal 
 segment. (After Kellogg) 
 
Fig. 407. The red ant {Mono7?iori!it)i phanjotiii 
 a, female ; b, worker, (.-^fter Riley) 
 
 (Enlarged) 
 
 Fig. 40S. The little black ant {Moiioinoriiun i>ti;iiitin?i). (Much enlarged) 
 
 a, female, or queen ; b, same with wings ; c, male ; d, workers ; e, pupa ; /, larva ; g, egg of 
 worker. (After Marlatt, United States Department of Agriculture) 
 
 257 
 
Fig. .^09. The Argentine ant {IriJomyrmex humilis Mayr.) 
 1?, worker; b, fertile queen. (After Newell) 
 
 Fig. 410. Mound nest of western agricultural-ant [Pogonomymtex occideutalis 
 Cress.), showing entrance hole in mound, and cleared space around it 
 
 (After Headlee and Dean) 
 
 258 
 
HYMENOPTKRA 
 
 259 
 
 nests are made underground, and around the entrance all vegeta- 
 tion is cleared off and regular runways radiate out 
 
 Fig. 411. Western agricultural-ant, 
 or mound-building prairie ant {Poiro- 
 nomyrmex occiJentalis). (Enlarged) 
 
 a, worker: b, queen. (After Headlee 
 and Dean) 
 
 among the neighboring grasses, the seeds 
 the nest and furnish food. A few years ago 
 into New Orleans from Argentina, known as 
 the Argentine ant (Iridomyt-mex Juimilis), 
 and has now spread over Louisiana and 
 neighboring states, becoming a ver\- serious 
 household pest as well as attacking vegeta- 
 tion. Another common species of this fam- 
 ily {Solenopsis 
 geminata) is 
 one of the 
 most impor- 
 tant enemies 
 of the lar\ae of 
 the cotton-boll 
 weevil. It will 
 thus be seen 
 that our com- 
 mon ants are 
 of ver)- diverse 
 habits and of 
 var}ing eco- 
 nomic impor- 
 tance. They 
 are much more 
 abundant in 
 
 of which are stored in 
 a species was imported 
 
 Fig. 412. Solenopsis geminata 
 Fab., a native ant which is a val- 
 uable enemy of the cotton-boll 
 weevil. (Much enlarged) 
 
 (After Hunter and Hinds, United 
 States Department of Agriculture) 
 
 Fig. 413. Work of the 
 
 black carpenter-ant (Cam- 
 
 poiiotus pennsylvanicits) in 
 
 black spruce 
 
 The injury to the living tree 
 allowed the ants to enter, so 
 that the heamvood was com- 
 pletely destroyed by them and 
 the tree fell. (After Hopkins) 
 
26o 
 
 ELEMENTARY ENTOMOLOGY 
 
 the South, and in the tropics become veritable pests. Various arti- 
 ficial nests have been devised whereby colonies may be maintained 
 indoors for study, for which no insects are of more interest.^ 
 
 2. WASPS 
 
 Every small boy soon makes the acquaintance of the bees and 
 wasps, which he naturally classes together from their ability to sting 
 most painfully. The males, however, are entirely harmless, but 
 
 Fig. 414. A digger-wasp {Ainniophila sp.). (Natural size) 
 
 a, wasp putting an inch-worm into its nest burrow ; h^ tlie nest burrow with food for the 
 
 young, paralyzed inch-worms in bottom and burrow nearly filled ; c, wasp bringing a bit of 
 
 material to put over the filled nest burrow. (From life, after Kellogg) 
 
 unfortunately we have no means of recognizing them in the field. 
 The wasps may be distinguished from the bees by the first seg- 
 ment of the hind tarsus being cylindrical and naked, and the body 
 hairs being simple and unbranched. 
 
 Digger-wasps {Sphecind). Several families of wasps are grouped 
 together under this name, which is due to their habit of digging 
 
 1 See Kellogg's "American Insects," p. 548. 
 
HYMENOPTERA 
 
 261 
 
 holes in the ground or in wood, in which their nests are made. 
 They are distinguished from the true wasps( [ rj;?^z';/«) by the wings 
 lying flat on the body when at rest. They are solitary forms, each 
 female making her own nest in which the eggs are laid, and pro- 
 visioning it with spiders, caterpillars, or other insects, upon which 
 the larvae feed. The food is stored alive in a remarkable manner. 
 The female seizes the spider or insect and stings it in the nerve 
 ganglia of the thorax, thus paralyzing it so that it remains alive 
 but helpless. The prey thus para- 
 lyzed is placed in the burrow, the 
 egg is laid with it, and the tube is 
 then sealed up, several compart- 
 ments usually being made, one after 
 another. When the egg hatches, 
 the young larva finds an abundant 
 supply of well-preserved food for 
 its nourishment. Many of the nests 
 are made in burrows in sandy banks, 
 others in the pith of plants, such as 
 the sumac and elder, while others 
 make mud nests or tubes, as do the 
 common mud daubers. 
 
 Velvet-ants (Mutillidae). In the 
 warmer parts of the country one 
 will often see large, antlike insects 
 thickly covered with black, red, or 
 yellow hair, which has given them 
 this name. The males are winged, 
 but the females are wingless and can sting severely. One of the 
 largest species is bright scarlet and black, two thirds of an inch 
 long, and provisions its burrows, made in beaten paths, with flies 
 and other insects, though it is known to enter beehives and 
 kill bees. 
 
 The spider-wasps (Psammocharidae) are slender, long-legged, 
 blackish wasps with reddish or black wings, the body often marked 
 with red or orange ; they provision their nests with spiders. They 
 are mostly medium-sized wasps, though the tarantula hawk {Pepsis 
 formosa), which preys upon the tarantulas of the southwest, is 
 
 Fig. 415. A velvet-ant {Sphaero- 
 
 phthalma siniilima), female. (Four 
 
 times natural size) 
 
 (After Lugger) 
 
262 
 
 ELEMENTARY ENTOMOLOGY 
 
 the largest species of the order, being nearly two inches long 
 and having a wing expanse of over three inches. Not infrequently 
 it is overpowered and destroyed by its formidable prey. 
 
 Fig. 416. The tarantula-killer {Pepsis formosa). (Natural size) 
 
 The thread-waisted wasps (Sphecidae) are readily recognized by 
 the very long, threadlike petiole of the abdomen, and include our 
 common mud-daubers, which make their nests under the eaves of 
 
 buildings and in barns, attics, etc. 
 
 The nests are composed of sev- 
 eral tubes placed side by side, 
 each of which is provisioned 
 with spiders. They may be seen 
 around pools, collecting mud for 
 their nests, and jerking their 
 wings from side to side in a 
 nervous manner. 
 
 A nearly related family {Beni- 
 becidac), which burrows in the 
 sand and provisions its nests with 
 flies and similar insects, includes 
 the large cicada-killer. This is 
 
 Fig. 417. 
 
 A mud-dauber {Pelopaeus 
 cetneiitariiis) 
 
 (After S. J. Hunter) 
 
HYMENOPTERA 
 
 263 
 
 one of our largest wasps, one and one fourth inches long, black 
 or rusty in color, with the abdomen banded with yellow, which 
 pounces upon a cicada and carries it off to its burrow in the ground 
 as food for the larva. Other nearly related families of digger-wasps 
 make their nests in the pith of plants or bore into more solid 
 
 Fig. 418. Mud-dauber wasp {Pelopaeiis sp.) and nest. (Natural size) 
 (After Linville and Kelly) 
 
 wood, or often use the deserted burrow of some other insect (such 
 as some of the bees which have similar habits), provisioning them 
 with flies, spiders, and various insects. 
 
 The true wasps (Vespina) may be distinguished from the digger- 
 wasps by having the wings folded on the back like a fan when at 
 rest, and the legs are not adapted to burrowing, being free from 
 spines and bristles. The solitary-wasps {Enmenidae) resemble the 
 
264 
 
 ELEMENTARY ENTOMOLOGY 
 
 digger-wasps in their habits, making burrows in the earth or in 
 wood, or forming their nests of mud and provisioning them with 
 
 insects. (3ne of our common 
 species {Euvicnes fratermis) 
 makes a little mud nest on 
 the twigs of bushes and trees, 
 which looks like a miniature 
 water-jug. The young are fed 
 on caterpillars, and enjoy 
 cankerworms when these are 
 available. Other species of 
 this family look like small yel- 
 low-jackets. The Social- wasps 
 
 Fig. 419. Female Sphecius spcciosus carry- 
 ing cicada to her burrow. (Natural size) 
 
 (After Riley, United States Department of 
 Agriculture) 
 
 ( ] ^espidac) live in colonies and, be- 
 sides males and females, have a 
 form of undeveloped females known 
 as workers, all of which are winged. 
 They build their nests either in the 
 ground or attached to bushes, trees, 
 or buildings, and construct them of 
 paper made from bits of wood chewed 
 up and formed into a paste, for they 
 discovered the possibility of making 
 paper from wood pulp long before 
 man thought of it. They are very 
 jealous of their homes and enforce 
 a wholesome respect for them upon 
 whoever even accidentally disturbs 
 them, as every one who has attacked 
 a nest of yellow-jackets or hornets is 
 
 Fig. 420. The fraternal potter 
 
 wasp {Einnoies fraiefuiis) and its 
 
 earthen nest 
 
 (Photograph by Weed) 
 
Fig. 421. Poiisies annularis and its nest. (Two thirds natural size) 
 (After Quaintance and Brues, United States Department of Agriculture) 
 
 Fig. 422. Nest of yellow-jacket {]~espa sp.) ; at right, nest opened to show combs 
 
 (Photograph by Weed) 
 
 265 
 
266 
 
 ELEMENTARY ENTOMOLOGY 
 
 Fig. 423. White-faced wasp 
 (I'e.spa iiiaciilata) 
 
 well aware. The adults are predacious and feed their young on 
 
 insects which have been masticated. Not infrequently, where an 
 
 outbreak of caterpillars occurs, wasps 
 will be seen carrying them off to their 
 nests in considerable numbers ; we 
 have observed them at work on the 
 cotton boll-worm and leaf-worms in 
 the South. But two genera are com- 
 mon in the East. Polistcs are black 
 ringed with yellow, or are brownish, 
 and have long, spindle-shaped abdo- 
 mens. Their nests are composed of a 
 
 single comb and are attached by a short stem. The genus Vespa 
 
 includes the hornets and yellow-jackets, which are black, spotted 
 
 or banded with yellow, or yellowish-white, 
 
 with a short, stout body, and the abdomen 
 
 attached by a very short peduncle. Their 
 
 nests are formed of several layers of combs, 
 
 all of which are covered with a waterproof 
 
 covering of paper, made from weatherworn 
 
 wood of stumps, trees, fences, and buildings. 
 
 The nests are gradually enlarged, new combs 
 
 being added and the 
 
 outer envelope being 
 
 enlarged to cover 
 
 them. The males and 
 
 workers die in the fall, 
 
 and the females hiber- 
 nate over winter and 
 
 start a new colony in 
 
 the spring. 
 
 3. BEES [APINA) 
 
 Most of our com- 
 mon bees are readily 
 distinguished as such 
 by the general shape 
 and hairy clothing of 
 
 Fig. 424. (7, mouth-parts of a short-tongued bee 
 {Pivsopis piibescens) (note short, broad, fiaphke 
 tongue, or glossa) ; b, mouth-parts of a long-tongued 
 bee {Anthophora pilipes) (note greatly extended 
 tongue). (Much enlarged) 
 
 (After Sharpe, from Kellogg) 
 
HYMENOPTERA 
 
 267 
 
 the body. Some of them, however, may be confused with some of 
 the wasps, from which they may be separated by the structure of the 
 first segment of the hind tarsus (which is dilated, flattened, and 
 usually provided with numerous hairs 
 to aid in carrying pollen) and also by 
 the fact that the body hairs are covered 
 with short branches instead of being 
 simple, as in wasps. They are quite 
 variable in habit : some are solitary, — 
 that is, each female makes a nest for her 
 young, as do the solitary wasps ; others 
 lay their eggs in the nests of other bees ; 
 while others, of which the honey-bee is 
 the best example, live in colonies. The 
 nests may always be recognized, how- 
 ever, by their being stored with pollen 
 and honey and never with insects. Two 
 families are recognized, which are dis- 
 tinguished by the length of the tip of 
 the labium, or glossa. 
 
 In the Short-tongued bees {Andre- 
 nidac) the tip of the labium is shorter 
 than the base, while in the Long-tongued 
 bees (Apidae) it is much longer and en- 
 ables them to secure the nectar from 
 deeper flowers. All of the bees are of 
 great economic importance, for as they 
 go from flower to flower the pollen be- 
 comes attached to the hairs of the body 
 as well as to the special structures on the 
 legs, by which they transport it, and is 
 brushed off on the stigma of the next 
 flower visited. Thus the bees are the 
 most important agents in the cross-fer- 
 tilization of flowers, without which many plants will not set their seed 
 or fruit. For this reason those who grow cucumbers and tomatoes 
 under glass always have a hive of bees to fertilize the flowers, and 
 where bees are scarce, many of our common fruits set but sparingly. 
 
 Fig. 425. Nest of Aiidrena, 
 the mining bee 
 
 (After Packard) 
 
268 
 
 ELEMENTARY ENTOMOLOGY 
 
 Fig. 426. A common 
 
 short-tongued bee (A/i- 
 
 drena sp.). (Slightly 
 
 enlarged) 
 
 None of the short-tongued bees hve in colonies, and many of 
 
 them make their nests in the ground, which has given them the 
 name of "mining bees." Their tunnels are 
 usually branched, each branch terminating in 
 a single cell, which is lined with a sort of 
 glazing. After this cell is filled with nectar 
 and pollen, the ^g^ is laid and the cell is then 
 sealed up. Quite commonly, large numbers 
 of these tunnels will be found near together, 
 forming large villages. Some of the smaller 
 
 forms mine into the sides of sand banks and 
 
 cliffs, their numerous holes making the surface 
 
 appear as if it had received a charge from a 
 
 shotgun. These little females of the genus 
 
 Halictiis have the interesting habit of making 
 
 a common burrow into a bank and then each 
 
 making a side passage to her own cells, so 
 
 that, as Professor Comstock aptly remarks, 
 
 "While Andrcna builds villages composed of individual homes, 
 
 Halictns makes cities composed of apartment houses." 
 
 Fig. 427. A mining- 
 bee {Ha I ictus lerouxii 
 var. nthomm Ckll.). 
 (Slightly enlarged) 
 
 Fig. 428. The leaf-cutter bee and a leaf-covered cell removed from its burrow. 
 
 (Natural size) 
 
 (After Linville and Kelly) 
 
HYMENOPTERA 
 
 269 
 
 The majority of the Long-tongued bees (Apidac) are soHtary and 
 
 have most diverse nesting habits : some make their cells in the 
 ground, as do the miners ; others are potters, and 
 fashion nests of mud, which are attached to the 
 stems of plants ; some are carpenters, boring holes 
 in wood ; while some go so far as to upholster 
 their nests with neatly cut pieces of leaves, with 
 which the cells are lined and covered. The leaf- 
 cutter bees are peculiarly interesting forms, though 
 of no particular economic importance. They bore 
 a hole in soft or decaying wood, in the bottom of 
 which is deftly fitted a piece of a leaf, rose leaves 
 being commonly used, so as to make a thimblelike 
 cup. In this the pollen and nectar are placed and 
 an egg is laid, and then a circular-shaped piece of 
 leaf is jammed down so as to make a tight wad 
 over the cell, and another similar cell is made 
 above it. The circular areas cut from rose leaves 
 b\' these bees may frequently be noticed. Others 
 are known as carpenter-bees, making their nests 
 in wood. The smaller carpenter-bee {Ceratitia 
 ditpla) inhabits the dead stems of sumac or the 
 hollow stems of other plants, which are cleaned 
 out and used over again by the young. Several 
 cells are made and separated by little chips. When 
 
 the tunnel is full, the female waits for her children to grow up. 
 
 " The lower one hatches first," says Professor Comstock, " and after 
 
 it has attained its 
 
 growth, it tears down 
 
 the partition above 
 
 it, and then waits 
 
 patiently for the one 
 
 above to do the same. 
 
 Finally, after the last 
 
 one in the top cell has 
 
 matured, the mother ^.^ ^3^ ^^ carpenter-bee (Xylocopa caroUna Linn.) ; 
 leads forth her full- b, first segment of hind tarsus ; c, same of bumble-bee 
 fledged famil\- in a (After Waish) 
 
 Fig. 429. Nest 
 
 of carpenter-bee. 
 
 (Reduced) 
 
 (After Jordan and 
 Kellogg) 
 
270 
 
 ELEMENTARY ENTOMOLOGY 
 
 flight into the sunshine." The larger carpenter-bee {Xylocopa 
 virginicd) closely resembles a bumble-bee, being fully as large, 
 yellow and black in color, with a metallic blue reflection on the 
 abdomen. It excavates its nests in solid 
 wood, often boring for a foot or more. 
 
 Many of the long-tongued bees are known 
 
 as guest-bees, from their habit of laying 
 
 their eggs in the cells of other bees, which 
 
 rear the larvae of the intruders as they do 
 
 their own. The largest of these {Psythiriis) 
 
 so closely resemble bumble-bees that it is 
 
 difficult to distinguish them from the males, 
 
 though the females are readily recognized 
 
 from their lacking the pollen-basket borne 
 
 by the hind-legs of the bumble-bees. Just 
 
 why they are tolerated is a mystery, for the 
 
 I bumble-bees allow them to go in and out 
 
 of their nests with the greatest freedom. 
 
 The social bees include our 
 
 common bumble-bee and the 
 
 domesticated honey-bees. The 
 
 bumble-bees are of considerable 
 
 importance to the farmer, for 
 
 they are the only ones whose 
 
 tongues are long enough to feed 
 
 TTrr. .-,T AT^cf „f K ui^ k^^ m h on red-clover blossoms, so that 
 
 1"IG. 431. JNest 01 bumble-bee (Bombiis ' 
 
 sp.), showing opening at the surface of they are entirely responsible for 
 the ground and also brood cells in the jj-g pollination, and where they 
 
 cavity beneath . . ,.„^ , 
 
 are scarce it is ditticult to secure 
 
 (Adapted from McCook by Kellogg) r 1 1 t • 
 
 a crop 01 clover seed. It is 
 hardly necessary to describe the nest of a bumble-bee, for what 
 country boy does not look back upon the stirring experiences in- 
 cident to the robbing of their nests, or of accidentally disturbing 
 one while mowing, and being given good reason to remember the 
 fact. The queens are larger than the males or workers, and are 
 the only forms which live over winter. In the spring the queen 
 finds some deserted mouse nest and within it places a ball of pol- 
 len and her eggs. The larvae feed on the pollen and, when full 
 
HYMENOPTERA 
 
 71 
 
 a 
 
 Fig. 432. Jiumble-bees 
 
 a, worker; /', queen, or fertile female. (After Jordan 
 and Kellogg) 
 
 grown, make strong, brown, silken cocoons, in which they change 
 to pupae. These cocoons are strengthened with wax by the queens, 
 
 and are used for storing 
 honey, after the young 
 emerge. The first broods 
 are all workers, and af- 
 ter their appearance the 
 queen has nothing more 
 to do but lay her eggs. 
 Later in the season the 
 males and other queens 
 appear, all living together 
 in the same nest. In the 
 fall the young queens 
 crawl away to a suitable 
 hibernating place, and in 
 the spring start new colonies, in the manner previously described. 
 Honey-bees. Probably no other insect is of quite as much human 
 interest as the honey-bee. Apiculture is a well-developed art, its 
 hterature is extensive, and its devotees have well-organized associ- 
 ations. The honey-bee was 
 brought from Europe by 
 the early settlers of this 
 country, and swarms have 
 escaped, which have become 
 the wild bees now found in 
 hollow trees. There are 
 three forms in every hive, 
 — the queen, the drones, or 
 males, and the workers, 
 which are imperfectly devel- 
 oped females. The workers 
 are the common forms with 
 which we are familiar, and which do all the work of the colony. The 
 drones are larger than the workers, are reared in larger cells, and are 
 blunter and broader in shape. They are relatively few in number, 
 and occur only in the early summer, during the swarming season, 
 after which they are expelled from the nest or killed by the workers. 
 
 Fig. 433. The honey-bee {A/>/s mellifica) 
 .{, queen ; B, drone ; C, worker. (After Kellogg) 
 
272 
 
 ELEMENTARY ENTOMOLOGY 
 
 The queen bee 
 is much larger 
 than the work- 
 er, and has a 
 long, pointed 
 body. She is 
 developed in a 
 special cell sev- 
 eral times the 
 size of an or- 
 dinary cell and 
 readily distin- 
 guishable, as it 
 extends at a 
 right angle to 
 the other cells. 
 The larvae are 
 all fed by the 
 
 workers, who provide honey and bee-bread, composed of pollen and 
 nectar, for the ordinary cells which are to develop workers and 
 
 Fig. 434. Queen cells of the honey-bee, and worker brood in 
 various stages 
 
 (After Benton, United States Department of Agriculture) 
 
 Fig. 435. Honey-bees building comb (side of hive removed) 
 (After Benton, United States Department of Agriculture) 
 
HYMENOPTERA 
 
 273 
 
 drones, but for the queen cell a royal jelly, which is excreted from 
 the mouths of the workers and is very nutritious. Any worker egg 
 may be developed into a queen 
 at the desire of the workers 
 by enlarging the cell and feed- 
 ing the larva with this royal 
 jelly. In the spring new 
 queens appear in the colony, 
 which are defended from the 
 old queen by the workers, 
 when the old queen, with 
 many of her subjects, forms 
 a new swarm and goes off 
 to start a new colony, thus 
 insuring the multiplication 
 and continuance of the spe- 
 cies. The comb is made of 
 wax, and is constructed in 
 thin, hexagonal cells so as 
 to use as little material as 
 possible, for it takes twenty- 
 one pounds of honey to make 
 one pound of wax. To secure 
 the wax, some of the workers 
 gorge themselves with honey 
 and hang in a curtainlike mass 
 in the hive. In a day or so the 
 wax commences to exude 
 from the wax plates on the 
 underside of the abdomen 
 and is scraped off and used 
 by other workers in construct- 
 ing the comb. From the buds 
 of various trees, particularly 
 the poplar, they collect a 
 sort of resin, called propolis, 
 which is used for cementing 
 crevices in the hive. The 
 
 Fig. 436. Legs of the honey-bee 
 
 .-/, left front leg of worker (anterior view), show- 
 ing position of notch (M) of antenna cleaner 
 on base of first tarsal joint (/ Tar) and of clos- 
 ing spine (cc) on end of tibia (77^) ; B, left 
 hind-leg of worker (anterior view), showing the 
 pollen-basket (67') on outer surface of tibia 
 (Ti) ; C, inner view of first tarsal joint of hind- 
 leg of worker, showing rows of pollen-gather- 
 ing hairs and the so-called " wax shears." 
 (After Snodgrass, United States Department 
 of Agriculture) 
 
2 74 ELEMENTARY ENTOMOLOGY 
 
 bee-bread on which the larvae are fed is made from the pollen of 
 flowers and is carried to the nest on the hind-legs, which have a 
 hair-encircled area, called the pollen-basket, for transporting it. 
 The honey is stored for food during the winter, and is made from 
 the nectar of flowers, which is taken into the honey-stomach, where 
 it is changed to honey, and is then regurgitated into the cells of 
 the comb. 
 
 Summary of the Hymenoptera 
 
 Suborder I. Boring Hymenoptera {Terebratitia). With ovipositor and two- 
 segmented trochanters. 
 Section I. Plant-eating Hymenoptera. Abdomen not constricted. 
 Family. Saw-flies {Tenthredinidae). 
 Horn-tails {Siricidae). 
 Section 2. Gall-inhabiting Hymenoptera {Cynipidae). 
 Section 3. Parasitic Hymenoptera. Abdomen petiolate. 
 Family. Ichneumon-flies (IcJmeiimonidae). 
 Braconid-flies {Braconidae). 
 Chalcis-flies {Chalcididae). 
 Proctotrypid-flies {Proctotiypidae). 
 Suborder II. Stinging Hymenoptera {Aculeata). Females bearing a sting; 
 simple trochanters. 
 Section i. Ants (superfamily Fo)-)nicind). 
 Family. Common ants (Camponotidae). 
 Stinging ants {Myrmicidae). 
 Section 2. Wasps. First segment of metatarsi cylindrical ; hairs simple. 
 
 A. Digger-wasps (superfamily Sphecina). 
 
 Family. Velvet-ants {Mutillidae). 
 
 Spider-wasps {Psatumocharidae). 
 Thread-waisted wasps (SpJiecidae). 
 Bembecids {Bembecidae\ 
 and others. 
 
 B. True wasps (superfamily Vespina). Wings folded fanlike on 
 
 back when at rest. 
 Family. Solitary wasps {Eujuenidae). 
 Social wasps {Vespidae). 
 Section 3. Bees (superfamily Apina). First segment of metatarsi, 
 broad, flattened, hairy ; body hairs, plumose. 
 
 Family. Short-tongued bees {Andrenidae). 
 Long-tongued bees (Apidae). 
 
 Solitary bees, guest-bees, social bees. 
 
PART III. LABORATORY EXERCISES 
 
 CHAPTER XVI 
 
 THE EXTERNAL ANATOMY OF THE LOCUST 
 
 Note. Beyond a doubt, one of the most difficult problems every instructor in 
 the biological laboratory has to meet is to determine the amount of assistance 
 which shall be given individual students. In advanced work, probably the best 
 plan is to train students to rely on their own resources and to solve their own 
 problems. In elementary classes, however, far too much time is often wasted in 
 the laboratory because the instructor does not happen to be at hand to aid and 
 direct the student. For this reason the following instructions are given, more or 
 less in detail, with the hope that the students may intelligently carry on their 
 work without the constant attention of the instructor. 
 
 In order to derive the most benefit from the laboratory work, it is essential 
 that the students should verify every detail of structure herein given before pro- 
 ceeding with the drawings, the latter being considered simply as a means to an 
 end. In fact, the amount of good derived by the student from the laboratory work 
 is largely dependent upon the energy of the individual. For this reason the lab- 
 oratory work should not be judged entirely by the drawings, and, if possible, the 
 actual amount of information obtained by the student in the laboratory should be 
 determined by examinations similar to those given in lecture or recitation work. 
 
 For details concerning laboratory methods and equipment, see Chapter XXIII. 
 
 Section I, External Anatomy of the Grasshopper (Type 
 OF Class Insecta) 
 
 Material. The red-legged locust {Melanoplus femi(i--rubruni) has been 
 selected as the type of the class Insecta, partly on account of its abundance 
 and the ease with which it may be collected, and partly on account of its 
 simplicity of structure. Specimens for class work should be collected in the 
 late summer or early fall, and preserved in 85 per cent alcohol for three or four >- 
 days. After this time has elapsed, they should be transferred to 80 per cent ^ 
 alcohol, to which 10 per cent of pure glycerin has been added. If soaked in p: 
 warm water a short time before using, the specimens will be rendered soft and « 
 pliable. The students should verify the following points : q 
 
 1. Body covering. Carefully examine with a hand lens the body "b 
 covering of the specimen, and note that it is made up of a series 
 
 27 s 
 
 
 
276 ELEMENTARY ENTOMOLOGY 
 
 of hardened plates. These plates are known as sclerites, and the 
 depression between two plates is called a suture. The hardness 
 of the plates is due to the deposition of a horny substance called 
 chitin. 
 
 2. General divisions of the body. Typically the bodies of all 
 insects are divided into a series of rings, or segments. In many 
 places two or more of these rings have grown together, or are fused. 
 Again, in certain regions of the body, parts of the segments may be 
 lost. Regardless of the amount of variation in this respect, however, 
 we find that the segments are always grouped into three regions, 
 known as head, thorax, and abdomen. 
 
 a. The head. The head is made up of a number of segments, 
 which are fused together, forming a boxlike structure. On the 
 head are found the eyes, mouth-parts, and antennas. 
 
 b. TJie thorax. This is the second division of the body, and 
 consists of three segments, known as the prothorax (division nearest 
 the head), mesothorax, and metathorax. Each of these segments 
 bears a pair of walking appendages, and in addition the meso- 
 thorax and metathorax are provided with wings. 
 
 c. 71ie abdomen. This is the third division of the body, and is 
 made up of eleven segments. The posterior segments, however, 
 are not complete, showing modifications. 
 
 Exercise 1. Pin the specimen to the bottom of a dissecting dish, spread the 
 wings and wing-covers of one side, and make an enlarged drawing (dorsal view) 
 of the entire insect, showing the above-named divisions. 
 
 3. Detailed study of the head. As already noted, the head of the 
 locust is made up of a number of segments which have been firmly 
 fused together. The following divisions should be noticed : 
 
 a. The epicrarimm. This is a boxlike piece which surrounds the 
 eyes and forms the basis of attachment for the movable parts of 
 the head. It extends down the front of the head, between the eyes, 
 to the transverse suture, and down the sides of the head to the 
 base of the mouth-parts. The sides of the epicranium below the 
 compound eyes are known as the genae, or cheeks, while the front 
 of the head between the compound eyes is called the frons. 
 
 b. The eonipojind eyes. These are situated upon the upper por- 
 tion of the sides of the head, and are large, brown, oval areas with 
 
THE EXTERNAL ANATOMY OF THE LOCUST 277 
 
 smooth, highly poHshed surfaces. If examined with a lens, the 
 surface will be seen to be made up of a number of hexagonal 
 areas, which are known as facets. 
 
 c. The ocelli. These are sometimes called the simple eyes, and 
 consist of three very small, almost transparent oval areas. One of 
 the ocelli is situated on the front of the head just below the lowest 
 margin of the compound eyes ; the other two are placed in the 
 top of the impression which contains the bases of the antennas, 
 and in contact with the upper portion of the compound eyes. 
 
 d. The aiiteiuHC. These are two long, threadlike processes situ- 
 ated median to the compound eyes. Each consists of about twenty- 
 six segments. Each antenna arises from an oval depression known 
 as the antennary fossa, and is attached by a thin membrane which 
 admits of motion in all directions. 
 
 e. TJie clypeus. This is a short, rectangular piece attached to 
 the lower straight edge of the epicranium. 
 
 f . TJte mouth-parts. These consist of a number of separate parts 
 attached to the ventral region of the epicranium, and will be 
 studied in detail later. 
 
 Exercise 2. Make an enlarged drawing of the front of the head, showing 
 the above parts. 
 
 Exercise 3. Make an enlarged drawing of the side of the head, showing all 
 the parts. 
 
 Exercise 4. Remove the head and notice the occipital foramen, or the 
 large opening by which the cavity of the head communicates with that of the 
 neck and thorax. 
 
 Section II. Mouth-Parts of Locusts 
 
 Material. In order to effectively study the mouth-parts of the locust each 
 student should be provided with prepared slides as well as with the alcoholic 
 specimens. As the parts are removed for study they should be mounted on 
 glass slides in a glycerin solution, and may then be compared with the pre- 
 pared mounts. The parts may be removed by grasping them at their attachment 
 with a pair of stout forceps and pulling them back at right angles to their 
 attachment. 
 
 1. Labrum. The labrum, or upper lip, is a flaplike piece at- 
 tached to the lower edge of the clypeus. The free edge is deeply 
 notched on the median line. 
 
278 ELEMENTARY ENTOMOLOGY 
 
 2. Mandibles. These lie directly beneath the labrum and con- 
 sist of a pair of. short, thick pieces. The inner edge is somewhat 
 flattened and provided with a number of toothlike projections 
 which form the grinding surface of the mandibles. 
 
 3. Maxillae. These are the second pair of jaws ; they lie directly 
 beneath the mandibles and are much more complicated in struc- 
 ture. After they have been removed and mounted in glycerin, 
 the following parts can be distinguished : 
 
 a. The cardo. This forms the attachment or basal piece of the 
 maxilla, and is triangular in shape. 
 
 b. Tiie stipes. This is a quadrangular-shaped segment forming 
 the central part of the maxilla. One side is attached to the cardo, 
 and two of the other sides form the attachment for the remaining 
 structures. 
 
 c. The lacinia. This is attached to the inner edge of the 
 stipes, and is a long, curved piece terminating in a row of sharp 
 teeth. 
 
 d. TJie galea. This portion of the maxilla articulates with the 
 stipes on its outer edge, just below the attachment of the lacinia. 
 It closely resembles this latter structure, except that the end is 
 rounded instead of being toothed. 
 
 e. The maxillary palpcs. These arise from a basal portion 
 known as the palpifer, which articulates with the stipes between 
 the attachment of the galea and the cardo. The palpae consist of 
 five long, slender segments, and, like the antennae, are sensory in 
 function. 
 
 4. Labium. The labium, or under lip, forms the under part of 
 the mouth and, together with the upper lip, almost incloses the 
 mandibles and maxillae. The labium is a complicated structure 
 made up of the following parts : 
 
 a. The submentimi. This forms the attachment to the epicra- 
 nium and is a crescent-shaped piece. It is also joined to the 
 membrane which connects the head with the thorax. 
 
 b. TJie inentiLiii. This is the central portion of the labium, and 
 is joined to the distal margin of the submentum. 
 
 c. TJie ligula. The ligula consists of two large, movable flaps 
 attached to the distal, or outer, edge of the mentum, and forms 
 the terminal, central portion of the labium. 
 
THK EXTERNAL ANATOMY OE THE LOCUST 279 
 
 d. The labial palpcc. These resemble the maxillary palpae, but 
 consist of only four segments, which are attached to the palpifers. 
 These are located on either side of the mcntum, below the attach- 
 ment of the ligula. 
 
 5. Hypopharynx. The hypopharynx, or tongue, is located on 
 the floor of the mouth, between the maxillae. It is diamond-shaped 
 when viewed from above, and is covered with numerous small 
 taste setae. 
 
 Exercise 5. Make a careful drawing of the mouth-parts, showing all of the 
 above-named structures. 
 
 Section III. The Thorax 
 
 Material. Each student should be provided with both alcoholic and dry speci- 
 mens, and should remove the wings and legs from one side of the body only. 
 
 1. Divisions of the thorax. As has already been noted, the 
 thorax is divided into three segments, known as the prothorax, 
 mesothorax, and metathorax. 
 
 2. Prothorax. This is the segment to which the head is attached, 
 and may be divided into two regions, — a dorsal region known as 
 the pronotum, and a ventral region known as the sternum. 
 
 a. The pronotum. This is a bonnetlike piece extending over 
 the dorsal and lateral region of the prothorax. It is made up of 
 a fusion of four plates, which are indicated by the transverse sutures. 
 Anteriorly there is an opening corresponding to the occipital fora- 
 men of the epicranium. 
 
 b. TJic stcrniim. The ventral side, or sternum, of the prothorax 
 is also made up of separate plates, or sclerites. The anterior sclerite 
 bears a spine on the median line. 
 
 c. The prothoracic legs. These arise from the ventral, lateral 
 region of the prothorax. Their structure will be noted later. 
 
 3. Mesothorax and metathorax. The sclerites of these two 
 segments are very intimately associated, and their structure will be 
 discussed together. The mesothorax is joined to the prothorax by 
 a membrane which permits of more or less movement. Posteriorly 
 the metathorax is joined immovably with the first abdominal seg- 
 ment. The hiesothorax and metathorax form a strong, boxlike struc- 
 ture for the support of the wing and leg muscles. Like the prothorax 
 
28o ELEMENTARY ENTOMOLOGY 
 
 these segments are made up of separate plates, held together by 
 a tough, connecting membrane. These plates may, however, be 
 divided into three groups : the tergum, or dorsal region ; the 
 sternum, or ventral region ; and the pleuron, or lateral region. On 
 the dorsal and ventral regions of the body the sutures separating the 
 mesothorax from the metathorax are not very distinct. On the sides 
 of the body, however, there is a very distinct line, or suture, running 
 from the posterior border of the attachment of the second pair 
 of legs toward the dorsal part of the body. This suture divides 
 the mesothorax from the metathorax. The pleura of each of the 
 posterior thoracic segments are again divided by transverse sutures, 
 so that each pleuron consists of two sclerites. 
 
 a. The legs. The mesothoracic and metathoracic legs arise from 
 the lower posterior border of the pleura of their respective seg- 
 ments, and are joined to the thorax by a tough, elastic membrane, 
 
 b. The wings. The wings have a more anterior origin in respect 
 to their thoracic segments than do the legs. Each pair arises at 
 the union of the pleura and tergum. 
 
 c. The spij-aeles. The spiracles, or openings of the respiratory 
 system, consist of two pair 6i liplike structures situated on either 
 side of the bqdy on the anterior margin of the pleural plates. The 
 mesothoracic spiracle is concealed by the posterior edge of the 
 pronotum. The metathoracic spiracle is located just dorsal to 
 the mesothoracic leg, near the suture separating the two segments. 
 There is another spiracle just dorsal to the attachment of the meta- 
 thoracic leg, but this belongs to the first abdominal segment. 
 
 Exercise 6, Make a full-page drawing of a side view of the thorax of a 
 locust with the wings and legs removed, showing all of the parts noted above. 
 
 Section IV. The Thoracic AppENDACiES 
 
 Material. With a pair of fine-pointed scissors remove the legs from one 
 side of the body of the locust and arrange them on a piece of white paper in 
 their regular order. Also remove the wing and wing-cover (mesothoracic wing) 
 from one side and pin to a thin sheet of cork, spreading the wing to its full 
 dimension. 
 
 1. Legs. Make a comparative study of the legs, which will be 
 found to consist of the following segments : 
 
THE EXTERNAL ANATOMY OF THE LOCUST 28 1 
 
 a. TJic coxa. This is the first segment, and is attached to the 
 thorax by a tough, elastic membrane. It is short, almost globular, 
 and is more distinct on the prothoracic legs than on the other two. 
 
 b. TJic trocJiaiitcr. This is the second segment, and is consid- 
 erably shorter than the coxa, and partially or entirely fused with the 
 next segment. It is hard to distinguish except in the first pair 
 of legs. 
 
 c. The fcj/uir. lliis is the third and largest segment of the leg, 
 and in the case of the metathoracic leg contains the muscles used 
 in jumping. 
 
 d. The tibia. This is the fourth segment, and is much more 
 slender than the femur, although about equaling it in length. 
 
 e. 77ie tarstts. This is the last division, and is made up of three 
 short segments freely articulating with each other. These seg- 
 ments bear a series of pads, which terminate on the last one in a 
 large, suckerlike disk known as the pulvillus. On each side of the 
 pulvillus is a pair of claws, the ungues. 
 
 Exercise 7. Make drawings of the first and third thoracic legs, showing all 
 the parts. 
 
 2. Wing-covers. The wing-covers are leathery in texture and 
 do not fold fanlike over the abdomen, as do the two wings. They 
 are strengthened by numerous veins and cross veins. 
 
 Exercise 8. Make an enlarged drawing of a wing-cover, noting the arrange- 
 ment and number of the veins and cross veins ; also note the attachment to 
 the mesothorax. 
 
 3. Wings. These are sometimes called the second, or meta- 
 thoracic, wings. They are membranous in texture and fold fanlike 
 when not in use. They are also strengthened by numerous veins 
 and cross veins, as are the wing-covers. 
 
 Exercise 9. Make an enlarged drawing of a wing, showing the arrangement 
 of the veins, method of folding, attachment, etc. 
 
282 ELEMENTARY ENTOMOLOGY 
 
 Section V. The Abdomen 
 
 Material. Each student should be provided with one alcoholic specimen 
 each of the male and the female locust. The remains of the specimens used in 
 previous sections will be sufficient. 
 
 1. Abdomen of the male. The abdomen of the male locust con- 
 sists of eleven segments ; only seven of these, however, are complete. 
 
 a. The first abdominal segmejtt. This is made up of a curved, 
 dorsal shield, the tergum, which terminates just above the attach- 
 ment of the third pair of legs. This piece partially surrounds the 
 tympanic membrane, or ear, which is a large, crescent-shaped area 
 covered with a semitransparent membrane. Between the ear and 
 the attachment of the legs are the spiracles, which have already 
 been noted. The ventral part of the first segment, the sternum, 
 is not attached to the tergum, owing to the large size of the attach- 
 ment of the legs. The pleura are entirely absent. 
 
 b. The second to eighth abdominal segments. These are all quite 
 similar, consisting of a dorsal tergum, which extends laterally to 
 near the ventral part of the body, where it joins the sternum. 
 The pleura, or side pieces, noted in connection with the thorax, 
 have been inseparably fused to the tergum. One pair of spiracles 
 is located at the anterior margin of each segment near the union 
 of the sternum and tergum. 
 
 c. Segments nine and ten. The terga of these two segments 
 are partially fused together, the union of the two being indicated 
 by the presence of a transverse suture. The sterna of these two 
 segments are entirely fused and much modified, forming a broad, 
 platelike piece. 
 
 d. Segment eleven. This is represented only by the tergum, 
 which forms the terminal, dorsal, shield-shaped piece. 
 
 e. TJie cerci. These are a pair of plates attached to the lateral, 
 posterior border of the tenth segment, and extend back past the 
 end of the eleventh tergum. 
 
 f. The snbgenital plate. This is attached to the ninth sternum 
 and forms the most posterior ventral plate of the body. 
 
 g. The podical plates. These lie directly beneath the cerci and 
 ventral to the eleventh tergum. The anus opens between these 
 plates, and the genital chamber lies directly below them. 
 
THE EXTERNAL ANATOMY OF THE LOCUST 283 
 
 Exercise 10. Make an enlarged drawing of the side view of the abdomen of 
 the male locust, showing all of the above parts. 
 
 2. Abdomen of the female. The abdomen of the female from the 
 first to the seventh segment is nearly the same as in the male. 
 
 a. Segment eigJit. This segment resembles the other segments, 
 except that the sternum is nearly twice as long, and is known as 
 the subgenital plate. 
 
 b. Segments nine, ten, and eleven. These are essentially like 
 those of the male, the tergum of nine and ten being partially fused, 
 and tergum eleven forming the terminal, dorsal shield. 
 
 c. The eeiri and podieal plates. These plates are similar to 
 those in the male, except that the podieal plates are much more 
 prominent. 
 
 d. TJie ovipositor. The ovipositor consists of three pairs of 
 movable plates. The dorsal pair lie just ventral to the eleventh 
 tergum and are long, lance-shaped pieces with hard, pointed tips. 
 The ventral pair arises just dorsal to the eighth sternum and 
 resembles the dorsal pair. When these four pieces are brought 
 together, their points are in contact, forming a sharp organ b}' 
 means of which the female bores the holes in the ground in which 
 to deposit her eggs. The third set of plates are known as the egg 
 guides. These are much smaller and are located median to the 
 plates of the true ovipositor. 
 
 Exercise 11. Make a drawing of the side view of the last five segments of 
 the female locust. 
 
CHAPTER XVII 
 
 A COMPARISON OF THE DIFFERENT TYPES OF ARTHROPODA 
 
 Section VI. Comparison of Insects and Crustaceans 
 (Types, Locust and Crayfish) 
 
 Material. Alcoholic specimens of both crayfish and locusts should be pro- 
 vided, although the student by this time should be familiar with the structure 
 of the locust. The lobster is much larger and easier to work than the crayfish, 
 and instructions here given will apply to either. Both the lobster and the crayfish 
 may be obtained from any of the natural-history supply companies. Crayfish 
 may be collected in many sections of the country from streams and ponds, 
 and should be preserved in the same manner as recommended for the locust. 
 Material for Exercise 17 (the sow-bug) can be obtained in abundance under 
 boards and stones and in other damp locations. It may be preserved in 
 alcohol. 
 
 Exercise 12. Comparison of the anatomy of the crayfish atid the locust. 
 With the two specimens at hand, write out a careful comparison of the following 
 points : 
 
 1. Nature of the body covering. 
 
 2. General divisions of the body. (A fusion of the head and thorax is known 
 as the cephalothorax.) 
 
 Exercise 13. The head and head appendages. Remove the appendages 
 from one side of the crayfish, beginning with the first appendage anterior to 
 the first walking leg. These may be removed by grasping them near their 
 attachment with a pair of strong forceps, and pulling them backwards toward 
 the posterior end of the body. As each one is removed, it should be laid on a 
 piece of wet blotting paper in regular order. The appendages of the crayfish 
 are numbered from the anterior to the posterior end of the body. The head 
 appendages are as follows : 
 
 1 . The antennule, consisting of a basal piece and two long, slender filaments. 
 
 2. The antenna, consisting of a basal piece, one long, slender filament, 
 known as the endopodite, and a short, platelike projection, known as the 
 exopodite. 
 
 3. The mandibles. 
 
 4. 5. The first and second maxillae. The above include all the head append- 
 ages. Write out a careful comparison of these appendages and corresponding 
 appendages in the locust. Also with a hand lens make a comparative study 
 of the eyes. 
 
 284 
 
THE- DIFFERENT TYPES OF ARTHROPODA 285 
 
 Exercise 14. ./ coiiiparison of the llioracit appendages. Appendages 6, 7, 
 and 8 of the thorax are known as the first, second, and third inaxillipeds, and 
 the appendages from 9-13 are the walking appendages. Write out a comparison 
 of the thoracic appendages, noting the number, segmentation, etc. 
 
 Exercise 15. A comparative study of the abdomens of the crayfish and 
 locust. Appendages 14-20 of the crayfish are known as the swimmerets. 
 Compare these with the more anterior appendages of the crayfish. Also write 
 out a careful comparison of the segmentation of the abdomens of the crayfish 
 and locust. 
 
 Exercise 16. Make a drawing of the side view of the crayfish, naming the 
 different appendages and divisions of the body. 
 
 Exercise 17. Make drawings of appendages 2, 10, and 16. 
 
 Exercise 18. Comparison of the locust and sow-bug. Write out a careful 
 comparison of these two forms, noting : 
 
 1. The nature of the body covering. 
 
 2. The general divisions and segmentation of the body. 
 
 3. The nature of the appendages. 
 
 4. The number and position of the appendages. 
 
 Exercise 19. Make a drawing of the ventral view of the sow-bug, showing 
 the number, position, and arrangement of the appendages. 
 
 Section VII. Comparison of Insects and Myriapoda 
 (Types, Locust and Centipede) 
 
 Material. Centipedes are flattened, wormlike animals living under logs, stones, 
 and other damp localities. They are quite common in most places, and may be 
 collected and preserved in 75 per cent alcohol. Large specimens may usually 
 be supplied by most of the natural-history supply houses. 
 
 Exercise 20. Write out a detailed comparison of a centipede and locust, noting 
 the following points : 
 
 1 . The general divisions of the body. 
 
 2. The nature of body covering. 
 
 3. The segmentation of the body. 
 
 4. The eyes and antennae. 
 
 5. The mouth-parts. 
 
 6. The legs, number of their segments, etc. 
 Exercise 21. Make a drawing of the dorsal view of the head. 
 Exercise 22. Make a drawing of a ventral view of the head. 
 
2 86 ELEMENTARY ENTOMOLOGY 
 
 Section VIIL Comparison of Insects and Arachnida 
 (TvpES, Spider {Argiopc) and Locust) 
 
 Material. When possible, the ladder-spider should be collected for this work, 
 as it is large, brilliantly colored, and can usually be collected in large numbers 
 in the fall. 
 
 Exercise 23. Write out a careful comparison of the following parts: 
 
 1. The cov'ering of the body and segmentation. 
 
 2. The general divisions of the body. 
 
 3. The eyes (located on the anterior portion of the cephalothorax), their 
 number, arrangement, etc. 
 
 4. The mouth-parts, consisting of the mandibles, with terminal fang, maxillae, 
 hypopharynx, and a rudimentary labium. 
 
 5. The legs, number, number of segments, etc. 
 
 6. The abdomen, including the following structures : 
 
 a. The opening of the book-lungs, which lie on either side of the me- 
 
 dian line at the anterior end of the abdomen and are respiratory 
 in function. 
 
 b. The genital opening, situated in the female on a prominent median 
 
 tubercle located between the book-lungs. 
 
 c. The spinnerets, consisting of six papillae at the posterior end of the 
 
 body. 
 Exercise 24. Make a drawing of a dorsal view of the spider. 
 Exercise 25. Make a drawing of the mandibles and maxillae of the spider. 
 
CHAPTER XVIII 
 
 A COMPARISON OF DIFFERENT TYPES OF INSECTS; STRUCTURE 
 OF THE BEE, FLY, AND BEETLE 
 
 Section IX. Anatomy of the Honey-Bee (Second Type of 
 THE Class Insecta) 
 
 Material. The ordinary honey-bee can be easily collected for this work, and 
 should be in as fresh a condition as possible. While alcoholic specimens will 
 do, it is much better to furnish the students with fresh material, or to dry the 
 specimens and place them in a moist chamber about two hours before using. 
 It is almost imperative that the students be supplied with prepared slides of 
 the legs to supplement the dry material. As this section's work will not deal 
 with the mouth-parts, prepared slides of these will not be needed until later. 
 
 1. General anatomy of the honey-bee. The bee furnishes an ex- 
 cellent example of the specialization of insects, all of the parts being 
 modified for a special purpose. This laboratory section's work is 
 intended to give the student an idea of these modifications, with 
 the exception of the mouth-parts, which will be studied later. The 
 plan of structure does not differ much from that of the locust ; the 
 student, however, should notice the following points : 
 
 Exercise 26. Write out a careful comparison of the bee and locust as follows : 
 
 1. The nature of the body covering. 
 
 2. The segmentation of the body. 
 
 3. The divisions of the body. 
 
 4. The number and position of the appendages. 
 
 5. The structure of the head (except the mouth-parts). Note the compound 
 eyes, ocelli, and antennas. 
 
 2. Modifications of the prothoracic leg. Carefully remove the 
 prothoracic legs and mount in the glycerin solution. Compare 
 with the prepared slides and notice the following points (the gen- 
 eral divisions of the leg are the same as those of the locust) : 
 
 a. TIic coxa. This basal piece is a rather large, triangular seg- 
 ment attached to the prothorax. 
 
 287 
 
288 ELEMENTARY ENTOMOLOGY 
 
 b. TJic trocJiajitcr. This is proportionally larger than in the 
 locust ; aside from this it shows no special modifications. 
 
 c. TJie fcimir. This is a large, club-shaped joint covered with 
 long hairs. 
 
 d. The tibia. This segment is smaller than the preceding and 
 is provided with a spine at the lower end. 
 
 e. The tarsus. The tarsus consists of five segments, the first 
 being nearly as large as the tibia. It is provided with a notch, near 
 its attachment to the tibia, which, together with the spine on the 
 latter segment, forms the antenna cleaner. 
 
 Notice also the bilobed claws on the end of the tarsus, together 
 with the median, flaplike structure known as the empodium. This 
 secretes a slicky substance, which enables the bee to walk on a 
 smooth surface. 
 
 Exercise 27. Make an enlarged drawing of a prothoracic leg, showing the 
 segmentation, antenna cleaner, claws, etc. 
 
 3. Mesothoracic leg. The mesothoracic leg differs but slightly 
 from the prothoracic leg, except that the antenna cleaner is absent 
 and that on the inner side of the tibia there is a spur used in loosen- 
 ing the pollen from flowers. 
 
 Exercise 28. Make drawing of the inner side of the tibia and tarsus of the 
 mesothoracic leg, showing the spine. 
 
 4. Metathoracic leg. This resembles the prothoracic leg, with 
 the following modifications : 
 
 a. T]ic pollen-basket. The outer surface of the tibia of the third 
 thoracic leg is smooth and surrounded with a row of long, incurved 
 hairs. This is known as the pollen-basket, and is used in carr)dng 
 the pollen to the hive. 
 
 b. TJie ivax piiieeis. Between the end of the tibia and the tarsus 
 is a pincerlike structure consisting of a row of thick, flattened spines 
 on the edge of the tibia, which come in contact with the smooth 
 edge of the tarsus. These wax pincers are supposed to be used in re- 
 moving the plates of wax from the abdomen, where they are secreted. 
 
 c. TJie pollen eomb. This structure is located on the inner sur- 
 face of the flat, basal segment of the tarsus, and consists of nine 
 parallel rows of bristles, which are used in combing the pollen from 
 the body, where it collects while the bee is gathering nectar. 
 
COMPARISON OF DIFFERENT INSECTS 289 
 
 Exercise 29. Make a drawing of the inner surface of tlie third thoracic leg. 
 
 Exercise 30. Make a drawing of the outer surface of the third thoracic leg. 
 
 Exercise 31. Examine the wings of the bee under the compound micro- 
 scope and make a drawing showing the fine hooks and groove by means of 
 which the wings ai'e locked together during flight. Also notice the arrangement 
 of the veins. 
 
 Section X. Comparison of the Flv with the Loclst and Bee 
 
 Material. Probably the best material for the study of the anatomy of the 
 Diptera is some of the large horse-flies, like Taba)iiis atra/us, although these 
 may be hard to secure in sufficient numbers. If these cannot be secured, any 
 of the smaller, more abundant species will suffice. The material may be pre- 
 served in 75 per cent alcohol, or dried, the latter method probably being pref- 
 erable for a study of the external parts ; the specimens should, however, be 
 placed in a moist chamber at least twenty-four hours before they are wanted 
 for use. 
 
 Exercise 32. Write out a careful comparative description of the external 
 anatomy of the fl}\ comparing it with the locust and the bee, and noting the 
 following points of structure : 
 
 1 . The divisions of the body, the body covering, and the segmentation. 
 
 2. The head and its appendages, with the exception of the mouth-parts. 
 
 3. The thorax and thoracic appendages. 
 
 4. The abdomen and its segmentation. 
 
 Exercise 33. Make a drawing of the wing of a fly, comparing it with the text 
 figure. 
 
 Section XI. Comparison oi' a Beetle with the Locust 
 
 AND Bee 
 
 Material. Almost any of the larger beetles will serve for this work, although 
 the May-beetle will probably be the easiest to secure. These should be pre- 
 served in the alcohol-glycerin solution. 
 
 Exercise 34. Write out a comparison of the beetle with the locust and bee, 
 noting : 
 
 1 . The nature of the body covering, the segmentation, and the divisions of 
 the body. 
 
 2. The head, including the eyes and antennae. 
 
 (If time permits, the mouth-parts of the beetle might profitably be dissected 
 and compared with those of the locust.) 
 
 3. The thorax, including the wings and wing-covers, especially noting the 
 modification of the wing-covers. 
 
 4. The abdomen, the number of segments, etc. 
 
 Exercise 35. Make a drawing of the antennas, wings, and wing-covers of 
 the beetle. 
 
CHAPTER XIX 
 THE INTERNAL ANATOMY OF THE LOCUST 
 
 Section XII 
 
 MateriaL Fresh material will be found the most satisfactor}' for this work, 
 the specimens being placed in 85 per cent alcohol for about an hour before 
 being used. If fresh material is not available, alcoholic specimens that have been 
 previously soaked in warm water for a short time will work very satisfactorily. 
 After removing the wings and legs from the right side of the locust, make a 
 longitudinal, dorsal incision to the right of the median, dorsal line, and the 
 entire length of the body. Make a similar longitudinal ventral incision to the 
 right of the midventral line. Remove carefully the right side of the chitinous 
 covering, exposing all of the internal organs, of which the following systems 
 should be studied : 
 
 1. Digestive system. The digestive system occupies the greater 
 part of the thoracic and the ventral part of the abdominal cavity. 
 It is essentially a continuous tube, divided into the following re- 
 gions, each with a particular function to perform. 
 
 a. TJic esophagus. This is a cylindrical tube, with tough, mus- 
 cular walls. It runs from the mouth, opening dorsally to a point 
 opposite the foramenal aperture, where it bends at right angles 
 and enters the thorax. 
 
 b. TJie crop. This is an enlargement of the esophagus and, be- 
 ginning in the mesothorax, runs to the abdomen, almost filling the 
 mesothoracic and metathoracic cavities, 
 
 c. The giaaard {provejitriciilus). This is the next division (not 
 found in the genus Aeridiiun) . The walls are thick and muscular, 
 and on the inside are lined with a series of chitinous plates which 
 are used in completing the mastication of the food, 
 
 d. The stomach (ventrietdiis). This division is separated from 
 the gizzard by a slight constriction. It is approximately the same 
 diameter as the gizzard and extends from the first to the seventh 
 segment of the abdomen, 
 
 e. TJie large intestine. This is of somewhat smaller diameter 
 than the stomach and runs from the seventh to the tenth segment, 
 
 290 
 
THE INTERNAL ANATOMY OF THE LOCUST 29 1 
 
 f , TJic small intestine. The small intestine is a short, muscular 
 tube running from the end of the large intestine toward the dorsal 
 part of the body and ending in segment eleven, 
 
 g. The rectuui. The rectum is a short, muscular enlargement 
 in segment eleven and ends in the anal opening. 
 
 2. Accessory organs of digestion. In connection with the ali- 
 mentary tract are a certain number of glands or glandular structures 
 which either aid in the digestion of the food or assist in eliminating 
 the waste products. 
 
 a. TJie salivary glands. These are small, white glands located 
 on either side of the esophagus in the thorax. They open out into 
 two main ducts which lead to the mouth. 
 
 b. The gastfie cccca. The gastric caeca consist of a set of eight 
 double, cone-shaped pouches which open at the union of the crop 
 and stomach. They form a complete belt around the alimentary 
 tract at this point and secrete a fluid which aids in digestion. 
 
 c. The Malpigiiian tubules. The Malpighian tubules are a sys- 
 tem of ver}' fine, hairlike tubes which arise from the most anterior 
 end of the large intestine. Their function is excretory, similar to 
 that of the kidneys. 
 
 3. Reproductive system. The ease with which the organs of 
 this system may be distinguished depends considerably on the sex 
 and the time of year at which the specimens were collected. 
 
 a. Female reproduetive organs. In the fall, just before the eggs 
 are deposited, the entire abdomen of the female is filled with a 
 yellow, coarsely granular organ known as the ovary. There are a 
 pair of these, one located on either side of the body. Running 
 from the posterior end of the ovary are two small tubes called the 
 oviducts, which unite near the posterior end of the body to form 
 the vagina. This opens externally upon the upper surface of the 
 subgenital plate, between the ovipositor. On a median line slightly 
 dorsal to the ^g^ guides there is a second opening, which communi- 
 cates with a long, slender tube ending in an enlarged pouch known 
 as the spermatheca. This entire structure is very difficult to locate. 
 
 b. Male reproductive organs. The general arrangement of the 
 male reproductive organs is quite similar to that of the female, only 
 much smaller. The two pair of testes (corresponding to the ovaries) 
 lie on the dorsal side of the stomach and are inclosed in a saclike 
 
2 92 ELEMENTARY ENTOMOLOGY 
 
 membrane. Leading from the testes are two very fine, hairlike 
 tubes known as the vas deferens. These pass down to the ventral 
 side of the body on either side of the alimentary tract and unite, 
 forming the ejaculatory duct, which opens dorsally to the subgenital 
 plate. Just before the union of the vas deferens they are joined 
 on either side by a number of fine tubules known as the seminal 
 vesicles, the function of which is to store up the products of the 
 reproductive glands. 
 
 Exercise 36. Make a careful drawing of the side view of a locust, showing 
 the alimentary tract, accessory organs of digestion, and either the male or the 
 female reproductive system. 
 
 4. Nervous system. With a pair of fine scissors cut the alimen- 
 tary tract through the esophagus and small intestine, and carefully 
 remove, together with the reproductive organs. Great care must be 
 taken to not injure or displace any of the other organs. Also care- 
 fully remove the right side of the chitinous portion of the head. 
 
 The nervous system consists principally of a supra-esophageal 
 ganglion, or brain, which lies dorsal to the esophagus. This is a large, 
 whitish mass of nervous tissue and, if carefully dissected, can be 
 seen to be directly connected with the compound eyes. Running 
 on either side of the esophagus is a small, white nerve cord that 
 unites on the ventral side, forming the sub-esophageal ganglion. 
 Running from this ganglion toward the posterior end of the body 
 is the ventral nerve cord. If carefully examined, this will be found 
 to consist of two parallel white cords that are occasionally united 
 by the ventral ganglia, from which arise numerous lateral nerves. 
 These ventral ganglia occur in the following segments, — the 
 prothorax, mesothorax, metathorax, and abdominal segments two, 
 three, five, six, and seven. 
 
 5. Muscular system. In elementary work of this sort no attempt 
 will be made to trace out the different sets of muscles, but the 
 general relation of the different muscles to the segments should be 
 noted. In the mesothorax and metathorax notice the large wing mus- 
 cles ; also in the abdomen notice the longitudinal and ventral bands. 
 
 6. Respiratory system. The respiratory system is made up of 
 tubes known as trachea. These open out along either side of the 
 body ; the openings, which have already been noted, are termed the 
 
THE INTERNAL ANATOMY OF THE LOCUST 
 
 293 
 
 spiracles. Soon after entering the body the trachea unite to form 
 two large lateral trunks. T^rom these, dorsal branches are given off, 
 which unite, forming two parallel dorsal trunks. Running off from 
 both the dorsal and lateral trunks are smaller branches, which 
 separate into extremely minute tubes and ramify through all the 
 tissues. 
 
 Exercise 37. If fresh specimens are at hand, mount in water some of the 
 fatty tissue surrounding the alimentary tract, and examine under the compound 
 microscope. The trachea will be seen as much-branched silver-colored tubes. 
 Make a careful drawing. 
 
 Exercise 38. Make a drawing of the side view of the locust, with the alimen- 
 tary tract and reproductive organs removed, showing the general arrangement 
 of the muscular, tracheal, and nervous systems. 
 
 7. Circulatory system. The circulatory system consists of a 
 dorsal, median, tubular heart. This can be seen in fresh specimens 
 by removing the dorsal body wall. 
 
 Exercise 39. In order to observe the rhythmic contraction of the heart, 
 obtain living larvae of mosquitoes, dragon-flies, or Ma3'-flies. Place them in 
 water on a slide and examine under the microscope. Draw. 
 
CHAPTER XX 
 
 MOUTH-PARTS OF INSECTS 
 
 The type of biting mouth-parts has already been considered 
 in Chapter XVI, the forms here considered being more highly 
 specialized. 
 
 Section XIII. Sucking Mouth-Parts (Type, Squash-Bug) 
 
 Material. Students should be provided with prepared slides of the mouth- 
 parts of the squash-bug. They should also have alcoholic specimens, as the 
 arrangement of the parts cannot be easily distinguished on the prepared slides. 
 Before studying the prepared slides the students should dissect out the mouth- 
 parts of an alcoholic specimen. With a pair of sharp-pointed scissors cut off 
 the ventral part of the head and place it in a thick glycerin solution, consist- 
 ing of equal parts of glycerin and alcohol. Then, under the lens of a dissect- 
 ing microscope, pull the long proboscis apart, noting the order of arrangement 
 of the different pieces. 
 
 The mouth-parts of the squash-bug consist of a long, jointed beak in which 
 are found four long, threadlike setae. They should be compared with the 
 mouth-parts of the locust. 
 
 1. Labrum. The labrum, or upper lip, is a long, triangular, 
 sharply pointed piece, with slightly serrated edge, and fits over 
 the groove of the lower lip. 
 
 2. Mandibles. The mandibles are a pair of long, hairlike setae 
 with sharp-toothed points. They adhere very closely together, and 
 are used in cutting into the tissues of plants in order to induce 
 a flow of sap. 
 
 3. Maxillae. These closely resemble the mandibles and, like 
 them, lock together, forming a lancelike structure. They are used 
 in piercing plants, the same as the mandibles. 
 
 4. Labium. The labium, or under lip, is formed into a long, 
 partially closed tube„ in which lie the mandibles and maxillae. It is 
 made up of four segments of about equal length. 
 
 Exercise 40. Make a careful drawing of the mouth-parts of the squash-bug, 
 showing the above details. 
 
 294 
 
MOUTH-PARTS OF INSECTS 295 
 
 Section XIV. Specialized Piercing Mouth-Parts 
 (Type, Horse-fly) 
 
 Material. Specimens of any of the common horse-flies (Tabaiais) will do 
 for this work, though only female flies can be used, as the mandibles are lack- 
 ing in the males. The two sexes may be distinguished by the position of the 
 eyes. In the male the eyes touch for a greater or less distance, while in the 
 female there is a narrow space between the eyes. The mouth-parts are quite 
 conspicuous and should be removed and mounted as in the previous section. 
 Students should also be provided with prepared slides. A comparison should 
 be made with the mouth-parts already studied. The mouth-parts of the fly are 
 more highly specialized than those of the squash-bug, and consist of a number 
 of stylets, or flat, pointed pieces, more or less completely inclosed in the fleshy 
 under lip. They consist of the following parts : 
 
 1. Labrum. The labrum, or upper lip, is the uppermost stylet, 
 and consists of a flat, unpaired piece, bluntly tipped. It is broader 
 than any of the remaining stylets. 
 
 2. Mandibles. These consist of a pair of flat, smooth, sharply 
 pointed pieces adapted for piercing. 
 
 3. Maxillae. These are the second pair of stylets and are under- 
 neath the mandibles, which they very closely resemble. The max- 
 illae are narrower than the mandibles, are less strongly chitinized, 
 and are, provided with palps, which are attached to the base of each 
 maxilla. The palps consist of two segments and are thick, clublike 
 structures covered with very fine hairs. 
 
 4. Hypopharynx. The hypopharynx, or tongue, is a slender, 
 unpaired piece resembling very much the labrum, but is narrower 
 and more sharply pointed. It lies directly underneath the maxillae. 
 
 5. Labium. This is a conspicuous, proboscislike structure, 
 which partially incloses the other mouth-parts. At the end of the 
 labium is a large, fleshy, disklike piece called the labella. It con- 
 sists of two lobes, which fit closely around the stylets when they 
 are being used. 
 
 Exercise 41. Make careful drawings of the above mouth-parts. 
 
296 ELEMENTARY ENTOMOLOGY 
 
 Section XV. Sucking Mouth-Parts 
 (Type, Butterfly) 
 
 Material. The commonest type, and one of the best for this work, is the 
 monarch butterfly [Anosta plexippus). These may be collected and dried and 
 the scales carefully removed from the head with a stiff camel's-hair brush. 
 Part of the specimens should be boiled in caustic potash (KOH) and the head 
 mounted in balsam. The remainder of the specimens should be placed in the 
 moist chamber for a day or so before they are wanted. The mouth-parts of the 
 Lepidoptera are greatly modified, and only careful study reveals the relation 
 between them and the biting mouth-parts of the locust. 
 
 1. Labrum. This is a very short, quadrangular piece, ahnost or 
 entirely indistinguishable in some species, as it is immovably joined 
 to the clypeus. 
 
 2. Mandibles. The mandibles are almost entirely wanting in the 
 monarch butterfly, although they are represented in some forms 
 by two triangular pieces which are of little or no use to the insect. 
 In some of the moths they are more highly developed. 
 
 3. Maxillae. The maxillae are the most conspicuous part of the 
 mouth, the two together forming a long, coiled sucking tube used 
 in drawing up nectar. Each maxilla is deeply grooved on the 
 inner side, the two fitting together, forming a complete tube. The 
 maxillary palps are wanting in this form, although present 'in some 
 of the lower forms. 
 
 4. Labium. The labium consists of a small, triangular flap 
 almost completely fused with the base of the maxillae. Extending 
 out from either side of the labium are the large labial palps, which 
 form two prominent, plumelike projections from either side of the 
 head. They are three-jointed and covered with scales. 
 
 Exercise 42. Make a drawing of the mouth-parts of the monarch butterfly, 
 showing the above in detail. 
 
 Section XVI. Sucking and Biting Mouth-Parts 
 (Type, Honey-bee) 
 
 Material. The honey-bees for this section's work may be preserved in 75 
 per cent alcohol. It may be found advantageous to substitute the bumble-bee, 
 as the mouth-parts are larger and more easily dissected. In either case it is 
 desirable that the students be provided with prepared slides. The mouth-parts 
 
MOUTH-PARTS OF INSECTS 
 
 297 
 
 of the honey-bee are made up of the typical number of parts, but are adapted 
 both for biting and sucking. The student should refer to the other types of 
 mouth-parts already studied. 
 
 1. Labrum. This consists of a small, rectangular piece attached 
 to the clypeus, and resembles closely the labrum of the locust. 
 
 2. Mandibles. These are hard, well-developed structures, more 
 elongated than in the locust, and are devoid of teeth. 
 
 3. Maxillae. The maxillse are complicated structures and, as in 
 the locust, consist of the following parts : 
 
 a. TJie cardo. This serves as the attachment to the epicranium 
 and is an elongated piece. 
 
 b. TJic stipes. These are rather thick, club-shaped pieces strongly 
 chitinized. 
 
 c. The maxillary palps. These are short and almost atrophied, 
 located at the distal, outer edge of the stipes. 
 
 d. TJie laeinia galea. These two structures are fused together 
 in the bee and form a pair of elongated pieces deeply grooved on the 
 inner edge. When fitted together, they form a partially closed tube 
 more or less completely surrounding the parts of the labium, 
 
 4. Labium. The labium, or under lip, is even more modified 
 than the maxillae, and consists of the following parts : 
 
 a. TJie subfuentiim. This is a triangular, basal piece, running off 
 from which are two small, rodlike pieces known as the lora. 
 
 b. The mentinn. This is a large, pear-shaped piece attached to 
 the submentum. 
 
 c. TJie labial palps. The labial palps are greatly modified, form- 
 ing two long, four-jointed structures grooved on the inner edge. 
 When these are fitted together, they form a tube which in turn is 
 inclosed by the laeinia galea of the maxillae. 
 
 d. TJie paraglossa. This is a sheathlike arrangement which 
 incloses the base of the tongue, lies median to the palps, and is 
 attached to the mentum. 
 
 5. Tongue. The tongue is a long, flexible rod, densely covered 
 with hairs. Along the ventral side there is a deep groove, forming 
 almost a complete tube, and at the end is a flaplike structure known 
 as the flabellum. 
 
 Exercise 43. Make a careful drawing of the mouth-parts of the honey-bee, 
 showing the above structures in detail. 
 
CHAPTER XXI 
 
 THE LIFE HISTORY OF INSECTS 
 
 Section XVII. Life History of a Plant-Louse 
 (Family Aphididae) 
 
 Material. The family Aphididae probably furnishes some of the best ex- 
 amples for the study of incomplete metamorphosis of insects. It does not 
 matter much what particular species is selected for this work, as any of the 
 ordinary aphids attacking greenhouse plants will be found quite satisfactory. 
 Among the forms most easily managed may be mentioned the lettuce aphis and 
 the rose aphis. These may almost always be secured at any time of year. For 
 work on the lettuce aphis each student should be provided with a flowerpot 
 in which is growing one small lettuce plant. The instructor should keep on 
 hand a supply of aphids. These should be grown on lettuce under a large bell 
 jar, to prevent the escape of the winged forms. Each student should be given 
 one wingless, viviparous female just before the insect reaches maturity. 
 
 It will be recalled that the life history of the Aphididae may vary 
 considerably with the different species. Nearly all of them, how- 
 ever, have two forms of reproduction, known as viviparous repro- 
 duction (in which the living young are brought forth without the 
 fertilization of the female by the male) and oviparous reproduction 
 (in which eggs are deposited by fertilized females). The sexual 
 forms are usually brought forth in the fall by a viviparous female, 
 and after mating, the oviparous female deposits eggs which are not 
 hatched until the next spring. From these eggs are hatched the 
 viviparous females, this form of reproduction continuing throughout 
 the summer. It will also be recalled that of the viviparous forms 
 part may be winged and part wingless. 
 
 Exercise 44. Watch the viviparous female carefully and write up a detailed 
 set of notes, including the following observations : 
 
 1. Date of birth of first young, giving the hour when the observation was made. 
 
 2. Date of birth of subsequent young, giving the number of young, the day, 
 and the hour when observed. Be sure that only one viviparous female is present 
 on each culture, and keep careful track of all the offspring. 
 
 298 
 
THE LIFE HISTORY OF INSECTS 299 
 
 3. Number the offspring consecutively, according to age, and note which 
 developed into winged and which into wingless forms. 
 
 4. Note the age at which each of these individuals begins reproduction. It 
 might be suggested that when the first of this generation begins reproducing, 
 it is best to remove the young in order to prevent confusion of the generations. 
 
 Exercise 45. Make a chart from your above notes, giving the number of the 
 individual, whether winged or wingless, date of birth, date of maturity (when 
 first young is produced). 
 
 Exercise 46. Notes on the rapidity of growth. Isolate some newly born 
 individuals, noting the date and hour of birth. Watch these carefully, and note 
 the date and the hour that molting occurs. The cast skin will usually be found 
 near the young aphids, which begin feeding soon after molting. Those indi- 
 viduals just having molted will be found to be the lightest in color, but the cast 
 skin should be taken as the only proof that the insect has molted. As soon as 
 these individuals begin to reproduce, tabulate your above notes, giving the 
 number of hours between each molt for each individual. 
 
 Exercise 47. Write up a detailed set of notes describing one wingless in- 
 dividual after each molt, up to and including the adult form, noting all the 
 changes which may occur. 
 
 Exercise 48. Write up a detailed set of notes, similar to the above, for the 
 winged form. 
 
 Exercise 49. Mount a wingless individual in the alcohol-glycerin solution 
 and make a drawing of the dorsal view. (The aphids should first be dipped in 95 
 per cent alcohol, and may then be mounted directly in the glycerin solution.) 
 
 Exercise 50. Mount a winged individual in the alcohol-glycerin solution 
 and make a drawing of the dorsal view. 
 
 Section XVIII. Life History of the Dragon-Fly 
 
 Material. It will be quite impractical for a class in elementary entomology 
 to try to trace the complete life history of the dragon-fly, but this form will 
 give the student a good idea of the habits and structure of aquatic nymphs. 
 The dragon-flies deposit their eggs on water plants, and as soon as these hatch, 
 the young nymphs settle to the bottom of the pond and may be found, at almost 
 any time of the year, crawling about in decaying vegetation or other sediment. 
 The easiest way to secure them is to rake out the sediment from the quiet pools 
 of a stream, or from the edge of ponds, with an ordinary garden rake. The 
 nymphs, together with a small amount of sediment, should be placed in an 
 aquarium until ready for observation. This applies especially to material collected 
 in the fall, as it will be difhcult for each individual student to provide food and 
 suitable conditions for the nymphs that he may have under his observation. 
 
 When this work is undertaken by a class, each student should be provided 
 with a glass dish containing three or four of the largest-sized nymphs. As it is 
 necessary to feed the nymphs on other aquatic insects, it might be better not 
 to collect the material until early spring. 
 
300 ELEMENTARY ENTOMOLOGY 
 
 Exercise 51. Obseri'a/io/is on the structure of i/ie nymphs. Write up a 
 careful description of the nymphs, noting the details of structure. In the 
 description, refer to and use the terms with which you have already become 
 familiar in your description of other forms. 
 
 Exercise 52. Habits of the nymphs. Make as many notes as possible on 
 the general habits of the nymphs, noting their methods of feeding, locomotion, 
 secreting themselves, etc. (see page 98). 
 
 Exercise 53. Observations on the transfoiinaiion of nymphs. Note care- 
 fully whether or not the nymph molts, or sheds its skin, and, if observed, how 
 the act is performed. Toward spring the nymphs should be placed in the sun- 
 light as much as possible. Each dish should also be provided with a number 
 of sticks, up which the nymphs may crawl when they are ready to transform to 
 the adult stage. If possible, observe this transformation and write up a com- 
 plete set of notes on the subject. 
 
 Section XIX. Complete Metamorphosis, Life History of 
 THE Cabbage Butterfly {Pontia rapae) 
 
 Material. The following instructions have been prepared especially for the 
 study of the cabbage butterfly, though the life history of any of the other Lepi- 
 doptera may be studied in the same manner, substituting, of course, -the proper 
 food plants. Each student should be provided with a flowerpot in which is grow- 
 ing a young cabbage plant. If this work may be begun by the middle of Septem- 
 ber, cabbage butterflies should be collected and one pair placed in each of a 
 number of breeding cages (see Chapter XXIII). The pots containing the young 
 plants can be placed in the cages, and daily observations made for the presence 
 of eggs. After the eggs hatch, a large lantern globe, the top of which has been 
 covered with cheesecloth, should be placed over each plant, to prevent the 
 escape of the larvae. 
 
 Exercise 54. Egg deposition. The student should, if possible, determine 
 and make notes of the following points : 
 
 1. On what part of the leaf are the eggs deposited .-^ 
 
 2. Are they deposited in clusters or singly.-* 
 
 3. The number of eggs deposited by one female. 
 
 4. The period of incubation. 
 
 5. Describe and make drawings of the eggs. 
 
 Exercise 55. Observations on the larva. Determine and make notes of the 
 number of molts, describing each of the larval stages. 
 
 Exercise 56. Observations on the pupce. If possible, observe the transfor- 
 mation of the larvae to the pupal form. Note the locality selected for pupation, 
 the attachment of the pupa, and length of time in the pupal stage. Also draw 
 and describe. (After pupation the pupse should be removed to a cool, dark 
 place and left until spring, or, if wanted for more immediate use, they should 
 be placed in a light, warm room, where they will probably emerge in a short 
 
THE LIFE HISTORY OF INSECT'S 30 1 
 
 time. Low temperatures are not injurious, but too much moisture must be 
 avoided. The latter part of March the pupae may be brought out and again 
 placed under observation.) 
 
 Exercise 57. The emergence of the adult. Note the date and the method 
 of emergence, and write a brief description of the adult. 
 
 Section XX. Complete Metamorphosis. Life History of 
 THE Fruit-Fly {Drosophila sp.) 
 
 Material. Material for this work may be secured by placing decaying 
 bananas in the sunlight for a few days. The material should then be cov- 
 ered with a bell jar and used as a stock culture. Each student should be pro- 
 vided with a glass tumbler containing about one fourth of an inch of decayed 
 banana. Cut a piece of black paper the size of the tumbler and lay on top of 
 the banana, and cover the tumbler securely with a glass plate. The student 
 should then place three or four adult fruit-flies in the tumbler. 
 
 Exercise 58. Write up a careful set of notes on the following points : 
 
 1. Describe, and make a drawing of egg, which will be deposited on the 
 black paper. 
 
 2. Note the length of time of incubation. 
 
 3. Describe, and make a drawing of a larva. 
 
 4. If possible, determine the length of the larval stage. 
 
 5. Describe, and make a drawing of a pupa. 
 
 6. Determine the length of the pupal stage. 
 
 7. Describe the adult, and determine the distinguishing characters of the 
 sexes. 
 
CHAPTER XXII 
 CLASSIFICATION OF INSECTS 
 
 Section XXI. Classification of the Orders of Insects 
 
 Material. One of two methods may be employed for this work : (a) Each 
 student should be required to make a collection of insects containing repre- 
 sentatives of at least eight of the principal orders. (/>) Provide each student 
 with a representative collection of twenty-five insects. These should be num- 
 bered from one to twenty-five, and should contain as nearly representative 
 forms as possible. 
 
 Exercise 59. On a sheet of paper place the numbers one to twenty-five. 
 After each number write the order (to be determined by the key) to which the 
 corresponding insect belongs. 
 
 Section XXII. Classification of Families 
 
 Material. Give each student a collection representing as nearly as possible 
 the different families of insects treated in the key. It will be found convenient 
 to place twenty-five insects on a block, each block containing only the insects 
 of one order, thus obviating the necessity of classifying every insect to its 
 order before placing it in the family. The insects should be distributed as 
 follows : One block containing representatives of the lower orders (Neuroptera 
 and Neuropteroid insects) ; one block of Hemiptera ; two of Coleoptera ; two 
 of Lepidoptera ; one of Hymenoptera ; and one of Diptera. 
 
 Exercise 60. Classification of the families of the lower orders. 
 
 On a sheet of paper place the numbers one to twenty-five. After each 
 number write the family (to be determined by the key) to which the corre- 
 sponding insect belongs. If possible, by referring to the text or by compari- 
 son with a named collection, identify common forms to genus and species. 
 
 Exercise 61. Classification of the families of Hemiptera. 
 
 Exercise 62. Classification of the families of Coleoptera. 
 
 Exercise 63. Classification of the families of Coleoptera. 
 
 Exercise 64. Classification of the families of Lepidoptera. 
 
 Exercise 65. Classification of the families of Lepidoptera. 
 
 Exercise 66. Classification of the families of Hymenoptera. 
 
 Exercise 67. Classification of the families of Diptera. 
 
 302 
 
CLASSIFICATION OF INSECTS 303 
 
 KEY TO THE ORDERS OF INSECTS 
 
 The principles underlying the classification of insects have already- 
 been discussed in the text. In arranging this key an attempt has 
 been made to eliminate all useless characters and to include only 
 those families commonly encountered. Possibly this elimination has 
 been carried too far for some of the extreme forms of the different 
 orders ; however, in an elementary textbook it is not deemed prac- 
 tical to include material that would be of use only to the specialist. 
 
 Several families are included in the key which are not mentioned 
 in the text. This becomes necessary for the complete arrangement 
 of the key, and may be of use in aiding students to determine the 
 more uncommon families which they may collect. In giving out 
 specimens for determination the teacher should, if possible, use 
 only those families described in the text. 
 
 The following key is intended only for the identification of typical 
 adult forms. An attempt has been made to produce a usable key in 
 preference to a strictly natural one. An ideal key should, of course, 
 combine these two characteristics, but it has been found necessary 
 many times to sacrifice the natural arrangement for clearness. 
 
 In the production of these keys the authors are indebted to all 
 previous workers in entomology. Due credit is given in every case 
 where a key has been adapted from another author's work. 
 
 KEY TO THE ORDERS 
 
 A. Mouth-parts adapted for biting. 
 
 B. Without wings, or rudiments of wings. 
 
 C. Mouth-parts retracted within the head. (Page 73) . . Aptera 
 CC. Mouth-parts not retracted within the head. 
 
 D. Abdomen joined to thorax by slender petiole. Ants. (Page 
 
 243) Hymenoptera 
 
 DD. Abdomen broadly joined to thorax. 
 
 E. Insects small, body antlike or louselike in form. Bird-lice ; 
 
 book-lice; white ants. (Page 103) . . . Platyptera 
 
 £E. Insects of medium or large size. Body not antlike or 
 
 louselike in form. 
 
 jF. Head prolonged into beak, at the end of which are 
 
 the biting mouth-parts. Scorpion-flies. (Page 93) 
 
 Mecoptera 
 E/\ Head not prolonged into beak. 
 
304 ELEMENTARY ENTOMOLOGY 
 
 G. Antennae filiform. Cockroaches ; grasshoppers ; 
 walking sticks. (Page 76) . . . Orthoptera 
 GG. Antennae serrated, or of various types, but not fili- 
 form. Fireflies, etc. (Page 136) . . Coleoptera 
 BB. Winged insects. 
 
 C. First pair of wings horny, meeting in a straight line down the back. 
 D. Abdomen with forceplike appendages. Earwigs. (Page 87) 
 
 EUPLE.XOPTERA 
 
 DD. Abdomen without forceplike appendages. (Page 136) 
 
 Coleoptera 
 CC. First pair of wings leathery or membranous. 
 
 D. Wings membranous ; the second pair, if present, not folded in 
 plaits under first. 
 E. Head prolonged into beak, at the extremity of which are 
 the biting mouth-parts. Scorpion-flies. (Page 93) 
 
 Mecoptera 
 EE. Head not prolonged into beak. 
 
 F. Wings with but few cross veins. (Page 243) 
 
 Hvmexoptera 
 FF. Wings net-veined ; abdomen broadly joined to thorax. 
 G. Abdomen provided with two or three long, many- 
 jointed filaments. (Page 95) . . Ephemerida 
 GG. Abdomen without jointed filaments. 
 
 H. Antennae short, awl-shaped, and inconspicuous ; 
 wings of equal size, held horizontal, vertical, or 
 parallel to the body; not rooflike. Dragon-flies. 
 
 (Page 98) Odonata 
 
 HH. AntennEE not awl-shaped, more or less prom- 
 inent. 
 /. Wings folded flat on body. Body compact, 
 antlike, and flattened or louselike in form. 
 
 Platvptera 
 //. Wings rooflike over body; body linear. (Page 
 
 90) Neuroptera 
 
 DD. First pair of wings more or less leathery, with second pair 
 folded under first. 
 E. Wings clothed with hairs. Caddis-flies. (Page 93) 
 
 Trichoptera 
 EE. Wings not clothed with hairs. 
 
 F. First pair of wings leathery, second membranous. Not 
 
 alike in structure. (Page 76) ... Orthoptera 
 
 FF. Wings alike in structure, both more or less leathery. 
 
 G. Tarsi 5-jointed. (Page 90) . . . Neuroptera 
 
 GG. Tarsi less than 5-jointed. Stone-flies. (Page 97) 
 
 Plecoptera 
 
CLASSIFICATION OF INSECTS 305 
 
 AA. Mouth-parts adapted for sucking. 
 
 B. Mouth-parts not adapted for piercing. 
 
 C. Body covered with scales, wings usually broad. Butterflies and 
 
 moths. (Page 172) Lepidoptera 
 
 CC. Body not covered with scales, wings comparatively narrow. 
 D. Mandibles, if present, not fitted for biting. 
 
 E. Two pair of wings, fringed with hair. Thrips. Physopoda 
 EE. One pair of wings usually naked, or with microscopic hairs. 
 
 Flies. (Page 218) Diptera 
 
 DD. Mandibles normally developed Hymexoptera 
 
 BB. Mouth-parts adapted for piercing. 
 
 C. Mouth-parts consisting of a jointed tube containing the brisdelike 
 mandibles and maxillae. Bugs. (Page 107) . . . Hemiptera 
 CC. Mouth-parts consisting of a fleshy tube containing usually bristle- 
 like mandibles and maxillae. 
 D. Wingless insects ; body laterally compressed. Fleas. (Page 240) 
 
 Siphonaptera 
 DD. Winged or wingless insects, body not laterally compressed. 
 E. Tarsus provided with single strong, hooklike claw. Wing- 
 less parasitic lice of mammals. (Page 107). Hemiptera 
 EE. Tarsus normal. Winged or wingless insects. (Page 218) 
 
 Diptera 
 
 KEY TO THE FAMILIES OF APTERA 1 
 
 A. Abdomen elongate, composed of at least ten segments; antennae many- 
 jointed ; abdomen usually provided with a pair of two-or-more-jointed, fila- 
 mentous, or forceplike appendages. (Page 74) Suborder I, Thysanura 
 
 B. Body covered with scales Lepismidae 
 
 BB. Body not covered with scales. 
 
 C. Abdomen without caudal appendages . . . Anisophaeridae 
 CC. Abdomen with caudal appendages. 
 
 D. Caudal appendages sickle-shaped Japygidae 
 
 DD. Caudal appendages consisting of many-jointed filaments. 
 
 Campodeidae 
 A A. Abdomen composed of not more than six segments; antennae of not 
 more than eight segments ; ventral spring usually present, but no ter- 
 minal abdominal appendages. Springtails. (Page 74) 
 
 Suborder II, Collembola 
 B. Ventral spring present. 
 
 C. Ventral spring attached on penultimate abdominal segment. 
 D. Abdomen globular, only slightly longer than broad. 
 
 Sminthuridae 
 DD. Abdomen cylindrical, longer than broad. Entomobryidae 
 
 1 Revised from Dr. K. W. v. Ualla Tone's " Die Gattungen und Arten der 
 Apterygogenea." 
 
3o6 ELEMENTARY ENTOMOLOGY 
 
 CC. Ventral spring attached to antepenultimate abdominal segment. 
 
 PODURIDAE 
 
 BB. Ventral spring absent Aphoruridae 
 
 THE EPHEMERIDA 
 
 This order includes only a single family, the members of which have deli- 
 cate membranous wings with a fine network of veins. The fore-wings are 
 large, and the hind-wings much smaller or wanting. Mouth-parts rudimentary. 
 May-flies. (Page 95) Ephemeridae 
 
 KEY TO THE FAMILIES OF ODONATAi 
 
 A. Front and hind wings similar in outline, distinctly narrow at base, held 
 vertically over the back when at rest. Damsel-flies. (Page 98) Sub- 
 order Zygoptera 
 B. Wings with not less than five antecubital cross veins. Calopterygidae 
 BB. Wings with not more than three, usually two, antecubital cross veins. 
 
 Agrionidae 
 
 A A. Front and hind wings dissimilar, the hind-wings being much wider at the 
 
 base ; wings held horizontally when at rest. Dragon-flies. (Page 98) 
 
 Suborder Axisoptera 
 B. Antecubital cross veins of first and second rows usually meeting each 
 
 other Libelluudae 
 
 BB. Antecubital cross veins of first and second rows not meeting each other. 
 C. Eyes meeting above in median line of head ; abdomen with lateral 
 
 ridges Aeschnidae 
 
 CC. Eyes separate, or nearly so ; abdomen without lateral ridges. 
 D. Eyes touching at a single point, or barely apart. 
 
 CORDULEGASTERIDAE 
 
 DD. Eyes distinctly separated Gomphidae 
 
 THE PLECOPTERA 
 
 This order includes only a single family, having four membranous wings, 
 the hind-wings being folded plaitlike under the fore-wings. The mouth-parts 
 are biting, but slightly developed. Stone-flies. (Page 97) . . . Perlidae 
 
 KEY TO THE FAMILIES OF NEUROPTERA 
 
 A. Hind-wings broad at base, the inner margin folded in plaits. Dobsons. 
 (Page 90) SlALIDAE 
 
 A A. Hind-wings narrow at base, not folded in plaits. 
 B. Prothorax greatly prolonged into necklike stalk. 
 
 ^ Revised from Kellogg's "American Insects." 
 
CLASSIFICATION OF INSECTS 307 
 
 C. Prothoracic legs normal Raphidiidae 
 
 CC. Prothoracic legs fitted for grasping Mantispidae 
 
 BB. Prothorax normal. 
 
 C. Wings clear, densely net-veined. 
 
 D. Antennae filiform, without terminal knob. Lace wings. 
 
 (Page 92) Chrvsopidae 
 
 DD. Antennas filiform, with terminal knob. Ant-lions. (Page 93 ) 
 
 Mvrmeleoxidae 
 
 CC. Wings more or less opaque, with many longitudinal but few cross 
 
 veins Hemerobiidae 
 
 THE MECOPTERA 
 
 This order includes only one family, having four membranous wings, fur- 
 nished with numerous veins. The head is prolonged into a beak, at the end 
 of which are the biting mouth-parts. Scorpion-flies. (Page 93) Panorpidae 
 
 THE TRICHOPTERA 
 
 This order includes but one family, having four membranous wings, fur- 
 nished with numerous longitudinal but few cross veins ; wings more or less 
 densely covered with hair ; rudimentary biting mouth-parts. Caddis-flies. 
 (Page 93) Phryganeidae 
 
 KEY TO THE PLATYPTERA 
 
 A. Body cylindrical, social insects with white, antlike bodies. White ants. 
 
 (Page 103) Termitidae 
 
 A A. Body depressed, if cylindrical, not antlike. Nonsocial, louselike insects. 
 B. Antennae of not more than five segments. Bird-lice. (Page 106) 
 
 Suborder Mallophaga 
 C. Antennas exposed, consisting of three or five segments. 
 
 D. With three-segmented antennae ; tarsi with one claw ; infesting 
 
 mammals only Trichodectidae 
 
 DD. With five-segmented antennas ; tarsi with two claws ; infesting 
 
 birds only Philopteridae 
 
 CC. Antennas concealed in shallow cavities on underside of head, con- 
 sisting of four segments. 
 D. Tarsi with one claw ; infesting mammals only . Gyropidae 
 DD. Tarsi with two claws ; infesting birds only , . Liotheidae 
 BB. Filiform antennae of more than five segments. 
 
 Suborder Corrodentia 
 C. Wings well developed ; ocelli present in addition to the compound 
 
 eyes. Bark-lice. (Page 105) Psocidae 
 
 CC. Wings and ocelli wanting. Book-lice. (Page 105) . Atropidae 
 
3o8 ELEMENTARY ENTOMOLOGY 
 
 THE EUPLEXOPTERA 
 
 This order includes a single family the members of which have four wings : 
 the first pair are leathery or horny, meeting in a straight line down the middle 
 of the back ; the second pair are membranous, with numerous radiating veins 
 folded lengthwise like a fan and then crosswise under the first pair. Earwigs. 
 
 (Page 87) FOKFICULIDAE 
 
 KEY TO THE FAMILIES OF ORTHOPTERA 
 
 A. Third pair of legs not adapted for leaping. 
 
 B. Body oval, dorsoventrally compressed. Cockroaches. (Page jj) 
 
 Blattidae 
 BB. Body elongate, not dorsoventrally compressed. 
 
 C. First pair of legs fitted for grasping and holding their prey ; prono- 
 tum longer than any of the other body segments. Praying mantis. 
 
 (Page 78) Maxtidae 
 
 CC. First pair of legs not fitted for grasping and holding prey ; prono- 
 
 tum short. Walking-sticks. (Page 80) Phasmidae 
 
 A A. Third pair of legs adapted for leaping. 
 
 B. Antennae shorter than body. Locusts. (Page 81). . . Acrididae 
 BB. Antennae longer than body. 
 
 C. Tarsi consisting of four segments. Long-horned grasshoppers. 
 
 (Page 83) LocusTiDAE 
 
 CC. Tarsi consisting of three segments. Crickets. (Page 85) 
 
 Gryllidae 
 
 THE THYSANOPTERA 
 
 This order includes but a single family of very small insects with long, 
 narrow, membranous wings, having but few or no veins and bordered by a 
 fringe of long hair : the tarsi swollen, bladderlike, with or without claws. 
 
 Physopodae 
 
 KEY TO THE FAMILIES OF HEMIPTERAi 
 
 A. Wingless insects with fleshy unjointed beak; parasitic on mammals. 
 (Suborder Parasitica.) Suctorial lice. (Page 121) . . Pediculidae 
 AA. Winged or wingless insects, with a jointed beak. 
 
 B. First pair of wings leathery at the base, membranous at the tip, the 
 tips overlapping on the back ; beak arising from front part of head. 
 
 Suborder Heteroptera 
 C. Antennae shorter than head. Aquatic or shore insects. 
 
 D. With two ocelli. Toad-bugs Galgulidae 
 
 DD. Without ocelli. 
 
 1 Adapted from Kellogg's "American Insects." 
 
« 
 CLASSIFICATION OF INSECTS 
 
 309 
 
 E. Hind tarsus without claws. 
 
 F. Pronotum overlapping head above. Back-swimmers. 
 
 (Page 108) NOTONECTIDAE 
 
 FF. Head overlapping prothorax above. Water-boatman. 
 
 (Page 108) CoRisiDAE 
 
 EE. Hind tarsus with claws. 
 
 F. Caudal end of abdomen furnished with a respiratory 
 tube. Water-scorpions. (Page 109) . . . Nepidae 
 FF. Caudal end of abdomen without respiratory tube. 
 
 G. Hind legs flattened, adapted for swimming. Giant 
 water-bug. (Page 109) . . . Belostomatidae 
 GG. Hind legs slender, not adapted for swimming. 
 
 Naucoridae 
 CC. Antennae at least as long as head. 
 
 D. Head as long as entire thorax Limnobatidae 
 
 DD. Head shorter than thorax. 
 
 E. Last segment of tarsus more or less split, with claws 
 inserted before apex. 
 F. Body elongated ; beak four-jointed. Water-striders. 
 
 (Page 109) Hydrobatidae 
 
 FF. Body usually stout and oval ; beak three-jointed. 
 
 Velidae 
 EE. Last segment of tarsus entire, and with claws inserted at 
 apex. 
 F. Antennae of three or four segments. 
 • G. Beak three-jointed. 
 
 H. Body very long and slender . . Emesidae 
 HH. Body not long and slender. 
 
 /. Front legs with greatly thickened femora. 
 
 Ambush-bugs. (Page 114) . Phvmatidae 
 
 //. Front legs with normal femora, or at least not 
 
 unusually wide. 
 
 J. Antennasof three segments. Assassin-bugs. 
 
 (Page 112) Reduviidae 
 
 JJ. Antennas of four segments. 
 
 K. Tarsus of two segments : body very 
 flat. Flat-bugs .... Aradidae 
 KK. Tarsus of three segments. 
 
 L. Dorsal portion of body more or less 
 rounded ; beak long, reaching to or 
 beyond second coxa. Shore-bugs. 
 Saldidae 
 LL. Dorsal part of body flat ; beak not 
 reaching beyond second coxa. Bed- 
 bugs. (Page I 14) ACANTHIDAE 
 
3IO 
 
 ELEMENTARY ENTOMOLOGY 
 
 GG. Beak four-jointed. 
 H. Ocelli absent. 
 
 /. Membrane of front wings with two large cells 
 at the base, from which arise about eight 
 branching veins. Red-bugs. Pyrrhocoridae 
 //. Membrane of front wings with one or two 
 closed cells at the base, and with no longitudi- 
 nal veins. Leaf-bugs. (Page 117) Capsidae 
 HH. Ocelli present. 
 
 /. Front legs fitted for grasping prey, the tibia 
 being armed with spines and capable of being 
 closed tightly on the femora, which are unusu- 
 ally stout. Damsel-bugs . . . Nabidae 
 //. Front legs not differing from the others. 
 J. Body and legs very long and slender. 
 
 Stilt-bugs Berytidae 
 
 JJ. Body not unusually slender. 
 
 K. Tarsus two-jointed; wing-covers resem- 
 bling lace network. Lace-bugs. (Page 
 
 117) TiNGITIDAE 
 
 KK. Tarsus three-jointed. 
 
 L. Membrane with four or five 
 simple veins arising from its base. 
 Chinch-bug family. (Page 120) 
 
 Lygaeidae 
 LL. Membrane with many forked veins 
 springing from a transverse basal 
 vein. Squash-bugs. (Page 121) 
 
 Coreidae 
 FF. Antennae of five segments. 
 G. Dorsal portion of body flat. 
 
 H. Tibia with few or no spines. Stink-bugs. (Page 
 
 115) Pentatomidae 
 
 HH. Tibia armed with rows of spines . Cydnidae 
 GG. Dorsal portion of body strongly convex. 
 
 H. Prothorax rounded in front, nearly straight be- 
 hind ; lateral margin of scutellum with a furrow 
 in which the edges of the wing-covers fit when 
 closed. Negro-bugs . . . Thyreocoridae 
 HH. Prothorax not as above ; lateral margin of 
 scutellum without furrow. Shield-backed bugs. 
 
 Scutelleridae 
 BB. Wings membranous or sometimes leathery throughout ; beak arising 
 from the hinder parts of the lower side of the head. 
 
 Suborder Homoptera 
 
CLASSIFICATION OF INSECTS 311 
 
 C. Beak evidently arising from head ; tarsi three-jointed ; antennae 
 minute, bristlelike. 
 D. With three ocelli ; males with musical organs. Cicadas. (Page 
 
 122) CiCADIDAE 
 
 DD. With two ocelli or none ; males without musical organs. 
 E. Antennae inserted on sides of cheek beneath the eyes. 
 
 FULGORIDAE ^ 
 EE. Antennas inserted in front of and between the eyes. 
 
 E. Pronotum prolonged posteriorly over the abdomen or 
 at least over the scutellum. Tree-hoppers. (Page 124) 
 
 Membracidae 
 FF. Pronotum not prolonged above abdomen. 
 
 G. Hind tibia armed with one or two stout teeth and 
 with short, stout spines at tip. Spittle-insects. (Page 
 
 124) Cercopidae 
 
 GG. Hind tibia with two rows of spines. Leaf-hoppers. 
 
 (Page 125) Jassidae 
 
 CC. Beak apparently arising from between the front co.\ae, or absent ; 
 tarsi one- or two-jointed. 
 D. Hind femora fitted for leaping; antennas of nine or ten seg- 
 ments with two bristles on apex. Jumping plant-lice. (Page 
 
 127) Psyllidae 
 
 DD. Hind femora normal ; antennae usually with less than ten 
 segments. 
 E. Legs long and slender ; wings transparent. Plant-lice. 
 
 (Page 127) Aphididae 
 
 EE, Legs short ; wings usually opaque. 
 
 F. Tarsus consisting of two joints ; body covered with a 
 whitish powder, male and female each with four wings. 
 
 Aleyrodidae 
 
 FF. Tarsus consisting of one joint ; adult male with two 
 
 wings ; female wingless, with the body scale-like or 
 
 gall-like in form. Scale insects. (Page 129) Coccidae 
 
 KEY TO THE FAMILIES OF COLEOPTERA 
 
 Head not prolonged into beak. [Coleopfera geiutiiia.) 
 B. First and second tarsus consisting of five segments ; third tarsus con- 
 sisting of four segments Section Heteromera 
 
 C. Head without distinct neck ; narrower than thorax and more or 
 less inserted in it; body wall hard. Darkling-beetles. (Page 165) 
 
 Texebrionidae 
 CC. Head with distinct neck and as wide as prothorax ; body soft and 
 
 elytra flexible. Blister-beetles Meloidae 
 
 BB. First, second, and third tarsi of same number of segments. 
 
312 
 
 ELEMENTARY ENTOMOLOGY 
 
 C. Tarsi consisting of five segments . . . Section Pentamera 
 £). Antennas filiform, with distinct cylindrical segments. 
 
 Tribe Adephaga 
 £. Legs adapted for swimming, aquatic in habits. 
 
 /^. Eyes divided laterally, making apparently four compound 
 eyes. Whirligig-beetles. (Page 140) . . Gvrixiuae 
 /^f. Eyes not divided. Predacious diving-beetles. Dvtiscidae 
 JSE. Legs adapted for running ; terrestrial in habit. 
 
 /^. Antennae inserted on front of head above base of man- 
 dibles. Tiger beetles. (Page 137) . Cicixdelidae 
 /7\ Antennae inserted on sides of head between base of 
 mandibles and eyes. Predacious ground-beetles. (Page 
 
 138) Carabidae 
 
 DD. Antennae not filiform. 
 
 £. Antennas capitate or clavate . . . Tribe Clavicornia 
 /^. Aquatic, legs fitted for swimming. Water-scavenger 
 
 beetles. (Page 141) Hydrophilidae 
 
 /-T^. Terrestrial, legs not fitted for swimming. 
 
 G. Antennas moniliform, the segments gradually en- 
 larging toward the end ; elytra covering only basal 
 half of abdomen. Rove-beetles . Staphylinidae 
 GG. Antennae of various forms (clavate or capitate) ; 
 elytra covering most of abdomen. 
 H. Abdomen with six or more ventral segments ; an- 
 terior coxas conical ; antennae gradually thickened 
 or clavate. Carrion-beetles. (Page 142) 
 
 Silphidae 
 ////. Abdomen with five ventral segments ; anterior 
 coxae conical and projecting from the coxal cavi- 
 ties ; last three segments of the antennas forming 
 a large club. Larder-beetles, etc. Dermestidae 
 EE. Antennae serrate or lamellate. 
 
 E Antennas serrated. Saw-horned beetles. (Page 144) 
 
 Tribe Serricornia 
 
 G. Head inserted in thorax, which extends as far as 
 
 compound eyes ; body elongated or elliptical. 
 
 //. First two abdominal segments fused together on 
 
 ventral side. Metallic wood-borers. (Page 146) 
 
 Buprestidae 
 ////. First two abdominal segments not fused. Click- 
 beetles. (Page 144) .... Elateridae 
 • GG. Head not inserted in thorax as far as compound eyes. 
 //. Head bent nearly at right angles to thorax, which 
 protrudes over it. Size usually less than one 
 fourth of an inch Ptiniuae 
 
CLASSIFICATIOxN OF INSECTS 313 
 
 HH. Head normal, but partially or nearly covered by 
 thin anterior margin of thorax. 
 /. Wing-covers flexible ; body elongated and 
 flattened ; antennas not enlarged at tip. Fire- 
 flies. (Page 147) .... Lampyridae 
 //. Wing-covers firm ; body not much flattened ; 
 antennas often enlarged at tip. Checkered- 
 beetles Cleridae 
 
 FF. Antennas lamellate, composed of a stemlike portion 
 on the end of which are a number of flat, bladelike 
 
 segments Tribe Lamellicornia 
 
 G. Antennas elbowed ; terminal lamella consisting of 
 fixed transverse plates. Stag-beetles. (Page 148) 
 
 LUCANIDAE 
 
 GG. AntenncE not elbowed ; terminal lamella consisting 
 
 of flat plates which fold together. Leaf chafers and 
 
 scavenger-beetles. (Page 149) . Scarabaeidae 
 
 CC. Tarsus less than five segments. 
 
 D. Tarsus consisting of four segments. (Page 153) 
 
 Section Tetramera 
 E. Body short and more or less oval ; antennas short. 
 
 F. Front of head not prolonged as a short, broad beak ; 
 elytra usually covering tip of abdomen ; larvas and adults 
 leaf feeders. Leaf-beetles. (Page 153) 
 
 Chrvsomelidae 
 FF. Front of head prolonged as a short, quadrate beak ; 
 elytra short, exposing tip of abdomen. Pea- and bean- 
 weevils. (Page 158) Bruchidae 
 
 EE. Body long and cylindrical; antennae long. (Page 158) 
 
 Cerambvcidae 
 
 DD. Tarsus consisting of three segments ; comparatively small 
 
 beetles with semispherical bodies. Ladybird beetles. (Page 
 
 161) (Section Trimera) Coccixellidae 
 
 A A. Head prolonged into a beaklike structure at the end of which are biting 
 
 mouth-parts. 
 
 B. The dorsum of the last segment of the male divided transversely so 
 
 that, when viewed dorsally, this sex appears to have one more body 
 
 segment than the female. 
 
 C. Mandibles with a scar of the anterior aspect . Otiorhynchidae 
 
 CC. Mandibles without scar on anterior aspect. Curculios. (Page 167) 
 
 Curculionidae 
 BB. Dorsum of last segment of both sexes undivided. 
 
 C. Tibia not serrated. Bill-bugs and granary-weevils. (Page i6g) 
 
 Calandridae 
 CC. Tibia serrated. Bark-beetles. (Page 1 70) ... Scolytidae 
 
s c ^^ ^^ rrr^ 
 
 Fig. 437. Diagram of wings of 
 
 Hepialus gracilis, showing jugum 
 
 (/) and similarity of venation of 
 
 fore- and hind-wings 
 
 (After Comstock, from Kellogg) 
 
 Fig. 438. Venation of a tortricid 
 moth (Cacoecia cenisivora>ia) 
 
 (After Comstock, from Kellogg) 
 
 f^rj r-f 
 
 Fig. 439. Venation of a pyralid moth 
 (Py rails farinalis) 
 
 cs, costal vein ; sc, subcostal vein ; r, radial 
 vein ; m, medial vein ; c, cubital vein ; a, 
 anal vein. Note the hairlike projection, the 
 fraenulum, at the base of the hind-wing. 
 This fits into a little pocket on the fore- 
 wing. (After Comstock, from Kellogg) 
 
 Fig. 440. Venation of a saturniid 
 
 {Bombyx niori) 
 
 (After Comstock, from Kellogg) 
 
 314 
 
a a 
 
 P"iG. 441. Venation of a cossid 
 {Prioiioxysiiis robinae) 
 
 (After Comstock, from Kellogg) 
 
 Fig. 442. ^'enation of a hes- 
 perid {Epargyreus titynis) 
 
 (After Comstock, from Kellogg) 
 
 ri f^rs 
 
 Fig. 443. Venation of a notodontid 
 
 {Notodo7Jta stragtila) 
 
 (.After Comstock, from Kellogg) 
 
 Fig. 444. Venation of a geome- 
 trid {Dyspepteris abortivaria) 
 
 (After Comstock, from Kellogg) 
 
 315 
 
e^r^ 
 
 Fig. 445. Venation of a noctuid 
 (Ag/viis ypsilon ) 
 
 (After Comstock, from Kellogg) 
 
 a a 
 
 Fig. 446. Venation of a lasio- 
 campid {Malacasomaamtricana) 
 
 (After Comstock, from Kellogg) 
 
 Fig. 447. Venation of a zygaenid 
 [Ctenucha virgin tea) 
 
 (After Comstock, from Kellogg) 
 
 Fig. 448. Venation of a lycaenid 
 
 ( Ch r\iso]. haniis ihoe) 
 
 (After Comstock, from Kellogg) 
 
 316 
 
'C2 
 
 Fig. 449. Venation of a papilionid 
 
 (Papilio folyxenes) 
 
 (After Comstock, from Kellogg) 
 
 Fig. 450. Venation of an arctiid 
 
 {Halesidota tessellata) 
 
 (After Comstock, from Kellogg) 
 
 Fig. 451. Venation of a nymphalid 
 [Basila)xhia astyaiiax) 
 
 (After Comstock, from Kellogg) 
 
 Fig. 452. Venation of a pierid 
 {PoHtia protodice) . ( Enlarged) 
 
 (After Comstock, from Kellogg) 
 
 317 
 
31 8 ELEMENTARY ENTOMOLOGY 
 
 KEY TO THE FAMILIES OF LEPIDOPTERAi 
 
 A. Lepidoptera with slender antennae, the tips of which are expanded or 
 dilated. Mostly diurnal in habits. Butterflies and skippers. 
 B. Dilation of antennae terminated by recurved hook. Wing venation 
 
 as in Fig. 261. Skippers. (Page 174) Hesperidae 
 
 BB. Dilation of antennas not terminated by recurved hook. 
 C First pair of legs normal, or simply reduced in size. 
 
 D. First pair of legs reduced in size. Wing venation as in Fig. 448. 
 
 (Page 178) Lycaenidae 
 
 DD. First pair of legs normally developed. 
 
 E. Front tibia without pads ; claws toothed ; cubital of fore- 
 wing three-branched. Fig. 452. (Page 178) . Pieridae 
 EE. Front tibia with pads ; claws not toothed ; cubital of fore- 
 wing four-branched. Fig. 449. Swallowtails. (Page 175) 
 
 Papilionidae 
 CC. First pair of legs atrophied, without claws ; wing venation as in 
 
 Fig. 451. (Page 179) Nymphalidae 
 
 A A. Lepidoptera with antennae of various forms but never enlarged at tip. 
 Mostly nocturnal in habits. Moths. 
 B. Hind-wings with not over two complete anal veins. 
 
 C. Second and third median veins arising together ; w" not arising 
 from center of discal cell. 
 D. Humeral vein present in hind-wing, arising at base of costal. 
 Fraenulum absent. Fig. 446. (Page 216) . Lasiocampidae 
 DD. Humeral vein absent ; fraenulum present. 
 
 E. Subcosta and radius of hind-wing fused to near apex of 
 discal cell ; ocelli present. Tiger moths. Fig. 450. (Page 
 
 207) Arctiidae 
 
 EE. Subcosta and radius of hind-wing distinct, or but slightly 
 
 fused. 
 
 E. Diurnal moths with simple antennae and contrasting 
 
 coloration. Wood nymphs .... Agarlstidae 
 
 EE. Nocturnal moths with simple or pectinate antennae and 
 
 without contrasting coloration. 
 
 G. Ocelli absent ; antennae pectinate. Tussock-moth. 
 
 (Page 203) Liparidae 
 
 GG. Ocelli present ; antennas usually simple. Owlet 
 moths. Fig. 445. (Page 199) . . . Noctuidae 
 CC. Second and third median vein not arising together, arising from 
 center of discal vein. 
 D. Fraenulum present. 
 
 E. Subcosta and radius of hind-wing connected near base by 
 crossbar. Hawk moths. (Page 208) . . . Sphingidae 
 
 1 This key has been adapted from keys of Holland, Smith, Bunter, and others. 
 
CLASSIFICATION OF INSECTS 319 
 
 EE. Subcosta and radius of hind-wing not connected by crossbar. 
 
 E. Moths with heavy abdomens and narrow, strong fore- 
 wings. Prominents. Fig. 443. (Page 193) 
 
 NOTODONTIDAE 
 
 EE. Moths with narrow, slender abdomens, and broad, deli- 
 cate wings. Fig. 444. (Page 195) . C}eometridae 
 DD. Fraenulum absent. 
 
 E. Tongue absent ; tibia without spurs. Fig. 440. (Page 212) 
 
 Superfamily Saturxoidea ^ 
 EE. Tongue present ; tibia with spurs. Royal moths. 
 
 Ceratocampidae 
 BB. Hind-wing with three complete anal veins. 
 
 C. Wings transparent, free from scales. Fore-wings narrow. Clear- 
 winged moths. (Page 192) Sesiidae 
 
 CC. Wings covered with scales. 
 
 D. Hind-wings with subcosta fused with or approximate to radius. 
 
 Fig. 439. (Page 187) Pvraudae 
 
 DD. Hind-wings with subcosta and radius far apart. 
 
 E. Small moths with fringe on inner angle of hind-wing 
 unusually long. 
 
 F. Second anal vein of hind-wing forked at base. Leaf- 
 rollers. Fig. 438. (Page 186) . . . Tortricidae^ 
 
 EE. Second anal vein of hind-wing not forked at base. Leaf- 
 miners. (Page 184) TiNEIDAE 
 
 EE. Large or medium-sized moths, without unusual fringe on 
 hind-wing. 
 E. Anal veins of fore-wing partially fused. Bag-worm 
 
 moths PSYCHIDAE 
 
 EE. Anal veins of fore-wing not fused. Carpenter moths. 
 (Page 191) CossiDAE 
 
 KEY TO THE FAMILIES OF HYMENOPTERA3 
 
 Posterior trochanter consisting of two segments ; ovipositor modified into 
 a saw, or borer. 
 B. Abdomen broadly joined to thorax. 
 
 C. Tibia of forelegs with two terminal spurs ; female with sawlike 
 
 ovipositor. Saw-flies. (Page 244) .... Tenthredinidae 
 
 CC. Tibia of foreleg with one terminal spur ; female with ovipositor 
 
 fitted for boring. Horn-tails. (Page 246) .... Siricidae 
 
 BB. Abdomen joined to thorax by slender petiole. 
 
 1 Includes families Bombycidae, Saturniidae. 
 
 2 Includes families Grapholithidae, Conchylidae, and Tortricidae. 
 ^ Modified from Cresson. 
 
320 
 
 ELEMENTARY ENTOMOLOGY 
 
 C. Fore-wings with few or no cross veins ; if a few cross veins are 
 present, the abdomen is not compressed. \'ery small parasitic 
 Hymenoptera. 
 D. Ovipositor issuing before apex of abdomen . Chalcididae 
 I?D. Ovipositor issuing from apex of abdomen. (Page 253) 
 
 PROCTOTRYPID.A.E 
 CC. Fore-wings with one or more closed cells. 
 
 D. Fore-wings without a stigma, or costal vein. Gall-flies. (Page 
 
 246) CVXIPIDAE 
 
 D£>. Fore-wings with a stigma. 
 
 E. Fore-wing with two recurvent veins . Ichxeu.monidae 
 EE. Fore-wing with one recurvent vein . . Bracoxidae 
 A A. Posterior trochanter consisting of a single segment. 
 B. Fore-wings with no closed submarginal cells. 
 
 C. Abdomen long and slender ; antennas long and filiform. 
 
 Pelecixidae 
 CC. Abdomen short, but little longer than the head and thorax together ; 
 antennae short and elbowed. Cuckoo-fiies . . . Chrysididae 
 BB. Fore-wings with at least one closed submarginal cell. 
 
 C. First abdominal segment, and sometimes the second, forming a 
 knot, or node, on the upper side of the petiole. Ants. (Page 254) 
 
 Superfamily FOR.MICIXA 
 D. First segment of the abdomen forming the petiole. 
 
 E. Abdomen somewhat constricted between the second and 
 
 third segments ; sting present Poxeridae 
 
 EE. Abdomen not constricted between the second and third 
 
 segments : sting absent Campoxotidae 
 
 W. Petiole consisting of the first and second segments of abdomen ; 
 
 sting present IMvrmicidae 
 
 CC. Petiole normal, without scales or nodes. 
 
 £>. First segment of tarsus of hind-leg cylindrical, and naked, or 
 wdth little hair. 
 E. Wings folded longitudinally when at rest. True wasps. 
 
 (Page 263) Superfamily Vespixa 
 
 E. Antennae clavate or knobbed at tip . . Masaridae 
 EE. Antennas filiform or nearly so. 
 
 G. Tibia of second pair of legs with a single terminal 
 
 spur Eumexidae 
 
 GG. Tibia of second pair of legs with two terminal 
 spurs. Tarsal claws simple. (Page 264) 
 
 Vespidae 
 EE. Wings not folded longitudinally when at rest. Digger- 
 wasps. (Page 260) Superfamily Sphecixa 
 
 E. Sides of the pronotum extending back to the base of 
 the wings. 
 
CLASSIFICATION OF INSECTS 32 1 
 
 G. First abdominal segment distinctly separated from 
 the second on the ventral side by a constriction. 
 H. Tibia of second pair of legs with two terminal 
 spurs; females wingless. Velvet ants. (Page 
 
 261) MUTILLIDAE 
 
 HH. Tibia of second pair of legs with single terminal 
 
 spur SCOLIIDAE 
 
 GG. First and second segment of abdomen not separated 
 on ventral side by constriction. (Page 261) 
 
 PSAMMOCHARIDAE 
 
 FF. Prothorax forming a narrow collar, not reaching to base 
 of wing. 
 G. Base of abdomen with a long, slender petiole. (Page 
 
 262) Sphecidae 
 
 GG. Base of abdomen without long, slender petiole. 
 
 Bembecidae 
 DD. First segment of tarsus of hind-leg expanded and flattened, 
 furnished with numerous hairs, often poorly developed in para- 
 sitic bees. Bees. (Page 266) .... Superfamily Apina 
 E. Glossa short and flat, no longer than the mentum. Short- 
 
 tongued bees. (Page 267) Axdrenidae 
 
 EE. Glossa long and slender, not flattened. Long-tongued bees. 
 (Page 267) Apidae 
 
 KEY TO THE MORE IMPORTANT FAMILIES OF DIPTERAi 
 
 A. Adults nonparasitic upon the warm-blooded vertebrates; habits variable. 
 Abdomen distinctly segmented. Rarely viviparous. 
 B. Anal cell rarely narrowed at the margin ; antennas consisting of more 
 than 5 joints, usually elongate, filiform, and verticellate, rarely pecti- 
 nate or with a differentiated style or arista . . . Nematocera 
 C. Veins of the wings covered with hairs, the usual cross veins want- 
 ing. Small mothlike flies Psvchodidae 
 
 CC. Veins and margin of the wings fringed with scales. Mosquitoes. 
 
 (Fig. 455) Culicidae 
 
 D. Thorax with a distinct V-shaped suture ; wings variable. Crane- 
 flies. (Fig. 453) Tipulidae 
 
 DD. Thorax without the distinct V-shaped suture. 
 
 E. Discal cell present. False crane-flies . . . Rhyphidae 
 EE. Discal cell wanting. 
 
 F. Wings with few longitudinal veins ; tibiae without spurs. 
 
 Gall-gnats. (Fig. 458) Cecidomyiidae 
 
 FF. Tibiae with spurs ; coxae elongate. Fungus-gnats. 
 (Fig. 459) Mycetophilidae 
 
 ^ By C. W. Johnson, Curator Boston Society of Natural History. 
 
Fig. 453. Venation of a tipulid {Protoplasa fitchii) 
 (After Comstock) 
 
 )-4»S 
 
 Fig. 454. Venation of Blepkarocera sp. 
 (After Comstock) 
 
 
 Fig. 455. Venation of a mosquito {Cii/ex sp.) 
 (After Comstock) 
 
 r' 7-2*3 
 
 Fig. 456. Venation of a Chironomiis sp. 
 (After Comstock) 
 
 
 Fig. 457. Venation of a soldier-fly (Stratiofnyia sp.) 
 
 (After Comstock) 
 
 322 
 
CLASSIFICATION OF INSECTS 
 
 323 
 
 G. Abdomen slender ; wings narrow ; antennae plumose 
 
 in the males. Midges. (Fig. 456) Chironomidae 
 
 GG. Abdomen short and thick ; antennae shorter than the 
 
 thorax, nonplumose. 
 
 H. Wings very broad, anterior veins stout, the other 
 
 weak. The black-flics . . . . Slmuliidae 
 
 HH. Wings large but more normal in character ; legs 
 
 strong, front femora often thickened. 
 
 BiBlONIDAE 
 
 BB. Anal closed or distinctly narrowed, second vein never fucate ; antennae 
 usually with three joints, the third joint sometimes complex and com- 
 posed of numerous annuli Brachvcera 
 
 C. Third joint of the antennas with from 4- to 8-segmented annuli. 
 D. Squamae rather large : third joint of the antennas without a 
 
 style or arista. Horse-flies Tabaxidae 
 
 DD. Squamae small or vestigial. 
 
 E. Costal vein does not extend beyond the tip of the wing, 
 longitudinal veins covered anteriorly ; posterior veins often 
 weak; tibiae without spurs. Soldier-flies. (Fig. 457) 
 
 Stratiomyidae 
 
 EE. Costal vein encompasses the wing ; posterior veins strong ; 
 
 middle tibiae at least with distinct spurs ; antennae extremely 
 
 variable Leptidae 
 
 CC. Third joint of antennae simple, not composed of numerous annuli. 
 D. Antennae long, clavate, apparently 4-jointed ; palpi small or 
 
 wanting. Mydas-flies Mydaidae 
 
 DD. Antennae 3-jointed, often with a variable style or arista ; palpi 
 
 always present, usually prominent. Robber-flies . Asilidae 
 
 E. Antennae apparently 2-jointed ; anterior veins stout, the 
 
 others weak and extending obliquely across the wing. 
 
 Small hunch-backed flies Phoridae 
 
 EE. Antennae 2- or 3-jointed ; head small ; squamae very large ; 
 abdomen inflated. Parasitic on spiders . . Cyrtidae 
 E. Third antennal joint usually with a terminal style, pro- 
 boscis often prominent ; body frequently covered with 
 long, delicate hairs. Bee-flies. (Fig. 460) Bombyliidae 
 EF. Third antennal joint without terminal style ; fourth vein 
 terminates at or before the tip of the wing. Window- 
 flies SCENOPINIDAE 
 
 G, Small, for the most part bright-colored green or blue ; 
 second boscal cell confluent with the discal cell ; arista 
 dorsal or terminal. Predacious. Dolichopodidae 
 GG. Small, not brightly colored ; head small, eyes some- 
 times contiguous ; proboscis rigid. Predacious. 
 
 Empididae 
 
Fig. 458. Venation of a cecidomyiid gall-gnat 
 (After Comstock) 
 
 Fig. 459. Venation of a fungus-gnat {I\Iycetophilidae) 
 (After W'innertz, adapted from Comstock) 
 
 yS 13 
 
 la cu^ m3+cu' 
 
 Fig. 460. Venation of a bombyliid {Peniarbes capita) 
 
 (After Comstock) 
 
 "cvJyla 
 
 Fig. 461. Venation of a bot-fly {Gastrophihis sp.) 
 (After Comstock) 
 324 
 
CLASSIFICATION OF INSECTS 
 
 325 
 
 H. Third joint almost always with a dorsal arista ; a 
 
 spurious longitudinal vein between the third and 
 
 fourth longitudinal veins ; first posterior cell al- 
 
 waysclosed. Flower-flies. (Fig. 463) Svrphidae 
 
 HH. No spurious longitudinal veins. 
 
 /. Small ; hind tarsi enlarged and often orna- 
 mented in the male arista terminal. Flat- 
 footed flies Platypezidae 
 
 //. Small ; head large, composed chiefly of eyes ; 
 arista dorsal. Big-eyed flies. Pipuxculidae 
 /. Squamae small or vestigial ; eyes never con- 
 tiguous ; the front in both sexes of equal 
 width ; thorax vnthout complete transverse 
 
 suture Acalvpterae 
 
 K. Auxiliary vein distinct, the first vein 
 ends near or beyond the middle of the 
 wings ; a distinct bristle on each side 
 of the face; oval vibrissae present ; front 
 usually with well-developed bristles and 
 
 hairs Cordvluridae 
 
 KK. Front never brisdy near the antennas ; 
 abdomen cylindrical, contracted near 
 the base. Small shining black flies. 
 Cheese-maggot, etc. . . Sepsidae 
 L. No oral vibrissae ; abdomen elon- 
 gate, often narrowly constricted, 
 proboscis long and folded near the 
 middle. (Fig. 462) . Conopidae 
 LL. Upper fronto-orbital bristles only 
 present; preapical tibial bristle rarely 
 present ; arista rarely plumose ; ovi- 
 positor horny ; wings usually pic- 
 tured Ortalidae 
 
 M. Fronto-orbital bristles present 
 or absent ; second joint of the 
 antennas often elongate ; arista 
 plumose ; preapical tibial bristle 
 present; ovipositor not horny; 
 wings often pictured. Meadow- 
 flies . . . SCIOMYZIDAE 
 MM. One or two fronto-orbital bris- 
 tles ; third joint of the antennae 
 more or less elongate ; preapical 
 bristle absent or present. All 
 small species. Sapromyzidae 
 
cu*ia 
 
 Fig. 462. Venation of a conopid {Coiiops affinis) 
 •(After Comstock) 
 
 sc r' r2*3 Y**5 
 
 Fig. 463. Venation of a syrphid {Eristalis sp.) 
 (After Comstock) 
 
 la ciiz ^^^ 
 
 Fig. 464. Venation of a dixa midge {Dixa sp.) 
 (After Comstock) 
 
 Y4*S 
 
 Fig. 465. Venation of an empidid {^Rhamphomyia sp.) 
 
 (After Comstock) 
 326 
 
CLASSIFICATION OF INSECTS 327 
 
 N. Auxiliary vein absent or in- 
 complete; first vein usually 
 ends in the costa before the 
 middle of the wing; head 
 produced on each side into 
 a lateral process for the 
 eyes . . . Diopsidae 
 
 NN. Hind metatarsi incrassated 
 and usually shorter than the 
 second joint ; oval vibrissae 
 present. Small fiies about 
 excrement near water. 
 
 BORBORIDAE 
 
 O. Discal and basal cells 
 united, anal cell absent; 
 front bare or at most 
 bristly above. Small, 
 usually light-colored 
 
 flies . . OSCINIDAE 
 
 00. Front often brisdy, 
 face often very convex, 
 mouth cavity usually 
 large ; no oval vibrissas. 
 Small dark-colored flies 
 about water. 
 
 Ephvdridae 
 P. Anal cell complete ; 
 oral vibrissas pres- 
 ent ; aristae long, plu- 
 mose, or pectinate 
 above. Vinegar or 
 pomace flies. 
 
 Drosphilidae 
 PP. Aristabare or pubes- 
 cent ; front bristly 
 at least as far as 
 the middle. Very 
 small flies, compris- 
 ing most of the leaf- 
 miners. 
 
 Agromyzidae 
 Q. Oval vibrissae ab- 
 sent ; anal cell an- 
 gular ; no preapi- 
 cal tibial bristle; 
 
328 ELEMENTARY ENTOMOLOGY 
 
 ovipositor long 
 and jointed ; 
 wings usually 
 pictured. Fruit- 
 flies. 
 
 Trypetidae 
 QQ. Anal cell not pro- 
 duced ; antennae 
 usually elongated 
 and decumbent. 
 Rather small 
 elongate flies. 
 
 PSILIDAE 
 
 JJ. Squamae large ; front of male narrowed or 
 
 eyes contiguous ; thorax with complete 
 
 transverse suture . . . Calvpterae 
 
 K. Oval opening small ; the mouth-parts 
 
 small or vestigial. Larvae parasitic upon 
 
 mammals. Bot-flies. (Fig. 461) 
 
 Oestridae 
 KK. Oval opening of usual size, not vestigial ; 
 hypopleurae with a tuft of bristles ; first 
 posterior cell narrowed or closed ; arista 
 bare or somewhat pubescent. Larva 
 parasitic upon the early stages of other 
 
 insects Tachixidae 
 
 L. Arista bare on the outer half ; dor- 
 sum of the abdomen rarely bristly 
 on the anterior part. Larva usually 
 feeds on decaying animal matter. 
 Flesh-flies . . Sarcophagidae 
 LL. Arista entirely plumose ; dorsum of 
 the abdomen usually bristly on the 
 anterior part ; legs long. Larva para- 
 sitic on other insects . Dexiidae 
 M. Arista plumose; abdominal seg- 
 ments without bristles except 
 near the tip ; first posterior cell 
 narrowed or closed. House-fly, 
 
 etc MUSCIDAE 
 
 MM. Arista plumose, pubescent, or 
 bare ; first posterior cell very 
 slightly or not at all narrowed 
 at the margin. Larva are vege- 
 table feeders. Axthomvudae 
 
CLASSIFICATION OF INSECTS 
 
 329 
 
 A A. Adults usually cctoparasitic upon warm-blooded vertebrates; abdomen 
 
 indistinctly segmented. Larva; born when about to pupate. I'upipaka 
 
 />. Winged or wingless flies ; eyes faceted ; palpi forming a sheath for 
 
 the proboscis ; veins of the wing, when present, crowded anteriorly, the 
 
 weaker veins running obliquely across the wing. Parasitic upon birds 
 
 and mammals. House-flies Mippoboscidae 
 
 BB. Winged or wingless: when present the wings are pubescent, with 
 
 parallel veins and outer cross-veins ; eyes usually unfacetcd ; ocelli 
 
 wanting ; antennae 2-jointed ; palpi broad, not forming a sheath for 
 
 the proboscis. Usually parasitic upon bats .... Stkeblidae 
 
 C. Wingless; halteres present ; eyes vestigial ; head folding back on 
 
 the dorsum of the thorax. Small, spiderlike flies ; parasitic upon 
 
 bats. Bat-ticks Nycteribiidak 
 
 CC. Wingless; halteres absent; eyes vestigial; last joint of the tarsi 
 with a pair of comblike appendages. Parasitic upon the honey- 
 bee. Bee-louse Bkaulidae 
 
CHAPTER XXIII 
 
 METHODS OF COLLECTING INSECTS 
 
 The following instructions on the methods and equipment for 
 collecting and preserving insects have been compiled to give as 
 concise information on the subject as possible. Most of the methods 
 and equipment have been tried and tested out either by the author 
 or under his observation. There are a number of accessible bulletins 
 and papers on this subject, one of the best of which is United States 
 National Museum Bulletin No. 6j, " Directions for Collecting and 
 Preserving Insects," by Nathan Banks.^ 
 
 Field kit. In order to secure a collection that is at all valuable, 
 it is necessary to make special trips after insects, and to be provided 
 with special equipment. Therefore, among the first requirements 
 is a means of carrying the outfit so that every article will be 
 accessible. 
 
 TJic haversack. This is one of the most common means of 
 carrying collecting outfits, and if constructed of the proper material, 
 will be found very handy. The size will depend somewhat on the 
 length of the trip taken, but for ordinary purposes a sack twelve 
 by fourteen by four inches will be found most convenient. It should 
 be provided with a good flap, to fasten by means of a buckle or snap, 
 as well as with shoulder straps and loops for the belt. These latter 
 are very important, as they prevent the sack from flopping about 
 while collecting. Canvas or khaki makes very serviceable sacks, but 
 they are not waterproof. Some of the numerous imitation leathers 
 or heavy oilcloth will wear nearly as long and be much more 
 serviceable. The haversack should have at least three separate 
 compartments, and if manufactured at home, with a little ingenuity 
 one can provide a place for each article of the outfit. 
 
 Collecting coat. Any comfortable, loose-fitting coat may, with a 
 little alteration, be converted into an entomologist's collecting coat. 
 The requirements are a sufficient number of pockets to hold the 
 
 ^ See also the bottom of page 359. 
 330 
 
METHODS OF COLLECTING INSECTS 
 
 field outfit. The ordinary khaki or duck's-back hunting coat will 
 be found very convenient, having, as it does, an abundance of 
 room for accommodating cyanide bottles, folding nets, and other 
 necessar}' articles. 
 
 Collecting belt (Fig. 466). For short, half-day excursions a loose- 
 fitted, woven belt, about three or four inches wide, provided with 
 pockets to hold cyanide bottles, forceps, storage boxes, etc., is veiy 
 
 
 
 5^ 
 
 W *^ 
 
 9 
 
 Qj**-^ 
 
 i^^-'-^i^^.^-'-:;;: 
 
 
 m 
 
 
 » 
 
 Fig. 466. A collecting belt 
 (.A.fter Banks) 
 
 serviceable. The objection to this affair, however, is the unavoid- 
 able width of the belt. These belts may be obtained, with a complete 
 collecting outfit, from any of the entomological supply companies. 
 Insect nets. Of first importance to the entomologist is the insect 
 net. In its simplest form the net consists of a ring, or hoop, firmly 
 attached to a handle two or three feet in length. Attached to the 
 hoop is a net about eighteen inches in depth. A very serviceable net 
 may be constructed by bending a stout wire into a circle (Fig. 467), 
 then bending the ends back at right angles and lashing them 
 
332 
 
 ELEMENTARY ENTOMOLOGY 
 
 firmly to the stick with stout binding wire. The ring will be held 
 much more firmly if the ends of the wire are sharpened and again 
 bent at right angles and driven into the stick. Also, a groove cut in 
 either side of the stick for the reception of the wire will make it 
 much stouter. There are numerous other ways of constructing net 
 frames, but most of them are too complicated for practical use. 
 Many folding frames of various types may be obtained of entomo- 
 logical supply companies, but none of these are equal to the spring- 
 steel, folding landing nets sold by dealers in fish tackle. These 
 
 may be obtained with a three-foot, jointed 
 handle, are nearly as light, and will 
 stand much more wear than any of the 
 regular insect-net frames on the market. 
 The simplest and lightest net ring is that 
 of the simplex net (see Appendix) ; this 
 consists of a thin steel band which is 
 easily coiled up and carried in the pocket, 
 and readily attached to the handle. 
 Numerous materials are used in the 
 construction of the net itself. Mosquito 
 bar is sometimes used, but this lasts but 
 a short time and is too coarse to catch 
 small insects. A fine bobbinet is far 
 superior to the mosquito bar, as is also 
 cheesecloth. With any of these mate- 
 rials a hem of stout cotton cloth should 
 first be sewed to the net, through which 
 to run the net frame. The net should be about eighteen inches in 
 depth, tapering nearly to a point. 
 
 The net above described is to be used for all ordinary purposes, 
 such as catching butterflies, dragon flies, etc., but is scarcely suitable 
 for certain kinds of collecting. 
 
 The sweeping net. This type of net is very similar to the one 
 just described, except that the frame is much heavier and the net 
 of stronger material, such as denim or canvas. It is used by sweep- 
 ing it back and forth rapidly over the tops of the bushes, through 
 long grass, weed patches, etc. After sweeping back and forth a 
 number of times, the net is given a half turn, which prevents the 
 
 Fig. 467. A wire net frame 
 
METHODS OF COLLECTING INSP:CTS 333 
 
 insects from escaping. An improved form of this net consists of an 
 outer sack with square in place of tapering bottom, the sack to be 
 made out of cheesecloth, cotton cloth, or some such material. On 
 the inside of this is fitted a short, funnel-shaped net made out of 
 bobbinet or light cheesecloth. This net has an opening of about 
 two inches at the bottom. In sweeping, the insects pass down 
 through this opening between the two nets and are unable to es- 
 cape. In this way great numbers of grass insects may be collected 
 without stopping to remove them from the net. The insects may 
 be stupefied by placing the entire net in a pail together with a piece 
 of cotton saturated with ether. 
 
 For aquatic collecting certain other types of nets are desirable, 
 although the ordinary insect net may sometimes be used to 
 advantage. 
 
 Water dip net (Fig. 468). The frame of this type of net is usu- 
 ally flattened on one side so as to allow the net to be manipulated 
 
 Fig. 46S. A water dip net Fig. 469. A small dip net 
 
 (After Packard) (After Howard) 
 
 closer to the bottom. The net itself should be made of fine brass- 
 wire netting, about twelve inches in diameter and of about the same 
 depth. Fig. 469 shows a dip net with a flange, or lip, of tin or 
 sheet iron, which is useful in dislodging aquatic larvae or insects 
 from around stones, thick weeds, etc. 
 
 TJic sag net (Fig. 470), This form of aquatic net is described 
 by Professor James G. Needham, who is probably our best authority 
 on aquatic insects, as follows : 
 
 It consists of a ring of stout spring wire three to four feet in diameter, to 
 which is attached a very shallow bag of bobbinet, and at one side is a handle 
 only long enough to be held readily. It is intended to catch insects adrift in 
 the stream, and is accompanied by an instrument for dislodging them. Such 
 an instrument is figured below the net. It consists of a handle three or 
 
334 
 
 ELEMENTARY ENTOMOLOGY 
 
 four feet long, with a double hook at one side and a brush at the other side 
 at its distal end. To illustrate the use of this apparatus, suppose we wish to 
 
 collect the insects from the stones 
 obstructing a brook. We place the 
 net directly below the obstruction 
 and in the current, and adjust it to 
 the bottom by downward pressure 
 on the handle with one hand, while 
 with the other we rapidly overturn 
 the stone and with a brush sweep 
 free the clinging insects. These are 
 driven by the current into the net, 
 when it is then lifted and emptied. 
 
 Sag net, hook and brush for col- 
 lecting in rapids 
 
 (After Needham) 
 
 Fig. 470. 
 
 An aquatic sieve net (Fig. 471). This net is intended to be used 
 in stagnant water or on sandy bottoms where there is but httle 
 vegetation. The frame consists of a Hght steel rod, sides of heavy 
 tin or galvanized iron, and a bottom of fine brass or galvanized 
 
 Fig. 471. An aquatic sieve net 
 (After Needham) 
 
 wire netting. When provided with a long handle, this net may 
 be used from the shore, and is particularly recommended for 
 burrowing nymphs of aquatic insects. 
 
 Rake net. The rake net consists of an ordinary garden rake, 
 with a stiff semicircle of wire fastened on the upper side of the 
 rake above the teeth. This should be braced to the handle with 
 another piece of wire. A net is then attached to the upper part of 
 the rake and around the semicircle of wire. This is very useful in 
 slightly weedy water, or where there is a large amount of debris 
 on the bottom. When the bottom of a pond or stream is raked, 
 the insects, nymphs, and small crustaceans are either entangled in 
 the debris and brought to shore, or, in trying to escape the rake 
 teeth, swim back into the net. The debris should be carefully 
 
METHODS OF COLLECTING INSECTS 
 
 t-': 
 
 searched for any nymphs or larvae that may be entangled in it. 
 
 This form of net is particularly useful in collecting dragon-fly 
 nymphs, and is much superior to the ordinary 
 garden rake, which has often been recommended 
 for this purpose. 
 
 Cyanide bottle (Figs. 472 and 473). These 
 bottles should be provided in at least three sizes, 
 the largest with a di- 
 ameter of two and one 
 half inches or more, 
 a smaller, straight- 
 necked bottle with a 
 diameter of an inch 
 and a half, and an- 
 other much smaller 
 straight-necked bot- 
 tle with a diameter 
 of about half an inch. 
 Before much collect- 
 ing is done, the stu- 
 dent will probably 
 find it necessary to 
 provide himself with 
 two complete sets of 
 these bottles, with 
 
 possibly one or two extra of the smaller 
 
 sizes. Cyanide bottles are made in 
 
 the following manner : Place a few 
 
 good-sized pieces of potassium cya- 
 nide (a most deadly poison) in the 
 
 bottom of each bottle, and cover the 
 
 cyanide with dry plaster of Paris. 
 
 (As the fumes of potassium cyanide 
 
 are very poisonous, it should be 
 
 handled with extreme care.) Then 
 
 mix up a thick paste of plaster of 
 
 Paris and water, and pour over the dr}' plaster in the bottles. 
 
 Leave standing open for a few hours, until the water has evaporated 
 
 Fig. 472. A cya- 
 nide bottle for the 
 pocket. (One half 
 actual size) 
 
 Fig. 473. A larger cyanide bottle 
 with paper strips to give sup- 
 port to the insects 
 
 (After Banks) 
 
3J^ 
 
 ELEMENTARY ENTOMOLOGY 
 
 and the plaster of Paris set. After this the bottle should always be 
 kept corked, so as to retain the strength of the cyanide. The ad- 
 vantage in putting the dvf plaster of Paris in first is that it absorbs 
 the moisture and will keep the bottle dry longer than if the wet 
 plaster is poured directly over the cyanide. It will also be found 
 advantageous to place a few strips of dry blotting paper in each 
 cyanide bottle, as this serves the double purpose of helping to 
 absorb the moisture and preventing the insects from shaking about. 
 After the insects are caught in the net, they 
 should be transferred to the cyanide bottle, 
 which, if properly constructed, will stupefy 
 them in a few seconds. Insects, especially 
 beetles, should not be removed from the 
 bottle for an hour, although Hymenoptera 
 and Diptera will be killed within ten minutes. 
 If the cyanide is too dry, it does not act so 
 rapidly, and a few drops of soda water will 
 greatly increase its efficiency. Very small 
 cyanide bottles may be made by placing a 
 piece of cyanide in the bottom, covered with 
 cotton or blotting paper. 
 
 If possible, only insects of the same size 
 should be placed together in the cyanide bot- 
 tles. Fragile insects, or those with scaly wings, 
 should not be put in with the general collection. 
 Chloroform bottle (Fig. 474). While not an 
 absolute essential to the collecting of insects, 
 the chloroform bottle will be found one of the 
 most valuable assets, especially to the collector of Lepidoptera. 
 One of the most convenient forms consists of a small-mouthed 
 bottle, into the cork of which has been inserted a camel's-hair 
 brush. These will be found most useful in collecting very small 
 insects or butterflies. In collecting very small insects, touching them 
 with a brush moistened in chloroform is sufficient to kill them, and 
 at the same time the insects will adhere to the brush and may 
 thus be transferred to the storage bottle or box. In collecting 
 Lepidoptera the sides of the thorax should be moistened with the 
 chloroform before placing them in the c\-anide bottle. 
 
 Fig. 474. Chloroform 
 
 bottle with a brush 
 
 stopper 
 
 (After Banks) 
 
METHODS OF COLLECTING INSECTS 337 
 
 Another form of chloroform bottle suitable for stupefying large 
 Lepidoptera is made by inserting a fine-pointed medicine dropper 
 through the cork of the bottle. A few drops of chloroform can then 
 be applied directly to the specimens, through the net, before they 
 are removed. This will also be found convenient in collecting some 
 of the larger Hymenoptera. Since the chloroform has a tendency 
 to harden the specimens, only a sufficient amount should be used 
 to stupefy the insects, which should immediately be placed in the 
 cyanide bottle. 
 
 AlcohoL This is another accessory that should be used in the 
 field only in collecting very small insects, such as Thysanura, very 
 small larvae, Aphididae, etc. The alcohol outfit should consist of 
 a number of small, straight-necked vials, fitted with cork stoppers, 
 about half filled with 75 per cent alcohol. In addition to these 
 vials the collector should have a larger bottle and brush, similar to 
 the chloroform bottle described above. This bottle should contain 
 95 per cent of alcohol and 5 per cent of glycerin. The speci- 
 mens are killed b\' touching them witli the brush moistened in the 
 95 per cent alcohol, after which they are washed off into the bottle 
 containing the weaker alcohol. The reason of this combination of 
 two grades of alcohol is that many insects are protected with a 
 waxy secretion which the weaker alcohol will not penetrate. Of 
 course, specimens should not be collected in this way unless they 
 are to be preserved permanently in some liquid medium. In collect- 
 ing some Thysanura it may be found necessary to dispense with 
 the glycerin, although it has a tendency to retain the color better 
 than the alcohol alone. 
 
 Collecting forceps. While these are not absolutely essential to 
 the field kit, it will be found convenient to have a pair of stout, 
 broad-pointed forceps for handling stinging Hymenoptera, some 
 beetles, and other insects that are liable to injure the collector. 
 Fine-pointed forceps should also be taken along to handle very 
 small insects, although a moistened camel's-hair brush will serve 
 the same purpose. 
 
 Hatchet and chisel. These tools will be found very useful in 
 collecting wood-boring insects and their larvae. The marble safety 
 ax stands in a class by itself, being far superior to anything else on 
 the market for this purpose. Even in general collecting this ax will 
 
338 
 
 ELEMENTARY ENTOMOLOGY 
 
 be found very useful for numerous purposes. In addition to the 
 ax, many collectors always carry a chisel, but this will be found of 
 but little advantage except in collecting wood-boring larvae. 
 
 Receptacles for carrying insects. For general collecting, one 
 should always carry a number of receptacles in which to place the 
 insects as soon as they have been killed in the cyanide bottle. For 
 
 Fig. 475. The paper envelope for Lepidoptera, and method of folding it 
 /, first fold ; 2, second fold. (After Banks) 
 
METHODS OF COLLECTING INSECTS 339 
 
 this purpose ordinary pill boxes of various sizes are most conven- 
 ient. Each box should be partly filled with crushed tissue paper, 
 to prevent the insects from shaking about. Care should be taken 
 not to place too many insects together. If the insects cannot be 
 mounted at once, the date of collecting, the locality, and other 
 notes may be written on the outside of the box. For very small 
 insects gelatin capsules will prove more useful than the pill 
 boxes. Large-sized capsules especially adapted to this purpose 
 may be obtained of entomological supply companies or large drug 
 houses. Glass bottles should never be used for this purpose, as 
 the moisture from the bodies of the insects soon causes them to 
 deteriorate, or otherwise injures the more delicate specimens. 
 Also, cotton should not be used in the pill boxes or capsules, as 
 the claws and delicate hairs of the insects become entangled and 
 often broken off. Small paper envelopes will be found very useful 
 in carrying Lepidoptera, but they should be packed in a tin or 
 wooden box to prevent crushing. 
 
 Collecting larvae. The method of collecting larvae depends 
 somewhat upon the manner in which they are to be preserved. 
 Small larvae, to be preserved in alcohol or mounted on slides, may 
 be placed directly in the alcohol-glycerin solution, as indicated 
 above. The larger forms, which are to be blown (see page 353), 
 should be placed in tin boxes, together with a small amount of 
 their food plant. Aquatic forms which it is desirous to keep alive 
 must be packed in damp moss or damp paper, or else carried in 
 a large, open receptacle filled with water. If placed in a bottle or 
 tightly closed receptacle, they will soon die. One danger of carry- 
 ing aquatic larvae or nymphs in water is that the larger forms will 
 often destroy the smaller ones, especially if dragon-fly nymphs 
 have been collected. There is much less liability of this occurring 
 if the nymphs are packed in wet moss or paper. 
 
 Insect traps. Many insects can be collected much more easily by 
 means of traps than in any other way. These traps may consist 
 of some form of light for attracting insects, some attractive food 
 from which the insects may be collected as they come to it, or 
 a trap that the insects will fall into. 
 
 The funnel trap. The ordinary glass or tin funnel is fre- 
 quently employed in trapping insects. One of the simplest ways 
 
340 
 
 ELEMENTARY ENTOMOLOGY 
 
 of using this is to fit a cyanide or alcohol bottle over the lower 
 end of the funnel, and sink the bottle and funnel in the ground 
 level with the surface. This is particularly useful along the coast 
 or in sandy localities where ground beetles are numerous. This will 
 prove more effective for carrion beetles if a dead fish, mouse, or 
 piece of meat is strung on a wire and laid across the funnel. The 
 funnel is also used in collecting very small insects, like Thysanura. 
 The simplest method is to take an ordinary glass funnel, from 
 twelve to twenty-four inches in diameter, and place a cork stopper 
 in the lower end of the neck. The neck is 
 to be partly filled with alcohol. The funnel 
 should then be placed in a basin with 
 straight sides, which is partly filled with 
 water. The basin may be of tin or granite 
 ware, of slightly smaller diameter than 
 the top of the funnel, but deep enough so 
 that the neck of the funnel does not rest 
 on the bottom. If the funnel is not heavy 
 enough to prevent floating, it may be held 
 in position by strips of lead laid across the 
 top. This apparatus should then be placed 
 over a gas flame or some other even heat, 
 and the temperature of the water raised 
 to between sixty and one hundred degrees. 
 Since alcohol evaporates so rapidly, it 
 should not be placed in the funnel until 
 the apparatus is ready for use. The mate- 
 rial containing the insects, such as leaves, 
 decayed wood, etc., is next placed in a sieve, the diameter of which 
 is slightly smaller than that of the funnel. The sieve is then 
 placed over the top of the funnel, and the insects, attracted by the 
 heat, rapidly work their way through the material and drop down 
 into the funnel. The insects are removed from the funnel by taking 
 out the cork stopper and allowing the alcohol to run out into a bottle. 
 A very convenient time to collect these small insects is during the 
 early fall or winter. Cotton-cloth bags may be used to gather up 
 the decaying leaves, wood, etc., which are then brought to the 
 laboratory and the insects sorted out. 
 
 Fig. 
 
 476. A simple trap 
 lantern 
 
METHODS OF COLLECTING INSECTS 
 
 541 
 
 Many insects can be secured in the fall by providing suitable 
 places in which they may hibernate, such as boards, old gunny 
 sacks, etc. placed on the ground. Another method is to place 
 strips of cloth or gimny sacks around the tmnks of trees, and 
 examine them frequently for insects. 
 
 LigJit traps. Numerous forms of traps have been constructed, 
 to take advantage of the habit of some insects of flying toward the 
 light. One of the simplest of these 
 traps (Fig. 476) is made by placing 
 an ordinar}' lantern in a shallow 
 pan eighteen or twenty inches in 
 diameter and four inches deep. 
 This apparatus is then placed on 
 a stump, fence post, or other con- 
 spicuous locality. The lantern is 
 then lighted, and an inch or two 
 of water, covered with a film of 
 kerosene, is placed in the pan. 
 Leave the trap overnight (the 
 darker the better) and in the morn- 
 ing remove the insects and place 
 them in gasoline or benzine for a 
 short time, to remove the kero- 
 sene. Thev can then be laid on 
 blotting paper, dried, and mounted 
 in the usual way. 
 
 Another method of using the 
 trap lantern is to suspend a lantern 
 above a large tin funnel with a 
 diameter of twent}' or twenty-four 
 inches. At the bottom of the funnel is placed a cyanide bottle. 
 The insects, particularly beetles, fly against the light and fall into 
 the funnel and, the sides being smooth, roll down into the cyanide 
 bottle, ©ther more elaborate arrangements may be fitted up, but 
 either of the above forms will do for most cases. 
 
 Baiting insects. This form of collecting is used principally 
 in capturing moths and other insects that have a fondness for 
 sweets. As usually practiced, the entomologist goes out just at 
 
 Svrvs. 
 
 Fig. 477. The Gillette trap light 
 
 A lantern is hung over the mouth of the 
 funnel 
 
342 
 
 ELEMENTARY ENTOMOLOGY 
 
 twilight with a mixture of sugar and rum, sugar and vinegar, or 
 some such substance, which is painted on the trunks of trees. After 
 an hour or so the trees are visited by the entomologist, who is armed 
 with a dark lantern or a bicycle lantern. The moths are caught 
 either by means of a net or by carefully approaching the tree and 
 placing a large-mouthed cyanide bottle over the insects as they feed. 
 Warm, cloudy nights are best for this work, although one is not 
 always assured of success. 
 
 If pieces of decaying fish, meat, or other animal matter are 
 placed in a convenient locality and examined from time to time, 
 large numbers of beetles may be collected. 
 
CHAPTER XXIV 
 
 METHODS OF PRESERVING AND STUDYING INSECTS 
 
 The work of the entomologist is only just begun when the insects 
 are collected. They must then be pinned, dried, and labeled, the 
 latter mcluding the identification, which in itself is no little matter. 
 
 Mounting insects. Insects should be mounted as soon as pos- 
 sible after being killed. When it is impossible to mount them 
 immediately, put the insects in shallow pill boxes packed in tis- 
 sue paper, and set in a warm place to dry. When ready to mount, 
 remove the lid and place the box in a tight glass jar, together with 
 a sponge dipped in camphor water. The insects should be left in 
 this chamber for from 24 to 48 hours, when they can be mounted 
 as usual. 
 
 Insects should be mounted on insect pins. These are made 
 especially for the purpose, are about an inch and a half in length, 
 and range in size from No. 000, the most slender, up to No. 8, 
 which is the largest. Nos. i, 2, and 3, however, will do for nearly 
 
 Fig. 478. Pinning forceps 
 
 all purposes, with a few of No. 5 for the larger moths. No. 3 is 
 large enough for almost all larger insects, and insects too small for 
 No. I should be mounted on points. The pins may be obtained 
 in either the black japanned or the plain white metal ; the latter, 
 however, should be used only in mounting insects on points, as a 
 green verdigris is produced near the insect, which corrodes the pin. 
 The collector should be careful to have all the insects at the 
 same distance from the head of the pin ; this not only makes the 
 
 343 
 
344 
 
 ELEMENTARY ENTOMOLOGY 
 
 collection look better, but also makes it much easier to handle and 
 study. The general rule followed by entomologists is that one fourth 
 of the pin shall project above the insect. For this purpose a pinning 
 block is almost indispensable, the construction of which will be 
 readily understood by referring to Fig. 479. The lower hole should 
 be one fourth the length of the pin in depth, the second, one half 
 the length, and the third, three fourths the length. After the pin 
 has been pushed through the insect, the head is inserted in the 
 lower hole and the insect pushed down until the back touches the 
 block. The second hole is for evening up the labels, and the third 
 one for placing points on the pins. 
 
 A great deal of skill is required in pinning insects properly. 
 The specimen should be grasped by the thumb and forefinger 
 
 Fig. 479. A pinning block 
 
 and held very lightly in the groove formed between the tips of the 
 thumb and forefinger while the pin is inserted in the proper place. 
 Another method is to place the insects on some soft substance, as 
 a folded handkerchief, and turning the insect ventral side down, 
 insert the pin, finishing the operation on the pinning block. 
 
 Since the different groups of insects present certain structural 
 peculiarities, the following system of pinning the members of 
 different orders has gradually been formed. (The directions for 
 mounting on points and slides are given below.) 
 
 Thysanura and CoUembola. All of the smaller species are 
 mounted on microscope slides ; the larger forms are pinned through 
 the metathorax. A very fine wire is run entirely through the body, 
 to serve as a support. In the case of the Thysanura, this should 
 be inserted just underneath the long, median setae and run forward 
 well into the thorax. If the end is left projecting, it may be made 
 to serve as a support for the posterior setae. 
 
PRESERVING AND STUDYING INSECTS 
 
 345 
 
 May-flies, dragon -flies, and stone-flies. The pin is inserted in 
 the metathorax, and a fine wire run from the end of the body 
 into the thorax. In the case of the May-flies this wire should be 
 left projecting to serve as a support for the posterior setas, which 
 should be attached to the wire. The wings of both the May-flies 
 and dragon-flies should be spread. This is done by means of a 
 spreading board. 
 
 Spreading boards. Fig. 480 shows the construction of a simple 
 spreading board. Two soft-pine boards are placed parallel on short 
 crosspieces, the boards being 
 at a slight angle to each other. 
 The edges of the board should 
 be from one sixteenth to one 
 half an inch apart, depending 
 on the size of the insects to be 
 mounted. A thin sheet of cork 
 is glued to the underside of 
 the boards. When the spread- 
 ing board is used, the insect 
 is pinned in the ordinary man- 
 ner and the pin is then forced 
 through the sheet of cork until 
 the dorsal portion of the insect 
 is nearly level with the upper 
 surface of the boards. The 
 spreading board, of course, 
 must be selected with a groove 
 wide enough to accommodate the body of the insect. After being 
 placed on the spreading board, the wings of the insect are brought 
 forward and held in position by narrow strips of paper or tracing 
 cloth, as shown in the illustration. Glass-headed pins are handy 
 for pinning the strips. The spreading board is then set away until 
 the insect is thoroughly dry. 
 
 In the case of the May-flies the front margins of the first pair of 
 wings are brought forward until they are at right angles with the 
 body. In the case of the dragon-flies the hind margins of the first 
 pair of wings should be at right angles to the body. In pinning 
 stone-flies, usually only the wings of the right side are spread, 
 
 Fig. 4S0. Board showinc 
 spreading Lepidoptera. 
 
 method of 
 (Reduced) 
 
346 
 
 ELEMENTARY ENTOMOLOGY 
 
 Fig. 481. Showing method of pinning 
 Orthoptera 
 
 (After Washburn) 
 
 although some entomologists spread the wings on both sides. The 
 front margins of the hind pair of wings should be at right angles 
 to the body, the front pair being brought forward until they just 
 touch the hind pair. 
 
 Platyptera. White ants are usually mounted in alcohol, or on 
 microscope slides, although the winged forms may be pinned 
 through the metathorax. The wings are seldom spread. Book- 
 lice are mounted either on points 
 or on microscope slides, while 
 bird-lice are invariably mounted 
 on microscope slides. Earwigs 
 are mounted on points, or, in the 
 larger forms, the pin is inserted 
 through the anterior portion of 
 the right wing-cover. 
 
 Orthoptera (Fig. 481). In the 
 ordinaiy grasshopper, and in 
 those forms having the prono- 
 tum well developed, the pin is 
 usually inserted through the posterior margin of the pronotum. 
 In forms in which the pronotum is not well developed the pin is 
 run through the metathorax. The wings may or may not be 
 spread, but the usual method is to spread the wings on the right 
 side of the body. Care should be taken to arrange the legs and 
 antennae, the latter being laid back over the body, 
 if possible. The legs may be held in position by 
 running the pin through a square of stiff paper, 
 which is brought up to the proper distance and 
 the legs kept in a natural position until dry. 
 
 Hemiptera (Fig. 482). All of the larger He- 
 miptera are pinned through the metathorax ; the 
 smaller forms, with the exception of the Aphididae 
 and scale insects, are mounted on points. The two 
 latter groups require special methods of mounting. 
 The Aphididae are frequently mounted by plac- 
 ing them on a glass slide and covering them with a drop of Canada 
 balsam dissolved in xylol. They are allowed to stand for twenty- 
 four hours, when a small amount of fresh balsam is applied, and 
 
 Fig. 482. Showing 
 
 method of pinning 
 
 Hemiptera 
 
 (After Washburn) 
 
PRESERVING AND STUDYING INSBXTS 347 
 
 the specimens covered with a cover glass. This method is far 
 from satisfactory, as the balsam soon clouds, but at present it is 
 the only thing that can be recommended as a permanent mount. 
 
 Two methods are employed in mounting scale insects. The 
 entire scales are mounted by taking a thin strip of bark on which 
 is found a colony of scales, and after leaving it in the cyanide 
 bottle for twenty-four hours, it is placed between two pieces of 
 celluloid. The two plates of celluloid are held apart by a cell cut 
 out of cardboard, and the entire mount sealed with passe-partout 
 tape. The thickness of the cell depends upon the thickness of the 
 piece of bark to be mounted. It will be found very convenient to 
 have these cells cut the size of an ordinary microscope slide. This 
 form of mounting \\\\\ do only for very superficial study, and some 
 of the scales must be cleared and mounted in balsam. This is 
 done by removing the scales from the bark and, in the case of the 
 armored or flat scales, removing the insects from under the scales 
 and placing them in a small test tube with caustic potash solution. 
 These should be boiled until clear, the length of time depending 
 upon the thickness of the scales. They are then washed in water 
 by sedimentation ; that is, the test tube is filled with water and 
 held in a vertical position until the scales have settled to the bot- 
 tom. The water is then nearly all drawn off with a pipette, and the 
 process is repeated. After all of the caustic potash has been re- 
 moved, they are washed in 95 per cent alcohol and cleared in 
 xylol. They should then be removed to a glass slide by means of 
 a camel's-hair brush, and mounted in balsam. Since the last seg- 
 ment of the abdomen, the pygidium, is the only part of the insect 
 used in classification, this is all that it is necessary to mount, 
 
 Neuroptera, Mecoptera, and Tricoptera. These forms are all 
 pinned through the metathorax ; the wings may or may not be 
 spread, but it is usually best to spread the wings at least on one 
 side of the body, the hind borders of the front pair of wings being 
 brought forward at right angles to the body. 
 
 Lepidoptera (Fig. 480). In mounting Lepidoptera the pin is run 
 through the mesothorax or metathorax ; the wings are always spread, 
 the front pair being brought forward until the hind margins are at 
 right angles to the body. This rule is invariably followed both 
 with the moths and butterflies. The smaller forms are usually 
 
348 
 
 ELEMENTARY ENTOMOLOGY 
 
 Fig. 483. Showing 
 
 method of pinning 
 
 Coleoptera 
 
 (After Washbum) 
 
 mounted on elbow pins, or on bits of fine silver wire {ininntic7i- 
 nadeln), which are stuck through bits of cork or pith and pinned 
 like a cardboard point. 
 
 Diptera. In the Diptera the pin is run through the central part 
 of the thorax, and the wings, if not spread, should be extended. 
 In the long-legged flies, as the crane-fly, the 
 legs should be supported until the specimen 
 is dry. In fact, it is not a bad idea to place a 
 permanent piece of cardboard on the pins hold- 
 ing such specimens. The smaller Diptera are 
 usually mounted on wire or cardboard points. 
 
 Coleoptera (Fig. 483). All of the larger Cole- 
 optera are pinned through the anterior inner 
 portion of the right wing-cover. 
 The wings are never spread, 
 and but little attention need be 
 given the specimens after pin- 
 ning, as the legs usually adjust 
 themselves. The smaller forms 
 are mounted on cardboard points and should be 
 glued on the side to reveal the undersurface. 
 
 Hymenoptera (Fig. 484). These are pinned 
 through the metathorax ; the wings may or may 
 not be spread. Some of the more slender forms, 
 as the Ichneumon-flies, require a support until 
 they are dry. Many of the parasitic Hymenoptera 
 are mounted on slides in Canada balsam, but the usual way is to 
 
 mount on points, 
 either cardboard or 
 wire. 
 
 Mounting insects 
 on points. General 
 directions have al- 
 ready been given 
 for mounting insects on points. It may be well, however, to men- 
 tion some of the different types of points used in mounting insects. 
 Micro-pins (Fig. 486, d) are largely used for mounting Lepidoptera, 
 Neuroptera, and Diptera. These micro-pins {niijiutien-iiadchi) 
 
 Fig. 484. Showing 
 
 method of pinning 
 
 Hymenoptera 
 
 (.\fter Washbum) 
 
 Fig. 485. Point punch 
 
PRESERVING AND STUDYING INSECTS 
 
 349 
 
 consist of very fine pieces of steel wire, and may be run through 
 narrow strips of cork, pieces of paper, or small squares of cork, as 
 shown in Fig. 486, /;, <■/, and c. Elbow pins (Fig. 486, c) present 
 a neater appearance than the micro-pins, and may be obtained of 
 entomological supply companies. 
 
 4^x^. 
 
 V 
 
 ^7 
 
 ^ 
 
 \ 
 
 
 d c </ e 
 
 Fig. 486. Method of mounting insects on points 
 
 / 
 
 (7, with a cardboard point ; b, micro-pin in cork ; c, elbow pin : </, micro-pin in paper ; 
 e, micro-pin in side ; /, double point. (After Banks) 
 
 Most small Hemiptera and Coleoptera (Fig. 487) are mounted 
 on small, triangular points cut from light Bristol board. Punches 
 (Fig, 485) may be secured to cut these points accurately. 
 
 In mounting, the point is first placed on the pin at the required 
 height. The end of the point is next dipped in gum shellac dis- 
 solved in alcohol and then touched to the ventral side of the insect. 
 The insect will adhere to the point, and 
 should be arranged in position with fine 
 needles and forceps. The insect is mounted 
 so that when the point is directed to the 
 left, the head of the insect is away from 
 the person. For insects having long bodies 
 a double point should be used, as shown 
 in Fig. 486,/. 
 
 Whether micro-pins or points are used, 
 care should be taken not to obscure more 
 of the insect than is absolutely necessary. 
 
 Labeling. All specimens should be labeled as soon as possible 
 after pinning. The label should consist of the name of the town 
 and state, on the first line, and the date of collecting, on the 
 
 Fig. 4S7. Method of glu- 
 ing beetle on paper point 
 
 (After Banks) 
 
350 ELEMENTARY ENTOMOLOGY 
 
 second line ; some entomologists have the name of the collector 
 on the third line. These labels should be printed in diamond type 
 on the best paper procurable, and may be had for from twenty-five 
 to thirty cents a thousand. In having labels printed, the space for 
 the date should be left blank, to be filled in later. Only the best 
 India ink and very fine crow-quill pens should be used. Below 
 the locality label should be the accession number, the collection 
 being numbered serially and each insect given a separate number, 
 unless two or more of the same species were collected under 
 the same conditions. The accession number should refer to the 
 collector's notes, in which ever)'thing known about the insect is 
 recorded. The date and place of collecting should again be re- 
 corded and the food plant or nature of the locality where the 
 insect was found, etc. 
 
 Arrangement of insects. For the permanent storage of insect 
 collections two general types of box are used. One consists of 
 large glass-top drawers, about fifteen by eighteen inches, which fit 
 into cabinets. The other type consists of separate boxes, with cork 
 bottoms. For the beginner the latter type is probably the better. 
 Numerous boxes are on the market, made from both cardboard 
 and wood, the latter, of course, being far superior to the cardboard. 
 
 In selecting insect boxes care must be taken to obtain those 
 having tight-fitting lids. This is absolutely essential in order to 
 keep out certain Dermestid beetles, which, if they gain access to the 
 collection, will quickly destroy it. Further precaution against these 
 insects should be taken by placing flake naphthalene in the boxes. 
 By far the best on the market is the Schmitt box (Fig. 488). 
 This comes in two sizes, twelve by fifteen inches and eight and 
 one half by fifteen inches, and is lined with pressed cork. In using 
 the drawers, the insect pins are stuck into small blocks of wood, 
 or into a lining of sheet cork, by means of pinning forceps (Fig. 
 478). The blocks ^ are cut to a uniform length and are made in 
 multiple width. The width of the blocks used depends on the size 
 of the insects and the number of specimens of each species. The 
 advantage of this system is that it allows an indefinite amount of 
 expansion of a collection, without necessitating the transfer of each 
 individual insect. 
 
 ^ See Comstock's "Insect Life." 
 
PRESERVING AND STUDYING INSECTS 
 
 ;5i 
 
 Whether the boxes or drawers are used, all of the specimens 
 of one species should be kept together, which plan should be 
 followed out in genera, families, and orders. 
 
 Fig. 488. A Schmitt insect box, opened to show arrangement of insects 
 (After Banks) 
 
 Mounting insects on slides. Directions have already been given 
 for the mounting of aphides and scale insects. The directions 
 given for mounting scale insects may be used for mounting legs 
 
352 
 
 ELEMENTARY ENTOMOLOGY 
 
 or other hard parts of insects, where nothing but the chitinous 
 portion is desired. For most purposes, however, such as mount- 
 ing the legs of bees for laboratory use, or mounting small, 
 hard-bodied insects, the following method will be found more 
 desirable. 
 
 The insect or part of the insect to be mounted should first be 
 placed in 85 per cent alcohol. This rule applies to mounting both 
 fresh specimens and material previously preserved in alcohol or 
 glycerin. After the insect has become thoroughly saturated, it 
 should be transferred to 95 per cent alcohol and left for an hour 
 or longer. The specimens should then be transferred to xylol and 
 left until the alcohol is entirely replaced. The insect should then 
 be placed in the center of the slide, the excess of xylol removed 
 with a piece of blotting paper, and a drop of Canada balsam placed 
 over the insect. The balsam should then be warmed slightly over 
 an alcohol lamp, and a cover glass placed over it. Care must be 
 taken not to get on more balsam than is necessary to cover the 
 insect and fill out the space under the cover glass. For the be- 
 ginner there is less liability of having air bubbles in the mount if 
 the balsam is first placed on the slide and the insect laid on after- 
 wards. However, it is much more difficult to arrange the wings 
 and legs of the insect if mounted in this way. 
 
 Preserving material in liquids. Directions have already been 
 given for collecting small, soft-bodied insects in liquid. When this 
 material is first brought into the laboratory, it should be thoroughly 
 washed in 50 per cent alcohol and then transferred to 85 per cent 
 alcohol. If the specimens are large, soft-bodied larvae, or insects 
 of considerable size, the alcohol should be changed at least once 
 before permanently storing the specimens. For permanently 
 storing alcoholic material small, straight-necked vials will be found 
 the most convenient. These should be of one-, two-, and four- 
 dram sizes and fitted with the best cork stoppers procurable. The 
 bottles should be numbered and labeled as in pinned insects, the 
 labels being written on strips of good linen paper in India ink, 
 which must be absolutely waterproof. These should be placed 
 inside the bottles with the specimens. Numerous trays have been 
 devised for holding alcoholic material, the one shown in Fig. 489 
 being very satisfactory. An improvement of this tray consists in 
 
PRESERVING AND STUDYING INSECTS 
 
 353 
 
 having either end extend up above the top of the bottles. This 
 allows the trays to be stacked one above another without injuring 
 the bottles. 
 
 Numerous substitutes for alcohol have been employed, of which 
 a 4 per cent solution of formaldehyde is probably the best, as it 
 is cheaper, tends to preserve the color, and does not harden the 
 
 Fig. 489. The Marx tray for specimens in liquid 
 
 specimens. This, however, is not much superior to alcohol, and 
 in many cases shrinks the specimens more than alcohol would. 
 
 Material intended for dissection may be treated as above, but 
 if alcohol is used, should be permanently preserved in 70 to 85 
 per cent alcohol, to which 10 percent of glycerin has been added. 
 
 Inflating insect larvae. The larvae of most of the Diptera, 
 Coleoptera, and Hymenoptera are preserved in alcohol, as noted 
 above. It has been found, however, 
 that lepidopterous larvae may be* 
 preserved much better by inflating 
 them, the method of which is as 
 follows : 
 
 The lar\'^ are brought to the 
 laboratory alive, and when ready to 
 be inflated are killed or stupefied in 
 a cyanide bottle. This method will 
 be found much better than killing 
 the larvae in the field, as they should 
 be blown as soon as possible after 
 they are killed. Remove the larva from the cyanide bottle and 
 place it on a piece of blotting paper. A glass tube or pencil is 
 next rolled over the body from the head toward the tip of the 
 abdomen. This causes the alimentary tract to protrude, which is 
 then snipped off at the anus by a pair of sharp-pointed scissors. 
 
 Fig. 490. Homemade apparatus 
 for inflating larvae 
 
 (After Washburn) 
 
354 
 
 ELEMENTARY ENTOMOLOGY 
 
 Fig. 491. Method of mounting inflated larvae 
 (After Washburn) 
 
 The rolling is then continued until the entire contents of the body 
 have been forced out through the posterior end. A straw or a 
 glass tube which has been drawn out to a fine point is next in- 
 
 9 serted through the 'open- 
 ing. This may in turn be 
 attached to a rubber tube 
 and bulb, or the larva 
 may be inflated by blow- 
 ing gently through the 
 tube. In order to keep 
 the specimen on the end 
 of the tube, it should be 
 allowed to dry for a few 
 minutes. To thoroughly dry the skin it is kept distended inside a 
 glass lamp chimney, which rests in a pan of sand over a gas or 
 alcohol flame, as shown in Fig. 490. When the skin is thor- 
 oughly dried, it is removed from the glass tube and may then be 
 mounted on an elbow pin by bending the point of the elbow into 
 a loop, which is dipped into glue and inserted into the opening in 
 the abdomen. Another method is shown in Fig. 491. 
 
 Dissecting instruments. The number of 
 different instruments required for the study of 
 the anatomy of insects is not great. However, 
 owing to the small size of the specimens 
 studied, the instruments should be of the very 
 best material. 
 
 Forceps. Forceps should be of two kinds, 
 curved-pointed and straight-pointed (Fig. 492). 
 Both pairs should have very fine points which 
 are slightly roughened. 
 
 Scissors. Curved scissors will be found very 
 useful in carrying on minute dissecting work, 
 the difficulty being to secure a pair that will 
 cut entirely to the point. In using the fine- 
 pointed scissors, care must be exercised not 
 to strain them by cutting too thick objects. 
 
 Scalpels. These are of less importance in LTved^poin^eTand 
 entomological work than in most other forms straight-pointed 
 
PRESERVING AND STUDYING INSECTS 355 
 
 of dissecting, but two or three scalpels of various shapes will 
 be found useful. The short, curved, sickle-shaped scalpel will be 
 used in general dissection more than any other. 
 
 Needles. These are really of more impoitance than the scalpel. 
 They may be made by forcing the eye of an ordinary needle into 
 a small stick about the size of a lead pencil. Much more satisfac- 
 tory needle handles may be secured of the supply companies, with 
 arrangements for removing and exchanging the needle. One should 
 be provided with three of four of these needle holders and a num- 
 ber of needles bent into various shapes, — hooks of different 
 sizes, and curved and straight needles. 
 
 Brushes. An assortment of camel's-hair brushes will be found 
 useful on the dissecting table. 
 
 Pius. For holding the dissected specimens in position ordinary 
 insect pins will be found most convenient. The larger sizes, 
 Nos. 4, 6, and 8, are well adapted for minute dissection. A few 
 large pins with black glass heads will also be found useful for 
 heavier work. 
 
 Microscopes and lenses. Every collector should be provided with 
 at least one good pocket lens. For most work a half-inch lens, 
 procurable of any microscope supply company, will be found suf- 
 ficient. For very small insects, however, a one-fourth-inch lens 
 will be found much better. 
 
 Dissecting microscopes are almost an essential if careful work in 
 insect anatomy is to be done. Various types of these are sold by 
 all optical companies. Compound microscopes are essential for very 
 minute work, but for studying the general anatomy of insects they 
 can be more easily dispensed with than the dissecting microscope. 
 
 Dissecting trays. Dissecting trays, as found on the market, con- 
 sist of shallow tin or porcelain trays ranging in size from four by five 
 to twelve by fifteen inches, with a depth of from one to three inches. 
 The bottoms of these trays are usually covered with paraffin or bees- 
 wax, so that the specimens may be pinned out under water. Home- 
 made trays may be constructed by obtaining tin pans of the proper 
 size, and having two or three short pieces of wire soldered to the 
 bottom. The ends of the wire should be left projecting, so that 
 when hot paraffin or beeswax is poured into the pan, the wire will 
 hold it firmly in place and prevent it from floating when in use. 
 
356 
 
 ELEMENTARY ENTOMOLOGY 
 
 This sort of dissecting tray works very well for rough dissection, 
 where nothing more than a hand lens is required. It has the 
 objection, however, of the projecting sides, which frequently pre- 
 vent one from manipulating the dissecting instruments as desired. 
 By far the most successful dissecting tray for insect work that we 
 have used is made as follows : A glass plate four by five inches is 
 thoroughly washed in alcohol in order to remove all traces of dirt. 
 This is then placed in a shallow pan which has been previously 
 coated with vaseline or oil. A mixture of four parts paraffin and 
 
 one part beeswax is next 
 poured over the glass 
 plate to a depth of about 
 one inch. After this is 
 thoroughly cool, it is re- 
 moved from the pan and 
 the paraffin trimmed off 
 to the edge of the glass 
 plate. A trough is scraped 
 out in the center of the 
 plate to accommodate the 
 body of the insect to be 
 dissected. After a little 
 experience one can very 
 quickly regulate the size 
 and shape of this trough 
 to the best advantage. A 
 sufficient amount of par- 
 affin should be left be- 
 neath the insect to permit 
 of its being firmly pinned 
 in position. The work 
 
 Fig. 493. The Riley breeding cage 
 
 will also be greatly facilitated if glycerin, to which an excess of 
 chloral hydrate has been added, is used as a dissecting medium in 
 place of water. This form of tray has a number of distinct advan- 
 tages. In the first place, the work can be carried on entirely with 
 the dissecting microscope, or even a low power of the compound 
 microscope. There are no projecting sides to interfere with the 
 manipulation of the instruments, and if the dissection is not 
 
PRESERVING AND STUDYING INSECTS 
 
 \57 
 
 completed, it may be temporarily sealed by covering with a glass 
 plate which is firmly pressed in position. The glycerin has many 
 distinct advantages over water, its density 
 holding the more delicate structures in 
 position, and at the same time it has a 
 higher index of refraction. Plates of vari- 
 ous sizes and depths may be easily con- 
 structed to meet different requirements. 
 
 Rearing insects. If one wishes to study 
 the life history of insects, or if desirous of 
 procuring especially fine specimens, by far 
 the best method is to rear them under 
 artificial conditions. In this work an at- 
 tempt must always be made to simulate 
 natural conditions as closely as possible. 
 There is less liability of the larvae being 
 parasitized if they are placed in a breed- 
 ing cage when quite small. Numerous 
 breeding cages have been constructed for 
 the purpose of rearing larvae. Of these, 
 
 Fig. 494. A lamp-chimney 
 breeding cage 
 
 (After Banks) 
 
 one of the best is shown in Fig. 493. 
 
 This consists of a frame with a glass door 
 on one side, the other three sides being 
 covered with cheesecloth. If possible, the 
 food plant is placed in a flowerpot inside 
 the breeding cage. If this is impracticable, twigs and branches 
 can be placed in the cage in bottles of water, the top of the bottle 
 being stuffed full of cotton to prevent the lar- 
 vae from drowning. Another simple breed- 
 ing cage for smaller insects is made by 
 placing a lantern globe or lamp chimney, 
 the top of which is covered with a square of 
 cheesecloth, over the food plant (Fig. 494) 
 in a flowerpot. The food material should be 
 changed frequently, so that it may be kept 
 fresh and sufficient. 
 
 For rearing large quantities of larvae an 
 open tray three by five feet is most convenient. 
 
 P'iG. 495. A simple aqua- 
 rium for aquatic larvae 
 
 (After Washburn) 
 
358 
 
 ELEMENTARY ENTOMOLOGY 
 
 The sides of the tray are made of Hght six-inch boards, and the 
 bottom is formed by a piece of cheesecloth. Four-inch strips are 
 next tacked to the top of the tray, so that they project inward 
 around it. The inside of the projecting ledge formed by the four- 
 inch strips is coated with tanglefoot. The food and the larvae are 
 placed in the tray on the cheesecloth. The larvae are easily ob- 
 served all the time, and the food material may be quickly changed, 
 while the tanglefoot prevents the escape of the larvae. The larvae, 
 however, are not protected from parasites, and the pupae must be 
 
 removed and placed in 
 tight cages before the 
 adults emerge. 
 
 Aquatic larvae and 
 nymphs may be reared 
 in any suitable aquarium 
 (Fig. 495), but only 
 larvae of the same size 
 should be kept together, 
 and care should be taken 
 to separate those which 
 are predacious upon one 
 another. 
 
 Numerous cages for the study of special insects have been 
 
 devised, as the Comstock root-cage, devices for studying the life 
 
 history of ants, the limb cage for rearing insects out of doors in 
 
 their natural habitat, and the breeding cage for parasites (Fig, 496). 
 
 For further methods, consult the following books : 
 
 L. O. Howard, The Insect Book. (Doubleday, Page & Co.) 
 W. J. Holland, The Moth Book. (Doubleday, Page & Co.) 
 V. L. Kellogg, American Insects. (Henry Holt and Company) 
 J. H. and A. B. Comstock, Insect Life. (D. Appleton & Co.) 
 
 Fig. 496. Breeding cage for parasites 
 (After Banks) 
 
APPENDIX 
 
 r. DEALERS IN ENTOMOLOGICAL SUPPLIES 
 
 The American Entomological Co., 55 Stuyvesant Ave., Brooklyn, N.Y. 
 
 The Kny-Scheerer Co., 404 West Twenty-seventh St., New York City 
 
 The Entomological Society of Ontario, Guelph, Ontario 
 
 M. Abbott Frazer, 93 Sudbury St., Boston, Mass. 
 
 A. Smith and Sons, 269 Pearl St., New York City 
 
 Charles C. Reidy, 432 Montgomery St., San Francisco, Cal. 
 
 The Simplex Net Co., Ithaca, N.Y. (Nets.) 
 
 Bausch and Lomb, Rochester, N.Y. (Microscopes, lenses, instruments, etc.) 
 
 Queen & Co., loio Chestnut St., Philadelphia, Pa. (Microscopes, lenses, instru- 
 ments, etc.) 
 
 The Spencer Lens Co., Buffalo, N.Y. (Microscopes, lenses, instruments, etc.) 
 
 The Wiegner Printery, 2234 North Twenty-ninth -St., Philadelphia, Pa. 
 (Labels.) 
 
 C. V. Blackburn, 32 Chestnut St., Stoneham, Mass. (Labels.) 
 
 II. ADDRESSES OF STATE AGRICULTURAL EXPERIMENT 
 STATIONS AND OF STATE ENTOMOLOGISTS 
 
 Alabama, Auburn Iowa, Ames 
 
 Arizona, Phoenix Kansas, Manhattan 
 
 Arkansas, Fayetteville Kentucky, Lexington 
 
 California, Berkeley Louisiana, Baton Rouge 
 
 Colorado, Fort Collins Maine, Orono 
 
 Connecticut, New Haven Maryland, College Park 
 
 Delaware, Newark Massachusetts, Amherst 
 
 Florida, Gainesville Michigan, East Lansing 
 
 Georgia, State Entomologist, Atlanta Minnesota, St. Anthony Park 
 
 Hawaii, Honolulu Mississippi, Agricultural College 
 
 Idaho, Moscow Missouri, Columbia 
 
 Illinois, State Entomologist, LIrbana Montana, Bozeman 
 
 Indiana, Lafayette Nebraska, Lincoln 
 
 State Entomologist, Indianapolis Nevada, Reno 
 
 359 
 
360 ELEMENTARY ENTOMOLOGY 
 
 New Hampshire, Durham Pennsylvania, State Zoologist, Harris- 
 New Jersey, New Brunswick burg 
 
 New Mexico South Carolina, Clemson College 
 
 New York, Geneva South Dakota, Brookings 
 
 Cornell University Agricultural Ex- Tennessee, Knoxville 
 
 periment Station, Ithaca Texas, College Station 
 
 State Entomologist, Albany, N.Y. Utah, Logan 
 
 North Carolina, West Raleigh Virginia, Blacksburg 
 
 State Entomologist, Raleigh Washington, Pullman 
 
 North Dakota, Agricultural College West \'irginia, Morgantown 
 
 Ohio, Wooster Wisconsin, Madison 
 
 Oklahoma, Stillwater United States Department of Agri- 
 Oregon, Corvallis culture. Bureau of Entomology, 
 
 Washington, D.C. 
 
 III. A LIST OF BOOKS FOR THE REFERENCE LIBRARY 
 General Extomologv 
 
 COMSTOCK, J. H. A Manual for the Study of Insects. (Comstock Publishing 
 Co., Ithaca, N.Y., 1895.) 
 
 Comstock, J. H. and A. B. Insect Life. (D. Appleton & Co., New York 
 City, 1 90 1.) 
 
 FoLSOM, J. W. Entomology, with Special Reference to its Biological and Eco- 
 nomic Aspects. (J. B. Lippincott and Co., Philadelphia, Pa., 1906.) 
 
 Howard, L. O. The Insect Book. (Doubleday, Page & Co., New York, 1904.) 
 
 Kellogg, V. L. American Insects. (Henry Holt and Co., New York, 
 1905-1908.) 
 
 Packard, A. S. A Text-Book on Entomology. (The Macmillan Company, 
 New York, 1898.) 
 
 Sharp, D. The Cambridge Natural Histoiy. Insects. 2 vols. (The Macmillan 
 Company, London, 1 895-1899.) 
 
 (The works of Folsom, Kellogg, and Packard above are especially strong con- 
 cerning the anatomy of insects.) 
 
 Butterflies and Moths (Lepidopterd) 
 
 C0M.STOCK, J. H. How to Know the Butterflies. (D. Appleton & Co., New 
 York, 1904.) 
 
 French, G. H. The Butterflies of the Eastern United States. (J. B. Lippin- 
 cott and Co., Philadelphia, 1886.) 
 
APPENDIX 361 
 
 Holland. W.J The Butterfly Book. (I)oubleday. Page & Co., New York, 
 
 1905.) 
 The Moth Book. (I)oubleday, Page & Co., New \'()rk. 1903.) 
 Eliot, Ida M., and Sot'Li:, Cako C, Caterpillars and their Moths. (The 
 
 Century Co., 1902.) 
 DiCKER.sox, Mary C, Moths and Butterflies. (Ginn and Company, Boston, 
 
 1905.) 
 
 Economic Ento.mologv 
 
 S.MITH, J. B. Economic luitomology. (J. B. Lippincott and Co., Philadelphia, 
 
 1S96.) 
 Sanderson, E. D. Insects Injurious to Staple Crops. (John Wiley and 
 
 Sons, New York, 1902.) 
 Insect Pests of Farm, Garden and Orchard. (John Wiley and Sons, New 
 
 York, 1 91 2.) 
 Chittenden, F. H. Insects Injurious to \'egetables. (Orange Judd Co., 
 
 New York, 1907.) 
 Saunders, Wm. Insects Injurious to Fruits. (J. B. Lippincott and Co., 
 
 Philadelphia, Pa., 1883.) 
 
INDEX 
 
 Abdomen, 7, 11, 25, 282; of female, 
 
 283 ; of male, 282 
 Acalypterae, 325 
 Acanthidae, 114, 135. 309 
 Accessory organs of digestion, 291 
 Acrididae, 81, 30S 
 Actia luna, 215 
 Aculeata, 274 
 Adalia bipunctata, 162 
 Adephaga, 137, 171, 312 
 Adult, 53, 56 
 Aeschnidae, 306 
 Agaristidae, 318 
 Agrionidae, 306 
 Agromyzidae, 327 
 Alaus oculatus, 146 
 Alcohol, 337 
 Aletia argillacia, 202 
 Aleyrodidae, 311 
 Allorhina nitida, 152 
 Ambush-bugs, 114, 135, 309 
 American acridium, 83 
 Ampelophaga myron, 211 
 Amphibolips spongifica, 247 
 Anals, 24 
 
 Anasa tristis, 50, 121 
 Anatomy of insects, internal, 28 
 Andrenidae, 267, 274, 321 
 Angumois grain-moth, 186 
 Anisophaeridae, 305 
 Anisoptera. 306 
 Anisota rubicunda, 212 
 Anopheles, 223 
 Anosia plexippus, 179 
 Antennae, 7, 1 1 
 Anthomyiidae, 238, 242. 328 
 Anthonomus grandis, 168 
 Anthonomus signatus, 16S 
 Anthrenus scrophularia, 143 
 Antlered maple worm, 195 
 Ant-lions, 93, 307 
 Ants, 243, 254, 274, 303, 320 ; habits of, 
 
 255 ; relation of, to aphids, 255 
 Aorta, 23 
 Apanteles, 251 
 Aphides, 107, 127 
 Aphididae, 127, 135, 311 
 Aphis-lions, 92 
 
 36J 
 
 Aphis maidi-radicis, 129 
 Aphis pomi, 129 
 Aphodius, 150 
 Aphoruridae, 306 
 Apiculture, 271 
 Apidae, 267, 269, 274, 321 
 Apina, 266, 274, 321 
 Apple leaf-hopper, 125 
 Apple-leaf trumpet miner, 185 
 Apple-maggot, 239 
 Aptera, 73, 303 
 Aquatic bugs, 135 
 Aquatic sieve net, 334 
 Arachnida, 7 
 Aradidae, 309 
 Archips cerasivorana, 187 
 Archips rosaceana, 186 
 Arctiidae, 207, 217, 318 
 Argentine ant, 259 
 Argynnids, 182 
 Arilus cristatus, 112 
 Arista, 231 
 Armored scales, 132 
 Army-worm, 202 
 Arrangement of insects, 350 
 Arthropoda, 6 ; types of, 284 
 Articulata, 6 
 Asilidae, 230, 242, 323 
 Asparagus beetles, i 53 
 Assassin-bugs, 112, 135, 309 
 Atropidae, 307 
 Australian ladybird, 163 
 Autographa brassicae, 202 
 Automeris io, 213 
 
 Back-swimmers, 135, 309 
 Bacteria, 3 
 
 Bag-worm moths, 319 
 Baiting insects, 341 
 Bark-beetles, 170, 171, 313 
 Bark-lice, 307 
 Barnacles, 7 
 Bat-ticks, 242, 329 
 Bean-weevils, 313 
 Bedbugs, 114, 135, 309 
 Bee-bread, 274 
 Bee-flies, 231, 242, 323 
 Bee-lice, 242, 329 
 
364 
 
 ELEMENTARY ENTOMOLOGY 
 
 Bee-moth, 189, 217 
 Bees, 5, 243, 266, 274, 321 
 Beetles, 5, 136; families of, 137 
 Belostomidae, 109, 135, 309 
 Bembecia marginata, 193 
 Bembecidae, 262, 274, 321 
 Bembecids, 274 
 Beneficial insects, 2 
 Berytidae, 120, 135, 310 
 Bibionidae, 323 
 Big-eyed flies, 325 
 Bill-bugs, 169, 17'. 3 '3 
 Bird-lice, 303, 307 ; biting, 106 
 Blackberry-gall, 247 
 Black damsel-bug, 114 
 Black-flies, 226, 242, 323 
 Blattidae, 77, 308 
 Blepharoceridae, 226 
 Blister-beetles, 166, 171, 311 
 Blond damsel-bug, 1 14 
 Blood, 32 
 Blood vessels, 32 
 Blow-flies, 236 
 Blue-bottle flies, 236 
 Body covering of locust, 275 
 Body structure, 10 
 Boll weevil, 2 
 Bollworm, 202 
 Bombyliidae, 231, 242, 323 
 Bombyx mori, 212 
 Book-lice, 105, 307 
 Borboridae, 327 
 Boring hymenoptera, 244, 274 
 Bot-flies, 233, 242, 328 
 Box-elder bug, 121 
 Brachycera, 229, 242, 323 
 Braconidae, 250, 274, 320 
 Braconid-flies, 250, 274 
 Brain, 37 
 
 Braulidae, 240, 242, 329 
 Bristletails, 73, 74 
 Brown ant, 250 
 Brown-tail moth, 204 
 Bruchidae, 158, 171, 313 
 Brushes, 355 
 Bud-borers, 217 
 Buffalo-moth, 143 
 Buffalo tree-hopper, 124 
 Bumble-bee, 270; flower-beetle, 152 
 Buprestidae, 146, 171, 312 
 Burying-beetles, 142 
 Butterflies, 5, 172, 174, 217 ; four-footed, 
 179 
 
 Cabbage aphis, 129 
 
 Cabbage butterfly, 178; life history of, 
 
 300 
 Cabbage looper, 202 
 
 Cabbage-maggot, 238 
 Caddis-flies, 93, 307 
 Caecal tubes, 31 
 Calandra granaria, i6g 
 Calandra oryza, 169 
 Calandridae, 169, 171, 313 
 Callosamia promethia, 216 
 Calopterygidas, 306 
 Calosoma scrutator, {39 
 Calypterae, 328 
 Campodeidae, 305 
 Camponotidae, 256, 274, 320 
 Camponotus pennsylvanicus, 256 
 Capsidae, 117, 135, 310 
 Carabidae, 138, 171, 312 
 Carnivorous beetles, 137, 171 
 Carpenter-ant, 256 
 Carpenter-bee, 269 
 Carpenter-moths, 191, 217, 319 
 Carpet-beetle, 143 
 Carrion-beetles, 142, 171, 312 
 Catocala, 203 
 
 Cecidomyia, strobiloides, 228 
 Cecidomyiidae, 228, 242, 321 
 Cecropia moth, 215 
 Celery caterpillar, 175 
 Centipedes, 8 
 Cephalothorax, 7 
 Cerambycidae, 158, 171, 313 
 Ceratocampidae, 319 
 Cerci, 26 
 
 Cercopidae, 125, 135, 311 
 Ceresa bubalus, 124 
 Chain-dotted geometer, 197 
 Chalcididae, 253, 274, 320 
 Chalcis-flies, 253, 274 
 Checkered-beetles, 313 
 Cherry-tree leaf-roller, 187 
 Chestnut weevils, 168 
 Chilocorus bivulnerus, 162 
 Chinch-bug, 120, 135, 310 
 Chironomidae, 224, 242, 323 
 Chitin, 27, 276 
 Chloroform bottle, 336 
 Chrysalis, 48 
 Chrysididae, 320 
 Chrysomelidae, 153, 171, 313 
 Chrysomyia macellaria, 236 
 Chrysopidae, 92, 307 
 Cicadas, 122, 135, 311 
 Cicadidae, 122, 135, 311 
 Cicindelidae, 137, 171, 312 
 Cigar case-bearer, 185 
 Cingilia catenaria, 197 
 Circulatory system, 32, 293 
 Classification, 67, 302 
 Clavicornia, 141, 171, 312 
 Clear-winged moths, 192, 217, 319 
 
INDEX 
 
 J65 
 
 Cleridae, 313 
 
 Click-beetles, 144, 171, 312 
 
 Close- wings, 190, 217 
 
 Clothes moths, 1S6, 217 
 
 Clouded sulphur butterfly, 178 
 
 Clover-hay worm, 18S 
 
 Club-horned beetles, 141, 171 
 
 Coccidae, 129, 135. 311 
 
 Coccinella 9-notata, 162 
 
 Coccinellidae, 68, 161, 171, 313 
 
 Cockroaches, 77, 308 
 
 Cocoon, 48, 60 
 
 Codling moth, 1S7 
 
 Coleoptera, 136, 304, 311 ; families of, 
 
 311; mounting of, 348 
 Coleoptera genuina, 137, 171 
 Collecting belt, 331 
 Collecting coat, 330 
 Collecting forceps, 337 
 Collecting insects, methods of, 330 
 Collecting larvae, 339 
 Collembola, 74, 305 ; mounting of, 344 
 Colorado potato-beetle, 153 
 Complete metamorphosis, 57 
 Conopidae, 232, 242, 325 
 Cordulegasteridae, 306 
 Cordyluridae, 325 
 Coreidae, 121, 135, 310 
 Corimelaenidae, 116 
 Coriscus ferus, 1 14 
 Coriscus subcoleoptratus, 114 
 Corisidae, 135, 309 
 Corn root-aphis, 129 
 Corrodentia, 307 
 Corydalus cornuta, 90 
 Cossidae, 191, 217, 319 
 Costa, 24 
 
 Cotton-boll weevil, 168 
 Cotton square-borer, 179 
 Cotton-stainer, 119 
 Cottony maple scale, 132 
 Coxa, 22 
 Crabs, 7 
 Crambinae, 190 
 Crane-flies, 220, 242, 321 
 Crayfish, 7 , 
 
 Crickets, 85, 305 ; music of, 86 
 Crop, 30 
 Croton bug, 77 
 Crustacea, 6, 7 
 Cubitus, 24 
 Cuckoo-flies, 320 
 Cucujidae, 143, 171 
 Cucujus clavipes, 143 
 Culicidae, 222, 242, 321 
 Curculionidae, 167, 171, 313 
 Curculios, 167, 171, 313 
 Currant-borer, 193 
 
 Currant span-worm, 199 
 Currant worms, 245 
 Cutworms, 200 
 Cyanide bottle, 335 
 Cydia pomonella, 187 
 Cydnidae, 310 
 Cynipidae, 246, 247, 320 
 Cyrtidae, 323 
 
 Damsel-bug, 114, 135, 310 
 
 Damsel-flies, 98, 306 
 
 Darkling-beetles, 165, 171, 311 
 
 Datana ministra, 194 
 
 Dermestes lardarius, 144 
 
 Dermestidae, 144, 171, 312 
 
 Dermestid-beetles, 171 
 
 Dexidae, 328 
 
 Diaphania hyalinata, 188 
 
 Diaphania nitidalis, 188 
 
 Diastictis ribearia, 199 
 
 Diastrophus nebulosus, 247 
 
 Differential locust, 53, 82 ; habits of, 54 
 
 Digestive system, 29, 290 
 
 Digger-wasps, 260, 274, 320 
 
 Diopsidae, 327 
 
 Diptera, 18, 218, 305, 321 ; characteris- 
 tics of, 218; mounting of, 348; sum- 
 mary of, 242 
 
 Diptera genuina, 219, 242 
 
 Dissecting instruments, 354 
 
 Dissecting trays, 335 
 
 Diving-beetles, 140 
 
 Divisions of body, 276 
 
 Dixa-midges, 226 
 
 Dixidae, 226 
 
 Dobsons, 90, 306 
 
 Dog-day harvest-fly, 122 
 
 Dolichopodidae, 231, 323 
 
 Dragon-flies, 98, 306; mounting of, 345 
 
 Dragon-fly, life history of the, 299 
 
 Drasteria erechtea, 200 
 
 Drosophila, 239 
 
 Drosphilidae, 327 
 
 Dynastes tityrus, 152 
 
 Dysdercus suturellus, i ig 
 
 Dytiscidae, 140, 171, 312 
 
 Earwigs, 87, 307 
 
 Echinoderms, 5 
 
 Ecology, 2 
 
 Egg, 45- 50 ; laying, 56, 63 ; mass, 58 
 
 Elateridae, 144, 171, 312 
 
 Elbow pins, 348 
 
 Elm leaf-beetle, 154 
 
 Elytra, 24 
 
 Embryology, 1 1 
 
 Emesidae, 113, 135, 309 
 
 Empididae, ;^2t, 
 
366 
 
 ELEMENTARY ENTOMOLOGY 
 
 Empoasca mali, 125 
 Empoasca rosae, 125 
 Empodium, 22 
 Enchenopa binotata, 124 
 Engraver-beetles, 170, 171 
 Entomobryidae, 305 
 Ephemerida, 95, 304, 306 
 Ephydridae, 327 
 Epicauta vittata, 166 
 Epilachne, 163 
 Epitrix fuscula, 156 
 Eriocampa cerasi, 245 
 Esophagus, 30 
 Eumenes fraternus, 264 
 Eumenidae, 263, 274, 320 
 Euphoria inda, 152 
 Euplexoptera, 87, 304, 308 
 Euproctis chrysorrhoea, 204 
 Euvanessa antiopa, 63 
 Eyed elater, 146 
 Eyes, 12 
 
 Eye-spotted bud moth, 187 
 External anatomy of locust, 275 
 
 Facets, 12, 40 
 Fall army-worm, 202 
 Fall web-worm, 208 
 Families, 71 
 Feelers, 1 1 
 Femur, 22 
 Field kit, 330 
 Fireflies, 147, 171, 313 
 Flat-bugs, 309 
 Flat-footed flies, 325 
 Flat-headed borers, 147 
 Fleas, 240 
 
 Flesh-flies, 236, 242, 328 
 Flies, 5, 218 
 Flower-beetles, 152 
 Flower-bugs, 1 14 
 Flower-flies, 232, 242, 325 
 Forceps, 354 
 Forficulidae, 308 
 Formicina, 254, 274, 320 
 Four-lined leaf-bug, 118 
 Fritillaries, 182 
 Frog-hoppers, 125, 135 
 Fruit-flies, 239, 242 
 Fruit-fly, life history of, 301 
 Fruit-tree bark-beetle, 170 
 Fulgoridae, 31 1 
 Fungus-gnats, 227, 242, 321 
 Funnel trap, the, 339 
 
 Galea, 14 
 
 Galerucella luteola, 154 
 Galgulidae, 308 
 Gall-flies, 246, 320 
 
 Gall-gnats, 228, 242, 321 
 
 Gall-inhabiting Hymenoptera, 274 
 
 Ganglia, 28, 37 
 
 Garden web-worm, 187 
 
 Gastric caeca, 31 
 
 Gelechia cerealella, 186 
 
 Genus, 68, 71 
 
 Geometridae, 195, 217, 319 
 
 Geometrinae, 199 
 
 Giant crane-fly, 221 
 
 Giant water-bugs, 135, 309 
 
 Gizzard, 30 
 
 Gomphidae, 306 
 
 Gossamer-winged butterflies, 178 
 
 Granary weevil, 169, 313 
 
 Grape leaf-hopper, 125 
 
 Grape phylloxera, 129 
 
 Grape thrips, 125 
 
 Grapevine hog caterpillar, 211 
 
 Grasping Orthoptera, 78 
 
 Grasshopper, external anatomy of, 
 
 275 
 Green apple aphis, 129 
 Green bug, 129 
 Green-fly, 127 
 Green soldier-bug, 115 
 Green-striped maple-worm, 212 
 Green tomato worm, 209 
 Ground-beetles, 138, 171 
 Growth, 47, 54 
 Gryllidae, 85, 308 
 Guest-bees, 274 
 Gypsy moth, 204 
 Gyrinidae, 140, 171, 312 
 Gyropidae, 307 
 
 Halictus, 268 
 
 Halteres, 24 
 
 Handmaids, 194 
 
 Harlequin cabbage-bug, 115 
 
 Harlequin milkweed caterpillar, 207 
 
 Hatchet, 337 
 
 Haversack, 330 
 
 Hawk-moths, 208, 217 
 
 Head, 10, 11 ; study of, 276 
 
 Hearing, 42 
 
 Heart, 32 
 
 Heliothis obsoleta, 202 
 
 Hellgramite, 90 
 
 Hemerobiidae, 307 
 
 Hemerocampa leucostigma, 204 
 
 Hemiptera, 17, 107, 135, 305, 308; 
 
 mounting of, 346 
 Hesperidae, 31S 
 Hesperina, 174, 217 
 Hessian fly, 228 
 Heterocampa gutivitta, 195 
 Heteromera, 163, 171, 311 
 
INDEX 
 
 367 
 
 Heteroptera, 107, 135, 308 
 
 Hexapoda, 8 
 
 Hickory-borer, 160 
 
 Hippoboscidae, 240, 242, 329 
 
 Hog caterpillars, 211 
 
 Holorusia rubiginosa, 221 
 
 Homoptera, 122, 135, 310 
 
 Honey-bees, 270 ; anatomy of, 287 ; 
 life history of, 271 
 
 Hop merchant, 179 
 
 Hornblower, 209 
 
 Horned passalus, 149 
 
 Horn-tails, 246, 274, 319 
 
 Hornworms, 209 
 
 Horse-flies, 229, 242, 323 
 
 House-fly, i, 234, 242, 32S 
 
 Humming-bird hawk-moths, 211 
 
 Hydrobatidae, 135, 309 
 
 Hydrophilidae, 141, 171, 312 
 
 Hymenoptera, 18, 243, 303, 304, 305, 
 319; characteristics of, 243; gall-in- 
 habiting, 246 ; larvae of, 243 ; mount- 
 ing of, 348 ; parasitic, 247 ; plant- 
 eating, 244; stinging, 254 ; summary 
 of, 274 
 
 Hypopharynx, 15, 279, 295 
 
 Ichneumon-flies, 250, 274 
 
 Ichneumonidae, 250, 274, 320 
 
 Ichneumons, 243 
 
 Identity of insects, 67 
 
 Ileum, 31 
 
 Inch-worms, 195 
 
 Incomplete metamorphosis, 50, 53 
 
 Indian-meal moth, 1S9 
 
 Inflating insect larvae, 353 
 
 Injury to crops, 2 
 
 Injury to domestic animals, 2 
 
 Injury to household and stored goods, 2 
 
 Insecta, 8 
 
 Insect nets, 331 
 
 Insect pins, 343 
 
 Insects, and disease, i ; near relatives 
 of, 5 ; classes of, 67 ; compared with 
 Arachnida, 2S6; compared with Crus- 
 taceans, 284 ; compared with Myri- 
 apoda, 2S5 ; comparison of types of, 
 287; external anatomy of, 10; growth 
 and transformation of, 45 ; number 
 of, 3 ; structure and growth of, 5 
 
 Insect traps, 339 
 
 Integument, 26 
 
 Intestine, 31 
 
 Invertebrates, 5, 6 
 
 lo moth, 213 
 
 Iridomyrmex humilis, 259 
 
 Isabella tiger-moth, 207 
 
 Isosoma tritici, 253 
 
 Japygidae, 305 
 Jassidae, 125, 135, 31 1 
 Jug-handle grub, 209 
 Jumping plant-lice, 311 
 June-bugs, 151 
 
 Labeling, 349 
 Labium, 14, 278, 294-297 
 Laboratory exercises, 275 
 Labrum, 13. 277, 294-297 
 Lace-bugs, 117, 135, 310 
 Lace wings, 307 
 Lachnosterna, 151 
 Lacinia, 14 
 
 Ladybird-beetles, 161, 171, 313 
 Lamellicornia, 148, 171, 313 
 Lampyridae, 147, 171, 313 
 Laphygma frugiperda, 202 
 Larder-beetles, 143, 312 
 Larger carpenter-bee, 270 
 Larva, 47, 58, 63 
 Lasiocampidae, 216, 318 
 Lasius niger americanus, 256 
 Leaf-beetles, 153, 171, 313 
 Leaf-bugs, 117, 135, 310 
 Leaf-chafers, 313 
 Leaf-cutter bees, 269 
 Leaf-folders, 217 
 Leaf-hoppers, 125, 135, 311 
 Leaf-horned beetles, 148, 171 
 Leaf-miners, 217, 319 
 Leaf-rollers, 186, 217, 319 
 Leaf worm, 202 
 Leather-jackets, 220 
 Lebia grandis, 139 
 Lecanium, 132 
 Legs, 21, 280 
 Lenses, 355 
 Leopard moth, 191 
 
 Lepidoptera, 17, 172, 305, 318; mount- 
 ing of, 347 ; summary of, 217 
 Lepismidae, 305 
 Leptidae, 323 
 
 Leptinotarsa decemlineata, 153 
 Leptocoris trivittatus, 121 
 Lesser migratory locust, 81 
 Leucania unipuncta, 202 
 Leucocytes, t,^ 
 Libellulidae, 306 
 Lice, 121 
 
 Life history of insects, 298 
 Light traps, 341 
 Ligula, 15 
 Limnobatidae, 309 
 Liotheidae, 307 
 Liparidae, 203, 217, 318 
 Lobsters, 7 
 Locust-beetle, 157 
 
368 
 
 ELEMENTARY ENTOMOLOGY 
 
 Locust-borer, i6o 
 
 Locustidae, 83, 308 
 
 Locusts, 81, 308; internal anatomy of, 
 
 290 ; preservation of, 275 
 Long-horned beetles, 158, 171 
 Long-horned grasshoppers, 83, 308 
 Long-legged bugs, 135 
 Long-legged flies, 231 
 Long-tongued bees, 267, 269, 274, 
 
 321 
 Louse-flies, 240, 242 
 Loxostege similalis, 187 
 Lucanidae, 148, 171, 313 
 Lucilia caesar, 236 
 Luna moth, 2 1 5 
 Lycaenidae, 178, 217, 318 
 Lygaeidae, 120, 135, 310 
 Lygus pratensis, 117 
 Lysiphlebus tritici, 251 
 
 Machilis, 74 
 
 Macrolepidoptera, 191, 217 
 Maggots, 219 
 
 Malacosoma americana, 57 
 Malarial fever, i, 223 
 Mallophaga, 106, 307 
 Malpighian tubes, 31 
 Mandibles, 13, 278, 294-297 
 Mantidae, 78, 308 
 Mantids, 78 
 Mantispidae, 307 
 Mantis religiosa, 79 
 Marx tray, 353 
 Masaridae, 320 
 Maxillae, 14, 278, 294-297 
 May-beetles, 151 
 
 May-flies, 95, 306; mounting of, 345 
 Meadow-flies, 325 
 Meadow maggots, 220 
 Meal snout-moth, 189 
 Meal-worm beetle, 165 
 Meal-worms, 217 
 Mealy-bugs, 131 
 Measuring-worms, 217 
 Mecoptera, 93, 303, 304, 307 ; mount- 
 ing of, 347 
 Media, 24 
 
 Mediterranean flour-moth, 189 
 Melanolestes picipes, 113 
 Melanoplus atlantis, 81 
 Melanoplus differentialis, 53, 82 
 Melanoplus femur-rubrum, 81 
 Melanoplus spretus, 82 
 Melittia ceto, 193 
 Meloidae, 166, 171, 311 
 Melon aphis, 129 
 Melon caterpillar, 188 
 Melophagus ovinus, 240 
 
 Membracidae, 124, 133,311 
 
 Mesothorax, 20, 279 
 
 Metallic wood-borers, 146, 171, 312 
 
 Metamorphosis, complete, 46, 47 
 
 Metathorax, 20, 279 
 
 Milkweed butterfly, 179 
 
 Millers, 199 
 
 Minutien-nadeln, 348 
 
 Mites, 7 
 
 Molluscs, 5 
 
 Monarch butterfly, 179 
 
 Monomorium pharaonis, 256 
 
 Monostegia rosae, 245 
 
 Mosquitoes, 218, 222, 242, 321 
 
 Mossy rose-gall, 247 
 
 Moth, 60, 172, 183, 217, 318 
 
 Mounting insects, 343 
 
 Mounting on points, 348 
 
 Mounting on slides, 351 
 
 Mouth-parts, 11, 12, 277, 294 ; suctorial 
 
 type of, 1 5 
 Mud-daubers, 262 
 Murgantia histrionica, 115 
 Muscidae, 242, 328 
 Muscids, 234, 242 
 Muscina, 234, 242 
 Muscular system, 36, 292 
 Mutillidae, 261, 274, 321 
 Mycetophilidae, 227, 242, 321 
 Mydaidae, 323 
 Mydas-flies, 323 
 Myriapoda, 8 
 Myriapods, 6 
 Myrmeleonidae, 93, 307 
 Myrmicidae, 256, 274, 320 
 
 Nabidae, 1 14, 135, 310 
 
 Naucoridae, 309 
 
 Necrophorus, 142 
 
 Needles, 354 
 
 Negro-bugs, 116, 310 
 
 Nematocera, 220, 242, 321 
 
 Nematus ribesii, 245 
 
 Nepidae, 135, 309 
 
 Nervous system, 37, 292 
 
 Neuroptera, 90, 304, 306 ; mounting of, 
 
 347 
 Nezara hilaris, 1 15 
 Nine-spotted ladybird-beetle, 162 
 Noctuidae, 199, 217, 318 
 Nodus, 98 
 
 Northern grass worm, 200 
 Notodontidae, 193, 217, 319 
 Notonectidae, 135, 309 
 Notum, 21 
 
 Nycteribiidae, 240, 242, 329 
 Nymph, 50, 54 
 Nymphalidae, 179, 217, 318 
 
INDEX 
 
 369 
 
 Oak-apple, 247 
 
 Oak-pruner, 160 
 
 Oberea bimaculata, 161 
 
 Oblique-banded leaf-roller, 186 
 
 Ocelli, 12, 39 
 
 Odonata, 98, 304, 306 
 
 Odontota dorsalis, 157 
 
 Oestridae. 233, 242, 328 
 
 Ommatidium, 40 
 
 Onion-maggot, 238 
 
 Ophion flies, 250 
 
 Orders, 68, 71 
 
 Orneodidae, 190 
 
 Ortalidae, 325 
 
 Orthoptera, 76, 304, 30S ; mounting of, 
 
 346 
 Oscinidae, 327 
 Otiorhynchidae, 313 
 Ovipositors, 26 
 Owlet-moths, 199, 217, 31S 
 Ox-bot, 2 
 Oyster-shell bark-louse, 134 
 
 Palpus, 14 
 
 Panorpidae, 307 
 
 Papilionidae, 175, 31S 
 
 Papilionina, 174, 217 
 
 Papilio polyxenes, 175 
 
 Parasita, 121, 135 
 
 Parasitic Hymenoptera, 274 
 
 Passalus cornutus, 149 
 
 Pea aphis, 129 
 
 Peach-tree-borer, 192 
 
 Pear psylla, 127 
 
 Pear-slug, 245 
 
 Pea-weevils, 158, 171, 373 
 
 Peddlers, 157 
 
 Pediculidae, 30S 
 
 Pelecinidae, 320 
 
 Pentamera, 137, 171, 312 
 
 Pentatoma sayi, 1 16 
 
 Pentatomidae, 114. 310 
 
 Pepsis formosa, 261 
 
 Periodical cicada, 122 
 
 Perlidae, 306 
 
 Pharynx, 29 
 
 Phasmidae, 80, 30S 
 
 Philopteridae, 307 
 
 Phlegethontius quinquemaculata, 209 
 
 Phoridae, 323 
 
 Phryganeidae, 307 
 
 Phycitinae, 189 
 
 Phyla, 6 
 
 Phymata wolfii, 1 14 
 
 Phymatidae, 114, 135, 309 
 
 Physopoda, 305 
 
 Physopodae, 308 
 
 Phytophaga, 153 
 
 Pickle-worm, 188 
 
 Piercing mouth-parts, 295 
 
 Pieridae, 178, 217, 318 
 
 Pimpla flies, 250 
 
 Pinning block, 344 
 
 Pins, 343 
 
 Pipunculidae, 325 
 
 Pissodes strobi, 168 
 
 Plant-bugs, 116, 135 
 
 Plant-eating Hymenoptera, 274 
 
 Plant-hoppers, 124 
 
 Plant-lice, 127, 135, 311 ; jumping, 127, 
 
 135; life history of, 298 
 Platypezidae, 325 
 Platyptera, 103, 303, 304, 307 ; mounting 
 
 of, 346 
 Plecoptera, 97, 304, 306 
 Pleurum, 21 
 
 Plodia interpunctella, 189 
 Plum curculio, 168 
 Plume-moth, 190 
 Podisus spinosus, 115 
 Poduridae, 306 
 Poecilocapsus lineatus, 118 
 Polistes, 266 
 Pollenization, 2 
 Polygonia comma, 179 
 Polyphemus, 213 
 Pomace-flies, 239, 327 
 Poneridae, 320 
 Pontia rapae, 300 
 Porthetria dispar, 204 
 Potato flea-beetle, 156 
 Praying mantis, 308 
 Predacious bugs, 112, 135 
 Predacious diving-beetles, 171, 312 
 Predacious ground-beetles, 312 
 Preserving, 352 
 Preserving insects, 343 
 Prionids, 160 
 
 Proctotrypidae, 253, 274, 320 
 Proctotrypid-flies, 274 
 Proctotrypids, 253 
 Productive insects, 2 
 Prominents, 193, 217, 319 
 Prothorax, 20, 279 
 Protozoa, 3 
 Proventriculus, 30 
 Psammocharidae, 261, 274, 321 
 Pseudoneuroptera, 95 
 Psilidae, 328 
 Psocidae, 105, 307 
 Psocids, 106 
 Psychidae, 319 
 Psychodidae, 321 
 Psylla pyricola, 127 
 Psyllas, 127, 135 
 Psyllidae, 127, 135, 311 
 
370 
 
 ELEMENTARY ENTOMOLOGY 
 
 Psythirus, 270 
 
 Pteromalus puparum, 253 
 
 Pterophoridae, 190 
 
 Ptinidae, 312 
 
 Puddle butterflies, 178 
 
 Pulvillus, 22 
 
 Pupa, 47, 60, 63 
 
 Pupipara, 219, 220, 239, 242, 329 
 
 Pyloric valve, 31 
 
 Pyralidae, 187, 217, 319 
 
 Pyralids, 187 
 
 Pyralis costalis, iSS 
 
 Pyralis farinalis, 189 
 
 Pyrrharctia isabella, 20S 
 
 Pyrrhocoridae, 119, 135, 310 
 
 Radial sector, 24 
 
 Radius, 24 
 
 Railroad worm, 239 . 
 
 Rake net, 334 
 
 Raphidiidae, 307 
 
 Raspberry cane-borer, 160 
 
 Raspberry geometer, 199 
 
 Raspberry root-borer, 193 
 
 Rearing nets, 357 
 
 Rectum, 31 
 
 Red ant, 256 
 
 Red-bug, 119, 135, 310 
 
 Red-humped apple caterpillar, 194 
 
 Red-legged locust, 81 
 
 Red milkweed-beetle, 161 
 
 Red-necked blackberry-borer, 147 
 
 Reduviidae, 112, 135. 309 
 
 Reproductive system, 291 
 
 Reptiles, 5 
 
 Respiratory system, 33 
 
 Rhagoletis pomonella, 239 
 
 Rhinoceros beetle, 152 
 
 Rhodites rosae, 247 
 
 Rhynchophora, 137, 167, 171 
 
 Rhyphidae, 321 
 
 Rice weevils, 169 
 
 Robber-flies, 230, 242, 323 
 
 Rocky Mountain locusts, 82 
 
 Root-maggot flies, 238, 242 
 
 Rose-chafer, 151 
 
 Rose leaf-hopper, 125 
 
 Rose-slug, 245 
 
 Round-headed apple-tree borer, 160 
 
 Round-headed borers, 158 
 
 Rove-beetles, 143, 171, 312 
 
 Royal moths, 319 
 
 Running Orthoptera, 77 
 
 Sag net, 333 
 Saldidae, 309 
 Salivary glands, 29 
 Samia cecropia, 215 
 
 San Jose scale, 134 
 
 Sanninoidea exitiosa, 192 
 
 Sapromyzidae, 325 
 
 Sarcophaga sarracenia, 236 
 
 Sarcophagidae, 236, 242, 328 
 
 Saturnians, 212, 217 
 
 Saturnoidea, 212, 217, 319 
 
 Saw-flies, 243, 244, 274, 319 
 
 Saw-horned beetles, 144, 171, 312 
 
 Saw-toothed grain-beetle, 143, 144 
 
 Sawyer beetle, 160 
 
 Scale insects, 107, 129, 135, 311 
 
 Scalpels, 354 
 
 Scarabaeidae, 149, 171, 313 
 
 Scarabasid beetles, 171 
 
 Scavenger-beetles, 313 
 
 Scenopinidae, 323 
 
 Schistocerca americana, 83 
 
 Schizura concinna, 194 
 
 Schmitt box, 350 
 
 Scientific names, 68 
 
 Sciomyzidae, 325 
 
 Scissors, 354 
 
 Sclerites, 21 ; of locust, 276 
 
 Scoliidae, 321 
 
 Scolytidae, 170, 171, 313 
 
 Scolytus rugulosus, 170 
 
 Scorpion-flies, 93, 303, 307 
 
 Scorpions, 7 
 
 Screw worm, 2 
 
 Screw-worm fly, 236 
 
 Scutelleridae, 310 
 
 Searcher, 139 
 
 Senses of insects, 39 
 
 Sepsidae, 325 
 
 Serricornia, 144, 171, 312 
 
 Sesia tipuliformis, 193 
 
 Sesiidae, 192, 217, 319 
 
 Sheep maggot, 2 
 
 Sheep-tick, 240 
 
 Shield-backed bugs, 310 
 
 Shield-shaped bugs, 135 
 
 Shore-bugs, 309 
 
 Short-horned flies, 229 
 
 Short-horned grasshoppers, 81 
 
 Short-tongued bees, 267, 274, 321 
 
 Shot-hole borers, 170 
 
 Shrimps, 7 
 
 Sialidae, 306 
 
 Sight, 39 
 
 Silkworm, 2, 212 
 
 Silkworm moths, 217 
 
 Silpha, 142 
 
 Silphidae, 142, 171, 312 
 
 Silvanus surinamensis, 143 
 
 Simuliidae, 226, 323 
 
 Siphonaptera, 240, 305 
 
 Siricidae 246, 274, 319 
 
INDEX 
 
 371 
 
 Skippers, 174, 217, 318 
 
 Slugs, 245 
 
 Smell, 42 
 
 Sminthuridae, 305 
 
 Snapping beetles, 144 
 
 Snout-beetles, 137, 167, 171 
 
 Social bees, 270, 274 
 
 Social-wasps, 264, 274 
 
 Soft scales, 131 
 
 Soldier-beetles, 14S 
 
 Soldier-bugs, 1 15 
 
 Soldier-flies, 230, 242, 323 
 
 Solenopsis geminata, 259 
 
 Solitary bees, 274 
 
 Solitary-wasps, 263, 274 
 
 Sow-bugs, 7 
 
 Species, 68, 70 
 
 Sphecidae, 262, 274, 321 
 
 Sphecina, 260, 274, 320 
 
 Sphingidae, 208, 217, 318 
 
 Spiders, 6 
 
 Spider-wasps, 261, 274 
 
 Spined soldier-bug, 115 
 
 Spiny elm caterpillar, 179; the life of 
 
 the, 63 
 Spiracles, 34 
 
 Spittle-insects, 125, 135, 311 
 Spreading boards, 345 
 Springtails, 73, 74 
 Squash-bug, 50, 121, 135, 310 
 Squash-vine-borer, 193 
 Stable-fly, 236 
 Stag-beetles, 148, 171, 313 
 Staphylinidae, 143, 171, 312 
 Stegomyia, 223 
 Sternum, 21 
 Stigmata, 34 
 Stilt-bugs, 120, 135, 310 
 Stinging ants, 256 
 Stinging hymenoptera, 274 
 Stink-bugs, 114, 135, 310 
 Stomach, 31 
 
 Stone-flies. 97, 306; mounting of, 345 
 Stratiomyidae, 230, 242. 323 
 Strawberry root-louse, 1 29 
 Strawberry weevil, 168 
 Streblidae, 329 
 Striped blister-beetle, 166 
 Striped cucumber-beetle, 156 
 Subcosta, 24 
 
 Sucking mouth-parts, 294, 296 
 Suctorial lice, 308 
 Sugar-maple-borer, 160 
 Suture, 276 
 Swallowtails, 175. 31S 
 Sweeping net, 332 
 Sympathetic system, 38 
 Synchlora glaucaria, 199 
 
 Syrphidae, 23 
 Syrphus, 232 
 
 242 
 
 Tabanidae, 229, 242, 323 
 
 Tachina-flies, 237, 242 
 
 Tachinidae, 237, 242, 328 
 
 Tarantula hawk, 261 
 
 Tarnished plant-bug, 117 
 
 Tarsus, 22 
 
 Taste, 41 
 
 Telea polyphemus, 213 
 
 Tenebrio molitor, 165 
 
 Tenebrionidae, 165, 171, 311 
 
 Tent caterpillar, 216; life history of 
 
 the, 57 
 Tent-caterpillar moths, 217 
 Tenthredinidae, 244, 274, 319 
 Terebrantia, 244, 274 
 Tergum, 21 
 Termes flavipes, 104 
 Termitidae, 103, 307 
 Tetramera, 153, 171, 313 
 Tetraopes tetraophthalmus, 161 
 Texas fever, 2 
 Thorax, 7, 11, 20, 279; appendages of, 
 
 2S0 
 Thread-waisted wasps, 262, 274 
 Thyanta custator, 116 
 Thyreocoridae, 310 
 Thysanoptera, 308 
 Thysanura, 74, 305 ; mounting of, 
 
 344 
 Tibia, 22 
 Ticks, 2, 7 
 
 Tiger beetles, 137, 171, 312 
 Tiger moths, 207, 217, 318 
 Tineidae, 184, 217, 319 
 Tineids, 184 
 
 Tingitidae, 112, 135, 310 
 Tipulidae, 220, 242, 321 
 Tischeria malifoliella, 185 
 Tmetocera ocellana, 187 
 Toad-bugs, 308 
 Tobacco-worm, 209, 251 
 Tongue, 297 
 Tortoise-beetles, 157 
 Tortricidae, 186, 217, 319 
 Touch, 41 
 
 Toxoptera graminum, 129 
 Trachea, ^^ 
 Transformations, 46 
 Tree-hoppers, 124, 135, 311 
 Trichodectidae, 307 
 Trichoptera, 93, 304 ; mounting of, 347 
 Trimera, 161, 171 
 Trochanter, 22 
 Trypetidae, 239, 242,328 
 Tumble-bugs, i 50 
 
zi-^- 
 
 ELEMENTARY ENTOMOLOGY 
 
 Tussock-moths, 203, 217, 318 
 Twelve-spotted Diabrotica, 156 
 Twice-stabbed ladybird, 162 
 Two-spotted ladybird, 162 
 Tympanum, 43 
 Typhlocyba comes, 125 
 Typhoid fever, 2 
 
 Uranotes mellinus, 179 
 
 Vedalia cardinalis, 163 
 
 Veins, of wings, 24 
 
 Velidae, 309 
 
 Velvet ants, 261, 274, 321 
 
 Ventriculus, 31 
 
 Vermes, 6 
 
 Vertebrates, 5 
 
 Vespa, 266 
 
 Vespidae, 264, 320 
 
 Vespina, 261, 263, 274, 320 
 
 Vinegar flies, 327 
 
 Walking Orthoptera, 80 
 Walking-sticks, 80, 308 
 Warble, 2 
 
 Wasp-flies, 232, 242 
 Wasps, 243, 260, 274 
 Water-boatman, 135, 309 
 
 Water dip net, -^-^^t^ 
 
 Water-scavenger beetles, 141, 171, 31; 
 
 Water-scorpions, 135, 309 
 
 Water-striders, 135, 309 
 
 Weevils, 167 
 
 Western cricket, 85 
 
 Wheel-bug, 1 12 
 
 Whirligig-beetles, 140, 171, 312 
 
 White ants, 103, 307; work of, 105 
 
 White grub, 151 
 
 White-marked tussock-moth, 204 
 
 White-pine weevil, 168 
 
 Window-flies, 323 
 
 Wing-covers, 281 
 
 Wings, 23, 281 
 
 Wire-worms, 146 
 
 Wood nymphs, 318 
 
 Woolly apple aphis, 129 
 
 Woolly bears, 207 
 
 Worms, 5 
 
 Xylocopa virginica, 270 
 
 Yellow fever, i 
 Vellow-necked caterpillar, 194 
 
 Zeuzera pyrina, 192 
 Zygoptera, 306 
 
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