Class _XB-23J Book ' /o ?^ CjJPVRIGKT DEPOSm CLASS BOOK OF ECONOMIC ENTOMOLOGY LOCHHEAD T. W. Harris Asa Fitch TowNEND Glover B. D. Walsh C. V. Ri;.EY W. Saunders J. Fletcher C. J. S. Bethune Some Pioneer Workers in Economic Entomology. CLASS BOOK OF ECONOMIC ENTOMOLOGY WITH SPECIAL REFERENCE TO THE ECONOMIC INSECTS OF THE NORTHERN UNITED STATES AND CANADA BY WILLIAM LOCHHEAD, B. A., M. S. (Cornell) PROFESSOR OF BIOLOGY IN THE MACDONALD COLLEGE OF McGILL UNIVERSITY; F. A. A. S.J MEMBER OF THE ENT. SOC. OF AMERICA, AND THE AM. ASSOC. ECON. ENT.; EX-PRESIDENT ENT. SOC. OF ONTARIO; PRESIDENT QUEBEC SOC. FOR THE PROTECTION OF PLANTS, ETC. WITH 257 ILLUSTRATIONS PHILADELPHIA BLAKISTON'S SON & CO. 1012 WALNUT STREET ^-^^i" ^-^u.* Copyright, 1919, by P, Blakiston's Son & Co. APR 18 !9I9 ^/ THH MAPliE FKKB^ T O R K PA PREFACE All teachers are agreed that the best results in the classroom are secured only by the adoption of the best pedagogical methods, with ready access to the necessary specimens and literature. Just what these methods comprise, however, is, with many teachers, a matter of opinion. Quot homines tot sententice, nevertheless the indulgent reader may concede that an experience of over twenty years as a teacher of economic entomology in agricultural colleges may warrant the voicing of the author's conviction that instruction in this subject should con- sist of (i) studies on the structure, metamorphosis, and bionomics of insects, carried on both in the laboratory and in the field; (2) practice in the classification and description of the more common insects in their various stages; and (3) studies of the methods of control, with practical exercises in the preparation and appHcation of insecticides. Although several most excellent manuals on Economic Entomology have been published in recent years, there seems to be a need for a book providing the necessary information for the student in the class- room, laboratory and field along the lines indicated above. This class-book, therefore, has been prepared to meet the needs of the class-room instructor, and his needs have influenced the mode of presentation of the subject material. It does not presume to take the place of the invaluable and well-known works of Folsom, Comstock, Slingerland and Crosby, and others; but rather, it aims to present such material as will best help the student in acquiring a fair working knowl- edge of the modern science of Economic Entomology. The treatment of many of the topics is necessarily limited, and the keys for the identification of orders, famiHes, and genera make no pre- tensions to completeness. The descriptions of the species discussed in Part III are stripped of all unnecessary verbiage so that all the essential facts of the life-histories may be included in the space at the author's disposal. Vi PREFACE Laboratory exercises have been omitted, as the intelligent teacher is in a better position than the author to prepare practicums adapted to local conditions. It was thought advisable to limit the species discussed mainly to those belonging to the Northern United States and Canada, i.e., to the Canadian, Transition, and Upper Austral Zones. It was also deemed advisable to make but brief mention of the insects affecting forest trees. Students interested in such studies are referred to the recent bulletins of A. D. Hopkins of Washington and J. M. Swaine of Ottawa for the results of the latest investigations. The author is indebted to many fellow- teachers and workers for valu- able aid and suggestions in the preparation of this book. In most respects it is a compilation from recent text-books, bulletins, and arti- cles. In a work of this kind errors are likely to appear in spite of every precaution, but considerable care has been taken to reduce them to a minimum. Special mention must be made of the kindness of many authors and publishers in furnishing illustrations, and the writer here thanks his friend and teacher. Professor J. H. Comstock of Cornell University, for permission to use illustrations of wing-venation from his recent work, ''The Wings of Insects;" Dr. C. G. Hewitt, Dominion Entomolo- gist, for free use of cuts from the publications of the Canadian Ento- mological Branch; Dr. L. O. Howard, Chief of the U. S. Bureau of Entomology, for many electrotypes of the Bureau illustrations; Pro- fessor J. H. Sanders of the Pennsylvania Agricultural Experiment Station, for permission to use his admirable figures of pygidia of scale insects; Mr. J. J. Davis, Federal Agent of the U. S. Bureau of Entomol- ogy, Lafayette, Indiana, for several photographs of breeding cages, etc.; Professor L. Caesar of the Ontario Agricultural College, and Dr. S. Hadwen, Dominion Pathologist, Health of Animals Branch, Ottawa, for furnishing several cuts; Mr. Arthur Gibson, Entomological Branch, Ottawa; Professor W. H. Brittain of the Truro Agricultural College; Professor P. J. Parrott of the New York Agricultural Experiment Station; Professors Herrick, Crosby and Johannsen of Cornell Univer- sity; Professor W. A. Riley of the Minnesota Agricultural College; Dr. Edith Patch of the Maine Agricultural Experiment Station; Professor W. E. Britton of the Connecticut Agricultural Experiment Station; Professor V. L. Kellogg of the Leland Stanford Jr. University, Professor PREFACE Vii W. B. Herms of the University of California; and the MacMillan Co., the Comstock Publishing Co., Henry Holt and Co., and P. Blakiston's Son and Co., for permission to use certain illustrations from their entomological publications. To Mr. E. M. DuPorte, M. Sc, of Macdonald College, the author is specially indebted for the drawings illustrative of the structure of insects in Part I, for valuable criticisms, and for substantial help in proof-reading. W. LOCHHEAD. Macdonald College. CONTENTS INTRODUCTION PART I— THE STRUCTURE, GROWTH AND ECONOMICS OF INSECTS Page The Branch Arthropoda i The Class Insecta 2 Structure of Insects 2 External Anatomy 2 Internal Anatomy ip The Development of Insects 30 Embryology, Metamorphosis — stages 30 Losses due to Insects 38 Beneficial Insects 3q Insects and Birds ,. 44 Insects and Plants 4^ Insects as Plant Disease Carriers 46 Insects and Disease 4q Insect Behavior toward Stimuli ry Relation of Insects to Temperature and Humidity ^g Distribution of Insects 60 Methods of Studying Economic Insects 64 PART II.— THE IDENTIFICATION OF INSECTS INJURIOUS TO FARM, GARDEN AND ORCHARD CROPS, ETC. Insects injurious to Cereal Crops yj Insects injurious to Indian Corn or Maize 72 Insects injurious to Clover and Alfalfa 73 Insects injurious to Peas and Beans 74 Insects injurious to Stored Grain Products 74 Insects injurious to Root Crops 75 Insects injurious to the Potato Crop y5 Insects injurious to Garden Vegetables yy Insects injurious to the Apple 77 Insects injurious to the Plum g^ Insects injurious to the Cherry 32 Insects injurious to the Peach g^ Insects injurious to the Raspberry and Blackberry g3 Insects injurious to the Gooseberry and Currant 84 ix X CONTENTS Pace Insects injurious to the Grape 85 Insects injurious to the Strawberry 86 Insects affecting Shade Trees 87 Insects injurious to Greenhouse plants 90 Insects affecting Domestic Animals 90 Insects of the Household 92 PART III.— CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS Common Orders 93 Aptera group 94 Thysanura 95 Neuropteroida group 96 Mallophaga 100 Orthopteroida group 102 Isoptera 102 Corrodentia 103 Blattoidea 103 Mantoidea 105 Dermaptera 106 Phasmoidea 106 Orthoptera 107 Thysanoptera 118 Homoptera 122 Hemiptera 158 Siphunculata 167 Lepidoptera 169 Diptera 239 Siphonaptera 279 Coleoptera 280 Hymenoptera 343 Invertebrates other than Insects 363 PART IV.— THE CONTROL OF INJURIOUS INSECTS Factors of Insect Control 373 Methods of Control 374 The Action of Insecticides 400 Utilization of Parasitic Insects 401 Bibliography 407 Glossary 409 Index 415 INTRODUCTION Economic Entomology is that phase of Entomology which relates to the control of injurious insects. Its scope is much wider than that of applied entomology, for the latter, properly speaking, is the application of the principles that have been formulated by the economic entomolo- gist as a result of his investigation of insects and their relations to their environment. Its scope embraces a study of the structure, habits and life-histories of the injurious insects and of their relations to all the natural and artificial conditions to which they may be subjected. It also includes the investigation of the nature of the losses and the prac- ticable means by which they may be prevented or lessened. Considering the great variety of insect forms, their diverse methods of food habits, the large number of kinds of hosts which supply them with food, and the enemies which tend to destroy them, it becomes evident that the problem of insect control is most complex. As Professor Forbes says: " The subject matter of this science is not insects alone, nor plants alone, nor farming alone. One may be a most ex- cellent entomologist er ^botanist, or he .may have the whole theory and practice of agriculture at his tongue's end, and at his fingers' end as well, and yet be without knowledge or resources when brought face to face with a new practical problem in economic entomology. The subject is essentially the relation of these things to each other; of insect to plant and of plant to insect, and of both of these to the purposes and opera- tions of the farm, and it involves some knowledge of all of them." The Rise of Economic Entomology The records of the rocks reveal the existence of insects at an early period in the world's history, long before man made his appearance. Early historic records also show clearly that not only man himself but also his crops and flocks suffered from insect attacks. The ravages of locusts, canker worms and palmer worms are frequently described in graphic language by the Old Testament prophets. xi Xll INTRODUCTION In America, too, before the advent of Europeans, the Indians were acquainted with insects that injured their corn fields, and during the seventeenth and eighteenth centuries the crops of the early settlers were seriously ravaged by ''canker worms" and grasshoppers. One may say, therefore, with Webster: "the actual economic element in entomology is inevitably as old as Agriculture itself." On account, however, of the ignorance and superstition that prevailed even among the learned classes regarding the nature and habits of insects, no progress in the control of insect pests was made or was possible until the latter half of the nineteenth century. The introduction of rational methods of control had to wait until considerable advance had been made in the classification of insects and in a knowledge of their structure, habits and life-history. In so far as America is concerned, it may be said that outbreaks of certain insects, viz., the Rocky Mountain locust, the cotton worm and the Colorado potato beetle during the last quarter of the nineteenth century produced wide-spread attention to the great losses caused by them, and forced the U. S. government at that time to appoint a commission of entomological specialists for the purpose of investi- gating the conditions. It was during this period that some of the modern insecticides and improved spraying machinery were introduced, Paris green becoming the standard remedy against the Colorado potato beetle and the cotton "worm, and kerosene emulsion against sucking insects. The reports of Harris, Fitch and Riley, especially those on the Rocky Mountain locust laid the foundation for future ecological studies when the relations of injurious insects to other organisms and to external factors were closely investigated. About the beginning of this century the San Jose scale and the cotton boll-weevil threatened two important industries, and as a result of the investigations many advances were made in the use of spraying machinery and insecticides, notably lime-sulphur wash and hydrocyanic acid gas, and in the application of biological processes and principles. In the attempt to solve the problem of the control of the gypsy and brown- tail moths during the last twelve years another very important advance was made toward a better understanding of parasitic insects and of the part they are likely to play in the control of insects in the future. Regarding the outlook of fighting insects along this line Dr. Howard says: ''There will be a very considerable development of this INTRODUCTION XIU method of warfare against injurious insects in the future. It should be termed "the biological method of fighting insects" and, looking at the problem in a broad way, so far as this country is concerned, when we consider that more than one-half of our principal crop pests have been accidentally imported from other countries, there seems no reason why a systematic study of a very large number of parasitic and predatory insects native to the countries from which these pests were accidentally imported should not be made with a view of ultimate importation of all of them into the United States. In fact, since there exist all over the world beneficial insects, many of which can undoubtedly be accli- matized here, and some of which will undoubtedly prove of value to American agriculture, carefully planned work should be begun looking to the ultimate increase of our insect population by the addition of as many of these beneficial forms as possible. Of course this would mean a very great amount of careful biological study in the countries of origin by men specially trained in this sort of work, if results of value are to be obtained. Strikingly beneficial results could not be expected speedily, and, in fact, we might not be able for many years to estimate the bene- fits derived from such a service; but it seems clear that we should have in this country as many of these surely beneficial forms as can be acclimatized." The greatest impetus to the development of economic entomology was perhaps the establishment of Experiment Stations and Agricultural Colleges where courses of instruction were given in this branch of zoology, and where hundreds of students have been trained to undertake investigations of the many insect problems that were awaiting solution. An interesting feature of the latest development in the study of inju- rious insects is the method of investigation that has been adopted in most entomological stations. ''Field stations" where the insects are studied under both field and laboratory conditions are established in infested areas, each in charge of an expert and a staff of assistants. These officers also keep in close touch with the insect conditions of the district, and are often able to "test out" control measures at many places by interesting the farmers and orchardists in the valuable work they are conducting. Even in a sketch of the main features of the rise of American eco- nomic entomology, such as this is, mention must be made of some of the pioneer entomologists who laid firmly and well the foundations of XIV INTRODUCTION this modern science. Dr. T. W. Harris (i 759-1856) in Massachusetts, Dr. Asa Fitch (i 809-1879) in New York, Townend Glover at Washing- ton, B. D. Walsh (1808-1869), Dr. C. V. Riley (1843-1895) in Missouri and at Washington, Dr. W. Le Baron and Cyrus Thomas in Illinois, and Dr. W. Saunders (i835-i9i4),Dr. C.J. S. Bethune (1838 ) and Dr. James Fletcher (1852-1908) in Canada stand out prominently on account of the excellent investigations of the life-histories of injurious insects and their careful determination of effective methods of control, (See frontispiece.) ECONOMIC ENTOMOLOGY PART I THE STRUCTURE, GROWTH AND ECONOMICS OF INSECTS BRANCH ARTHROPODA (Arthropods) Crabs, crayfish and lobsters, spiders and scorpions, centipedes and millipeds have in common with insects jointed appendages and seg- mented, bilaterally symmetrical bodies with a chitinized external skeleton (exo-skeleton) — distinguishing characteristics of the great branch Arthropoda of the Invertebrate animals. These near relatives of insects may be grouped into four classes: 1. Crustacea. — Aquatic, gill-breathing, wingless Arthropods with two pairs of antennae and at least five pairs of legs. Examples: Crabs, crayfish, lobsters, shrimps, sow-bugs, etc. 2. Arachnida. — Air-breathing, wingless Arthropods without anten- nae, and usually with four pairs of legs. Examples: Spiders, mites, ticks, and scorpions. 3. Diplopoda. — Air-breathing, wingless Arthropods with one pair of antennae and numerous body segments each of which bears two pairs of legs. The mouth-parts consist of a pair of mandibles and a compound plate. Example: Millipeds. 4. Chilopoda. — Air-breathing, wingless Arthropods with one pair of antennas and numerous body segments each bearing one pair of legs. The mouth-parts consist of one pair of mandibles and two pairs of maxillae. Example: Centipedes. (Classes 3 and 4 are frequently grouped as sub-classes of the class Myriapoda.) 2 ECONOMIC ENTOMOLOGY Class Insecta (Insects) The Hexapoda or Insecta are air-breathing Arthropoda with one pair of antennae, three pairs of legs, and usually one or two pairs of wings in the adult state. Insects form a well-defined class of animals, remarkable for the large number of species. The abundance of some species is so great that frequently they constitute a menace to the life of plants upon which they feed. The economic importance of insects is being rapidly realized by the public in recent years on account of the prominence given to the part taken by the common house fly in the spread of typhoid fevers and other diseases, the mosquitoes in malaria and yellow fever, the San Jose scale and codling worm in orchards, the boll-weevil in cotton fields, the army worm and hessian fly in grain fields, the tent caterpillar and bark beetles in orchards and forests, and many other pests that are causing much annoyance, danger and loss. The Structure of Insects • EXTERNAL ANATOMY The body of the insect is bilaterally symmetrical and is divided into three distinct parts — the head, the thorax and the abdomen, each composed of a number of segments separated by membranous portions (Fig. i). Each segment again is made up of a number of sclerites, hardened plates separated from each other by seams or impressed lines known as sutures. The skeleton is external, and is in form a hollow cylinder with the muscles attached within. The skin layer or cuticle is laminated, consisting of two layers secreted by the underlying hypodermal cells. The hard tough texture of the skin is due to chitin, an organic substance resembling that which gives the characteristic texture to horns and hoofs. {a) Head. — The skeleton of the head or skull is composed of six or seven closely united segments, and carries the eyes and antennce. The mouth is situated on the front ventral surface. The following regions can be easily recognized: STRUCTURE, GROWTH AND ECONOMICS OF INSECTS Epicranium (a) Vertex or crown, the summit of the head, often with oceUi. (b) Front or face. (c) Genae or cheeks. (d) Occiput, which surrounds the posterior opening of the skull. (e) Clypeus, to which the labrum or upper lip is attached. (/) Gula, to which the labium or lower lip is attached (see Figs. 2 and 3). Forem/jg ,v H/ndmh Fig. I. — Diagram showing the position and arrangement of the principal organs and appendages of an insect. Ant., Antenna; Br., brain; Ao., aorta; LM., leg mus- cles originating in the thorax; DM., dorsal longitudinal muscles of abdomen; H., heart; MT., Malpighian tubules; ED., efferent duct (oviduct or vas deferens) of reproductive system; C, gonad (ovary or testis); Cer., cercus; A., anus; Gon., gonapophyses; CD., common duct (vagina or seminal vesicle) of reproductive sys- tem; VG., ganglia of ventral nerve chain; Ty., tracheal trunk showing origin and distribution of ventral, dorsal and visceral tracheal branches; VM., ventral longi- tudinal muscles; TS., tergo-sternal muscles; Cox., coxa; Tro., trochanter; Fern., femur; Tib., tibia; Tar., tarsus; SGI., salivary gland; SD., salivary duct; SG., sub- oesophageal ganglion; Ph., pharynx; S., stomodasum or fore intestine; M., mesen- teron or mid intestine; P., proctodaeum or hind intestine. In addition there is in the head an internal chitinous skeleton called the tentorium, which acts as a supporting structure. It varies in form in different insects but consists essentially of a central plate and two pairs of arms connecting with the skull. (The tentorium may be isolated by boiling the head in a 5 per cent, solution of caustic potash for ten minutes.) Mouth-parts. — In general there are three types of mouth-parts: mandihulate, present in the generalized orders and in the Orthoptera, ECONOMIC ENTOMOLOGY Pig. 2. Fig. 3. Pig. 2. — Cephalic view of the head of cricket, a., Antenna; e., compound eye; E., epicranium; o.L, lateral ocellus; a.m., median ocellus; e.s., sutures of the epi- cranium; G., gena; Cp., C.a., clypeus; L., labrum; Md., mandible; p.m., maxillary palpus; p.l., labial palpus. Pig. 3, — Caudal view of head of cricket. E., Epicranium; O., occiput; F.P., occipital foramen; P.G., postgena; SM., submentum; M., mentum; gl., glossa; pgl., paraglossa; pg., palpiger; pi., labial palpus; C.i, C.2., cardo, pf., palpifer; g., galea; s., stipes; /., lacinia; p.m., maxillary palpus; md., mandible. Pig. 4. — Labrum and clypeus of cricket. STRUCTURE, GROWTH AND ECONOMICS OF INSECTS Ephemerida, and Coleoptera; suctorial ^ present in the Hemiptera, Lepidoptera and Diptera; and mandibulate-suctorial in the Hymen- optera. The mouth-parts with the exception of the labrum are true appendages of the head segments, and in the embryo arise in exactly the same way as the legs and antennae. Mandibulate Mouth-parts. — The mouth-parts of biting insects consist of: the labrum or upper lip attached to the clypeus (Figs. 2 and 4) ; a pair of mandibles, simple and unjoin ted, articulated to the gence; a pair of maxillcB, each made up of a basal one-, or two-jointed Pig. 5. Fig. 6. Fig. 5. — Mandible of cricket. A, Cephalic view; B, caudal view; mh., mem- brane; mc.i, mc.2, adt., adductor muscles; abt., abductor muscles. Fig. 6. — Maxilla of cricket. C.i, C.2, Cardo; Mb.2, base of maxilla; pf., pal- pifer; St., stipes; p.m., maxillary palpus; g., galea; /., lacinia. hinge segment, the cardo, a central segment the stipes which bears the palpifer to which the typically five-jointed palpus is attached, and two distal lobes the outer of which is termed the galea and the inner the lacinia (Fig. 6). The labium or lower lip, composed of a broad basal part, the submentum, joined to the gula, a mentum or central portion, a pair of jointed palpi attached to the mentum by means of a small sclerite, the palpiger, and a median part which may be simple or slightly bilobed in which case it is termed the ligula, or it may consist 6 ECONOMIC ENTOMOLOGY of a distinct pair of inner and outer lobes termed respectively the glosscB and paraglossce (Figs. 3 and 7). A comparison of Figs. 6 and 7 will show a perfect homology between the segments of the maxillae and of the labium. The hypopharynx or tongue united to the base of the labium; and the epipharynx under the labrum and clypeus bearing teeth, tubercles or bristles (Figs. 8 and 9). These parts differ greatly in the different orders. Suctorial Mouth-parts. — The suctorial mouth-parts of flies, bugs, moths and other insects have been evolved from the primitive mandibu- late type. In some forms such as the squash bug and mosquito all of the mouth-parts are present and it is comparatively easy to identify them with the corresponding append- ages of the biting insects. In other forms, however, the house-fly for ex- ^pg^f ample, some of the mouth-parts are missing or fused with others, and it is Fig. 7. Fig. 8. Fig. 7. — Labium of cricket, hyp., Hypopharynx; gl., glossa; pgl., paraglossa; pl., labial palpus; pg., palpiger; m., mentum; sm., submentum. Fig. 8. — The labrum-epipharynx of cricket. more difficult to determine their homology. The following descrip- tions will illustrate the typical arrangements in the three chief purely suctorial orders of insects. Three types occur in the Diptera — the piercing type, with all the mouth-parts present, e.g., the female horse fly and mosquito; the piercing type with some of the mouth-parts missing or fused, e.g., the horn flies and stable flies, and the non- piercing type such as the house-fly and blow flies in which the beak is used for rasping and sucking. Mouth-parts of the Horse Fly (Tabanid). — The mouth-parts of the female are composed of six blades loosely ensheathed in the labium STRUCTURE, GROWTH AND ECONOMICS OF INSECTS 7 which is the conspicuous median portion terminating in a large labellum (Fig. lo). The mandibles are flat and sword-hke; the maxillae are narrower, but with broad conspicuous palpi; the hypo pharynx and labrum-epipharynx are also narrow and lancet-like. ad.md. Fig. 9.— Front of head of Gryllus pennsylvanicus with face and vertex renioved. Upper Figure.— £^jc., Epicranium; Ad., prd.. Id., dilator muscles of the pharynx; Md., mandible; Ph., pharynx. ,. Lower Figure.— Longitudinal dorsoventral section through the head ot L^ryUus pennsylvanicus. prd., prd. 2, prd.3, pstd., Vd., Dilators of the pharynx; Oc, ocellus; Ad.md., adductor of the mandible; Dep.hyp., depressor of the hypopharynx; Hyp., hypopharynx; r.hyp., retractor of the hypopharynx; ap.lb., apodeme of the labium; r.hyp., retractor of the hypopharynx; fl.st., flexor of the stipes; T.C., central plate of the tentorium. Mouth-parts of Mosquito.— Tht mouth-parts are similar in number to those of the horse fly but they are more bristle-like (Fig. 11). Mouth-parts of the House-fly.— When the head of a living house-fly is pinched between the thumb and finger the mouth-parts are protruded to their full length. They constitute a soft "proboscis" enlarged at 8 ECONOMIC ENTOMOLOGY the tip into a pair of soft cushion-like lobes, the oral lobes or labella (Fig. 12). The under sides of these lobes are traversed by a large number of open channels, the pseudo-trachecB, which open into the mouth situated near the middle; the greater portion of this proboscis is the modified labium. Lying above the grooved labium is the small spade- like labrum which may be raised by a pin. Near the base of the probos- cis and above the labrum are two small lobes, the maxillary palpi, the maxillae being fused with the fleshy base of the labium. Fig. 10. — Head and mouth-parts of a horse-fly (Tabanus). The maximum number of parts is retained, but the piercing structures are distinctly blade-Hke. Dipteron type, second subtype. A, Side view of head showing: i, antenna (brachy- cerous); 2, compound eye; 3, labium; 4, labella; 5, maxillary palpus; B, piercing structures exposed, labium removed; 6, mandibles; 7, maxillae; 8, hypopharynx; 9, labrum-epipharynx. (After Herms.) Mouth-parts of the Stable Fly. — The proboscis is awl-shaped and is adapted for both piercing and sucking (Fig. 13). It projects forward horizontally and has a prominent elbow. The labella are small and are provided with cutting and adhesive structures. Lying above and within the folds of the proboscis or labium are two unequal, sharp heavy bristles, the larger representing the labrum and the smaller the hypo- pharynx. The maxillary palpi are not so large as those of the house- fly. The palpi of the Horn Fly are longer and more flattened, and the proboscis is plumper and not thrown so far forward. Mouth-parts of the Squash Bug. — The mandibles and maxillae are reduced to needle-like structures, the two innermost (the maxillae) are united to form a piercing tube. The needles fit in the groove of the STRUCTURE, GROWTH AND ECONOMICS OF INSECTS 9 jointed beak, the modified labium. The labrum closes the base of the groove (Fig. 14). I li h m Pig. II. — Mouth-parts of female mosquito (Culex pipiens). A, Dorsal aspect; B, transverse section; C, extremity of maxilla; D, extremity of labrum-epi- pharynx; a., antenna; e., compound eye; h., hypopharynx; I., labrum-epipharynx; /*., labium; m., mandible; mx., maxilla; p., maxillary palpus. {After Folsom and Dimmock.) Fig. 12. — Mouth-parts of the house-fly (Musca domestica). lb., Labrum; tnx.p., maxillary palpi; li., labium; la., labellum. {After Kellogg.) Mouth-parts of the Butterfly. — The long sucking tube is composed of the two maxillae joined together, while the other mouth-parts are rudimentary (Fig. 15). lO ECONOMIC ENTOMOLOGY Mandibulate-suctorial Mouth-parts. — Among the Hymenoptera we find a combination of the two types — well-developed biting mandibles and a labium or hypopharynx fitted for sucking or lapping liquid food. In ants and sawflies the mandibles are more in evidence, while the bees and wasps have well-developed sucking apparatus. Ants use their mandibles for various purposes, including the comminution of food, building of nests, transportation of larvae, slaves, etc., and in attack and defence against their enemies; the hypopharynx is used in lapping liquid food. Setae Shealh, = labium *Setae,* Mandible and Moxti/ot- Pig. 13. Fig. 14. Fig. 13. — Side view of the head and mouth-parts of the stable fly (Stomoxys calci- irans). Stylets reduced in number and closely ensheathed by the labium, i, Antenna; 2, compound eye; 3, labium; 4, labella; 5, labrum; 6, hypopharynx; 7, maxillary palpi. {After Herms.) Fig. 14. — Beak of a hemipteron. {After Riley and Johannsen.) < .. Mouth-parts of the Honey Bee. — These consist of the labrum and epipharynx above with the short trowel-like mandibles on each side for moulding wax; the maxillce forming conspicuous lateral wings with the galea and lacinia fused into one piece, and the palpi minute (Fig. 16). The labium is the long portion on each side of the tongue and ends in a pair of palpi. The middle tongue is the hypopharynx ending in a small labellum. Antennae. — The antennae or feelers are sensory organs, and are very variable in structure. They carry the organs of touch, and probably those of smell and hearing in some cases. On the surface of some of the STRUCTURE, GROWTH AND ECONOMICS OF INSECTS II segments are fine hairs, connected below with nucleated nerve cells, which are believed to be tactile hairs. There are too in some cases pits or oval depressions, also connected with a nerve cell, which are thought to be gustatory organs. Other pits situated in patches at the lower end of the segments are beheved to be auditory organs. Eyes.— The eyes of insects are of three kinds: simple, compound and agglomerate. The simple eyes or ocelli appear externally as a single convex lens, and are borne by the most primitive insects such as the Collembola, all eyed larvae, and in the adults of most of the winged insects. In winged forms there are usually three, supple- mentary to the compound eyes, and borne on the vertex or on the front, arranged generally in a triangle. The agglomerate eye is a compound eye in which the facets are not fused but well separated from each other, e.g., male Coccids. Organs of Hearing.— Several kinds of auditory organs occur in insects and these are variously located. In locusts they are tympanic membranes, located on the base of the abdomen; in the katydids and crickets on the tibiae of the fore legs. In the mosquitoes and many other groups certain sensitive hairs on the antennae serve to take up and transmit sound waves. Organs of )cated— on the antennae in flesh bJscS.' ' (After Folsom.) flies, ants, bees and wasps, some moths and beetles; on the maxillary and labial palpi in Perla and Silpha; and on the cerci in the cockroach and some Orthoptera. Organs of Taste.— Taste organs are also variously located— on the hypopharynx in the honey bee, on the epipharynx of most biting insects, and on the maxillary palpi in wasps. All sense organs consist essentially of the following parts: (i) a nerve of the central nervous system communicating with (2) one or two modified hypodermal cells, and (3) external supporting or accessory structures such as setae, tubercles or pits. Fig. 15. — H e a d of a Smell. — These organs are butterfly {Vanessa). ^ a., An- variously located — on the antennae in flesh boscS' ' ^ ^^ ^^^^' ^' pro- 12 ECONOMIC ENTOMOLOGY ;4!t|iiL Fig. i6. — Head and mouth-parts of the honey bee {Apis mellifera). Both types of mouth-parts well developed but the mandibles are used chiefly for portage and modeling (Hymenopteron type). A, Front view of the head showing: i, antennae; 2, compound eyes; 3, simple eye; 4, labrum; 5, mandibles; 6, maxillae (lacinia); 7, labium (palpi only); 8, hypopharynx(?); B, mouth-parts removed to show the parts; 5, mandibles; 6, maxillae (lacinia); 7, labium (palpi only); 8, hypopharynx (?); 9, bouton; 10, maxillary palpus; 11, mentum; 12, submentum; 13, cardo; 14, stipes. {After Herms.) Fig. 17. — Section through the thorax of an insect. L., Leg; P., pleuron; 5., sternum; J"., tergum; W., wing. STRUCTURE, GROWTH AND ECONOMICS OF INSECTS 13 Special Organs of Sense. — ^The halter es of Diptera contain sensory organs, but their function has not yet been definitely ascertained. pron. \ 6 —^..Scz ^^ ^ -^^^Sclz "^71 -)N.\ v^ .5C.3 s^^ /""V ■Viz ^ScU - — -^ 5 'P.5Cl. \ pron. Fig. 18. — Gryllus pennsylvanicus . A, Ventral view of thorax; B, dorsal view of thorax, distal portion of pronotum removed; C, lateral view of thorax and abdomen. Cox., C0X.2, Cox.z, First, second and third coxae; Stl., prosternellum; St.2, St. 3, meso- and meta- sternum; Pron., pronotum; Es.2, Es.3, meso- and meta-episternum; Em. 2, Ein.3, meso- and meta-epimeron; i, 2, 3, etc., abdominal tergites; i', 2', 3', etc., abdominal sternites; p., peritreme; 5., spiracle; sp., supra anal plate; C, cercus; Ovp., ovipositor; pi., pleuron; Sc.2, Sc.3, meso- and meta-scutum; Scl.2, Scl.3, meso- and meta-scutellum ; p.scL, postscutellum; W., W.2, wing bases. When deprived of halteres flies cannot maintain their equilibrium in the air. 14 ECONOMIC ENTOMOLOGY tb (b) Thorax. — The thorax is composed of three segments — the pro-, meso-, and metathorax, each having a pair of legs. The meso- thorax and metathorax bear wings. Each segment is divided into a dorsal part, the notum or tergum, a ventral part, the sternum, and two laterals, the pleura (Fig. 17). Each part is again divided by sutures into sclerites— the notum into prcescutum, scutum, scutellum and post-scutellum, and the pleuron into episternum and epimeron (Fig. 18). In most hymenopterous insects the first abdom- inal segment — ^the propodeiim or median segment — is fused with the thoracic mass, so that the petiole of such insects is not the first but the second abdom- inal segment. Legs. — Each leg is composed of the following parts: coxa, trochanter, femur, tibia, and tarsus (Fig. 19). The trochanter in certain Hymenoptera is made of two segments, while the tarsus in most in- sects is composed of several segments, the last bear- ing a pair of claws. In some insects, e.g., the Diptera, three appendages are borne between the claws, in which case the outer pair are termed pulvilli and the middle one the empodium. Wings. — The two pairs of wings are attached to the meso- and the metathorax. They are membran- ous expansions of the body wall with hollow thick- enings along certain lines called veins or nerves. These veins often branch and interlace, and the spaces between the veins are called cells. Much import- ance is attached in classification to the wing and its veins on account of the great variation not only in the orders and families but even in the genera of a family. Structurally the wings of insects may be grouped into three divisions: I . Where the fore and hind wings are of similar texture and more or less fan-like. Under this division fall the Dragon flies, in which both the size and form of the wings are very much alike. Butterflies, wasps, and bees have their hind wings smaller than the fore wings, while some of the d Fig. 19.— Leg of a beetle {Calo- soma calidum). c, Coxa; c/., claws; /., femur; i., spur; f.W.^, tarsal seg- ments; th., tibia; tr., trochanter. {After Folsom.) STRUCTURE, GROWTH AND ECONOMICS OF INSECTS 15 May flies and the males of scale insects have their hind wings very much reduced or entirely wanting. In the flies {Diptera) the hind wings are converted into halter es (balancers). 2. Where the fore wings are either wholly or partially chitinized. Examples of such thickening of the wings occur among the grass- hoppers and crickets, the beetles and the heteropterous bugs. 3. Where the hind and fore wings are strongly reduced or completely atrophied, as in the fleas {Siphonaptera) , bird-lice {Mallophaga) and sucking lice {Siphunculata) . Venation. — It has been found that the system of veins in the different orders of insects is fundamentally ahke, being de- rived from the primitive type fairly well seen in some stone- flies and some cockroaches. This fact becomes evident only when a comparison is made of the wings of the more general- ized members of the different orders, as specialization has greatly modified their structure in most genera. Comstock and Needham have shown by a study of the developing wings of nymphs and pup^ that the /^^- 20.— Several stages in the de- . . , , • T 1 • • velopment of the wmgs of a cabbage butter- prmcipal longitudmal vems m fly. {After Mercer.) the more generalized orders are formed about tracheae (Fig. 20). In the development of the wing these tracheae grow out into the wing-bud, and later the veins are formed about them. The cross veins, however, as a rule do not arise in this manner, as tracheae are apparently absent. In the course of development specialization has brought about changes in the venation, recognized, first, by the addition of veins through branching of the prin- i6 ECONOMIC ENTOMOLOGY cipal veins as in many Neuropteroids and Orthopteroids; second, by the addition of cross veins; and third, by the reduction of the number of veins ^ .§£L Sc2 Fig, 21. i^iA Cu2 3dA 2dA '^^^ -The hypothetical primitive type of wing venation. Needham.) (After Comstock and through coalescence of adjacent veins, or by the disappearance of veins, as in most moths, flies and hymenopters. The chief longitudinal veins are the costa (C), an unbranched vein on or near the front margin; the subcosta (Sc); the radius (R); the media (M); the cubitus (Cu); and the anal veins (A), typically three but often reduced to one or two. A knowledge of the different types of venation is very important in classifica- tion. The Comstock-Needham system of terminology is adopted in this Classbook, and students should consult the recent work of Professor Comstock — The Wings of Insects — for a full discussion of the general characteristics of the wings of the several orders of insects. Clothing of the Wings. — While the wings of many insects are naked, many are covered with fine setae, hairs, or scales. The coating of scales is the most distinc- tive feature of the wings of the Lepidop- tera. These scales are modified setae, being evaginations of greatly enlarged hypodermal cells. They are provided with ridges, these serving to increase their rigidity and their protec- FiG. 22. — Various forms of scales. A, E, Thysanuran (Machilis); B, beetle {Anthre- nus); C, butterfly {Pieris); D, moth {Limacodes). STRUCTURE, GROWTH AND ECONOMICS OF INSECTS 1 7 tive value (Fig. 22). In addition, the beautiful colors are due to the scales, and are produced (i) by the pigments present, (2) by the reflection, refraction or diffraction of light, or (3) by a combination of these causes. Scent glands, called androconia, are associated with the scales, mainly on the wings of males. (c) Abdomen. — The abdominal segments show a greater uniformity in form than do the thoracic segments, owing to the fact that the former are not specialized for the bearing of legs and wings. This uniformity is not merely external but extends to some of the internal organs, notably the muscular, respiratory and nervous systems. A greater differentiation and consequent difference from the other segments is usually found in the terminal segments which are modified to bear the genitalia and cerci, in the first segment in the Hymenoptera which has united closely with the thoracic mass, and in the petiole of the same insects which is greatly reduced in diameter and often nodulated (ants). Typically the abdomen consists of ten segments, but in some Orthoptera eleven have been found and twelve in a few embryos. In the adult insect it is often difficult to distinguish ten abdominal segments owing to the fusion or disappearance of certain of the segments, to the modification which the terminal segments undergo, or to the telescoping of these last within the other segments. Each segment is made up of a dorsal sclerite, the tergum, a ventral scleriie, the sternuniy and a pair of pleural membranes connecting the two. The first seven or eight abdominal segments usually bear a pair of spiracles each. Typically the anus opens in the tenth or last segment and the reproductive system between the eighth and ninth. Appendages of the Abdomen. — In the embryo the abdominal seg- ments bear paired appendages which are homodynamous with the legs and mouth-parts. These usually for the most part disappear on hatch- ing, but they persist as prolegs during the larval life of the Lepid- optera, Tenthredinidae and Mecoptera; in certain Thysanurans they persist as rudimentary abdominal appendages throughout the life of the insect. The cerci which are present in most of the more generalized orders and in the thysanuriform larvae are usually the appendages of the tenth abdominal segment. The gonapophyses or plates of the genitalia are the appendages of the seventh, eighth and ninth segments and are known respectively as i8 ECONOMIC ENTOMOLOGY the ventral, inner and dorsal plates. The inner pair usually forms the ovipositor or the intromittent organ, and the outer pairs may form a sheath or claspers. The Genitalia. — A knowledge of the genitalia is of importance to the taxonomist because in certain families the separation of species is based largely on these structures. It is also of importance to the economic entomologist because it enables him to understand the method of egg deposition in injurious and beneficial insects and the poisonous action in certain forms in which the ovipositor has been modified to form a sting. 9%a Fig. 23. — Abdomen of female house-fly, showing extended ovipositor, a., Anus; c, cercus; d.p., dorsal plates; v. p., ventral plate. There is no true ovipositor in the Neuropteroida, Coleoptera, Lepidoptera or Diptera, the vagina opening directly to the exterior (Fig. 2^. In some of these insects, however, a whip-like or tubular pseudo-ovipositor is formed by the last few segments of the abdomen (e.g.yCerambyx, Cecidomyia, Musca). A true ovipositor is developed in the Thysanura, Orthopteroida, Hemiptera and Hymenoptera (Fig. 24). In the Orthoptera the gona- pophyses are used for making holes in the ground or sHts in stems for the reception of the eggs. In the Hymenoptera there are various peculiar modifications of the ovipositor: Megarhyssa, one of the larger ichneumon flies, uses its long ovipositor as a drill, forcing it, in spite of its extreme slenderness, up to the hilt in the trunk of hardwood trees in order to deposit its eggs in the burrows of the horn-tail borer STRUCTURE, GROWTH AND ECONOMICS OF INSECTS 19 {Tremex columba); the saw flies have the inner plates united to form the egg channel, the upper plates form a sheath, while the lower have serrate edges and are wielded like a saw, making slits in leaf or stem for the deposition of the eggs. In the stinging hymenoptera the ovipositor is modified to form a sting; the upper valves of the honey bee are soft, forming a pair of palpi, the inner lobes form a sheath, and the ventral lobes are represented by a pair of barbed darts. The poison is of two kinds, one alkaline the other acid, and is secreted by glands within the abdomen. INTERNAL ANATOMY The internal anatomy of an insect may be discussed under the following heads: (a) muscular system; (b) respiratory system; (c) circulatory system; (d) intestinal or digestive system; (e) nervous system; (/) reproductive system (Fig. 25). (a) Muscular System. — The muscular system of insects is well developed. The muscles are attached to the inner surfaces of the exoskeleton. In the abdomen the arrangement of the muscles is the same in each segment, except at the extremity where special mus- cles exist for moving the ovipositor, the cerci or other terminal organs. In the sternum of each abdominal segment there are one or two sets of longitudinal muscles on each side of the nerve chain. These are the longitudinal sternals or ventral recti (Fig. 26). In the tergum also similar sets of muscles occur on each side of the dorsal vessel; these are the longitudinal tergals or dorsal recti. Between these longitudinal muscles and the integument are numerous f?&/i^we and trans- verse muscles, and these, with the longitudinal muscles, bring about the various turning, wriggling or telescoping movements of the abdomen. In each abdominal segment there are also two muscles which pass from the tergum to the sternum. These are the tergo-sternals which Fig. 24. — Sting and poison apparatus of honey bee. ag.. Accessory gland; p., palpus; pg., poison gland; r., reser- voir; s., sting. {After Krae- pelin.) 20 ECONOMIC ENTOMOLOGY bring about the contraction and expansion of the abdomen necessary for respiration. In the thorax of larval insects and of the wingless forms the arrange- ment of muscles follows the same general plan as in the abdomen, but the presence of the leg muscles makes it more complicated (Fig. 27). In the winged insects, however, this primitive arrangement cannot be readily recognized owing to the presence of large wing muscles and also to the fact that the thoracic segments are very often fused together. The muscles which move the head originate in the prothorax and are inserted into the base of the head. Within the head are muscles Fig. 25. — Internal organs of the cricket {Gryllus pennsylvanicus) . AN., Anten- nal nerve; Oes., oesophagus; Br., brain; T., teutorium; Ao., aorta; 5., suspensorium of ovary; H., heart; Ov., right ovary; Col., colon; JR., rectum; A., anus; MT., Mal- pighian tubules; Od., oviduct; Op., ovipositor; BC, bursa copulatrix (copulatory pouch); Vag., vagina; RS., receptaculum seminalis; Mes., mesenteron; VC, con- nectives of ventral nerve chain; VG., ganglia of ventral nerve chain; S.GL, salivary glands; Lb.N., labial nerve; SG., subcesophageal ganglion; Md.N., mandibular nerve; SD., salivary duct; HP., hypopharynx; P., pharynx; Mx.N., maxillary nerve; LN., labial nerve; ON., optic nerve; C, crop; P., proventriculus; GC., gastric caeca. for the control of the mouth-parts and antennas. In the mandibulate insects the muscles which move the mandibles occupy the greater part of the head cavity. Mention should also be made of the alary muscles of the heart, the circular and longitudinal muscles of the digestive canal, and the spiracular muscles which bring about the closure of the spiracles during respiration. A muscle consists of a bundle of long fibres, each with several nuclei and a sheath, the sarcolemma. In most cases the fibres present a striated appearance due to the presence of alternate light and dark bands. STRUCTURE, GROWTH AND ECONOMICS OF INSECTS 21 hcrmin. Fig. 26.-^ Ventral surface- of larva of Sphida obliqua, showing arrangement of parts. AN., Antennal nerve; CL., clypeo-labral nerve; Al.c, alimentary canal; LG., lateral ganglion; tr., tracheal trunk; tr.lat., tergo-sternal muscles; v.r.maj., v.r.min., ventral longitudinal muscles; S.lig., suspensorium of testes; Test., testis; V.d., vas deferens; Sp., spiracle; T., thoracic ganglia; /, //, [II. etc. abdominal ganglia; o,l., op^Ung 'nto leg;Jr.y,, transverse nerve; BB., brain. 2 2 ECONOMIC ENTOMOLOGY (b) Respiratory System. — The exchange of gases in respiration is effected by means of a system of small tubes called trachecB which extend inward from the surface and branch to all parts of the body. The external openings, called spiracles, are situated on the sides of the thoracic and abdominal segments (Fig. 28). From each spiracle a short tube runs inward and connects with the trunk tube running along the side of the body. There are thus two main or trunk tracheal tubes, one on each side of the body. Each gives off three large branches to each segment, the upper, the middle, and the lower. Each of these Ext. Tib. FITib. TlTlhFl.Tars Ext. Tanii FI.C. Fig. 27. — Muscles of hind leg of Gryllus pennsylvanicus. Ext.F., Extensor of femur; Ext. Tib., extensor of tibia; Ext.Tar.i, extensor of first tarsal joint; Ext. Tar. 2, extensor of second tarsal joint; Ext.Tar.3, extensor of third tarsal joint; Fl.Tm.i, flexor of first tarsal joint; Fl.Tar.2, flexor of third tarsal joint; FI.C, flexor of claws; Ext.C, extensor of claws; Fl.F., flexor of femur; Fl.Tib., flexor of tibia. branches subdivides frequently so that every portion of the segment is entered. Moreover, these fine tubes anastomose to form a deli- cate network, and allow a continuous circulation of air to take place. In many insects, in addition, are large sac-like dilatations of the tracheas which serve as air reservoirs. Tracheae have a striated appearance due to the thickening of the chitinous wall into a compact elastic spiral, thus preventing the collapse of the tubes. Special respiratory devices are seen in aquatic insects. Nymphs of May-flies and Damsel-flies have lamellate tracheal-gills, STRUCTURE, GROWTH AND ECONOMICS OF INSECTS 23 nymphs of Stone-flies and Caddice- flies have filiform or cylindric tra- cheal-gills, larvae of Culex, Corethra, Simulium and Chironomus have blood- gills, while nymphs of Dragon Flies have inlernal tracheal-gills. Tracheal gills are outgrowths of the body wall with fine tracheal tubes, in which there occurs during res- piration an exchange of gases be- tween the air in the tubes and the water. They are usually external but in the nymphs of Dragon Fhes they are internal, being arranged in rows on the inner walls of a gill chamber in the posterior portion of the ahmentary canal. Blood-gills are outgrowths of the body wall in which the blood flows. The exchange of gases in respira- tion occurs between the blood in- side and the water outside. Structurally a trachea consists of a chitinous wall or intima as a lining membrane spirally thickened at regular intervals by elastic threads called tcenidia, and a cellu- lar wall of hypodermal cells, the pavement epithelium. {c) Circulatory System. — While there is a blood circulation in insects the only blood vessel is a dorsal tube lying just beneath the notum. The heart or posterior portion of Fig. 28. — Respiratory system of the , , , . , . 1 larva of the budmoth {Tmetocera ocel- the dorsal tube COntams a number ^^^^^ (insect opened along the median of ventricles or chambers, each with dorsal line.) C, tracheal commissure; - - , !_• I, n 4^U D., dorsal branch; H., supplying heart; a lateral valve which allows tne y., ventral branch; F^.. visceral branch. blood to flow in but not out. There 24 ECONOMIC ENTOMOLOGY are also valves between the chambers so that when the latter con- tract the blood is forced forward. The blood on leaving the ventri- cles passes into the aortic portion of the dorsal tube, toward the head, and thence flows into the body cavity bathing all the organs. The blood is usually colorless and consists of two portions— the watery serum and the white blood corpuscles. Fat-hodies.—ThQst are masses of fat-cells occupying a large part of the cavity of the body, and lying between the organs. At first the fat- cells are large and spherical, but they lose their structure to a large extent through breaking down. They contain nourishing albuminoid matter, besides uric acid and urates. Their exact function is not . m Pig. 28a. — Apparatus for closing the spiracular tracheae in a beetle (Lucanus). A, Trachea opened; B. closed; &., bow; bd., band; c. external cuticula; /., lever; m., muscle; s., spiracle; t., trachea. {After Judeich and Nitsche.) definitely known. Associated with the fat-bodies in the abdomen of larvce are large yellow cells called cenocytes which, according to Glaser, secrete an oxidizing enzyme. {d) Intestinal or Digestive System. — This system occupies the central portion of the body, and is divided into distinct regions with special functions (Fig. 29). The food passes from the mouth into the pharynx where it is subjected to the action of saliva secreted by the salivary glands. Thence it passes in the Orthoptera and Coleoptera through the oesophagus into the crop, a folded and membranous pouch, where the action of the saHva is completed. The partially digested food then passes into the gizzard or proventriculus, a muscular enlargement armed with teeth for the purpose of straining the contents before entering the true stomach or ventriculus. In many caterpillars the food passes STRUCTURE, GROWTH AND ECONOMICS OF INSECTS 25 Fig. 29. — Digestive canal of Gryllus pennsylvanicus. sd.. Salivary duct; Oes., oesophagus; Sg., salivary gland; C, crop; pv., pv.", proventriculus; gc, gastric caeca; m., mesenteron; Mv., valve between two divisions of the mesenteron; gl., digestive glands; il., ilium; u.d., duct of malpighian tubules; ut., malpighian tubules; Col., colon; rt., rectum; An., anus. 26 ECONOMIC ENTOMOLOGY Fig. 30. — Dorsal view of ali- mentary canal of the larva of the budmoth (Tmetocera ocellana). Ph., Pharynx; Oes., oesophagus; SM., suspensory muscles; Tr., vis- ceral tracheae of left side; MT., Malpighian tubules; Mes., mesen- teron; Int., small intestine; In., intestinal nerve; R., rectum. directly into the stomach which is long. Further digestion occurs here through the action of secretions of the coecal tubes, often called the gastric coeca, which con- sist of glandular pouches emptying into the anterior end of the stomach. Most of the digested food is here absorbed and passes into the circulation. Pos- terior to the stomach is the intestine which consists of three parts — iletim, colon, and rectum. Into the ileum open the Malpighian tubes which are excretory in function, similar to the kidneys of higher animals. The undigested portions of food are expelled through the rectum and anus. Some variations may be noted. The oesophagus is long in those insects that suck their food, and short in herbivo- rous forms. In sucking insects the giz- zard may be absent, and the crop is often a side pocket of the oesophagus (Fig. 30). Structurally, the wall of the alimen- tary canal consists of: 1. An epithelial layer of cells which secrete the intima or lining layer. 2. The delicate basement membrane. 3. Circular muscles. 4. Longitudinal muscles, which aid in constricting and enlarging the canal (Fig. 31)- From an embryological pomt of view the ahmentary tract consists of three primary regions: 1. The Stomodceum, embracing the fore part as far as the stomach. 2. The Mesenteron, or mid-intestine embracing the stomach, and STRUCTURE, GROWTH AND ECONOMICS OF INSECTS 27 m.d Fig. 31. — Sections through the proventriculus of Gryllus pennsylvanicus. (All greatly enlarged.) i. Longitudinal section through the median denticles. 2. Transverse section passing through two folds of the anterior division of the proven- triculus. 3. Surface view of a portion of one of the dental folds showing the chi- tinous partition and four of the transverse rows of teeth. 4. Transverse section of proventriculus passing through the median denticles. 5. Transverse section of fold cut in the region of the lateral denticles. 6. Lateral view of two adjacent inner barbated lobes, br.. Bristles of anterior division of proventriculus; ch.p., chitinous partition between dental folds; cm., circular compressing muscles; c.v., cardiac valve; ep., epithelium; i.bl., inner barbated lobes; in., intima; l.d., lateral denticle; l.t., lateral tooth; m.d., median denticles; ni.t., median tooth; o.b.l., outer barbated lobes; r.m., relaxing muscle. 28 ECONOMIC ENTOMOLOGY 3. The Proctodoeiim, embracing the portion posterior to the stomach. The stomodoeum and proctodoeum are ectodermal in origin while the mesenteron is probably entodermal. {e) Nervous System. — The nervous system of insects consists essentially of a series of ganglia joined by a double nerve-cord lying along the ventral surface of the body. Each primitive segment had a double ganglion, but in most insects fusion of ganglia occurs in the head, the thorax, the anterior and the posterior portions of the abdomen. Great variations occur even in the same order. The largest ganglion is in the head, and is the result of the fusion of three pairs. It forms the hrain or supra-ossophageal ganglion, lying above the oesophagus. There is also another large ganglion, the suh-oesophageal, lying below the oesophagus, and connected with the brain by a double nerve-cord about the oesophagus, the oesophageal nerve collar or commissure. It also repre- sents the fusion of three pairs of ganglia. From the brain nerves are given off to the antennae, eyes, and labrum. The sub- oesophageal ganglion controls the mouth-parts. From the ganglia in the thorax and abdomen nerves supply the various segments and control their movements and activities (Fig. 26). In addition there is the Sympathetic nerve system which mainly lies along the dorsal line of the alimentary canal. It consists of a recurrent nerve arising from 2i frontal ganglion and ending in a stomachic ganglion. Two pairs of lateral ganglia are connected with the recurrent nerve and supply nerves to the dorsal vessel and the tracheae of the head. A ventral system lies in the main nerve cord and activates the spiracles. Nerve-cord and Ganglia. — The nerve-cord consists of an axis-cylinder of fibrillae and a sheath. It is concerned with the transmission of impulses and stimuli. The ganglion is a centre for the regulation of nutrition. It consists of a dense cortical layer of ganglionic cells with large nuclei, a clear medulla from which nerve fibrillae originate, and a nerve sheath. (/) Reproductive System. — In all insects the sexes are distinct. The sexual organs are situated in the abdomen and consist in the female of a pair of ovaries and a pair of oviducts opening into the vagina and frequently externally by an ovipositor, and in the male of a pair of testes and a pair of seminal ducts {vasa deferentia) opening into the ejaculatory duct and externally by an intromittent organ. The external opening lies between the eighth and ninth segments of the ab- STRUCTURE, GROWTH AND ECONOMICS OF INSECTS 29 domen — never in the last. In most insects there is in the female a seminal receptacle, a dorsal pouch of the vagina, and in the male a seminal vesicle, a dilated portion of the vas deferens. The ova are formed in the ovarian tubes in different stages of growth, the largest and oldest being nearest the oviduct. The spermatozoa arise in the -susp. Fig. 32. Fig. 33. Pig. 32. — Male reproductive organs of Gryllus pennsylvaniciis. T., Testis; Susp., suspensorium of testis; vd., vas deferens; uhr., u.maj., accessory glands on surface of seminal vesicle; ed., ejaculatory duct; sp.c, spermatophore cup; int., intromittent organ or penis. Fig. 33. — Female reproductive organs of Gryllus pennsylvanicus. Susp., Sus- pensorium of ovaries; O., ovaries; ov., ovarian eggs; od., oviduct; C, cercus; r.s., seminal receptacle; d., duct of seminal receptacle; vag., vagina; be, copulatory pouch; Ovp., ovipositor. follicles of the testes. There are also usually accessory glands which secrete mucus that envelopes the spermatozoa and ova (Figs. 32 and 33)- Parthenogenesis, or reproduction without fertiHzation, occurs in many insects — in aphids, Cynips, Lasius (Ant), and some Coccids. 30 ECONOMIC ENTOMOLOGY Several generations of females only which bring forth living young may occur, but at intervals males appear and fertilized eggs are laid. In some species of the Cecidomyiidae the young are produced by larvae. Such a method is called pcedogenesis. After several genera- tions, however, the last larvas pupate and form normal male and female flies. Examples are Tanytarsus dissimilis and Miastor americana (Fig. 2,7,a), Another method of asexual reproduction, called polyembryony occurs in certain parasitic insects, e.g., Polygnotus, belonging to the Hymenoptera. Each egg produces many embryos, instead of one, which develop into as many adult insects of the same sex. Pig. 33a. — Young paedogenetic larvae of Miastor in the body of the mother larva. Greatly enlarged. (After Pagenstecher from Folsom.) The Development of Insects All insects that reach maturity pass through two distinct stages of development — the embryonic changes within the egg, and the changes after leaving the egg until the adult condition is reached. The growth of the embryo within the egg progresses from the seg- mentation of the ovum to the formation of the blastoderm with its ventral plate and germinal groove, and the gradual growth of the ectoderm, mesoderm and entoderm, from which layers the various organs of the body arise. {a) Embryology. — The egg or ovum is a single cell containing — (i) The nucleus or germinal vesicle. (2) The yolk, or nutritive material. (3) The cytoplasm. (4) The cell wall or vitelline membrane. (5) The egg shell or chorion. (6) The micropyle or opening in the chorion to admit the spermatoza (Fig. 34). When the sperm nucleus unites with the nucleus of the egg, and forms a segmentation nucleus, fertilization is accomplished. By division of the segmentation nucleus a large number of nuclei are formed many migrating outward toward the margin of the egg. There a layer of cells internal to the yolk membrane called the blasto- STRUCTURE, GROWTH AND ECONOMICS OF INSECTS 31 derm is finally produced. This stage of the embryo is known as the blastula. ^-Ase. Pig. 34. — Formation of the blastoderm and the germ band. Fk., Cleavage nuclei; BL, blastoderm; Kst., germ band. {After Escherich.) '\ The blastoderm thickens by cell division in one region forming the primitive streak or germ hand which presents in surface view an oval or elongated area along the ventral face of the egg. Soon a groove Fig. 35. — Diagrammatic sagittal sections to illustrate invagination of germ band in Calopteryx. a., Anterior pole; ac , amnion cavity; am., amnion; h., blastoderm; d., dorsal; g., germ band; h., head end of germ band; p., posterior pole; s., serosa; v., ventral; y., yolk. (Folsom after Brandt.) appears in the centre of the germ band due to invagination of the blastoderm. The lips of the groove close over the invaginated portion, producing an outer layer, the ectoderm or ectoblast and the inner layer, 3^ ECONOMIC ENTOMOLOGY the endoblast {meso-entoderm) . This stage of the embryo is known as the gastrula. Meanwhile the blastoderm is folding over the germ band from either side, producing an inner membrane — the amnion, and an outer membrane — the serosa (Fig. 35). Two types of germ bands may be noted. The overgrown type retains its original position (Fig. 36), and the blastoderm folds over the germ band from either side forming the two layers amnion and serosa. In the invaginated type, seen in aphids and Odonata (Fig. 37), the germ band invaginates into the egg so that its ventral surface faces the dorsal surface of the egg. At a later stage the embryo turns and regains its original position. The germ band shows early signs of segmentation, beginning first at the anterior end. An in- vagination of the ectoderm near the anterior end forms the stomo- dceum or fore gut, and a similar posterior invagination forms the proctodoeum or hind gut. The segmentation shows about 21 seg- ments, 6-7 to the head, 3 to the thorax, and 11-12 to the abdo- men. On each segment except the first and last a pair of tiny limbs (buds) are seen. Soon the germ band widens and closes over the yolk to form the dorsal wall. Before dorsal closure occurs the beginnings of the nerve-cord form in the median groove. This primitive nerve-cord is double, and a pair of swellings in each segment develop into the ganglia of the ventral system. The tracheae arise as invaginations of the ectoderm. The entoderm arises from the endoblast, the inner embryonic layer, as two cell masses situated at either end of the embryo. These masses grow backward and forward respectively, and unite to form the mid- gut {mesenteron). The rest of the inner layer forms the mesoderm from which arises Fig. 36.- membranes nion; Ect., Ser., serosa. —Formation of the embryonic —overgrown type. Am., am- ectoderm; Ent., entoderm; {After Korschelt and H eider.) STRUCTURE, GROWTH AND ECONOMICS OF INSECTS 33 the blood system, muscles, reproductive organs, fat-body, etc. The division of the mesoderm into two layers produces paired cavities in each segment — the coelomic pouches (Fig. 37). {b) Metamorphosis. — The various changes that occur after the hatching of the egg are comprised under the term metamorphosis. After the escape of the embryo from the egg the development may be (i) holo- metabolic, i.e., with complete metamorpho- sis, the insect passing through two distinct phases, larva and pupa, before assuming the adult form; (2) heterometabolic, i.e., with incomplete metamorphosis, without a dis- tinct pupal stage, the larva being like the adult but without wings or mature repro- ductive organs; (3) ametabolic, i.e., without metamorphosis, the young being like the adult. Insects belonging to the orders Neuroptera, Mecoptera, Trichoptera, Lepidoptera, Coleoptera, Diptera, Sipho- naptera, and Hymenoptera are holome- tabolic; the Orthoptera, Platyptera, Pie- coptera, Odonata, Ephemerida, Thysan- optera, Homoptera and Hemiptera are heterometabolic; and the Thysanurans and Collembolans are ametabolic. Most insects are oviparous, but some like cer- tain scale insects and Sarcophagid^e are larviparous. Larval Stage. — In general two types of larvae are recognized: the thysanuriform and the eruciform. The former type is considered quite generalized and primitive in form, and is common among the hetero- metabola. The body is flattened, the legs and antennae are long, the caudal cerci are well-developed, and the mouth-parts are mandibulate. Pig. 37. — Embryo of ^Ecan- thus, ventral aspect, a. An- tenna; a.^-a.^, abdominal ap- pendages; e., end of abdomen; I., labrum; li., left fundament of labium; Ip., labial palpus; l.^-l.^, thoraciclegs; w., mandi- ble; mp., maxillary palpus; mx., maxilla; p., procephalic lobe; pr., proctodoeum. (From Fol- som after Ayers.) 34 ECONOMIC ENTOMOLOGY The eruciform type prevails among the holometabola. The body is cylindrical, and the legs, antennae and cerci are much reduced. Many transitional forms, however, occur, and it is believed that the eruciform type has been developed from the thysanuriform. Ecdysis or Moulting. — All larvae shed their outer skin (cuticula), at intervals to allow for growth. The number of moults varies in different insects, but is constant for the same species under the same conditions. In the Lepidoptera the larva is known as a caterpillar, and is char- acterized by the possession of three pairs of true legs, and usually Pig. 38. — Types of larvae, a. Grub of asparagus beetle; b, cutworm; c, cabbage root maggot; d, fall canker worm-; e, maggot of honey bee; /, spring canker worm; g, false caterpillar of saw fly; h — a, b, c, nymphs of locust; i — o, b, c, d, e, nymphs of squash bug. {After various authors.) five pairs of prolegs on the abdominal segments. In the Diptera and Hymenoptera the larva is a maggot, characterized by the absence of legs. In the group of Saw-flies of the Hymenoptera, however, the larvae are caterpillar-like, possessing three pairs of true legs and often seven or more pairs of prolegs. In the Coleoptera the larva is termed a grub, and has usually but three pairs of legs (Fig. 38). Classification of Larvae.— Escherich classifies larvae as follows: Primary Larvce. — Larvae like the adult, and without provisional larval organs — Thysanura, Mallophaga, Pedicidida, Orthoptera, Isoptera, Corrodentia. STRUCTURE, GROWTH AND ECONOMICS OF INSECTS 35 Secondary LarvcB. — ^Larvae like the adult, and with a few provisional larval organs — Ephemerida, Plecoptera, Cicadidce, Odonata, Coccida. Tertiary Larva. — ^Larvae unlike the adult and with numerous provisional larval organs — Lepidoptera, Diptera, Coleoptera, Hymenoptera, etc. Classification of Tertiary LarvcB. A. Larvae without prolegs. B. Larvae with well-formed sternum. C. Larvae more or less strongly chitinized; thorax or at least the prothorax dijffering from the other segments quite noticeably, large or more strongly chitinized, or otherwise sculptured; head generally with lateral eye points. Examples: Rhaphidians Ant-lions, Carahidce, Dytiscidcs, Silphidce, Coccinellidce, Elateridce, ChrysomelidcB. CC. Larvae weakly chitinized, soft skinned, and mostly whitish, but with chitinized dark head; thorax dififering but little from the other segments. Examples: White Grubs, Stag Beetles, Dung Beetles. BB. Larvae with poorly developed or rudimentary sternum. Examples: Many Cerambycids, Sirex. BBB. Larvae with sternum wholly atrophied or undeveloped. C. Larvae with a head-capsule and typically formed mouth-parts. Examples: Bark Beetles, Snout Beetles, Bees, Wasps, Ants, Ichneumons, Midges. CC. Larvae without a head-capsule or well-formed mouth-parts. Examples: Most Diptera. AA. Larvae with prolegs. B. Larvae usually with five pairs of prolegs. Butterflies and Moths. BB. Larvae with more than five pairs of prolegs. Saw flies. Provisional Larval Organs. — Provisional larval organs are those which belong to the larva and not to the imago. According to Escher- ich such organs represent adaptations for special functions, so that the more numerous these organs are the greater the difference in mode of life and in appearance between the larva and imago. As the imago is older phylogenetically than the larva the larval organs have arisen in a secondary manner. ''Secondary" larvae possess numerous imaginal characters, so that the form of the imago remains more or less evident. In "tertiary" larval forms the characters of the imago are so repressed by those of the larva that a new form unlike the imago results. Larval organization distinct from that of the imago may be observed: (i) in the amount of chitinization, the color and the armature of hairs, bristles, spines of the skin; (2) in the number of glands; (3) in the form 36 ECONOMIC ENTOMOLOGY and segmentation of the body; (4) in the development of feelers and mouth-parts, (5) in the number and development of organs of locomotion and (6) in the alimentary, tracheal and nervous systems. Examples can be readily found to illustrate the differences outlined above. Pupal Stage. — After a short period of rest the full-grown larva of holometabolic forms changes to a pupa within a pupal skin. Usually the outer skin is shed, but sometimes, as in the Diptera, the outer skin becomes a puparium. During the pupal stage not only are all the Fig. 39. — Types of pupae, i, Asparagus beetle (free); 2, puparium of cabbage root maggot (coarctate); 3, bud moth (obtect); 4, tobacco sphinx (obtect); 5, male of maple scale (free). external organs of the adult insect formed, but even the internal organs undergo profound changes. The organs break down and reform, and the structures are adapted to the new creature with its new mode of life. In most insects the pupa is quiescent but it is quite active in the CuUcidae and other families. There is but little difference, except the presence of rudimentary wings, between the larval and pupal stages of the insects belonging to the Hemiptera and the Orthoptera. Three types of pupae are recognized (Fig. 39): (i) obtect, where the appendages and body are closely united, as in Lepidoptera and some Coleoptera; (2) free, where the appendages are free, as in Neuroptera, STRUCTURE, GROWTH AND ECONOMICS OE INSECTS 37 Trichoptera, Coleoptera, Hymenoptera and Nematoceran Dipera; and (3) coarctate in which the entire pupa is surrounded with a hardened skin, and the appendages are not outwardly visible, e.g., higher Diptera (Muscids, etc). Pupae are protected in different ways: (i) in puparia, (2) in earthen cells in the ground, (3) in a rude cocoon in wood or earth, (4) in silken cocoons, (5) in folded leaves, (6) as chrysaHds. Examples of the above types are everywhere about us. Internal Changes. — In the heterometabola the internal changes are as direct as the external changes. In the holometabola, however, some Pig. 40. — Stages in the hypermetamorphosis of Epicauta. A, Triungulin; B, carabidoid stage of second larva; C, ultimate stage Jof second larva; D, coarctate larva; E, pupa; F, imago. E is species cinerea; the others are vittata. All enlarged except F. (After Riley, from Trans. St. Louis Acad. Science.) of the larval organs are reconstructed into imaginal or adult tissues. The imaginal organs arise from embryonal tissues (the imaginal buds) which for the most part remain practically dormant in the larval stage; in the pupal stage the purely larval organs disappear and the imaginal organs continue their development. Histolysis is the term used to ex- press the destruction of larval tissue by leucocytes, and histogenesis for the construction of imaginal tissues. Imaginal Buds. — The reproductive organs, the dorsal vessel, and the nervous system gradually mature, but many of the organs develop 38 ECONOMIC ENTOMOLOGY from "buds" in the larva. In the caterpillar, for example, from the inner skin or hypodermis arise buds which develop into the wings and legs of the butterfly. In a midge or fly the head with the eyes, feelers, and jaws, are developed by an inpushing of the skin. The food- canal, glands, and air-tubes of a moth or a bee arise from imaginal buds. Imago or Adult Stage. — The pupa transforms into the imago or adult insect. On the splitting of the pupal case the full-grown perfect insect emerges. (c) Hypermetamorphosis. — With some insects more than two intermediate stages may be noted in metamorphosis. In Meloe the young larva {triungulin) is thysanurif orm ; later it resembles a lamel- licorn larva, being cylindrical, fleshy, and less active (the scarahceidoid stage), then a pseudo-pupa (the coarctate stage), and later a legless cruciform larva. In Epicauta also triungulate, carabidoid, scara- hceidoid and coarctate or pseudo-pupa stages occur (Fig. 40). In Flatygasier, a proctotrypid, the following supplementary larval stages are observed: (i) the cyclops, (2) the oval, and (3) the elliptical. Losses Due to Insects While everyone will acknowledge the fact that damage is done by insects, the enormity of the losses is not generally recognized. How- ever, fairly reliable data covering such losses for several decades in the United States are available in State and Federal records. Every person admits large losses due to such pests as Potato Beetle, Codling Moth, San Jose Scale, Tent-caterpillar, Cattle Horn Fly, and Grasshoppers, but later pages will show many other injurious forms that remain practically unobserved by the average person, on account of their small size, or their underground or boring habits. The damage they do is often attributed to other causes, and frequently reports are unreliable, unless corroborated by competent observers. The following estimate is based on statistics prepared by experts and pubUshed in the Year Book, U. S. Department of Agriculture. The loss on farm products, such as cereals, hay and forage, cotton, to- bacco, truck crops, sugars, fruits, farm forests, miscellaneous crops and animal products, valued at 8370 millions of dollars in 1909, is greater than to per cent, for there is a loss of 972 millions, not includ- STRUCTURE, GROWTH AND ECONOMICS OF INSECTS 39 ing those in connection with natural forests and forest products, and products in storage, which would make a probable total loss of over one billion dollars. The losses are estimated at $1,182,000,000 for 1915, and $1,400,000,000 for 1917 (J. Ec. Ent., Feb., 1918). Estimates of the losses inflicted by insect pests on the farm products of Canada are mainly based on similar ones for the United States. At the present time it is difficult to form a reliable estimate of average annual losses due to insects from Canadian records. In some of the older provinces fairly complete records covering a series of years are available, but in the newer provinces the records are incomplete. Estimates have been made of the losses from some of the more serious pests that occasionally cause great damage, such as the Hessian Fly and the Pea Weevil. In Ontario the loss from the Hessian Fly in each of the years 1900 and 1901 was about two and one-half miUion dollars, and from the Pea Weevil in 1902 over two millions. If, however, the percentage loss in the United States, viz., 10 per cent, be taken as a fair basis for insect loss in Canada it can be readily reckoned that the total loss every year in that country exceeds 100 millions of dollars. Beneficial Insects While the damage done by insects is enormous it must not be sup- posed that all insects are injurious. As a matter of fact there are more insects that are either beneficial or non-injurious than there are in- jurious forms. Man owes much to the beneficial insects for their good service in keeping the injurious forms in check. The fact that most plants with colored flowers are largely dependent upon the visits of insects for their fertilization and the setting of their fruit should make it quite evident that insects play a most important part in the economy of nature, and are no mean things after all. Let one reflect for a moment on the loss to the world if the blossoms of apple, plum, peach, grape, strawberry and raspberry among fruits were not fertihzed by bees and wasps; if the clovers were not visited by bees, and if the hundreds of beautiful wild flowers of the fields and meadows were allowed to die without setting seeds. In addition, one should not forget the part played by scavenger and carrion insects that feed upon dead and decaying organic matter. They help to make our surroundings purer and cleaner. Besides, 40 ECONOMIC ENTOMOLOGY "insects constitute the most important portion of the food of adult fresh water fishes, furnishing 40 per cent, of their food," according to Dr. Forbes, of lUinois. They also furnish food for most of our birds, and this food may consist of many noxious forms. There are also many insects that are decidedly beneficial, inas- much as they prey upon injurious forms or are parasitic upon them. At the present time a great experiment is being conducted in Massa- chusetts for the suppression of the gypsy and brown-tail moths by the importation of certain parasitic insects from Europe and Japan (see Part IV). From an economic point of view it is important for us to know the beneficial forms so that we may not unwittingly destroy them. Few persons, perhaps, fully recognize the valuable work done by the modest lady-bird beetles in keeping plant-lice within bounds. Without their intervention it is quite probable that most plants would die from the attacks of the fast reproducing plant-lice. Ground-beetles are also important agents in the destruction of injurious larvae, and their value can hardly be estimated. Beneficial insects may, therefore, be classified into : {a) Those that prey, or are parasitic, upon injurious forms {en- tomophagous) such as lady-bird beetles, ground beetles, parasitic diptera and hymenoptera, etc. {h) Those that pollinate plants, such as bees, wasps, moths, etc. {c) Those that play the part of scavengers, feeding upon dead or decaying organic matter, such as carrion beetles, etc. {d) Those that serve as food for fresh-water fishes, birds, etc. {e) Those that secrete or elaborate substances of commercial value to man, such as honey-bee, lac insect, cochineal insect, silk- worm, etc. Berlese divides entomophagous insects into predatory and endopha- gous. Predatory insects are those which devour other insects and their eggs outside the maternal body; while endophagous insects are those which enter the body or eggs of their victim and destroy them. Some entomophagous insects feed exclusively on one species, while others feed on several species {polyphagous) . From the standpoint of efficiency in the destruction of injurious species Berlese arranges them in the following order: I. Those preying on a single species and having few enemies and adverse factors, e.g., Novius cardinalis, Prospaltella berlesei, etc. STRUCTURE, GROWTH AND ECONOMICS OF INSECTS 4I 2. Polyphagous endophagous species which are themselves sub- ject to severe competition and meet with many adverse factors, e.g., Scutellista cyanea, etc. 3. Predators with special victims, e.g., many lady-birds. 4. Polyphagous predatory species; Calosoma, Entomophagous insects include members of the Coleoptera, Hymen- optera, Diptera, Hemiptera and Neuroptera. The coleopterous mem- bers are the lady-bird beetles, murky ground-beetles, and tiger-beetles. The lady-birds are small, convex, nearly hemispherical beetles, generally red or yellow and spotted. Their antennae or feelers are club-shaped, and their tarsi are apparently three-jointed. They feed upon small insects and the eggs of larger species, and are specially valuable for keeping plant-lice in check. The larvae of lady-birds are quite active and hunt for their prey. Some bear spines, while others are protected by fine white down. Ground-beetles (Carabidce) are active forms that live on the surface of the ground. They are usually black, but some have bright colors. They hide under stones or boards in the day-time but leave their shelters at night. They destroy large numbers of caterpillars, such as cutworms, canker-worms, tent-caterpillars, and the grubs of curculio. The larvae feed underground on the larvae of leaf-feeding insects. The ground-beetles have thread-like antennae, five-jointed tarsi, and legs fitted for running. Tiger-beetles {Cicindelidce) are carnivorous insects, and are most active in the day time. Their activity, markings, and stealthy habits have given them their common name. In structure they are closely related to the ground-beetles, and like them have thread-like antennae and five- jointed tarsi. • The larvae of these beetles live in holes in the ground and prey upon unwary insects. They have large heads, immense jaws, long sprawling legs, and two prominent humps on the back. The Hymenoptera possess several very important beneficial forms, mostly parasites: Ichneumon-flies {I chneumonidce) vary greatly in size, and the females of some species possess a protruding ovipositor. A common ex- ample is Megarhyssa (Thalessa) a very long tailed ichneumon, which bores a hole in wood infested with pigeon Tremex borers and deposits an egg beside the larval Tremex (Fig. 41); other common ichneumons are: 42 ECONOMIC ENTOMOLOGY Tragus, which parasitizes the chrysalids of Papilio; and Ophion, a form with a compressed body, which lives on the Polyphemus moth and yellow-necked caterpillar. The Braconids {Braconidce) are smaller and are also parasitic. The most common genera are Microgaster, whose cocoons are often found on the backs of sphinx and cabbage butterfly larvae; and Aphidius which parasitizes plant-lice. Chalcids or chalcis flies (Chalcididce) are minute metallic insects. One species, Pteromalus puparum, is a parasite of the chrysalids of the Fig. 41. — Female of Megarhyssa (Thalessa) ovipositing. cabbage butterfly. Another, Aphelinus, is parasitic on scale insects (see also p. 354). Proctotrypids are very minute parasitic hymenoptera often prey- ing upon the eggs of other insects. Besides these parasitic forms there are predaceous Hymenoptera, such as the mud-wasps, digger-wasps, wood-wasps, etc., that feed their larvae on insects. They fill the brood cells with caterpillars, grass- hoppers, plant-lice, or grubs of small beetles or flies. Sphecius makes use of cicadas as food for its young. Several families of the Diptera are either parasitic or predaceous. The two best known are the Tachinids and the Syrphids. Tachinids or tachina flies (Tachinidce) are bristly flies closely related to the ordinary house-flies. They parasitize many kinds of caterpillars STRUCTURE, GROWTH AND ECONOMICS OF INSECTS 43 and sawfly larvae, either by inserting eggs within the bodies of their victims or by allowing the victims to swallow the eggs that are deposited on leaves. Syrphids or flower flies {Syrphidce) lay their eggs in colonies of plant- lice which are devoured by the larvae. They are large, often bee-like in form. The Hemiptera include a few beneficial forms, mostly belonging to the assassin-bug family {Reduviidce). They are predaceous, suck- ing the blood of other insects. Sometimes higher animals, including man, are attacked. The following forms may be noted: Melanolestes picipes is a large black form, and Opsicoetus personatus, or masked bed-bug hunter, is black and over J^ inch long. The Stink Bug Family {Pentatomidce) also furnishes a few beneficial species, although a very large percentage of the species is injurious to plant life. Two common forms are: Podisiis spinosus (spined tree bug) destroys potato beetles and currant worms, and Perillus circum- cinctiis which appeared recently in large numbers in potato fields where it de- stroyed potato beetles (Fig. 42). The Damsel Bugs {Nabidce) prey upon leaf-hoppers. The Ambush Bugs (Phymatidce) are also predaceous, destroying large numbers of injurious insects. Among the Neuroptera are some important beneficial forms, known as aphis-lions and ant-lions. The adults of aphis-lions, also called lace-winged flies, are readily recognized by their delicate veined green wings. Their larvae are pre- daceous and destroy large numbers of plant-lice. Their mandibles are very long. The genus Chrysopa is the main one in the family. The adults of Ant-lions (Myrmeleonidce) have "long narrow delicate wings and a slender body." The larvae are very predaceous and possess enormous mandibles. They capture their prey by using pitfalls. Hyper parasitism. — It happens that many of the primary parasites are often infested with parasites which reduce very appreciably the Fig. 42. — Perillus circunt- cinctus, an enemy of the Colo- rado potato beetle. 44 ECONOMIC ENTOMOLOGY effectiveness of the primary. Frequently, however, these secondary forms are infested with tertiary parasites. In the control of injurious forms it is evident that primary parasites are beneficial, secondary harmful and tertiary beneficial, on the other hand, when beneficial insects are parasitized the primary are harmful, the secondary beneficial and the tertiary harmful. Insects and Birds When it is known that about two-thirds of the food of our common birds consists of insects, it becomes evident that the agency of birds in the control of insects is of the highest importance. The seasonal diet of the robin, bluebird, catbird, king-bird, flycatchers, chickadee, wren, swallow, woodpecker, cuckoo, night-hawk, warblers, oriole and many other birds has been carefully studied in recent years, with the resulting discovery that insects form in most cases their only food, and only at certain seasons are small fruits eaten. Birds are no doubt of special value to the farmer in nipping incipi- ent scourges in the bud on account of their ability to move rapidly from place to place in search of food, and on account of their varied character and habits. Especially is this true of our winter birds which search every cranny and nook for the hibernating forms of insects at a season when every form destroyed means in most cases the absence of hundreds or thousands of their progeny the following summer. An international treaty between Great Britain and the United States for the protection of migratory birds in the United States and Canada was signed in Washington in August, 1916. For many years the numbers of such birds had been decreasing to such an extent, through careless and indiscriminate slaughter, that the agricultural and forest crops of the two countries were in danger of suffering serious losses from insect depredations. It was deemed advisable, therefore, in the interests of the two countries to adopt a uniform system of bird protection, such as the treaty provides. The most important provision relates to close seasons, viz: (i) a close season on migratory game birds from March loth to September ist except for maritime shore birds when the close season is from February ist to August 15th; (2) an open season for three and one-half months for wild fowl; and (3) a close season throughout the year on insectivorous birds. structure, growth and economics of insects 45 Inter-relations Between Insects and Plants The idea of inter-relations in Nature was first emphasized by Spren- gel, Darwin and Miiller, and later ecological studies reveal still more clearly how all Nature is linked together into a system, one part de- pendent upon another in an intricate web of life. Disturbances in one portion of the system are followed by disturbances in another. In this chapter reference is made to some of the relations be- tween insects and plants, between insects and birds, and between insects and their parasites. Numerous other relations might be mentioned but these are sufficient to show that a knowledge of these relations is an important part of the equipment of the economic entomologist who would deal successfully with the problems confronting him. In a region undisturbed by man the various parts of the system of Nature have practically reached a state of balance through the ceaseless action for long ages of the "struggle for existence." Plant struggles with plant, animal with animal, and both with the environment. With the advent of man, however, the balance has been disturbed by the clearing of the forests, the cultivation and drainage of the land, the growing of crops, and the introduction of foreign plants and animals, since the new set of conditions will be favorable to the increase in num- bers of certain plants and animals, including insects, and unfavorable to others. This disturbance is often widespread. Favored insects will multiply rapidly on account of the abundant supply of food fur- nished by the cultivated crops, faster at first than their parasitic enemies ; and insectivorous animals such as snakes, toads, birds and predaceous insects will be deprived of the necessary shelter and hiding places by the clearing of the land, and become less abundant. On the other hand insects not favored, by the destruction of their food plants under the new conditions, will diminish in numbers, as will also their parasites, both sometimes no doubt to the verge of extinction. If, however, as is sometimes the case, conditions again favor the insect it will multiply very rapidly because the development of the parasite lags behind its host. Moreover, there is always a limit to the increase of the parasite, otherwise it would exterminate its host, and eventually itself. Many examples of inter-relationships among insects in addition 46. ECONOMIC ENTOMOLOGY to that of parasite and host might be given. Certain ants attend certain plant-Hce with the object of feeding upon the nectar excreted — and not of feeding upon the plant-hce as some ignorantly suppose. Forbes has shown that the corn-root plant-louse is actually dependent upon the brown ant, Lasius niger americanus, for its existence, for its transfer to suitable winter quarters, to suitable weeds in early spring, and finally to the corn itself. In bumble-bees' nests one may often find a related bee, PsithyruSj living as a guest and fed by the worker bumble-bees. This guest bee is not content to live quietly in the nest; she often destroys the Bombus queen and gets ''the poor workers to rear her young instead of their own brothers and sisters" (Sladen). * Ants' nests or formicaries often contain a motley crew of other insects, among which are rove-beetles, pill-beetles, fly larvae, small crickets, thieving ants, and parasites — the majority being thieves and robbers. Again, no satisfactory explanation has yet been given for the preferences many insects exhibit in their feeding habits. As ex- amples, we are at a loss to know why in some districts the wheat midge does more damage to spring wheat than it does to fall wheat ; why the Hessian fly injures certain varieties of wheat more than others; why the grape blossom midge injures the early varieties of grapes most; why the Leconte and Kieffer pears are practically immune from the San Jose scale and the white peach scale; why the Northern Spy apple is not troubled with the woolly aphis; why the Red Dutch cabbages are free from the cabbage root maggot; why the spiny elm caterpillar and the European elm scale prefer the American elm to the imported English elm; why the European elm saw-fly and the elm leaf beetle prefer the European elm to the American; why the forest caterpillar attacks the sugar maple in preference to the soft maple; why the maple scale prefers the soft maple to the sugar maple; why the apple maggot is more injurious to sweet and sub-acid summer varieties than to fall and winter-acid varieties; why the brown mite is seldom seen in quince and apricot; and why the phylloxera is more injurious to the European vine than to the native American species., Long-continued observations show that there are ''all grades of association between plants and insects from most casual contact to STRUCTURE, GROWTH AND ECONOMICS OF INSECTS 47 mutual dependence, and that there are grades of fitness on both sides" (Needham, General Biology). Reference has aheady been made in the section deaHng with Beneficial Insects to the important part played by many insects in the fertilization of plants. To this end many beautiful adaptations occur among plants such as in legumes, iris, milk- weed, yucca, orchids, mints, figworts, honeysuckles, canna, Smyrna fig, etc., but it should be borne in mind that there has been also 'probably much adaptation on the part of the insects. Galls. — Another type of inter-relation is the galls seen on many plants, produced by certain insects belonging to the families Cecido- myiidcB, Trypetidce, Aphididce, Psyllidce, Cynipidce and Tenthredinidm. Mites (Acarina) also produce galls. Usually an egg is laid within the growing tissue and the larva excites the surrounding tissue to abnormal growth. The transformations occur within the gall, and the adult escapes to make new galls. Galls are of various forms, often characteristic of the insects pro- ducing them. The nutritive cells lying next to the contained larva contain both sugar and starch and appear to function as feeders for both the larva and the growing cells of the gall. Insectivorous Plants. — Certain plants such as the sundew, Venus' fly-trap, pitcher-plant and bladderwort entrap small insects and feed upon them. These plants secrete digestive fluids which convert the tissues of the captured insects into liquid food capable of being absorbed. Diseases of Insects. — Many insects are killed by the action of cer- tain fungi and bacteria. Such diseases are frequently epidemic, and attempts have been made to control insect infestations by the propaga- tion and distribution of artificial cultures. Probably the best known experiment of this nature was carried out by Dr. Snow and Dr. Forbes against the chinch bug in the middle States by the distribution of cultures of the fungus Sporotrichum glohuliferum. The result was only moderately successful, for it was found that the disease spreads rapidly in moist seasons, but not in dry ones when the chinch bugs are inju- rious. There is no doubt, however, that the fungus is an important factor in lessening the severity of the insect's attacks. In South Africa, Algeria and Argentina the locust has been con- trolled by the introduction of bacterial cultures of Coccohacillus 48 ECONOMIC ENTOMOLOGY acridiorum, but in other regions where the weather conditions are not so favorable this method has not met with success. In the southern States the San Jose scale is often attacked by SphcBrostilhe coccophila, but as a means of control artificial propagation of the disease on a large scale has not been successful. Tent-caterpillars, brown-tail and gipsy moth caterpillars are de- stroyed in large numbers by bacterial disease. Following is a list of the more important entomogenous fungi: Empusa musccB on flies, E. grylli on crickets, etc. and E, aphidis on plant-lice. Entomophthora aphidis on plant-lice, and E. sphcero- sperma on many caterpillars. Cordyceps militaris on larvae and pupae of white grubs, wireworms and some lepidopterous forms. Most of the conidial forms of Isaria and Sporotrichum belong to the ascus genus Cordyceps. Botrytis, Verticillium, Cladosporium, Mgerita and Fusarium attack many kinds of insects, especially scale insects, plant-Uce, white flies, and the chrysaUds of moths. Future investigations will probably lead to the better utilization of fungi in the control of many of the most noxious insects. Insects as Carriers of Plant Diseases Flea-beetles by eating holes in the leaves of potato permit the en- trance of the spores of Early Blight {Macrosporium solani) with conse- quent partial destruction of the leaves. It has also been shown fairly conclusively that certain aphids and other insects^ act as carriers of Twig Blight {Bacillus amylovorus) of apples and pears, that the beet leaf-hopper {Eutettix tenella) transmits to sugar beets the " Curly Leaf" disease, and it is now believed that the squash bug (Anasa tristis), the striped cucumber beetle {D. vittata), the 12-spotted cu- cumber beetle {D. 12-punctata), the cucumber flea-beetle {Epitrix cucumeris), the melon aphis {Aphis gossypii), and the 12-spotted lady-beetle {Epilachna borealis) frequently inoculate the stems of cucur- bits with the cucurbit wilt {Bacillus tracheiphilus). Again, the punc- tures made by the plum curculio in plum, cherry and peach permit entrance of the spores of the Brown Rot Disease {Sclerotinia fructigena) , ^ Gossard mentions among others Aphis avence, Empoasca mali, Eccoptogaster rugulosuSy and Lygiis pratensis. "Any sucking insect can become a carrier, also any insect with the bark-burrowing habit." STRUCTURE, GROWTH AND ECONOMICS OF INSECTS 49 and the greenhouse white fly (Aleyrodes vapor ar tor um) often transmits the disease Cladosporium fulviim to tomatoes. Tree crickets {(Ecanthus) are said to be responsible for the inocula- tion of trees and shrubs with canker, of raspberries with the cane blight, and probably for the production of other diseases. Insects and Disease (Consult Handbook of Medical Entomology by Riley and Johannsen, and Medical and Veterinary Entomology by Herms.) During the last twenty years important discoveries have been made regarding the transmission of certain diseases by arthropods such as the mosquitoes, house-flies, stable-flies, gad-flies, tsetse-flies, fleas, bed-bugs, lice and ticks. Insects and arachnidans cause disease in one or more of the fol- lowing ways: by direct injection, that is by the introduction of a patho- genic organism into the circulation, as in the case of the malarial mosquito, the yellow fever mosquito, the sleeping-sickness flies, horse flies and others; by indirect infection, that is by infecting food, as in the case of the house-fly; by internal parasitism as in the case of warble flies and bots; by external parasitism as in the case of lice, fleas, bed-bugs and ticks"; and by the introduction of poisons as in the case of bees, wasps, kissing bugs and others. Brues and Sheppard have divided the diseases that are carried by insects into three groups: Group A. — Characteristically insect-borne diseases. Group B. — Often insect-borne diseases. Group C. — Possibly insect-borne diseases. Under Group A are included malarial fever, yellow fever, filariasis, sleeping sickness, typhus fever, bubonic plague, African tick-fever. Rocky Mountain spotted fever of man, and Nagana and Texas fever of horses and cattle. Under Group B. are included typhoid fever, cholera, dysentery, diarrhoea, tuberculosis, septicaemia. Under Group C. are included anthrax, rabies, pellagra, hookworm, beriberi, black water and relapsing fever of man; and equine infectious anaemia. 4 so ECONOMIC ENTOMOLOGY Anopheles Mosquito and Malaria: Malarial fever and ague were common a generation ago, and our fathers vaguely attributed the disease to the presence of swamps whose numbers have fortunately been greatly reduced by drainage. The story of the discovery of the causal organism and of its life- history in connection with the Anopheles mosquito is one of the in- teresting chapters in modern biological investigation. The organism belongs to the amoeboid Protozoa and was discovered by Laveran, a French army surgeon, in 1880. The part of Anopheles as a second or intermediate host of the malarial organism was worked out later by Doctors Manson and Ross. (A full account of the discovery will be found in Kellogg's "American Insects.") The malarial plasmodium on gaining access to the human body lives within a red blood-corpuscle and thrives at the expense of the haemoglobin. A characteristic excretory product in affected cells is the black granules of melanin. In 48 hours the plasmodium reaches maturity and divides into many spores, termed merozoites, which are set free in the blood. These soon enter new blood-corpuscles and reach maturity in 48 hours as before. This production of spores coin- cides with the characteristic "chill" of ague, and is followed by a fever when the spores enter the blood-corpuscles. As a result of the de- struction of the red blood-cells the patient becomes ancemic. Certain of these spores, however, make no attempt to enter new blood-corpuscles and may remain in the blood for an indefinite period. These are the gametes — the micro- and macro-gametes — which, if taken into the stomach of an Anopheles mosquito, will, however, undergo further development. The male or micro-gamete produces a number of whip- like threads or fiagellce, which are capable of uniting with the female or macro-gametes, producing vermicules or ookinetes. These penetrate into the wall of the stomach of the mosquito where they rest as cysts, forming little lumps on the outer surface. These cysts mature in about ten days and burst, liberating large numbers of sporo-blasts into the body cavity, whence they find their way to the salivary glands. When such an affected mosquito bites a human being these spores are injected into the blood and enter the red cor- puscles. It will be seen, therefore, that ordinarily the Anopheles mosquito is the only agency for the transmission of malaria to man (Fig. 43)- STRUCTURE, GROWTH AND ECONOMICS OF INSECTS 5 1 Fig. 43. — Life history of malaria parasite, Plasmodium prcBcox. i. Sporozoite, introduced by mosquito into human blood; the sporozoite becomes a schizont. 2. Young schizont, which enters a red blood corpuscle. 3. Young schizont in a red blood corpuscle. 4. Full-grown schizont, containing numerous granules of melanin. 5. Nuclear division preparatory to sporulation. 6. Spores, or merozoites, derived from a single mother-cell. 7. Young macrogamete (female), derived from a mero- zoite and situated in a red blood corpuscle. 7a. Young microgametocyte (male) derived from a merozoite. 8. Full-grown macrogamete. 8a. Full-grown micro- gametocyte. In stages 8 and 8a the parasite is taken into the stomach of a mos- quito; or else remains in the human blood. 9. Mature macrogamete, capable of fertilization; the round black extruded object may probably be termed a "polar 52 ECONOMIC ENTOMOLOGY Stegomyia Mosquito and Yellow Fever: The demonstration of the causal relation between the Stegomyia mosquito and yellow fever is another interesting story, and was worked out mainly by Major Walter Reed of the U. S. Army Medical Service in Cuba in 1900 and 1901. In his experimental camp Major Reed and his associates proved that yellow fever could not be transmitted by contact with yellow fever patients, but only by the bites of infected mosquitoes and by the artificial injection of diseased blood. The causal organism has not yet been discovered on account of its being a filterable virus. It is known, however, that a 12-day incubation period is required in Stegomyia before its bite becomes infectious to a second person. Moreover, the mosquito can obtain infected blood from a patient during only the first three days of his disease. Based on these facts, the control of yellow fever has become an easy matter. The patients are isolated as soon as the disease appears, and standing water in which Stegomyia might develop is treated with kerosene. Besides, all rooms in the building and adjacent buildings are fumigated, for the purpose of destroying living mosquitoes. Culex Mosquito and Filar iasis: The tropical disease, filariasis, is caused by a minute nematode worm, Filaria, which lives in the blood of man and certain species of Culex (C Jatigans). The worms escape from the mid-intestine of the mosquito into the muscular tissue where they grow for two or three weeks. They then migrate to other portions of the body and often collect at the base of the proboscis, whence they are carried into the human blood circulation. Sometimes the worms become three or four inches long and obstruct the lymphatic canals, causing elephan- tiasis, characterized by enormous swellings of the legs, arms and other parts of the body. body." ga. Mature microgametocyte, preparatory to forming microgametes. gh. Resting cell, bearing six flagellate microgametes (male). lo. Fertilization of a macrogamete by a motile microgamete. The macrogamete next becomes an ookin- ete. II. Ookinete, or wandering cell, which penetrates into the wall of the stomach of the mosquito. 12. Ookinete in the outer region of the wall of the stomach, i.e., next to the body cavity. 13. Young oocyst, derived from the ookinete. 14. Oocyst, containing sporoblasts, which are to develop into sporozoites. 15. Older oocyst. 16. Mature oocyst, containing sporozoites, which are liberated into the body cavity of the mosquito and carried along in the blood of the insect. 17. Transverse section of salivary gland of an Anopheles mosquito, showing sporozoites of the malaria para- site in the gland cells surrounding the central canal. 1-6 illustrate schizogony (asexual production of spores); 7-16, sporogony (sexual production of spores). {After Grassi and Leuckart, by permission of Dr. Carl Chun.) STRUCTURE, GROWTH AND ECONOMICS OF INSECTS 53 House-fly and Typhoid Fever: Much attention has been directed in recent years to the dangers of the house-fly {Musca domestica) and other flies as agents in the trans- mission of disease. All Public Health Departments now take cognizance of the house-fly and issue warnings against its presence about the home. Epidemics of typhoid and cholera in many cities, as well as the out- breaks during the Spanish- American war brought out the fact that the house-fly was largely responsible for the troubles. The habits of this insect are such as to make its presence dangerous. It breeds in filth, and as an adult fly it feeds on all kinds of decaying and fecal matter as well as the sweets and liquids of the dining table. Its feet and proboscis are admirably adapted for carrying those bacterial germs that cause typhoid fever, cholera, dysentery, diarrhoea, tubercu- losis, etc. Moreover, it has been shown that typhoid bacilli swallowed by the house-fly when it feeds on and crawls over contaminated sub- stances survive the passage of the alimentary canal, so that "fly- specks" may contain many active typhoid germs. It has been shown that several other species of flies that frequent houses may also convey typhoid bacilli. The "little house-fly" (Fannia canicularis), the Latrine-fly {Fannia scalaris), the blow-fly {Calliphora erythrocephala) , Muscina stahulans, the cluster-fly {Pol- lenia rudis), and the stable-fly {Stomoxys calcitrans) have all been found guilty and precautions should be taken to guard against their presence. The charges proven against the house-fly as an active agent in dis- seminating not only typhoid fever but also cholera, dysentery and tu- berculosis are overwhelming. This insect pest should, therefore, be banished from our midst. If we do not care for our own health we should at least protect the helpless children who are perhaps the greatest sufferers. (For further particulars the excellent works of Doctors Hewitt and Howard should be consulted.) Anthrax and Infantile Paralysis: The stable-fly {Stomoxys calcitrans), the horn-fly {Hcematohia serrata), gad-flies {Tabanus and Chrysops), and the black-fly (Simulium) have both piercing and sucking beaks and are true blood-suckers. As such they are liable to introduce virus into the human blood. Anthrax is a disease of many domesticated animals and of man; and it is believed that these blood-sucking flies are agents of transmission 54 ECONOMIC ENTOMOLOGY by inoculation forming malignant pustule; but the pulmonary and intestinal forms of the disease require other methods of infection. In the recent outbreaks of acute anterior poliomyeHtis or infantile paralysis in different parts of the United States and Canada the stable- fly was strongly suspected at first of being the transmitter of the causal organism. Later, however, in many experiments in which monkeys, rabbits and other rodents were inoculated by stable-flies caught in the wards of hospitals containing poliomyelitis patients, and flies that had fed on animals inoculated with the virus were allowed to feed upon healthy animals, no symptoms of the disease developed. Besides, the disease spread on some occasions in mid-winter when stable-flies could not be active agents. The present opinion is that insects play a subordinate role, if any, in spreading the disease and that it is trans- mitted by contact with infected persons. The causal organism has not yet been isolated, being filterable and ultra-microscopic like that of yellow fever. Tsetse-flies and Trypanosomiasis: Tsetse-flies {Glossina spp.) are not native to America, but belong to tropical and sub-tropical Africa. They are blood-sucking flies, closely related to stable-flies, and in recent years have been shown to be causally related to severe diseases of both man and domesticated animals. Dr. Bruce made the important discovery that nagana, a very fatal disease to horses, cattle, dogs and donkeys in South Africa, was produced by a trypanosome carried to the blood by the bites of tsetse-flies. These trypanosomes are flagellate protozoa, and when they occur in the blood of certain warm-blooded animals set up a dis- ease called trypanosomiasis. They are carried from one host to another by certain invertebrates, such as mosquitoes, lice, fleas, and especially by such blood-sucking flies as the tsetse-flies. The Nagana disease is caused by Trypanosoma brucei and the tsetse- flies mostly concerned are Glossina morsitans and G. pallidipes. In the Congo Basin of Central Africa the terrible "sleeping-sickness" disease carries off tens of thousands of natives every year. Doctors Forde and Dutton isolated the specific causal organism of this disease, which was named Trypanosoma gambiense, and Bruce and Navarro traced the organism to the bite of the tsetse-fly, Glossina palpalis. Folsom states : " In the first ^tage of the disease, marked by the appear- ance of trypanosomes in the blood, negroes show no symptoms as a rule. STRUCTURE, GROWTH AND ECONOMICS OF INSECTS 55 though whites are subject to fever. The symptoms may appear as early as four weeks after infection or as late as seven years. ^'In the second stage trypanosomes appear in the cerebro-spinal fluid and in large numbers in the glands, those of the neck, axillae and groins becoming enlarged. There is tremor of the tongue and hands, drowsiness, emaciation and mental degeneration. The drowsiness passes into periods of lethargy which become gradually stronger until the patient becomes comatose and dies. Some victims do not sleep excessively but are lethargic and profoundly indifferent to all going on around them." Late investigations go to show "that Glossina morsitans may act as a host for a human trypanosome which is probably identical with T. gambiense." Probably also " that some of the vertebrates other than man may harbor T. gambiense and that there is a possibility of these things being transmitted to man" (Doane). With regard to the development of T. gambiense in Glossina palpalis it is known that "two days after biting an infected animal the fly becomes mcapable of mfectmg other animals and remains so for about 22 to 28 days, when it again becomes infective and may remain so for at least 96 days. During the infection period the salivary glands sire found to be invaded with the type of the trypanosome that is found in the vertebrate blood" (Doane). Rat Fleas and Plague: Plague, known in three forms as bubonic, septicaemic and pneu- monic, is caused by Bacillus pestis which attacks rats, mice, cats, dogs and other animals. The disease is transmitted mainly by fleas, some- times by bed-bugs, and the wounds made by the bites allow entrance to plague bacilH. "Plague is primarily a disease of rats, an epidemic of plague in these animals having often been observed to precede as well as to accompany an epidemic among human beings." The recent outbreak of pneumonic plague in Manchuria showed an- other phase of infection. This disease is not dependent on fleas for its transmission, but it could be traced to an outbreak of plague in the tarabagans or marmots, a kind of squirrel. Dr. Cantlie says that Plague may develop or appear in the following stages: (i) as a disease in ani- mals; (2) as pestis minor conveyed by infected insects; (3) bubonic plague, sporadic cases, carried from animals to man by insects; (4) epi- demic bubonic plague carried from man to man by insects; and (5) 56 ECONOMIC ENTOMOLOGY pneumonic plague passing from man to man directly, or conveyed by insects. Dr. Kitasato is quoted as saying that the (Manchurian) pulmonary plague cannot spread through the air as the digestive tract is plague-proof, and that direct contact is necessary. Lice and Certain Diseases: Typhus fever is transmitted from man to man by the Body Louse {Pediculus vestimenti), and Beriberi probably by the Head Louse (Pediculus capitis). Ticks and Certain Fevers: Although ticks are not true insects yet they have been considered as coming under the field of the entomologist. In certain western states, viz., Montana, Idaho, Wyoming, Utah and Nevada, the Rocky Mountain Spotted Fever occurs and is produced by the bites of ticks {Dermacentor venustus, et al.) which carry spirochaetes. The African tick-fever is carried by another tick {Ornithodoros moubata), the African Relapsing fever possibly by a tick, the African East Coast fever of cattle by ticks {Rhlpicephalus appendiculatus) and the Texan fever of cattle by a tick {Margaropiis annulatus) inoculating cattle with the protozoan spirochaete Babesia bovis, a fact observed by Dr. Theobald Smith. Other Diseases: The terrible "hookworm" disease of the South is probably carried by the common house-fly. The causal organism {Anchylo stoma duodenale) a round worm may also enter the skin from infected soil. Pellagra is transmitted, according to many authorities, by the bites of species of black-fiy {Simulium) or by the ingestion of mouldy corn. White grubs {Lachno sterna) are hosts for the thorn-headed worm {Echinorhynchus gigas) and food for swine which in turn becomes food for man. Leprosy, that most dreaded disease, is now believed to be trans- mitted by flies, fleas, mosquitoes and bed-bugs. Possibly also certain mites may be occasional carriers of the bacillus {B. leprce). It will be seen from this account that the insects concerned in the transmission of disease are of two kinds: those, like the mosquito which transmit malaria and filiariasis, which are essential hosts of the disease organisms, and those which transmit the disease mechanically. Any insect which habitually attacks man or which may enter the house or STRUCTURE, GROWTH AND ECONOMICS OF INSECTS 57 milking stable after having fed on human excreta is potentially a disease vector, so that we cannot too strongly emphasize the necessity of keeping all foods adequately screened and of preventing such insects as house-flies, blow-flies or mosquitoes from entering human dwellings. Besides carrying disease germs many insects may themselves cause disease in man. Many mites, hce and fleas cause dermatitis, scabies or ulcers in man. The larvae of many flies, notably the blue bottles, blow-flies, flesh flies and bot flies, cause intestinal, dermal, muscular, nasal or auricular myiasis in man. MacGregor in a recent paper (Bui. Ent. Res., Vol. viii, pp. 155-163) lists eighty organisms causing disease which may be transmitted by insects. Insect Behavior Toward Stimuli In recent years a large mass of facts regarding the behavior of insects toward their environment — both organic and inorganic — has been collected, and in a few cases this information has been of service in the control of injurious forms. In general, however, the application of such methods of control is still in its infancy stage, but it gives promise of valuable results in the near future. As the relations of insects to plants and to other insects have been discussed in previous sections attention will be confined here to the behavior of insects under the influence of environmental stimuli, such as light, heat, moisture, chemical contact, winds, etc. For some time it has been known that plants show tropistic move- ments with regard to light, heat, gravity, moisture, contact, etc. Moreover, some progress has been made toward an understanding of the processes. Plants, for example, bend toward the light because the cells on the side away from the light grow faster than those on the side next to the light. There is no conscious control of the movement by the plant. Animals, too, exhibit movements under the influence of tropic or taxic^ stimuli. In the case of insects, butterflies, bees, house- flies, and many moths and caterpillars are positively phototropic or phototactic and move toward the light, while maggots, bed-bugs and cockroaches move away from the light. ^ The term taxic is now more commonly used than tropic when applied to the locomotor movements of animals under the action of stimuli, tropic being usually reserved for the turning or orienting movements. 58 ECONOMIC ENTOMOLOGY Again, most moths move away from sunlight but move toward a lesser light such as electric or oil lamps. Davenport explains this difference by saying that "butterflies are attuned to a high intensity of light, moths to a low intensity." Loeb explains the circling of moths and other insects about a hght. The stimulus orients the insect by its more intense action on the muscles next the light, and the insect then moves toward the light. Loeb states that caterpillars of the brown tail moth as they emerge from hibernation in spring are positively phototropic, but after they have eaten this response disappears, showing that taxic reactions are sometimes dependent on the state of the body. ''Swaine finds that the destruction of piled logs by the wood-boring larvae of the sun-loving Monohammus can be prevented by forming a dense shade over the logs by means of brush. In his study of the army cutworm {Euxoa auxiliaris) in Alberta, Strickland found that the larvae are negatively phototropic and hide beneath the soil till about four or five o'clock in the afternoon when they come to the surface to feed. With the weaker hght they become positively phototropic and a general migration in a westerly direction takes place. When food is scarce hunger may overcome their aversion to sunshine with the result that the larvae come above ground, but they still display a modified negative phototropism and migrate in a northwesterly direction. These facts are of practical value in controUing outbreaks of this insect (Hewitt)." Insects are very responsive to the stimulus of heat, i.e., they are thermotactic. • ' Some insects respond to the stimulus of touch or contact, and are said to be either positively or negatively thigmotactic. Cock- roaches are in the habit of squeezing into narrow crevices, and Loeb mentions the case of a moth Pyrophila which also has the same habit. Chemical substances and foods also act as stimuli influencing the movements of insects. Maggots orient themselves with regard to their food and then move toward it, the orientation being the result of unequal chemical stimulation of the muscles of the two sides of the body. The deposition of eggs by most insects on certain plants is also the result of chemotropism. The house-fly and many piercing insects such as the biting flies and mosquitoes are repelled by phenol and other coal tar products. STRUCTURE, GROWTH AND ECONOMICS OF INSECTS 59 Wheeler and Loeb give several examples of geotropism among insects. They observed that lady-birds and cockroaches at rest placed themselves on vertical rather than horizontal surfaces. Observations show that taxic reactions are very adaptive. Ants and aphids are positively phototaxic when they get wings; and honey bees are periodically phototaxic, thus leading to swarming. Ants, moreover, are strongly thermotaxic, thus securing for their brood the optimum temperature conditions. Relation of Insects to Temperature and Humidity Two important factors influencing the life of insects are temperature and humidity. Their general regulatory action has been known for a long time, but scientific data obtained in recent years enable us to speak more definitely regarding the behavior of insects toward the varying temperature and humidity of their environment. Pierce in his studies of the cotton boll weevil and other forms says: '^A careful study of the records of any species, charting for the time required for each activity and the temperature and then similarly for the humidity, will disclose temperature and humidity points of maximum efficiency. With the boll weevil these points lie approxi- mately near 83°F., and 65 per cent, relative humidity." Ewing has found that a constant temperature of 9o°F. prevents the development of Aphis avence, and that the optimum temperature for the production of the wingless agamic forms is about 65°F. The larvae of the common house-fly are killed at a temperature of io5°F., and the close-packing of manure is sufficient to prevent the breeding of flies. With regard to changes in humidity, insects vary somewhat widely in their reactions. For example, moist air is favorable to most aphids and hastens the development of the larva of the Hessian fly. On the other hand, dry seasons favor the development of the chinch bug and wheat midge. Gardeners and florists have long observed that red spiders and most species of thrips are more abundant, and hence more injurious, under warm dry conditions. The investigations of Bachmetjew show that humidity is an im- ortant factor modifying the effects of temperature, and that the 6o ECONOMIC ENTOMOLOGY metabolic activities of insects are related to both temperature and humidity. He says: "Apparently there is a degree of atmospheric humidity which being the most favorable to the maximum speed of insect metabolism should be designated as the optimum; that this opti- mum varies for each species, for each stage of each species, and for each stage of each individual." The codling moth is an example of a common insect whose develop- ment is greatly influenced by weather conditions. Even within the limits of a single state or province the rate of its development and the time of its stages are influenced by latitude, by early and late seasons, by cool and warm seasons, and by wet and dry seasons. The student will find in the observations of Simpson in Idaho, Pettit in Michigan, Sanderson in New Hampshire, Hammar in Pennsylvania and Michigan, Jenne in Arkansas, Caesar in Ontario, Headlee in Kansas, Siegler and Simanton in Maine, Brooks and Blakeslee in Virginia, and Forbes in Illinois much valuable data for investigations on the relation of insects to climatic factors. The Distribution or Insects On account of the large increase of international trade many economic forms of importance have been introduced into Canada and the United States from other countries, and as it is a matter of public interest to know if such imported forms are likely to become injurious con- siderable attention has been given of late years to the investigation of this problem. The problem is not yet completely solved, but progress may be reported. The common natural means of dispersal are flighty wind, animals, and railways, etc. Many insects are able to fly long distances, many are carried by wind currents and many are transported on materials of commerce. A few examples of such dispersal may be cited. The" brown-tail moth is a good flyer, and is thus able to spread rapidly. On the other hand, the female of the gipsy moth cannot fly, consequently the spread of this insect follows the lines of trade. It has been observed that the Hessian fly spreads most readily in the direction of the pre- vailing winds at the time of the emergence of adults, and that the larvae of the San Jose scale are carried by the winds. Again, warble and bot flies are transferred from one district to another by their hosts. Man STRUCTURE, GROWTH AND ECONOMICS OF INSECTS 6 1 himself is responsible for the carrying of lice from district to district, often resulting in war time in serious epidemics. The Colorado potato beetle migrated eastward from its home in Colorado, preferring the cultivated potato to the wild solanums, and the asparagus beetles followed the lines of travel westward from the Atlantic. On the other hand, there are many barriers to the spread of insects: oceans, seas, mountain ranges and deserts are natural barriers and tend to prevent wide distribution. Climatic conditions, such as temperature and moisture, are also very important factors in insect distribution, often indirectly due to the absence of suitable food plants. The chinch bug and the Rocky Mountain locust, for example, do not thrive under moist conditions. As the habits of insects are very variable, some being limited, others almost cosmopolitan in their distribution; some sensitive to •emperature and moisture extremes, others more or less indifferent to these factors; some feeding only on one or two hosts, others more or less general feeders and therefore not so likely to be restricted in their range, the problem of the determination of probable insect distribution is not an easy one to solve. Moreover, the presence or absence of parasites complicates the problem. Dr. Merriam's map of the Life Zones of North America shows the distribution of birds and mammals and plants into seven zones running east and west, viz.: Arctic, Hudsonian and Canadian oi the Boreal region; the Transition, Upper Austral and Lower Austral of the Austral region; and Tropical (see Map).^ It must be understood, however, that the boundaries of these zones are not hard and fixed, for there is necessarily an overlapping to some extent. It is interesting to note that the great agricultural areas of Canada and the United States lie mainly in the Transition and Upper Austral zones. Recent studies go to show that in general insects tend to conform to the same zonal distribution, although several forms, such as the house-fly, mosquito, chinch bug and army-worm, range through several zones. ^ Merriam states the laws of temperature control as follows : I. "Animals and plants are restricted in northward distribution by the total quantity of heat during the season of growth and reproduction; and 2. "Animals and plants are restricted in southward distribution by the mean temperature of a brief period during the hottest part of the year." 62 ECONOMIC ENTOMOLOGY r ( ^^#-y ^i- 4s-^ i ''\ '"'.-.' ''*^-. ^V" I > l-.iiJI.iKJirAI, SlK-S'l-CV FmI'H I H l'Uii\ ISiDN A I ZONK .MAi'ol' NoKTM AMKKirA Fig. 44. — Map of North America showing the life zones. {After Metriam.) STRUCTURE, GROWTH AND ECONOMICS OF INSECTS 63 As a rule, however, insects diffuse most readily in the zone in which they originated, and in the direction of least resistance. The Transi- tion and Austral zones are differentiated into an eastern humid, a western arid and a Pacific humid division and certain insects occur in one division and not in the others. As examples of the economic importance of a study of the factors of distribution of insects the cases of the imported elm-leaf beetle and San Jose scale may be given. Fernald says: "The Elm-leaf Beetle . . . thrives in the Upper Austral Zone, but is noticeably absent in the highlands of the Pennsylvania mountain regions, though it is present again west of them. To the north it has caused serious loss to the elms of New England, resulting in the appropriation of large sums for spraying of the trees to protect them from its ravages. Careful studies of this pest in Massachusetts show that while a serious menace to the Ufe of the elms in the southern part of the state and in the river valleys, it becomes of little importance in the higher and northern parts, and many towns which formerly appropriated money for the protection of their elms from this insect have now learned that this was unnecessary, as the trees would suffer but little at most, in any case. "With the San Jose Scale similar facts are now coming to light. This pest finds the best conditions for its life in the Lower and Upper Austral Zones, where it has caused the loss of many millions of dollars. Even in the Upper Austral territory of Massachusetts, it is one of the most destructive enemies of the fruit-grower. As we pass into the Transition Zone, however, its ravages become less severe, and b}^ the time the centre of this zone has been reached it is of only medium importance. In this case it has seemed to those studying this problem that this insect was originally hmited by the Upper Austral, but has gradually acquired some degree of resistance to lower temperatures and has thus been able to extend into the Transition Zone." As Webster has shown, the migration and diffusion of insects have occurred along four main lines. The first was from the east by way of New York or one of the North Atlantic states and the open pathway into the interior past lakes Ontario and Erie. Examples of such migration are the imported cabbage butterfly, the two species of asparagus beetles, the clover-leaf weevil, the clover-root borer, the Hessian fly, the horn fly and the willow curculio. The second fine was northward from the West Indies by way of Florida up the Atlantic coast, bringing in many beetles, scale insects, the harlequin cabbage bug and other Hemiptera. The third hne was northward from Central 64 ECONOMIC ENTOMOLOGY and South America by way of Mexico, passing up the Mississippi valley or up the western valleys. Examples of such migration are the Diabroticas, the cotton boll weevil, the Argentine ant, the potato beetle, Halisidota, harlequin cabbage bug and the chinch bug. The fourth was southward from Asia by way of Alaska. Examples of such a dififusion are certain lady-birds, Lina spp. and Silpha spp. Regarding the fauna of British Columbia E. M. Walker believes it represents a mingling of Asiatic, Californian and Mexican types. With regard to insects that have come in from foreign countries it is generally true that they confine themselves to zones similar to those from which they have come. Of these mention may be made of Crio- ceris asparagi, Pieris rapcB, Hylastinus obscurus, the warble^ and bot flies, the San Jose scale, and the gypsy and brown-tail moths. Some forms, such as the codhng moth and other insects, tend to become cos- mopolitan, but they seldom become epidemic outside of their special zones. Similarity of climatic conditions in corresponding zones of two continents renders it easy for species introduced from one to the other to gain a footing, as the absence of native parasites affords an oppor- tunity for excessive multiplication. The influence of elevation on the distribution of insects is seen in the southward extension of the zones in hilly or mountainous regions. In an understanding of the distribution of many northern forms often isolated on summits south of their normal zone geological history comes to our aid. The great Tertiary extension of land areas in the north- east and the northwest, making land connections with Europe and Asia, permitted northern forms from these continents to pass to America, and the advance of the Great Glacier southward during the Glacial Period forced many northern forms southward, some of whom were left stranded on mountain summits on the retreat of the ice. Methods of Studying Economic Insects It has been already pointed out that one of the characteristics of modern-day investigations in economic entomology is the introduction of the "field station" method, whereby each pest is studied under natural conditions both in the open field and in the laboratory. By this method it is possible to study all or most of the factors that play a part in the life of both host and pest. No phase is too trivial for STRUCTURE, GROWTH AND ECONOMICS OF INSECTS 65 examination, for it may sometimes happen that apparently trivial and minor factors turn out to be important; for example, the discovery of a preoviposition period for many Diptera furnishes a means of con- trolling them at this vulnerable period. An important part of the equipment of the economic entomologist is a knowledge of the principles of "ecology" which enables him to analyze and scrutinize the various factors that play upon insects. The ecological sciences that have a more or less direct bearing upon economic entomology are Botany, Zoology, Chemistry, Physics, Geology and Geography, and their outgrowths. Bacteriology, Forestry, Meteorology, Physiology, and the group termed Agriculture. While a knowledge of these sciences is valuable in the study of in: sect problems it must necessarily be general in its character and in- sufficient for the solution of many of the more difficult problems. The worker should, therefore, confer with specialists in other depart- ments. Especially is this necessary in deahng with measures of con- trol. Sometimes recommendations are made which are at variance with the most approved farm practice. By consultation with an agronomist, horticulturist or forester such conflicting recommenda- tion would not be given to the public but would first be revised to meet all requirements. In the study of insects of farm crops, for example, the investigator, working along his own line, frequently reaches a position where he cannot make further progress without more information from workers in other branches and from experienced farmers. Such information may relate to methods and action of fertilizers, methods of cultivation and rotation, meteorological and physiographic influences, and the practical application of measures of procedure. Similarly in dealing with orchard insects progress in investigation can only be made when there is full co-operation with the expert horticulturist, the orchardist, the pathologist and others, who are able to give valuable advice and assistance. As one might expect, every kind of insect demands its own par- ticular method of investigation, for no two kinds of insects are oper- ated upon by the same factors. Hence the successful investigator must be able to contrive simple but effective devices for the determination of the various factors. Costly insectaries and appliances are not abso- lutely necessary; on the other hand, the tendency among the best work- 66 ECONOMIC ENTOMOLOGY ers is to use inexpensive appliances. Tlie most important consideration in the rearing of insects for the purpose of ascertaining their life history is to make conditions as nearly natural as possible. Cages of various kinds covered with muslin or wire netting are in common use. Some may be flower pots and lamp chimneys in which the host plants are Fig. 45. — Types of underground breeding cages, i, 15-inch pots with wire ^screen cover tops; 2, 15-inch pots with cyHnder-shaped tops. {After Davis.) growing; others, breeding cages of larger size and more elaborate construction. In the study of underground forms such as white grubs and wire- worms the cages are usually buried to the full depth in the earth. Davis has found large flower pot cages, deep cylinder-shaped cages and STRUCTURE, GROWTH AND ECONOMICS OF INSECTS 67 Fig. 46. — Insect breeding cage, a, Sliding glass door; b, galvanized iron base; c, galvanized iron holder for records; d, wooden base; e, wooden bottom detachable. Sides are covered with cheesecloth. {After Webster.) Fig. 47. — A gasoline or electric trap lantern with attachment of four cups for nsects, which fit into each other and are separated by netting of different sizes, and one for cyanide at the bottom. {After photo by Davis.) 68 ECONOMIC ENTOMOLOGY cages constructed of wire gauze useful. One-ounce tin salve boxes are employed to study the habits of the grubs, their growth and moults. In the breeding of aphids and other insects which readily succumb to heat, the cages are placed in ''shelters" covered with a canvas screen so as to permit free air circulation (Figs. 45-49). When trees are convenient the shelters may be placed under them and the screens removed. The rearing and distribution of parasites of insects demands special contrivances which may be easily made. Much valuable information Fig. 48. — Insectary and aphid breeding shelter, showing canvas curtain rolled up. {Photo by J. J. Davis.) is available as a result of the experiences of the workers in the Parasite Laboratory at Melrose Highlands, Mass. The economic entomologist should be a good photographer, and the laboratory should possess a full photographic outfit and a dark room. Camera records are among the most valuable. A very important part of the work of the investigator is the keeping and filing of records of the collections, experiments and observations. Two catalogues of the collections — the Accessions Catalogue and STRUCTURE, GROWTH AND ECONOMICS OF INSECTS 69 the Species Catalogue — and an Experiment Record of the experiments that are conducted should be kept. The Loose-leaf fiHng system is one that is admirably adapted for these purposes. The observational notes are best made on separate detachable slips of a note book that can be conveniently carried in the pocket. These slips are torn off and filed in card index trays under the name of the insect discussed. This method saves unnecessary transcribing, is Fig, 49. — A large breeding cage used in the study* of locusts, army worms, etc. {Photo by J. J. Davis.) simple, and serviceable in matters of correspondence and the prep- aration of reports and bulletins. Three types of collections should be made: (i) the reference collec- tion in standard cases such as the Schmitt, the Comstock or other form of box in which the specimens are arranged in systematic order accord- ing to the latest check lists; (2) the economic collection where the speci- mens are arranged according to host, where the life-stages and the work of the insect are given prominence; and (3) the illustrative collection in Riker mounts for lecture purposes. PART II TABLES FOR THE IDENTIFICATION OF INSECTS INJURIOUS TO FARM, GARDEN AND ORCHARD CROPS, ETC. I. INSECTS INJURIOUS TO CEREAL CROPS {Wheat, Rye. Barley, and Oats) (Consult Bull. 52 C. E. F. Ottawa, Bull. 44 W. Va., and Farmers' Bull. 132 U. S. Dep. Ag.) Roots: (a) Plants stunted, yellow, and withered or dead; roots eaten. 1. Smooth, slender, wire-like, six-legged worms present in the soil. — Wire- worms, p. 293. 2. Presence in the soil of large soft-bodied whitish grubs with brown heads, and hinder portion of body thicker than fore end. When disturbed grubs curl up. — White Grubs, p. 302. 3. Large dirty-brown maggots, 3^-i inch long. — Meadow Maggots, p. 242. Stems and Leaves: (a) Young plants dwarfed, and color changed to yellow or brown; stems shrivelled at the base, often bent or broken off; flaxseed objects found embedded at or near the base. Oats immune. — Hessian Fly {Mayetiola destructor), p. 245. {h) Stems above last joint dead, and the heads white — "silver top" or "white head" disease. Greenish maggot in stem above last joint. — Wheat Stem Maggot (Meromyza americana) and American Frit-fly (Oscinis carhonaria), pp. 260-1. (c) Swellings or galls on the joints, and stems bent or broken before harvest. — Joint Worm (Isosoma tritici), p. 354. {d) Stems broken down and tunnelled, blackish near the joints; heads turning white; presence in tunnel of yellowish- white larva of saw-fly; oats immune. — Western Wheat-stem Saw-fly (Cephus occidentalis) , p. 349. (e) Leaves sickly and whitish; the presence of small red and larger black- and-white bugs. — Chinch Bug (Blissus leucopterus), p. 161. (/) Stems and leaves sickly; the presence of many green or yellowish-green plant-lice. — Wheat Plant-louse {Aphis avence), English Grain Plant-louse (Macrosiphum granarium) , p. 142. (g) Stems and leaves eaten by large dingy striped caterpillars. — Army-worm (Cirphis unipuncta), p. 190. {h) Leaves eaten by locusts or grasshoppers. Red-legged and other Grass- hoppers, — {M elano plus femur-ruhrum et al.), pp. 109-113. 71 72 ECONOMIC ENTOMOLOGY Heads: (a) Heads turn white and grains are shrivelled or imperfectly filled. — Wheat Stem Maggot {Meromyza americana) and American Frit-fly {Oscinis car- honaria), p. 261. {h) Heads shrivelled and blighted, and imperfectly filled; the presence of orange-colored maggots. — Wheat Midge {Diplosis tritici), p. 249. {c) Heads covered with green plant-lice. — Grain Louse {Aphis avence), p. 142. {d) Heads turn white; minute dots or lines on leaves usually run parallel with the veins and remain white; the work of minute insects. — Grass Thrips, (Anaphothrips striatus), p. 119. (e) Spotting of the leaves, spots whitish at first, turning brown or black. — Six-spotted Leaf-hopper {Cicadula 6-notata), p. 154. (/") Heads blasted and stems withered; the presence of frothy masses on the stems. — Grass-feeding Froghop per {Philcsnus lineatus), p. 153. « n. INSECTS INJURIOUS TO INDL\N CORN OR MAIZE (Consult Bull. 44 Illinois Agric. Exper. Station) Planted Seed: (a) Plant fails to come up after planting; grain destroyed by a maggot which eats out the interior. — Seed-corn Maggot (Phorbia fusciceps), p. 277. (b) Plant fails to come up, or the young plant suddenly wilts after it is above ground; the presence of hard, smooth, yellowish, wire-like worms. — Wire-worms spp., p. 293. Roots: (a) Young plants killed or withered; roots eaten. — White Grubs or Wire-worms, P- 303- (6) Young plants unequal in growth; roots dwarfed without external injury; presence of ants. — Corn-root Louse {Aphis maidi-radicis). Stalks: {a) Plants cut off near surface of ground. — Cutworms, p. 185. {b) Plants unthrifty and covered with greenish plant-lice. — Corn Plant-louse {Aphis maidis), p. 142. {c) Stalks punctured and slit. — Corn Bill Bugs {Sphenophorus spp.), p. 338. {d) Pith of stalk and pedicel of cob tunneled by a flesh-colored caterpillar, terminal internode broken. — European Com Borer {Pyrausta nubilalis). Leaves: {a) Leaves thickly covered with green plant-hce. — Corn Plant-louse {Aphis maidis). {b) Leaves eaten. — Army-worm {Cirphis unipuncta) and Grasshopper, p. 190. (c) Leaves perforated by round or oblong holes arranged in parallel trans- verse rows. — Corn Bill Bugs, p. 338. {d) Leaves wilted and brownish, sometimes sickly and whitish; the presence of small red and larger black-and-white bugs. — Chinch Bug {Bliss us leuco- p terns), p. 161. (e) Leaves wilted and brownish caused by the maggot of a syrphid fly. — Corn-feeding^Syrphid Fly {Mesogramma politus), p. 251. IDENTIFICATION OF INSECTS INJURIOUS TO CROPS 73 Ears: (a) Developing kernels eaten; presence of much excrement. — Corn Ear Worm {Heliothis obsoleta), p. 195. (b) Stalks of ears covered with plant-lice. — Corn Plant-louse (Aphis maidis), p. 142. (c) Developing kernels eaten; cob and tassel stalk tunneled. — European Corn Borer {Pyrausta nubilalis), p. 212. III. INSECTS INJURIOUS TO CLOVER AND ALFALFA (Consult Bull. 134 Illinois Agric. Exper. Station, 1909) Roots: (a) Second year plants wilted and dead, breaking off easily at the crown. Main root, tunnelled and occupied by white footless grubs or little dark brown cylindrical beetles. — Clover Root Borer (Hylastinus obscurus), p. 341. {b) Plants wilted and leaves dead, mealy bugs near crown of root. — Clover Root Mealy Bugs (Pseudococcus trifolii), p. 133. Slems: (a) A long burrow with brown discolored walls in the pith of the stem which falls to the ground prematurely. — Clover Stem Borer (Languria mozardi). (b) Stems cut off or eaten. — Cutworms, Army-worms (Cirphis unipunda) and Grasshoppers, p. 109. (c) Stems and leaves withered and dead; plants covered with large green long-legged plant-lice. — Pea or Clover Plant-louse (Macrosiphum pisi), p. 149. Leaves: (a) Leaves full of round holes, and edges gnawed. — Clover Leaf Weevil {Phy- tonomiis punctatus), p. 331. {b) Leaves eaten and with a ragged appearance. — Grasshoppers, p. 109. (c) Leaves folded along midrib, yellowish or brownish, with white or orange maggots or silken cocoons within the folds. — Clover Leaf Midge {Dasyneura trifolii), p. 248. Heads and Seed: (a) Florets at blossoming-time green and undeveloped; the ovaries empty or with an orange pink or whitish maggot. — Clover Seed Midge (Dasyneura leguminicola) , p. 246. (b) Florets withered and seeds undeveloped; the presence of frothy masses on stems. — Meadow Froghop per (Philcenus spumarius), p. 153. (c) Seeds eaten, becoming brown, brittle, and hollow; affected seeds dull brown and often misshapen and of small size; maggot minute, white and footless. — Clover Seed Chalcid (Bruchophagus fimebris), p. 355. (d) Unopened blossoms destroyed, a cavity eaten in the head. — Clover Seed Caterpillar (Laspeyresia inter stinctana), p. 228. Stacked or Stored Clover Hay: (a) Hay containing white silky webs and particles of excrement. — Clover Hay- worm (Hypsopygia costalis), p. 208. 74 ECONOMIC ENTOMOLOGY IV. INSECTS INJURIOUS TO PEAS AND BEANS Planted Seeds: (a) Plant fails to come up, due to work of White Grubs or Wireworms, or Bean or Seed Corn Maggot, p. 277. Stalks and Leaves: (a) Plants cut ofif at night near surface of the ground. — Cutworms, p. 185. (b) Plants unhealthy, often killed by sucking lice. — Pea Louse {Macrosiphum pisi), p. 149. (c) Plants (beans) sickly and sooty, caused by a black aphis feeding at the tips at blossoming time.' — Bean Aphis {Aphis rumicis), p. 148. Seeds: (a) Seeds (peas) within the pod partly eaten and web-covered; pellets of excre- ment about injured seed. — Pea Moth (Laspeyresia nigricana), p. 226. {b) Seeds within the pod (peas) perforated with holes; footless grubs within. — Pea Weevil {Bruchus pisorum), p. 319. (c) Seeds (Beans) perforated with (sometimes many) holes; footless grubs within. — Bean Weevil {Bruchus obtectus), p. 319. V. INSECTS INJURIOUS TO STORED GRAIN PRODUCTS (After Girault, Bull. 156 Illinois Ag. Exp. St.) Moths or Millers, {a) Caterpillar small, whitish, living in grains of corn or wheat, pupating within the grain, and emerging through a round hole covered with silk at or near the tip of the kernel. Adult moths grayish clay- yellow, small. — Angoumois Grain Moth {Sitotroga cerealella), p. 214. {b) Caterpillars, spinning much silk, usually forming a silken tube to which they retire; this tube covered with food particles. Living in flour, meal, chaflf, sometimes among grain, or in food substances. Full-grown caterpillars make a cocoon. 1. Caterpillar free-living usually not concealed within a silken tube, olive-green to pinkish, infesting grain or meal, webbing particles together, covering bags of grain with a web of silk and generally scattering silk in all directions. The moth is brown and gray. Cocoon elliptical, slender, fragile and of clear silk. — Indian Meal Moth {Plodia inter punctella) , p. 214. 2. Caterpillars living in densely woven silken cases covered with particles of the food substance. Common in flour or chaflf in corners. (i) A yellowish white to pinkish caterpillar in flour, webbing it together and forming a cocoon covered with particles of flour. Moth dark grayish. — Mediterranean Flour Moth {Ephestia kuehniella), p. 213: (2) A soiled grayish caterpillar, darker at each end, living in chaff or other vegetable d6bris in dark damp places. IDENTIFICATION OF INSECTS INJURIOUS TO CROPS 75 securely webbing the food substance together, so that it becomes matted; larval case and cocoon completely hidden, covered with the food substance. Adults very beautiful and delicately colored moths. — Meal Snout Moth {Pyralis farinalis), p. 208. Beetles or Weevils. (a) Small insects living in kernels of grain, or among grain and other ■ stored products. 1. A very small, fat, humped-backed grub, in kernels of wheat or corn; yellowish- white, legless, and wrinkled, unable to crawl; pupa within the kernel. Adult smaller than a grain of wheat, with a snout, and elbowed feelers attached to the snout. (i) Adult beetle chestnut-brown, without spots on its upper wings. Slightly larger than the next, more common in the North. — Granary or Black Weevil {Calandra granaria), p. 337. (2) Adult beetle somewhat duller brown than the preceding with four reddish spots, one on each outer corner of the upper wing. A southern species. — Rice or Spotted Weevil (Calandra oryzce). 2. Small, more or less slender, somewhat flattened grubs, with dis- tinct head and thoracic legs, crawling about in the debris of var- ious grains or their products, or in vegetable foodstuffs. Adults flattened, longer than wide, the head not prolonged into a snout. They occur with the grubs, actively feeding. (i) Grub uniform in color, whitish, about one-fourth inch long, slender, its head narrower than the first body segment; pupa with the thorax not toothed laterally, but with most of the abdominal segments bearing a tooth-like lobe, acute at each outer corner and toothed along its sides. Adult beetle active, smooth, elliptical, and reddish brown. — Confused Flour Beetle {TrihoUum confusum), p. 328. (2) Grub whitish, with a rectangular yellowish area on each segment above, only the margin whitish as seen from above; head broader than first body segment. Pupa bears along each side of the thorax and abdomen a series of stout lobe-like teeth, which are cylindrical- rectangular and blunt. Adult beetle smaller than in the preceding species, color dark chocolate-brown, sides of the thorax saw-toothed. — Saw-toothed Grain Beetle {Silvanus surinamensis) , p. 326. (3) Grub dull white with a dark brown head; fleshy, three- fourths inch long; posterior end with two dark horny points. Pupa white, adult beetle, elongate, depressed, 76 ECONOMIC ENTOMOLOGY nearly black, one-third inch long. — Cadelle (Tenebroides mauritanicus) , p. 326. (b) Large insects, concealed in the bottoms of bins, corners, and the like, feeding upon flour, meal or bran. Adults large black beetles; the lar- vae, large, cylindrical, wormlike creatures, resembling wireworms. 1. Adult not quite black in color, shining, its third antennal joint not quite twice as long as the second; larva light yellowish, shining. — Yellow Meal-worm Beetle (Tcnebrio niolitor ), p. 327. 2. Adult black and without luster, its third antennal joint thrice as long as the second; larva very dark, shining. — Dark Meal-worm Beetle (Tenebrio obscurus), p 328. VI. INSECTS INJURIOUS TO ROOT CROPS (Turnips, rape, mangels, and carrots) (Consult Bull. 52 C. E. F.. Ottawa, and Bull. 60, 111. Exp. Sta.) Roots: (a) Tips of roots of young carrots with rusty patches on surface, or rust colored tunnels in the pulp, due to slender yellowish- white maggots. — Carrot Rust Fly (Psila rosce), p. 262. {b) Roots of turnips bored or tunnelled by minute grubs or maggots. — Turnip Flea Beetle (Phyllotreta vittata); Cabbage Root Maggot (Phorbia brassicce), P- 273- (c) Roots cut off. — Wireworms, White Grubs, Cutworms, pp. 185, 293, 302. Stem and Leaves: (a) Young plants cut off at the ground. — Cutworms, p. 185. {b) Surface of first leaves of turnip and rape eaten into small holes by small active black striped beetles. — Turnip Flea Beetle {Phyllotreta vittata), p. 314. (c) Leaves partly consumed by pale-green caterpillars. — Cabbage Worm (Pieris rapce), p. 175. (d) Leaves eaten by caterpillars with black and yellow stripes. — Zebra Cater- pillar (Ceramica picta), p. 188. (e) Leaves wilt and turn yellow, with presence of greenish lice. — Turnip Plant- louse (Aphis brassicce), p. 148. (/) Young leaves eaten into holes and irregular blotches by small active green caterpillars. — Diamond Back Moth {Plutella maculipennis), p. 232. (g) Under-surface of leaves covered with a very fine loose web; leaves yellow- ish in patches, and minute red objects present. — Red Spiders, p. 367. {h) Leaves eaten by red beetles with black stripes (Prairie Provinces). — Red Turnip Beetle (Entomoscelis adonidis), p. 309. VII. INSECTS INJURIOUS TO THE POTATO CROP Tubers: (a) Surface of tuber eaten and ej^es sometimes destroyed so that growth does not take place; or holes bored in the tuber.- — White Grubs, Wireworms, Millipedes, p. 369. IDENTIFICATION OF INSECTS INJURIOUS TO CROPS 77 Stalks and Leaves: (a) Stalks cut off at the ground. — Cutworms, p. 185. (b) Leaves eaten and infested with reddish soft grubs and striped beetles. — Colorado Potato Beetle {Lepiinotarsa decemlineata) , p. 308. (c) Leaves riddled with small holes or surface eaten in spots by small active jumping black beetles. — Potato Flea Beetle {Epitrix cucumeris), p. 313. (d) Leaves eaten and with a ragged appearance; presence of long black or striped soft beetles. — Blister Beedes {Epicauta spp.), p. 325. (e) Stalk wilts and dies, tunnel in stalk near the ground, and presence of a white footless grub. — Potato Stalk Borer {Trichoharis trinotata), p. 334. (/■) Green plant-lice on the leaves; migrating to the rose. — Potato Plant-louse (Macrosiphum solanifolice) . VIII. INSECTS INJURIOUS TO GARDEN VEGETABLES [Under the term "Garden Vegetables" may be included Asparagus, Beets, Cabbage, Cauliflower, Celery, Cucumber, Onion, Parsnip. (Carrots, beans, peas and potatoes have already been considered.)] Roots : (a) Roots of cabbage and cauliflower and bulb or base of onion mined by white maggots. — Root Maggots (Phorbia brassicce and Phorbia cepetorum), p. 273. (6) Roots of cucumber, squash, melon and pumpkin eaten, and plants fail to come up. — White Grubs, Wireworms. (c) Roots of cucumber, etc., gnawed and mined, plants wilt and die. — Striped Cucumber Beetle {Diabrotica vittata), p. 307. Stems and Leaves: (a) Young plants cut off near surface of ground. — Cutworms. (b) Stalks, vines and leaves of cucumber, etc., eaten, and base, mined by small white grubs. — Cucumber Beetles (Diabrotica spp.), p. 307. (c) Vines of cucumber, etc., wilted, and presence of large dark stink-bugs on leaves. — Squash Bug (Anasa tristis), p. 160. (d) Leaves and vines of cucumber, etc., sickly and dirty, under surfaces infested with greenish-black lice. — Melon Plant-louse {Aphis gossypii). {e) Surface of leaves of cucumber, etc., eaten by small black beetles. — Cucumber Flea Beetle {Epitrix cucumeris), p. 313. (/) Leaves of cabbage, etc., ragged, eaten by pale-green caterpillars. — Cabbage Worm {Pieris rapce), p. 175. (g) Leaves of cabbage, etc., wilted, and under-surface covered with greenish . plant-lice. — Cabbage Plant-louse {Aphis brassicce), p. 148. IX. INSECTS INJURIOUS TO THE APPLE (Consult Manual of Fruit Insects by Slingerland and Crosby) Roots: ia^ Bluish-white mouldy lice causing knots or swellings on the smaller roots. — Woolly Aphis {Schizoneura lanigera), p. 145. 78 ECONOMIC ENTOMOLOGY (b) Large white grubs feeding on the roots of nursery stock. — White Grubs (Lachnosterna spp.), p- 302. Trunk, Branches and Twigs: (a) A green curiously shaped bug producing longitudinal slits in the bark; eggs laid under the edges of the slits. — Buffalo Tree Hopper {Ceresa bubalus), p. 157- (b) White woolly patches on the twigs which are usually scarred. — Woolly Aphis {Sckizoneura lanigcra), p. 145. (c) Green soft-bodied sucking insects in clusters on young growths, particularly at ends of twigs, producing distortions. — Apple Aphids {Aphis mali, A. sorbi and A. avence), p. 143. {d) Snout beetles gnawing ofif the bark in patches. — Imbricated Snout Beetle {Epiccerus imbricatus). (e) Fixed to bark: 1. Scales round and gray and black producing an ashy gray incrusta- l tion on the bark. — San Jose Scale {Aspidiotus perniciosus) , p. 126. 2. Bark rough with mussel-shaped scales. — Oyster-shell Scale (Lepido- saphes ulmi), p. 124. 3. Bark scurfy with white scales. — Scurfy Scale {Chionaspis furfura), p. 125. (/) Making tunnels in the wood: 1. Large square-headed legless borer at or near the ground in tunnels, with sawdust-like excrement. — Round-headed Borer (Saperda Candida), p. 320. 2. Large flat-headed legless borer in upper trunk in tunnels with saw- dust-like excrement. — Flat-headed Borer {Chrysobothris femorata), p. 300. 3. Large grub in decaying wood. — Eyed Elater (Alans oculatus) and Rough Osmodenna (Osmoderma scabra), p. 305. 4. Making tunnels between the bark and wood. Fruit Bark Beetle {E'Xoptogaster rugulosus), p. 339. Buds: (a) Light green caterpillars with brown head and shield, folding together the opening leaves and feeding within. — Oblique Banded Leaf -roller (Caccecia rosaccana). Fruit-tree Leaf Roller (C. argyrospila), and Leaf Grumpier {Mineola indigenella) , p. 230. {b) Brownish caterpillar with black head and shield eating the centre of the bud, or tunnelling it. — Eye-spotted Bud Moth {Tmetocera ocellana), p. 225. (f) Measuring worms, eating leaves of buds. — Ganker Worms {Alsophila pome- tar ia and Palcacrita vcrnata), p. 205. (d) Caterpillars feeding within pistol-shaped cases and eating irregular holes in the bud leaves. — Pistol Gase Bearer (Haploptilia malivorella) , p. 235. {e) Caterpillars feeding within cigar-shaped cases and eating small round holes in the bud leaves. — Gigar Gase Bearer (Haploptilia fletcherella), p. 234. (/") Click beetles feeding on buds. — Gorymbites spp., p. 297. IDENTIFICATION OF INSECTS INJURIOUS TO CROPS 79 Leaves: (c) Gregarious caterpillars: Caterpillars protected by webs: 1. Webs in forks of branches in spring. — Tent-caterpillar {Malacosoma americana), p. 203. 2. Webs covering the leaves in summer and early autumn. — Fall Web Worm {Hyphantria textor), p. 181. 3. Leaves partly eaten and drawn together by a web. — Palmer Worm (Dichomeris pometella), p. 215. Caterpillars not protected by a web: 1. Clustered on limbs. — Yellow-necked Cater pillar (Datana ministra), p. 198. 2. Red-humped Apple-tree Caterpillar (Schizura concinna), p. 199. 3. Forest Caterpillar {M. disstria), p. 204. (b) Solitary caterpillars: Protected caterpillars: 1. Mining within the leaf, pupa inside of folded leaf. — Apple Leaf Miner {Tischeria malifoliella) , p. 235. 2. Mining within the leaf, mature larva and pupa within a small oval seed-like body. — Resplendent Shield Bearer {Aspidisca splendoriferella), p. 232. 3. Feeding within a pistol-shaped case which stands out from the leaf . — Pistol Case Bearer {Haploptilia malivorella) , p. 235. 4. Feeding within a cigar-shaped case which stands out from the leaf. — Cigar Case Bearer {Haploptilia jletcherella), p. 234. 5. Feeding within a folded leaf. — Leaf Roller (Teras malivorana), Cacoecia spp., Apple Leaf Sewer {Ancylis nubeculana), p. 230. 6. Feeding within a tube of silk, open at both ends, on epidermis and inner tissues, leaving the veinlets. — Bud Moth (Tmetocera ocellana), p. 225. 7. Feeding on tissues of leaves beneath a silk web. — Apple Leaf-skele- tonizer {Psorosina hammondi), p. 213. 8. Brown caterpillar feeding within a crooked black case and attached to twigs in winter. — Leaf Crumpler {Mineola indigenella) , p. 213. Unprotected caterpillars: 1. Measuring worms in spring, feeding in the daytime. — Canker Worms {A. pometaria and P. vernata), p. 205. 2. Sleek i6-legged caterpillars, feeding at night. — Cutworms, p. 186. 3. Large green caterpillar, covered with spiny tubercles. — Cecropia Moth {Samia cecropia), p. 180. 4. Large apple-green caterpillar with white oblique stripes on sides. — Polyphemus Moth {Telea Polyphemus), p. 180. 5. Hairy caterpillar with long black tufts over head and tail. — Tussock Moth (Hemerocampa leucostigma), p. 202. 6. Large green caterpillar with a reddish-brown horn at tail, and seven oblique stripes on each side. — Apple Sphinx {Sphinx gordius), p. 178. 8o ECONOMIC ENTOMOLOGY 7. Small caterpillars with brown head and yellowish-green body, feeding on leaves. — Apple-leaf Biiccnlatrix {Biicculatrix pomijoliella), p. 236. {c) Plant-lice. Greenish or rosy colored sucking insects feeding on the under sides of leaves, often distorting them. — Aphis mali, A. sorbi, and A. avencz, P- 143- (d^ Beetles: 1. Large brown beetles feeding at night on leaves. — May Beetles {Lach- nosterna spp.), p. 302. 2. Small brown beetles, feeding at night. — Leaf Beetles, p. 301. (e) Mites. Oval reddish-brown mites feeding on leaves causing them to become blanched, yellow or sickly. — Clover Mite {Bryobia pratensis), p. 367. Fruit: (a) Boring tunnels through the fruit: 1. Tunnels made mostly about the core; made by a pinkish caterpillar three-fourths inch long when full grown; brown excrement often visible at opening at blossom end of apple. — Codling Moth (Carpocapsa pomonella), p. 219. 2. Tunnels not so deep as in i, often blotched mines near the surface. Made by caterpillars not so large as codling worms. — Lesser Apple Worm {Laspeyresia prunivora), p. 227. 3. Tunnels irregular and numerous made by a maggot. — Apple Maggot {Trypeta pomonella), p. 266. {b) Puncturing the fruit: 1. Four-humped beetles puncturing the fruit and distorting it. — Apple Curculio {Anthonomus quadrigibbus), Plum Curculio (Conotrachelus nenuphar), p. 329. 2. Purplish spots about the circular scales. — San Jos6 Scale {Aspidiotus perniciosus), p. 126. 3. Puncturing and deforming the fruit. — Several species of Capsidce (False tarnished plant bug and the apple red bugs); and Syntomaspis druparum (p. 165). (c) Eating holes in the fruit: 1. Large light yellow or apple-green caterpillars with a narrow cream colored stripe along middle of the back. — Green Fruit Worms {Grap- tolitha spp.j, p. 197, 2. Yellowish hairy beetle one-half inch long. — Bumble Flower Beetle {Euphoria inda), p. 305. 3. Green worm-like saw-fiy larva hibernating in cavities scooped out of apple. — Dock False Worm {Ametastegia glabrata), p. 347. X. INSECTS INJURIOUS TO THE PLUM Roots: (a) Burrows made by a caterpillar about the crown of the roots, occasionally in young trees. — Peach-tree Borer {Synanthedon exitiosa), p. 216. Trunk, Branches and Tuigs: (a) Tunnels in the wood by flat-headed grubs; sawdust-like excrement at the mouth of tunnels. — Flat-headed Borer {Chrysobothris femorata), p. 300. IDENTIFICATION OF INSECTS INJURIOUS TO CROPS 8 1 (b) Tunnels in the bark by small legless grubs. — Fruit Bark-beetle {Eccopto- gaster rugulosiis), p. 339. (c) Bases of buds perforated, bark becomes discolored, and leaves and fruit wither. — Pear Blight Beetle (Anisandrus pyri), p. 340. (d) Fixed to bark: 1. Flat or saddle-shaped, or hemispherical dark-brown scales; wintering forms small and flattish. Large scales appear after mid-summer, brittle, contain only a whitish dust or empty egg-shells. — Fruit Lecanium {Lecanium corni), p. 129. 2. Ashy-gray appearance of bark of badly infested trees due to small gray or black circular scales. — San Jose Scale (Aspidiotus perniciosus), p. 126. 3. Mussel-shaped scales, with whitish eggs underneath in winter. — Oyster Shell Scale {Lepidosaphes ulmi), p. 124. 4. Bark scurfy with scales with purplish eggs underneath in winter. — Scurfy Scale (Chionaspis furftira), p. 125. (e) A grass green curiously shaped bug producing longitudinal slits and eventu - ally oval-shaped scars on the back of the twigs. — Buffalo Tree-hopper {Ceresa bubalus), p. 157. Leaves: (a) Feeding in Colonies. 1. Caterpillars protected by webs in the forks of branches. — American Tent-caterpillar {Malacosoma americana), p. 203. 2. Caterpillars protected by webs covering the leaves. — Fall Web-worm {Hyphantria text or), p. 181. 3. Not protected by webs; greenish lice with sucking mouths. — Plum- leaf Aphis {Aphis prunifolii). (b) Solitary. 1. Measuring worms, feeding in the day time in spring. — Canker Worms (Alsophila pometaria) , p. 205. 2. Fat greasy caterpillars, feeding at night in spring. — Cutworms, p. 192. 3. Hairy caterpillars with long black plumes over head and tail. — Tussock Moth {Hemerocampa leucostigma), p. 202. 4. Large buzzing beetles. — June Beetles (Lachnosterna spp.), p. 302. 5. Large apple-green caterpillar, with a horn near the tail, and with seven broad oblique white stripes along each side. — Plum-tree Sphinx {Sphinx drupiferarum) , p. 178. Other larvae are occasionally found feeding on the leaves of plum. — The Viceroy {Limenitis disippus), Polyphemus and Cecropia, p. 180. Fruit: {a) A snout-beetle puncturing and making a crescent-shaped slit in the skin of the young fruit which soon drops. — Plum Curculio {Conotrachelus nenuphar), P- 329- {b) Making a round hole in the young fruit. — Phim Gouger {Coccotorus scuteU laris). 82 ECONOMIC ENTOMOLOGY (c) A medium sized beetle eating holes in the ripe fruit. — Bumble Flower-beetle {Euphoria mda), p. 305. {d) A long-legged straw-colored beetle eating holes in the half-ripe fruit. — Rose Chafer {Macrodactylus stibspmosus), p. 305. XI. INSECTS INJURIOUS TO THE CHERRY Root: (a) A thick whitish grub, with brown head and legs, feeding in decaying roots. Beetle large with powerful mandibles. — Stag Beetle (Lucanus dama), p. 318. (b) A large white fleshy grub, with reddish head, feeding in old roots. — Rough Osmoderma {Osmoderma scabra), p. 305. Trunk, Branches and Twigs: (a) A snout beetle gnawing the twigs and fruit. — Imbricated Snout Beetle (Epiccerus imbricatus) . {b) A small beetle boring in the branches just above a bud, and burrowing downward. — Apple Twig Borer {Amphicerus bicaudatus), p. 327. (c) A flattened grub tunneling in the bark and sap-wood; beetle bronzy metallic. — Divaricated Buprestis {Dicerca divaricata) . (d) Large sucking insect with transparent wings, inflicting wounds on the smaller limbs and depositing eggs therein in August and September. — Dog-day Cicada {Cicada tibicen), p. 157. {e) Small circular scales, black in winter, with a circular depression about a central nipple. — San Jose Scale {Aspidiotus perniciosus) , p. 126. (/■) Dirty nests inclosing a colony of yellow caterpillars one-half inch long at end of twigs. — Cherry-tree Tortrix {Cacoecia cerasivorana), p. 230. Leaves: {a) A small beetle feeding on the leaves of red cherry. — Cherry Leaf Beetle {Galerucella clavicollis), p. 311. {b) A shiny, dark-green slug, one-half inch long, feeding on soft tissues, leaving the veins. — Pear or Cherry Slug {Eriocampoides limacina), p. 348. (c) Shining black plant-lice infesting the terminal twigs chiefly, which become distorted and discolored. — Cherry Plant-louse {Myzus cerasi), p. 144. {d) Large bluish-green caterpillar two inches long with blue warts on each segment, and coral red ones on the third and fourth segments. — Promethea Moth {Callosamia promethea), p. 180. {e) Large pale-green spiny caterpillar, striped on each side with white and lilac. — lo Moth {Hyperchiria lo), p. 180. (/) Caterpillars in colonies protected by webs in forks of branches in spring. — American Tent-caterpillar {Malacosoma americana), and Forest Tent- caterpillar {M. disstria) not in webs, p. 203. {g) Caterpillars in colonies protected by webs covering the leaves in summer and early autumn. — Fall Web Worm {Hyphantria textor), p. 181. IDENTIFICATION OF INSECTS INJURIOUS TO CROPS 83 Fruit: (a) A crescent cut on the cherry; grub, white and footless, with a brownish horny head, feeding within. — Plum Curculio {Contrachelus nenuphar),^. 329. ih) Yellowish-white maggots feeding on the pulpy juices near the pit, inducing a rotting. — Cherry Fruit Flies (Rhagolctis cingulata and R. fausta), p. 265. XII. INSECTS INJURIOUS TO THE PEACH Root and Lower Trunk: (a) Tunneling in the bark and sapwood of the root and lower trunk, causing an exudation of gum, which is seen at base of tree mingled with the castings. — Peach Tree Borer {Synanthedon exitiosa), p. 216. Trunk and Branches: (a) In early spring a minute caterpillar bores into the shoots of new leaves, killing the growing terminals. — Peach Twig Borer (Anarsia linealella), p. 215. ib) Black hemispherical scales attached to the bark. — Peach Leaf Lecanium (Lecanium nigrofasciatum) , .p. 129. (c) A beetle eating the buds and gnawing into the base of the twigs, causing them to break and fall. — New York Weevil {Ithycerus novehoracensis). {d) Round scales, gray or black; twigs presenting a scurfy appearance. — San Jose Scale (Aspidiotus perniciosus) , p. 126. (e) Oval scars and longitudinal slits on bark produced by a green buffalo- shaped bug. — Buffalo Tree Hopper {Ceresa bubalus), p. 157. Leaves: (a) Plant-lice, living in colonies under the leaves, causing them to thicken and curl. — Peach Tree Aphis {Myzus persicce), p. 144. (6) Minute round scales located usually along the veins. — San Jose Scale {Aspidiotus perniciosus) , p. 126. (c) Caterpillars protected; 1. In a tortuous tube. — Leaf Cnnnpler (Mineola indiginella) , p. 213. 2. In folded leaves. — Oblique Banded Leaf Roller {Cacoecia rosaccana), p. 230. Fruit: (a) Long-legged yellowish beetles eating holes in half-grown peaches. — Rose Chafer (Macrodactylus stib spinas us), p. 305. (b) Large yellow hairy beetles eating holes in ripe peaches. — Bumble Flower Beetle (Euphoria inda), p. 305. (c) Small snout-beetles making a puncture and crescent in the young fruit. — Plum Curculio {Conotrachelus nenuphar), p. 329. XIII. INSECTS INJURIOUS TO THE RASPBERRY AND BLACKBERRY Roots and Base of Canes: (a) Large grub over two inches long, boring large tunnels in the woody portion of main root. The canes suddenly die. — Giant Root Borer (Prionus laticollis) , p. 321. 84 ECONOMIC ENTOMOLOGY (/)) Canes at base of main root girdled by a yellowish-white caterpillar in late summer and autumn. — Bramble Croivn Borer {Bemhecia marginata), p. 218. Canes: (a) Longitudinal row of punctures on canes. — Black-horned Tree Cricket {(Ecan- thus nigricornis) , p. 116. (6) Tips of raspberry canes wilting in early summer, due to a girdling of the canes inside the bark. — Raspberry Cane Maggot {Phorbia rubivora), p. 277. (c) Tips of shoots of raspberry wilting in July and August; two rows of hori- zontal punctures one inch apart at base of wilted portion, with a small hole between. Canes burrowed to the base before autumn. — Raspberry Cane Borer (Oberea bimacidata), p. 321. (d) Swellings on canes of raspberry and blackberry. — Red-necked Cane Borer {Agrilus ruficollis), p. 301. Buds: (a) A small snout-beetle puncturing the flower stem close to the buds, and also the huds.— Strawberry Weevil {Anthonomus signatus), p. 232. (b) A small yellowish beetle eating the flower buds, which either fail to open or wither. — Pale Broivn Byturus {Byturus unicolor), p. 292. (c) A small brownish caterpillar eating the opening buds. — Bud Moth {Tmeto- cera ocellana), p. 225. Leaves: (a) Bugs sucking the sap of young growing parts, and arresting their develop- ment. — Tarnished Plant Bug (Lygus pratensis), p. 163. {b) Suckers and leaves curled up with enclosed lice. — Bramble Flea Louse (Trioza tri punctata), p. 152. (c) Small greenish larvse with spiny tubercles eating the leaves in spring. — Raspberry Saw-Fly {Monophadnus rubi), p. 347. Fruit: (a) A looper feeding on fruit of raspberry and blackberry. — Raspberry Geometer {Synchlora aerata) . XIV. INSECTS INJURIOUS TO THE GOOSEBERRY AND CURRANT Canes: (a) Tips of canes girdled and wilted; pith tunneled. — Currant Stem Girdler (Janus integer), p. 345. (b) Centre of cane tunneled by a white caterpillar. — Imported Currant Borer {Synanthedon tipuliformis), p. 217. (c) Small flat circular scales, black or gray, with a depressed ring about a central nipple in black forms. — San Jose Scale {Aspidiotus perniciosus) ^ p. 126. id) Oval hemispherical scales. — Currant Lecanium {Lecatiiumr ibis). (e) Longitudinal rows of punctures on canes. — Black-horned Tree Cricket (CEcanthus nigricornis), p. 116. IDENTIFICATION OF INSECTS INJURIOUS TO CROPS 85 Leaves: (a) Larvae, 20-legged, dull white when young, then greenish with black spots, finally greenish yellow, eating holes in the leaves in early spring. — Imported Currant Worm (Pteronus ribesii), p. 346. {h) Leaves curled, blistered, and with a reddish appearance on upper surface, caused by yellowish plant-lice — Currant Plant-louse (Myzus ribis), p. 145. (c) Leaves turning brown and dying. — Four Lined Leaf-bug {Pcecilocapsus lineatus), p. 1630 (d) Measuring worm feeding on leaves of gooseberry and black currant. — Currant Span-worm {Cymatophora ribearia), p. 206. (e) White spots on leaves, produced by a pale green sucking insect occurring on the under surface. — Currant Leaf Hopper (Empoasca), p. 155. (/) Green plant-lice. — Green Gooseberry Aphis {Aphis sanborni). Fruit: (a) Greyish caterpillar boring into young fruit and eating out its contents. — Gooseberry Fruit Worm {Zophodia grossularice). (b) Purplish spots surrounding small circular scales. — San Jose Scale (Aspidiotus perniciosus) , p. 126. (c) Yellow oval maggots eating the gooseberry. — Gooseberry Midge (Cecido- myia grossularice) . (d) Small white maggot eating the currant and gooseberry, causing the fruit to turn red and fall. — Currant Frtiit-miner {Epochra canadensis) , p. 265. XV. INSECTS INJURIOUS TO THE GRAPE (Consult Bull. 331, N. Y. Ag. Exp. St. and Farmers' Bull. 70, U. S. Dep. Ag.) Roots: (a) Producing soft yellow irregular spherical galls on rootlets and larger roots, causing death. — Grape Vine Phylloxera {Phylloxera vastatrix), p. 148. {b) Large borer, cutting a tube through the root near the surface. — Broad- necked Prionus {Prionus laticollis). {c) Grub eating the bark of both the large and small roots. — Grape Vine Fidia {Fidia viticida), p. 311. Branches: (a) Young shoots suddenly break ofif or droop in spring; a small hole just above the base of the shoot leading into a burrow. — Apple Twig Borer {Amphicerus bicaudatus), p. 327. (b) Canes show roughened longitudinal rows of perforations in the bark. — Tree Cricket {(Ecanthus nigricornis), p. 116. (c) Canes exhibiting white cottony masses attached to a reddish-brown scale. — Cottony Scale {Pulvinaria vitis), p. 130. Leaves: (a) Leaves riddled with irregular holes about mid-summer by a little beetle. — Grape Vine Fidia {Fidia viticida), p. 311. 86 ECONOMIC ENTOMOLOGY (b) Small, shining, blue beetle boring into buds in spring, also eating small holes in expanding leaves. — Grape Vine Flea Beetle (Haltica ckalybea), p. 315. (c) Long-legged brownish beetles eating the blossoms, leaves and fruit. — Rose Chafer (Macrodactylus subspinosus), p. 305. (d) Greenish caterpillar, feeding within a folded leaf and skeletonizing it, about mid-summer. — Grape Leaf Folder {Desmia funeralis). (e) Leaves blotched and scorched, finally curling up and falling, caused by- little jumping insects. — Grape Thrips or Leaf Hopper (Typhlocyba comes), P- 155- (/) Large greenish caterpillar, with a pale yellow stripe down each side and a horn near tail. — Grape Vine Sphinx {Ampeloeca myron), p. 178. (g) Several other sphingid larvae feed on the leaves of the grape. (h) Black beetle eating the tissues on the upper surface of the leaves, and discoloring them. — Red-headed Sysiena (Systena frontalis), p. 315. (i) Producing small, irregular, spherical galls on the lower surface of the leaves. — Grape Vine Phylloxera (Phylloxera vastatrix), p. 148. (j) Large reddish-yellow beetle with six black spots on wing cover, eating holes in leaves. — Spotted Pclidnota {Pelidnota punctata), p. 302. Fruit: (a) Ripening fruit discolored and burrowed by a whitish caterpillar. — Grape Berry Moth (Polychrosis viteana), p. 228. (b) Holes eaten in ripe fruit; beetle large, yellowish, hairy. — Bumble Flower Beetle (Euphoria inda), p. 305. (c) Holes eaten in young fruit by a long-legged beetle. — Rose Chafer (Macro- dactylus subspinosus), p. 305. XVI. INSECTS INJURIOUS TO THE STRAWBERRY Roots: (a) A pinkish caterpillar boring irregular channels through the crown and larger roots, causing them to wither and die. — Strawberry Root Borer (Anarsia lincatella), p. 215. (b) A white grub boring downward from the crown. — Strawberry Crown Borer (Tyloderma fr agar ice), p. 332. (c) A large white grub eating the roots. — May Beetle (Lachnosterna sp.), p. 302. (d) Grubs girdling the roots, causing death. — Strawberry Root-weevil (Otio- rhynchus ovatus), p. 336. Leaves: (a) Brownish caterpillars, in June and August, rolling the leaves into cases and fastening them with silk. — Strawberry Leaf Roller (Ancylus comptana), p. 232. (b) Young plants gnawed off at the surface. — Cutworms, p. 185. (c) Small pale spotted active beetles riddling the leaves with holes in June. — Spotted Paria (Paria 6-notata). (d) Small active jumping striped beetles, eating holes in the leaves. — Striped Flea Beetle (Phyllotreta vittata), p. 314. IDENTIFICATION OF INSECTS INJURIOUS TO CROPS 87 (e) Twenty-legged grubs eating holes in the leaves. — Strawberry Saw fly {Emphytus maculatus) Fruit: (a) Caterpillars feeding on the berry. — Stalk Borer (Papciperna nitela), p. 196. {b) Minute black bugs producing a buggy odor when eaten with berry. — Flea- like Negro Bug (Corimelcena pulicaria), p. 167. (c) Flower buds drooping and bending over. — Strawberry Weevil {Anthonomus signatus), p. 332. (d) Fruits deformed to "buttons. " — Strawberry Thrips (Euthrips tritici), p. 122. XVII. INSECTS AFFECTING SHADE TREES (Consult Insects Affecting Park and Woodland Trees by Felt) (a) Feeding on the leaves. (b) Feeding or resting under webbed tents. (i) Hairy yellowish-brown and black marked caterpillars feeding on leaves within webbed tents in July-Sept.; adult moths white or black-spotted. — Fall Web Worm (Hyphantria cnnea), p. 181. (2) Hairy black caterpillars, white stripe along middle of back, lateral white and yellow line with blue spots. Resting in silken webbed tents at angles of branches. — Orchard Tent-caterpillar {Malacosoma americana), p. 203. ^bb) Feeding free on the leaves. I. Adult moths not white. (1) Caterpillars with a broken line of white dots along back, and resting in masses on sides of branches and trunks, not within webs. — Forest Tent-caterpillar {Malacosoma disstria), p. 204. (2) Caterpillars with red heads and yellow and black tufts and pencils. Female moth wingless. — White-marked Tussock Moth (Hemerocampa leucostigma), p. 202. (3) Brownish caterpillars with blue and reddish warts; hibernat- ing as egg-masses covered with hair; adult female moth with white wings marked with dark wavy lines, wings of males light brown. — Gipsy Moth (Porthetria dispar), p. 200. (4) "Measuring worms" feeding in the daytime in spring and early summer. — Fall Canker Worm {Alsophila pometaria), p. 205. (5) Caterpillars with tufts of white, black, or yellow hairs, and pencils of black or orange or white hairs. Feeding on hickory, butternut, etc. — Tiger Moths {Halisidota spp.), p. 183. (6) Caterpillars with sharp pale yellow hairs and with a pair of long black hair pencils on the first and third abdominal segments, and a single one on the eighth. Feeding on elm, maple, hickory, oak, ash, poplar, etc. — American Dagger Moth {Acronycta americana), p. 198. 88 ECONOMIC ENTOMOLOGY (7) Caterpillars black with a loose covering of soft whitish hairs. Feeding in clusters on walnut, hickory, oak, beech, etc. — Walnut Caterpillar (Datana integer rim a), p. 199. (8) Small grcon caterpillars, skeletonizing the leaves of birches and forming small round white moulting cocoons on the twigs and leaves. — Birch Leaf Skelelonizer (Bucculatrix canadc'isiscllo), p. 236. (9) A bright yellow looper with rust-colored head and with ten crinkled black lines along the back. Attacks elm, basswood, hickory, apple, etc. — Lime-tree Winter Moth (Erannis tiliaria). 2. Adult moths white. (i) Caterpillars reddish-black with only two pairs of prolegs; with three pairs of small tubercles on back; hibernate as egg- masses of 20-100 on hranchcs.-^Snow-ivhite Linden Moth {Emiomos subs igniar ins), p. 206. (2) Dark brown caterpillars, with a lateral row of white hairs and bright red tubercles on sixth and seventh adbominal seg- ments; hibernate as one-fourth grown caterpillars in nests of webbed leaves on tips of trees; adult moth with a tuft of brown hairs at tip of abdomen. — Broivn Tail Moth {Enproctis chrysorrJuva), p. 200. 3. Adults are butterflies. Caterpillars large, black, red-marked and spiny, feeding in clusters on terminal branches of elm, willow, \)0\Aixx.— Spiny Elm Caterpillar {Aglais antiopa). p 176. 4. Adults are beetles. Adults eating irregular circular holes in elm leaves and grubs skeletonizing the under surface. — Elm Leaf Beetle {GalcniccUa lutcola), p. 309. 5. Adults are Saw-flies. (i) Larvaj cylindric, coiled, yellowish-white, with a black line down the middle of back, feeding on elm, poplar, willow, etc. — Elm Saw-fly {Cimbex amcricana), p. 347. (2) Larvaj with jet black head and green body, each segment except second marked with double parallel rows of dark dots; feeding on larch leaves. — Larch Saiv-fly {Lygceonemalus erichsonii), p. 346. (aa) Boring in trunks and branches. (b) Adults are moths. 1. Whitish caterpillars with distinct spots and tubercles making burrows in twigs and larger branches, which often die and project above leafy branches. Moths are white with blue and black markings. — Leopard Moth (Zctizcra pyrina), p. 237. 2. Large white or reddish-white caterpillars making large round irregular borings in oak, maple and locust. Moth is large, dark grey. — Carpenter Worm {Prionoxystiis robinice), p. 238. IDENTIFICATION OF INSECTS INJURIOUS TO CROPS 89 (bb) Adults arc beetles. 1. Long-horned or cerambycid beetles. (i) Large fleshy legless grubs making broad shallow tunnels in sapwood of sugar-maples, often killing limbs. Adult beetle brilliantly marked with yellow and black. — Sugar Maple Borer {Plagionolus speciosus), p. 323. (2) A whitish hairy grub making a central burrow plugged with sawdust, and cutting off twigs of maple or oak. — Twig Primer {Elaphidion vlUosum), p. 323. (3) White flattened legless grubs working under the bark of elm; adult a gray beetle with red lines and black spots. — Elm Borer (Saperda tridentata) , p. 321. (4) White legless grubs making large irregular channels in sap- wood and inner bark of poplar; large blackened swollen scars on the surface of the trunk and limbs of affected trees. — Poplar Borer {Saperda calcarata) tunnels in poplar producing rough discolored scars on the trunk. Saperda Candida bores into hawthorn, mountain ash, and fruit trees, and Saperda vestita into basswood. (5) Club-shaped grubs, making irregular ugly scars opening into burrows in black locust. Adult beetle is dull black brightly marked with golden yellow, and feeds on golden rod blossoms. — Locust Borer {Cyllene robinice), p. 321. 2. Metallic wood borers or Buprestid beetles. (i) Large headed flattened legless grubs making shallow tunnels. — Flat-headed Borer (Chrysobothris femorata), p. 300. (2) A flattened whitish grub with a large flattened head, making irregular spiral burrows in the inner bark of birch. — Bronze Birch Borer (Agrilus anxius), p. 301. (aaa) Sucking the juices from twigs or leaves. (b) On the leaves. 1. Producing terminal galls on white and Norway spruce; branch scraggly deformed. — Spruce Gall Aphis {Chermes similis), p. 150. 2. Producing galls on white and Norway spruce, not terminal, pine- apple shaped. — Spruce Gall Aphis {Chermes abietis), p. 149. 3. Snow-white woolly plant-lice on leaves of larch. — Larch Woolly Aphis {Chermes strobilobius). [bb) On the bark. 1. Clusters of woolly aphis on elm. — Woolly Aphis of Elm {Schizoneura americana), p. 145. 2. Reddish woolly bordered bark-lice on under surface of elm leaves. — Elm Bark-louse {Gossyparia spuria), p. 130. 3. Cottony masses attached to brown scales on under side of twigs of soft maple, elms, etc. — Cottony Maple Scale {Pulvinaria vitis), p. 130. QO ECONOMIC ENTOMOLOGY 4. Hemispherical reddish scales mottled with black lines on under side of branches of maples. — Terrapin Scale (Lecanium nigrofas- ciatuni), p. 129. 5. Flocculent white masses upon greenbark of cultivated white pine. — Pine Bark Aphis {Chermes pinicorlicis) , p. 150. 6. Twigs of balsam twisted and leaves curled by plant-lice. — Balsam Twig Aphis (Mindarus abietimis). XVIII. INSECTS INJURIOUS TO GREENHOUSE PLANTS (a) Minute active white four-winged flies living on the under side of leaves, sucking the juices; young are oval, flat and greenish. — White Fly {Aleyrodes vapor- ariorum), p. 151. (b) Small soft mealy-covered bugs, with eggs enclosed in cottony sacks. — Mealy Bugs (Pseudococcus spp.), p. 131. (c) Oval, flat or saddle-shaped scales, on leaves of lemons, ferns, oleanders, crotQns, etc. — Soft Scale {Lecanium hemisphericum), p. 134. (d) Round scales on leaves and twigs of ivy, date palms, etc. — Hard Scale (Aspidiotus spp.), p. 134. (e) White scales on leaves of Boston fern, aspidistra, etc., causing spotting and browning. — Aspidistra Scale {Hemichionaspis aspidistrce), p. 135. (/) Green plant-lice, often infesting violets and sucking the juices from the leaves, checking the growth. — Green Aphis {Myzus persicce), p. 144. (g) Black plant-lice sucking the juices of chrysanthemums. — Black Aphis (Macro- siphum sanborni), p. 149. (h) Red mites, spinning fine webs on under surface of leaves and sucking the juices rendering the leaves sickly yellow. — Red Spider {Tetranychus bimaculatus). (i) A small maggot, causing the edges of violet leaves to curl and turn yellow. — Violet Gall-fly {Diplosis violicola) . (j) A small greenish-white and striped caterpillar, eating lower epidermis of chrysanthemums, cinerarias, roses, carnations, etc., and tying the leaves together. — Greenhouse Leaf-tyer {Phlyctcenia ferrugalis), p. 210. {k) Maggots feeding in flower and leaf buds of greenhouse roses, causing them to brown, blacken and die. — Rose Midge (Dasyneura rhodophaga), p. 248. (l) Flesh-colored legless grubs attacking roots of cyclamen, gloxinia, primula. — Cyclamen Borer {Otiorhynchus sulcatus), p. 336. XIX. INSECTS AFFECTING DOMESTIC ANIMALS (Consult Insects Affecting Domestic Animals by Osborn, Bull. 5, U. S. Div. Ent.) A. Sheep (a) Maggots in nostrils and in nasal sinuses, causing catarrh and staggers; deposited by a two-winged fly in June and July. — Sheep Bot-fly {(Estrus oms). (b) Wool falls off in patches and large scabs form on body with much itching due to a mite. — Sheep Scab {Psoroptes communis)^ p. 366. IDENTIFICATION OF INSECTS INJURIOUS TO CROPS QI (c) Brownish flattened tick-like insects sucking the blood ; common on lambs in spring. — Sheep Tick {Melophagiis ovinus), p. 279. B. Cattle (a) Swellings or "warbles" along the back in winter; bee-like flies bothering cattle in June and July. — Ox-warble (Hypoderma lineaium and H. hovis), p; 255. {h) Small flies clustering on base of horns, flanks and belly of cattle in summer, causing them much annoyance, — Horn Fly {HcBmatohia serrata), p. 272. (c) Slaty-colored sucking lice, often abundant on neck and shoulders of neglected cattle. — Short-nosed Ox Louse {Hcematopinus eurysternus), p. 000. Long-nosed Ox Louse (Hcematopinus vituli), p. 169. (d) "Little red lice" feeding on the rough parts of the skin and on the hairs, causing irritation; most abundant in spring. — Biting Cattle Louse {Trichodectes scalar is), p. 100. (e) Hair falls off in patches and large scabs form — with much itching — due to mites. Common Cattle Scab Mites (Psoroptes Communis bovis), Sarcoptic Scab Mite (Sarcoptes scabiei bovis), Tail Mange Mite (Chorioptes bovis bovis). (See Farmers' Bull. 1017, U. S. Dep. Ag.). C. Horses (a) Bots attached to wall of stomach — adult fly light brown; does not bite but horse is worried; eggs laid on hairs of legs and shoulders. — Horse Bot-fly (Gastro- phiius intestinalis) , p. 258. (b) Similar to (a) but eggs are attached to hairs of lips and nostrils. — Chin Bot-fly (Gastrophilus nasalis) and the Red-tailed Bot-fly (G. hcemorrhoidalis) , p. 259. (c) Large black fly that flies swiftly and bites severely, giving much annoyance to horses. — Horse Gadfly (Tabanus atratus), p. 252. D. Hogs (a) Gray sucking lice, often quite large. — Hog Louse (Hcematopinus urlus), p. 169. E. Poultry (a) Yellowish or reddish mites infesting hens and chicks at night; piercing the skin and sucking the blood, causing much irritation and often death. — Chicken Mite (Dermanyssus gallince), p. 364. (b) Small pale yellow active insects feeding on rough parts of skin and bases of hairs and feathers, causing much irritation. — Common Hen Louse (Menopon pallidum), p. 100. (c) Minute mites burrowing under the scales of foot, leg, comb and beak, pro- ducing "scaly leg" with much irritation. Contagious. — Itch Mite (Sarcoptes mutans), p. 365- (d) Small mites causing the feathers to break off. Contagious. — Depluming mite (Sarcoptes gallincs). 92 ECONOMIC ENTOMOLOGY XX. INSECTS OF THE HOUSEHOLD A. Annoying the Inmates (a) Slender two-winged insects; only the females bite or pierce the skin; larvas and pupae live in stagnant water. — Common Mosquito {Culex pipiens), p. 243. (b) Similar to (a) but larger and with wings spotted. — Malarial Mosquito {Ano- pheles macidi pennis) , p. 244. (<■) Two-winged insects, with four black lines on thorax; they lap but do not pierce; eggs laid on manure or decaying organic matter. — House Fly (Musca do- mestica), p. 270, {d) Similar to (c) but with six black lines on thorax, and with piercing mouth- parts. — Stable Fly (Stomoxys calcitrans), p. 271. (e) Compressed, wingless long-legged insects with piercing and sucking mouth- parts, hiding in bedding and clothing; eggs laid among hairs of cat or dog. — Cat and Dog Flea (Pulex serraticeps), p. 280. (/) Reddish-brown, flat bugs with buggy odor, hiding in day time in cracks, but active at night; with piercing and sucking mouth-parts. — Bed-hugs {Cimex lectu- larius), p. 167. B. Feeding on or Destroying Clothing, Carpets, Upholstery, Etc. (a) Tiny dusky moths, laying eggs in furs or woolens, the larvje eating holes in them. — Case-making Clothes Moth {Tinea pellionella), p. 236. Webbing Clothes Moth {Tinea hiselliella) , p. 237. Tapestry Clothes Moth {Trichophaga tapetzella), p. 237. {b) Small oval red, black and white beetles, whose grubs are hairy, feeding on carpets on underside, usually along a crack of the floor. — Buffalo Carpet Beetle {Anthrenus scrophtdarixe), p. 291. {c) Tiny active wingless insects with silvery appearance, and with three long feelers at hind end of body, feeding on linen or paper containing starch, sugar, etc. Silver-fish {Lepisma saccharlna), p. 95. C. Feeding on Food Products (a) Active wary light-brown insects with a "roachy" odor, found in pantries and bakeries; several species but the most common is the Croton-bug or German Cockroach {Ectobia germanica), p. 105. {b) Brown beetles, one-third inch long, whose grubs are brown above, white below and covered with long brown hairs; found where meats, skins and feathers are kept. — Larder Beetle {Dcrmestes lardarius), p. 291. (c) Large black flies with bluish abdomen and with black spines on thorax; eggs laid on meat. — Blow or Meat Fly {Calliphora vomitoria), p. 273. {d) Little red ants that have their nests in the wall or beneath the flooring. — House Ants {Monomorium pharaonis), p. 361. (e) Black ants and pavement ants living outdoors sometimes invade houses. — Black Ants {Monomorium minutum), p. 361. PART III CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS THE COMMON ORDERS AND GROUPS OF INSECTS SYNOPSIS OF THE ORDERS OF INSECTS REFERRED TO IN THE CLASS BOOK Aptera Group. I. Thysanura. II. Collembola. Neuropteroida Group. Orthopteroida Group. Hemipteroida Group Dipteroida Group. I III. Plecoptera. IV. Ephemerida. V. Odonata. VI. Neuroptera. VII. Mecoptera. VIII. Trichoptera. IX. Mallophaga. X. Isoptera. XI. Corrodentia. XII. Blattoidea. XIII. Mantoidea. XIV. Phasmoidea. XV. Dermaptera. XVI. Orthoptera. XVII. Thysanoptera. XVIII. Homoptera. XIX. Hemiptera. XX. Siphunculata. XXI. Lepidoptera. XXII. Coleoptera. XXIII. Diptera. XXIV. Siphonaptera. XXV. Hymenoptera. A. With two wings; mouth-parts formed for sucking or piercing; metamor- phosis complete.— /)/Pr£i?^ (Flies). 93 94 ECONOMIC ENTOMOLOGY AA. With four wings. B. Mouth-parts formed for biting. C. Upper wings horny; metamorphosis complete. — COLEOPf^^^ (Beetles), p. 280. CC. Upper wings parchment-like; lower wings folded under the upper; metamorphosis incomplete. — ORTHOPTeROIDA Group (Locusts, etc.), P- 102. CCC. Upper wings membranous with many veins. — NEUROP- TEROIDA Group (Nerve- winged insects), p. 96. BB. Mouth-parts formed for sucking and biting; wings with few cross veins and similar in texture; metamorphosis complete. — HYMENOP- TERA (Bees, etc.), p. 343. BBB. Mouth-parts formed for sucking; wings covered with scales; metamor- phosis covaT^l&te.—LEPI DOPTERA (Butterflies and moths), p. 169. BBBB. Mouth-parts formed for piercing. C. Beak jointed; palpi absent; last joint of tarsi not bladder-like, D. Wings of uniform texture; beak arising from the hinder edge of under side of the head; metamorphosis incomplete. —HOMOPTERA , p. 1 2 2 . DD. Fore wings leathery at base, membranous at tip; beak arising from the front of the head; metamorphosis incom- plete.— .STEikf/PrE/?^ (True Bugs), p. 158. CC. Beak unjointed, palpi present; last joint of tarsi bladder-like, and without claws; wings similar; metamorphosis incomplete. — THYSANOPTERA (Thrips), p. 118. AAA. Wingless. B. Mouth-parts formed for biting; louse-like insects. C. Mouth-parts retracted within the head; no metamorphosis. — APTERA Group, p. 94. CC. Mouth-parts not retracted within the head. D. Antennae with many segments; metamorphosis incomplete. —CORRODENTIA (Book-lice), p. 103. DD. Antennae with not more than five segments; metamorpho- sis incomplete. — MALLOPHAGA (Biting-lice), p. 100. BB. Mouth-parts formed for sucking. C. Tarsus with a single hook-like claw; with a fleshy unjointed beak; parasitic on mammals {Parasitica). — SIPHUNCULATA, . p. 167 CC. Tarsus five- jointed; body compressed; metamorphosis complete. — • SIPHONAPTERA (Fleas). The Aptera Group Chief Orders and Families: A. Abdomen with at least 10 segments; antennae many-jointed; usually with terminal abdominal appendages. — Thysanura Order. B. Body covered with scales. — Lepistnidce. CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 95 BB. Body not covered with scales. C. Caudal appendages many-jointed. — Campodeidce. CC. Caudal appendages sickle-shaped. — Japygida. A A. Abdomen with not more than six segments; antennae with not more than eight joints; no caudal appendages. — Collemhola Order. B. Ventral spring present. C. Spring on penultimate abdominal segment. D. Abdomen globular. — Sminthurida. DD Abdomen cylindrical. — E^itomohryida. CC. Spring on antepenult abdominal segment. — Podurida. BB. Ventral spring absent. — AphoruridcB. Of the above Apterous families only one, the Lepismidcs of the Thysanura, contains forms that are of economic importance. ORDER THYSANURA LEPISMID^ (Fish-moths) The Fish-moth, Silver Fish, or "SUcker" [Lepisma saccharina Linn.) sometimes does injury to books, papers, labels and starched clothing. It shuns light and is quite active. Adult. — A minute, glistening, scaly, fish- like active insect, wingless, 3^-^ inch long, body tapering to hind end where are three long, bristle-shaped appendages; antennae prominent; coxae strongly developed; biting mouth parts. Another species, Lepisma domesHca Pack., is found in bakeries and mills in some locali- ties. It has dusty markings on its upper surface and is 3^^ inch long. Control. — Frequent use of fresh insect powder, sodium fluoride, or a poison-bait of sweetened gluey paste and white arsenic on bits of cardboard. PODURED^ (Springtails) Fig. 50. — The silver fish (Lepisma saccharina). (After Marlatt.) Two species may be noted in passing: Achorutes armatum sometimes attacking seedhngs causing disfigure- ment and loss, and A. nivicola often abundant in maple sap in early spring. Both species are minute, and have some of the habits of flea-beetles (Fig. 51). 96 ECONOMIC ENTOMOLOGY The Neuropteroida Group Certain orders of aquatic insects have a superficial resemblance of wing venation, and were formerly grouped together into one order, the Neuroptera. Of the six main Orders three have incomplete metamorphosis, viz., Plecoptera, Ephemerida and Odonata, and three complete metamorphosis, viz., Tri- choptera, Neuroptera and Mecoptera. It is probable, therefore, that the first three orders are not so highly evolved as the last three. The former are lower than the Orthoptera, while the latter are higher and come between the Hemiptera and the Lepidoptera. Chief Orders:^ The Neuropteroida (or nerve-winged) group of insects includes six main orders which may be sepa- rated as follows: A. Lower wings folded in plaits under the upper. B. Wings covered with hairs; tarsi 5-jointed; metamorphosis complete. — Trichoptera (Caddice-flies). BB. Wings not covered with hairs. C. Tarsi 5-jointed; wings equal and with many veins and cross-veins; mouth-parts well developed; metamorphosis complete. — Neurop- tera (Dobson flies, Aphis lions, etc.). CC. Tarsi 3-jointed; hind wings larger than fore-wings; with caudal filaments; biting mouth-parts poorly developed; metamorphosis incomplete. — Plecoptera (Stone-flies) (Fig. 54). AA. Lower wings not folded under the upper. B. Head prolonged into a beak; antennae long; metamorphosis com,- plele. — Mecoptera (Scorpion-flies). BB. Head not prolonged into a beak; antennae inconspicuous; metamor- phosis incomplete. 1 Handlirsch arranges these orders into groups as follows: Odonata Sub-class Libelluloidea. Plecoptera (Ephemerida) Sub-class Ephemeroidea. Plecoptera Sub-class Perloidea. Neuroptera | Megaloptera [ Sub-class Neuropteroidea. Raphidioidea J Panorpatae ] Trichoptera \ Sub-class Panorpoidea. Lepidoptera Fig. 51. — The snow flea (Achorutes nivi- cola). Enlarged greatly. {After Folsom.) CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 97 C. Abdomen with 2 or 3 long filaments; lower wings much smaller than upper; antenna; short.—Ep/icnicrida (May-flies) (Fig. 53). CC. Abdomen without jointed filaments; wings about equal in size; antennae short. Odonata (Dragon-flies). The larvae of most of the Neuropteroid insects are aquatic and are of little economic importance in agriculture. They are of importance, however, in fish- culture. In the Stone-flies Newcomer has recently reported that several species of Taniopteryx (especially T. pacifica) with well developed mouth-parts cause consider- able injury to foliage and fruit in Central Washington. Fig. 52. — May-fly (Hexagenia), adult. (After Folsom.) Fig. 53. — M ay-fly, nymph. LARVAL FORMS OF THE NEUROPTEROIDA A. Body cylindrical, caterpillar-like. — Mccoplcra. AA. Body more or less depressed, not caterpillar-like. B. Mandibles united with corresponding maxilla?. — Neuropiera. BB. Mandibles separate from corresponding maxilla;. C. Body encased in a shell of gravel, etc. — Trichoplera. CC. Body not encased in a shell. D. Abdomen with external lateral gills and terminated by 2 or 3 long gill processes. — Ephcmerida (Fig. 53). gS ECONOMIC ENTOMOLOGY DD. Abdomen without external lateral gills. E. Lower lip strong extensile and furnished with a pair of opposable hooks; abdomen terminated by 3 leaf -like tracheal gills, or with 5 spine-like appendages. — Odonata. EE. Lower lip not extensile and without hooks; caudal filaments and antennae long and slender; thorax with 3 pairs of tracheal gills. — Plecoptera. On account, however, of their common occurrence the economic entomologist should know a little at least regarding their habits and life-history. Stone-flies (Plecoptera). — The nymphs live under stones in swift streams, are flattish, and have tracheal gills, long legs, cerci and Fig. 54. — An adult stone-fly {Pteronarcys regalis). Folsom). Slightly reduced. {After antennae. The adults are greyish and have prominent wings. The hind wings are the larger and when at rest are folded under the front ones. The larvae furnish food for fishes (Figs. 54 and 55). May-flies (Ephemerida). — May-flies are well-known insects, being attracted to lights in immense numbers in early summer. They have large delicate wings and 2 or 3 long caudal filaments. The fore wings are much larger than the hind ones. The nymphs live at the bottoms of bodies of water, and have long legs, caudal filaments and prominent tracheal gills. They mature in i to 3 years, and furnish abundant food for fishes. CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 99 Dragon-flies and Damsel-flies (Odonata). — These insects are also well known. They are rapid fliers over bodies of water, feeding on flies and mosquitoes. The nymphs live at the bottom of ponds and streams. They have long legs, and are flat and spiny. Dragon-flies hold their wings horizontally when at rest, and the nymphs have rectal respiration; while the damsel-flies hold their wings vertically when at rest, and the nymphs have three caudal tra- cheal gills (Fig. 56). Caddice-flies (Trichoptera). — The larvce of these insects are known as caddice-worms, and live in water within protecting cases of fine gravel, leaves, sticks, stalks or small shells, fastened together by threads of silk. They crawl about carrying their cases with them. When full-grown they change to pupce within the cases and at length emerge as four-winged flies. During summer immense numbers are attracted to lights at night. The wings are hairy, and, at rest, are held like a roof over the back. The eggs are usually laid on water plants. Fig. 55. — Nymph of s t o n e-fl y (Pteronarcys regalis). Fig. 56. — Dragon-fly (Libellula pulchella). Last nymphal skin and wings. Slightly reduced. {After Folsom.) Dobson-flies, Lace-wings, Ant-lions (Neuroptera). — Dohson-flies are large insects with prominent biting mouth-parts and wings. Their larvae live under stones in swift streams, and have rather conspicuous tracheal gills. They become full-grown in about three years. lOO ECONOMIC ENTOMOLOGY Lace-wings are delicate pale-green insects with finely veined wings. The larvae have large jaws, and owing to their habit of feeding upon aphids are called aphis-lions. The pupae are enclosed in a white cocoon of silk (Fig. 57). Ant-lions are predaceous larvae, which lie in wait for their prey at the bottom of funnel- shaped pits. The adults have narrow delicate wings. (Chrysopa). siightirr'2 Scorpion-flies (Mecoptera.).— Scorpion-flies duced. {After Foisom.) have their head prolonged into a beak. The larvae live in the ground and are caterpillar- like. Both larva and adult are carnivorous. ORDER MALLOPHAGA (BITING LICE) * Chief Families and Genera: A. Antennae filamentous, exposed, 3- or 5-jointed; maxillary palpi absent; mandibles vertical; middle and hind segments of thorax fused. B. Antennae 3-jointed; tarsi with a single claw; infesting mammals. — TrichodectidcB. Genus: Trichodectes. BE. Antennae 5-jointed; tarsi with two claws; infesting birds. — PhilopteridcE. Genera: Docophorus, Lipeurus, Nirmus, Goniodes, Goniocotes. A A. Antennae clavate or capitate, concealed, 4-jointed; maxillary palpi 4- jointed; mandibles horizontal; middle and hind segments of thorax sepa- rated by a suture. J B. Tarsi with a single claw; infesting mammals. — Gyropidce. Genus: Gyro pus. BB. Tarsi with two claws; infesting birds. — Liotheidce. Genera: Menopon, Trinoton. (Consult Bull. 5i n.s. Divison of Etomology, U. S. Dept. of Agriculture, by Osborn) Although most commonly found on poultry, Biting Lice some- times infest the larger domestic animals. They do not suck blood but feed on the rough parts of the skin and at the base of hairs and feathers, causing considerable irritation. Young chicks frequently suffer severely from their attacks. The most abundant species found on fowls is the common hen louse {Menopon pallidum) y a pale yellow active insect, 3^^5 inch long, with six legs (Fig. 58). The eggs or ''nits" are oval objects attached to the vanes and CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS lOI barbs of the feathers, usually on the down feathers. They hatch in 8 to lo days and become full grown in 2 to 3 weeks. Dampness, filth and warm weather favor their increase. Control. — {a) Sanitary surroundings with access to a dust bath. {h) Dusting with lice powder, such as insect powder, or one pre- pared as follows: 3 parts gasoline, i part crude carbolic acid (90- 95 per cent.), or i part cresol. Mix together and add, with stirring, plaster-of-Paris to take up all the moisture (about 4 qts. to i qt. of liquid), {c) Dusting with sodium fluoride. All remedies should be applied more than once. Following are the common Mallophaga in- festing domesticated birds: A. Feather-lice Infesting Chickens: 1. Head nearly square, abdomen not con- spicuously marked, 3^^ 5 inch long. — Gonio cotes hologaster Nitzsch (Lesser Chicken Louse). 2. Head almost circular in front, nar- rowed behind, thorax small; head, thorax, and legs yellowish; white stripes on segment of abdomen, J^ inch long. — Goniocotes ahdominalis ^^^• Piaget (Larger Chicken Louse). 3. Yellowish with black markings, uncommon. — Goniocotes bur- netii Pack. 4. Smooth and shining, head squarish, }^iQ inch long, tawny, pubes- cent. — Goniodes dissimilis Nitzsch. 5. Body elongated, smooth and shining, black margins. — Lipeurus variabilis Nitzsch. 6. Yellowish, slender louse, J^o inch long, common. — Menopon pallidum Nitzsch (Hen or Chicken Louse) . B. Feather-lice of Ducks and Geese: 1. Head and thorax red with dark bands; abdomen whitish at middle, brown at sides, J.^ inch long. — Docophorus icterodes Nitzsch. 2. White, smooth, and shining, on goose. — Lipeurus tadorncB Denny. 58. — Chicken louse. {Menopon.) I0 2 ECONOMIC ENTOMOLOGY 3. Large, J^ inch long, elongated, yellowish, head cone-pointed, on ducks. — Lipeurus squalidus Nitzsch. 4. Large well-marked louse, J^ inch long, on ducks. — Trinotum luridum Nitzsch. 5. White, almost transparent louse, on goose. — Trinotum lituratum Nitzsch. C. Feather-lice of Turkey: 1. Head with hind angles extending backward into bristly styles; 3-^ inch long. — Goniodes stylifer Nitzsch. 2. Yellowish, elongated, flat pointed body, 3^f inch long. — Lipeurus poly trapezius Nitzsch. Orthopteroid Insects The old Order Orthoptera is now broken into several new Orders by the elevation of certain Families to ordinal rank. The relationship of these and other allied orders is shown by the following grouping: I. Sub-class: Orthopteroida. Orders: Orthoptera, Phasmoidea and the aUied orders Dermap- tera and Thysanoptera. IL Sub-class: Blattaeformia. Orders: Mantoidea, Blattoidea and the allied orders Tsoptera, Corrodentia and Mallophaga. Chief Economic Orthopteroid Orders: A. Hind femora large and fitted for jumping. — Orthoptera (Locusts, Crickets, etc. AA. Hind femora not large, not fitted for jumping. B. Body elongate; abdomen without movable forceps. C. Front legs spined and fitted for grasping. — Mantoidea (Mantids). CC. Front legs not formed for grasping, legs long and slender. — PhaS' moidea {Walking sticks). BB. Body elongate; abdomen with movable forceps; fore wings short and horny, hind wings nearly circular. — Dermaptera (Earwigs). BBB. Body oval, flattened; legs fitted for running. — Blattoidea (Cockroaches). ORDER ISOPTERA (WHITE ANTS) Family TERMITID^ This order is characterized by incomplete metamorphosis, biting mouth-parts and net-veined wings that fold flat upon the back. CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS IO3 There is but one Family — the Termitidce. The members of each species live in communities in the ground or sometimes on trees and include males, females and neuter workers and soldiers. They feed upon vegetable fibre, and are often injurious to furniture, books and wooden structures. Termites are most abundant in tropical or semi-tropical countries. A few species such as Leucotermes flavipes are found as far north as Canada. ORDER CORRODENTIA (BOOK-LICE) Family PSOCID^ These insects have biting mouth-parts and are either wingless or with roof-like wings. The Family FsocidcB includes the minute book-lice which are often injurious to old books, herbaria and insect collections. The most common species is Atropos divinatoria, a minute, pale-colored wingless insect. It feeds upon the paste of book bindings and upon decaying vegetable and animal matter. Control. — When severe infestations occur, fumigate with sulphur (2 lb. to 1000 cu. ft.) or with hydrocyanic acid gas. ORDER BLATTOIDEA (COCKROACHES) FamUy BLATTID^ Genera and Species: A. Last ventral segment of female abdomen plane not compressed; fore femora rarely provided with spines. B. Sub-genital stylets present in the males, upper wings of females short. — Ischnopiera. I. pennsylvanica brown, sides of pronotum yellow. BB. Sub-genital stylets absent in the males. Upper wings of both sexes long. — Blattella = Ectohia = Phyllodromia. B. germanica (Croton bug), length 3^^ inch, A A. Last ventral segment of female abdomen compressed and divided; fore femora spined. B. Wing-covers not reaching tip of abdomen. — Blatta. B. orientalis (Oriental Cockroach). BB. Wing-covers reaching beyond the abdomen. ^ — Periplanela. C. Wing-covers much exceeding abdomen. — P. americana. CC. Wing-covers but little exceeding abdomen; a bright yellow stripe on basal half of their outer margin. — P. ausiralasice. I04 ECONOMIC ENTOMOLOGY Several injurious species of cockroaches occur: (i) American (M)ckroach, (2) Australian cockroach, (3) Oriental cockroach, and (4) German cockroach or (Proton Bug. I. American Cockroach {Periplamia amcricanah.), a native species, is a large dark brown insect 1^2 inches long, with well-developed wings in holh sexes, i,'2~2 inches long; thorax with an obscure yellow border. iOggs held within a capsule until hatched. Duration of life-cycle about a year. Nocturnal. Fh,. 50. -The oriental roacli {Hlalld on'rnlalis) : a, fi'inali"; h. male. All natural size. {After Marlall, U. S. linr. lint.) 2. Australian Cockroach (Periplancta anstralasice L.), ij:^ inches long; resembles ])reeeding but the yellow band on thorax is much brighter and more definitely limited. Uj)|)er wings have a dash of yellow on each side. yVbundant in the south. 3. Oriental Cockroach {Blatta oricn/alis ¥o\.) or "black beetle," is a nearly wingless dark brown or black robust form, about an inch long- the male with wing cases one-half to three-fourths length of abdomen; female wingless. Notably gregarious and larger than the Crotoii iUig (l^'ig. (^()). CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 105 4. German Cockroach or Croton Bug {Edohia germanica L.), has a light brown thorax marked with two dark brown stripes. Both sexes with well-developed wings. Active and wary, relatively small, J^g inch long. All the roaches have a fcx'tid roachy odor, and are said to feed on the bedbug (Fig. 60). They are particularly abundant in pantries, kitchens and bakeries and they feed on almost any kind of dead animal matter and cereal products. The eggs are produced in a brown cap- sule which is often carried about for a time before deposited in a crev- ice or nook. Control. — A bait of powdered borax mixed with sweetened chocolate; a trap of flour and plaster-paris and water; fumigation with hydro- pic 60. — The German roach (Eclohia germanica) : a, first stage; h, second stage; c, third stage; d, fourth stage; e, adult; /, adult female with egg case; g, egg-case, enlarged; h, adult with wings spread. All natural size except g. (From Riley.) cyanic acid gas. Dust the runways or hiding places with sodium fluoride mixed with flour by means of a dust gun or blower. Boric acid is also effective. ORDER MANTOIDEA (PRAYING MANTIDS) Family MANTIDiE The Praying Mantids are predaceous insects and for centuries have been looked upon as uncanny creatures both in the old and new worlds. The most common American species is Siagmomantis Carolina, but this form does not breed normally north of southern New Jersey, Pennsylvania and Ohio. In 1899, however, the European species I06 ECONOMIC ENTOMOLOGY (Mantis religiosa Linn.) was found in New York State, and in 1914 in Ontario. The adult forms. are elongated, with large grasping forelegs, long prothorax and a small transverse head. The eggs are laid in shingled masses on twigs, coated with a hard gummy substance. ORDER PHASMOroEA (WALKING-STICKS) Family PHASMID^ This Family is represented by the common Walking-stick insect {Diapheromera femorata, Say), a peculiar creature with long slender body and legs. The outer wings are either wanting or very short. Life-history. — The eggs are dropped singly in autumn from the shrubs and rest on the ground all winter among the leaves, hatching in early summer. The nymphs feed upon leaves, and reach maturity in late summer and early fall, when they resemble the twigs upon which they rest. Occasionally this insect becomes injurious on hazel and beech. ORDER DERMAPTERA = EUPLEXOPTERA (EARWIGS) European Earwig (Forficula auricular i a lAnn.). — This insect is held in check in Europe by parasites and other natural agencies but the practical absence of these checks allows it to multiply rapidly in America wherever it has been introduced. At Newport, R. I., it is a serious pest of Lima-beans, dahlias, early roses, chrysanthemums, clovers, grasses, etc. The adult females hibernate in the soil, and the white eggs are laid in the soil. The nymphs are night feeders. They are white at first but gradually darken in color to a steel grey — 4. instars. Adults ap- pear about the middle of July. They are rich reddish brown with yellow brown wing-covers and legs; about % inch long. The forceps is nearly straight in the female, but curved in the male. Control. — Use poison bait before July ist and spray plants with arsenate of lead; collect by traps. Labia minor Linn., also an adventive earwig from Europe, is widely distributed in U. S. and Canada. Not of economic importance. CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS I07 ORDER ORTHOPTERA (LOCUSTS, GRASSHOPPERS AND CRICKETS) FAMILIES A. Antennae shorter than body. — Acrididce {Locusts or Short-horned Grass- hoppers) . AA. Antennae longer than body. B. Tarsi 4- jointed. — Locustidce (Long-horned Grasshoppers). BB. Tarsi 3- jointed. — Gryllidce (Crickets). AcRiDiDiE (Locusts or Short-Horned Grasshoppers) Sub -families, Genera and Species (Figs. 61-63). Sub-families: A. Pronotum extending over abdomen; claws of tarsus without pulvillus; size small. — Tettigince. C€K g.pl. ' oyp. Fig. 61. — Abdomen of female Melanoplus hivittatus. A, lateral view; B, dorsal view; C, central view; D, egg guide; au., the auditory organ; sp., spiracle; ovp., ovipositor; g.pl., genital plate; p.pl., podical plate; cer., cercus. {After Lugger.) A A. Pronotum not extending over abdomen; claws of tarsus with pulvillus; size larger, B. Prosternum with tubercle. — Acridince. BB. Prosternum without tubercle. C. Vertex and front of head meeting at an acute angle. — Tryxalina. CC. Vertex and front rounded. — (Edipodince. jo8 IH'ONOMIC I'.N rOMOl-OC.Y (.Iffura oj the rclliniihr: A. Anlcniur i .• joiiilcd ;iiir()iu)lum liori/.oiilid. Tclti^'tdca. (l''or sptrirs sit nhilchlcv's Orlliof'hru of Indiami.) ii'tnriii of tlif Acridiuw: A. Willis as long or longer than (lu- abdomen. |{. rronoluin sK>i)ing from median earina; ("xl remit y of ahdonun in males not swolliMi. Ainen t>f male Miliinol'l us hirillnlus. A, lali-ial \ irw ; />', dorsal view; ( ', vfiUral \ lew. (.1 //(•;■ l.l(( its A. AA. .S'/>(< Its A A A ()/ .1< lidium: Si/.e large; antenna* rather sliorl. .1. amcrhtitui. Si/e medium; antiMina' longiM'. 1>. Color yelK>wish brown oi' i»li\i" green. .1. oliihutui. WW. Color rusty brown; uo yeIK>wisli slripi- on dorsum. .1. rii}>i\^inos. Length of body to tip oi wing eovers ^^-2(1 mm. -M. allani.w Apex of last ventral segment of male entire, ov at least obscurely notched. W. Anal ii-rei enlargi^l at api-x. M . hivilhilns. lib. Anal cerci tapering. ('. Species o{ medium si/e; anal lerci much nai rowed, but without a n<>tch. .1/ . femur rubnini. ('('. Species of large si/.e; anal cerci suihlenly narrowed, making a promimnt right angled notih on lower side. — M. diffcrcnl'itilis. CLASSTFTrATTON AND DESPRIPTTON OF COMMON TNSErTR TOQ (icHmi of the 'Vryxalimr: A. I''()V(;oIiL' of vertex [)r('soii(, ;in«l visihUt froni above. I.aleial (:itiii;e of j>r()iu)Luni incurved. Slcnuhothnis < iirli /tenuis. AA. I'oveoltc absent; lateral carina- nearly parallel. — Chrysochrdon (onsl)irsnni. Genera and Species of (luUfxxHtKr: A. Wings witJi tlu; disk yellow. I{. Apical half of wing dusky. C. Dorsal aspect of liead with a slight median carina which is (juile prominent in the central iovcoUi.- J'lnco/Holoph us sordidus. (X'. Dorsal aspect of head without median carina; central foveola less distinct. — Chorlophaga viridijasciala. lili. Willi a dark band across the wings. Sph(irti^!,eni()n tcijUitle. A A. Wings wilh (he disk black. Dissosleira caroHtui. AAA. Wing.s transi)aren( willi dark V(;ins; Icgmina smoky brown willi darker spots and yellowish bloh hcs on sides. — Camnula pcUiicida. Pig. 6.^ 'I'ij) of male abfjonicn of Mrliinitplus, dorsal view. A, M . jrtnur YHhrum; Ji, M . sprclus; C , M . alliuiis; I), M. ilijlrrculidiis. In the West tlic Rocky Mountain Locust (Mdanoplus sprelus) did, and occasionally docs, |)roducc much injury lo [^rain and other crops. Another sj)ecies more widely distributed is M . atlanis which sometimes becomes migratory. The Red-legged Locust or (Grasshop- per {M . fcmur-rubrum) , the 'JVo-striped Locust {M . biviUatus) and tlie l*ellucid Locust {Camnula pellucida) in the Last and the DifTerential Locust {M . dijjercntiaiis) in Ihi; South are the si)ecies that do most injury. Red-legged Locust or Grasshopper {MrJanoplus femur -ruhnim J)e(i.). This locust is usually the most abundant form in the i*]asl, and is most numerous in low grounds and ( ullivaled fields where vege- tation is more or less rank (I'ig. 64). Adult. — Of medium size, about an inch long; reddish brown in color; tegmina sometimes without spots but usually sjwtted, surpassing the hind femora, which are reddish brown; hind tibia; red with black no ECONOMIC ENTOMOLOGY spines; cerci of male narrowing from lip to base and subgenital plate narrower at apex than at base. Fig, 64. — Red-legged grasshopper (Melanoplus femur -rubr 71m) : Above, adult male; below, adult female. About twice natural size. {After W. R. Walton, U. S. Bur. Ent.) Fig. 65. — Locust ovipositing; egg pod in ground at right. Enlarged one-half. {After Gibson, Ent. Circ. 5, Dept. Agric, Ottawa.) £gg5.^Deposited in pod-like masses in the ground; oblong-oval. Nymphs, — Vary in size according to age and month; all stages of developing wings; grey to yellow; five moults. CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS III Life-history. — Nymphs hatch from eggs in spring; these mature in August and September, when eggs are laid in the ground and over- winter there (Figs. 65 and 66). The Lesser Migratory Locust (Mela- noplus atlanis Riley). — A native Ameri- can species; often abundant in Eastern Canada, causing serious injury. Com- pared with M. femur-rubrum the fe- male has a yellow under surface, and more distinctly banded hind femora, and the male has the apex of the sub- genital plate notched, the cerci shorter and less tapering, and longer tegmina which are also more distinctly spotted. It has a distinct patch of black on the neck or collar. Egg deposition occurs from July to September. Mature forms appear from July ist, and are often abundant in open sandy regions with sparse vegetation. Fig. 66. — Egg pod of locust opened to show arrangement of eggs; individual eggs at side, natural size. {After Gibson, Ent. Circ. 5, Dept. Agric, Ottawa.) Fig. 67. — Lesser migratory grasshopper (Melanoplus atlanis): Above, adult male; below, adult female. About twice natural size. {After W. R. Walton, U. S. Bur. Ent.) The nymphs undergo five moults; the eggs are deposited in the ground in small pod-like capsules, and hatch in the spring (Fig. 67). 112 ECONOMIC ENTOMOLOGY Differential Locust {Melanoplus diferentialis Uhler). — This locust is larger than those described above, about i^i inches long, and is dark brownish-green or oKve-brown in color. The hind legs are yellow with black basal tibial ring and black spines. The subgenital plate short and broad, and the cerci of male boot-shaped. ' It is fond of the Greater Rag-weed. It is a southern form. Fig. 68. — Two-striped grasshopper {Melanoplus bivittatus): Above, adult male; below, adult female. Twice natural size. (After W. R. Walton, U. S. Bur. Ent.) Two-striped Locust {Melanoplus bivittatus Say). — This locust is not so large as the Differential locust, being about ij^ inches long, and is dull olive-brown above and yellowish beneath. A narrow yel- lowish stripe runs along each side from the eye to the tip of the teg- men. The hind femora are yellow, and the hind tibiae coral red with CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS II3 black spines. The cerci of the male are stout, and two lobed; the subgenital plate is narrow. The young and newly transformed adults are greenish (Fig. 68). Its transformations are later than those of M. atlanis. Clear-winged Locust (Camnula pellucida Scudder). — This locust occasionally does serious injury in the West, and frequents high dry soil. It is of a light brown color; the tegmina are smoky brown with darker spots and yellowish blotches on the sides and a yellowish brown stripe along each humeral angle. The wings are transparent and pellucid with dark veins. Body of male 19 mm. long, of female 22 mm. It is often associated with M. atlanis in the East, and is the earliest of the grasshoppers (Fig. 69). ^.f-^^^ Fig. 69. — Pellucid or clear- winged grasshopper {Camnula pellucida): Adult female. About twice natural size. {After W. R. Walton, U. S. Bur. Ent.) Carolina Locust {Dissosteira Carolina Linn.). — This locust is larger than the preceding species and is of a pepper-and-salt color, with varia- tions from grey to yellow or reddish. The hind wings are black margined with yellow. It is sometimes injurious to corn, wheat, alfalfa and soy beans. Natural Enemies of Locusts. — Robber-flies, bee-flies, flesh-fly and blow-fly larvae, digger wasps and bUster-beetle larvae; birds and domes- tic fowls; toads, snakes, moles, mice, ground squirrels, skunks and hogs; mites, spiders, "hair-snakes," etc. Control of Locusts. — {a) Application of poisoned baits (see Part IV, p. 398). {h) Use of hopperdozers. {c) Destruction of eggs by fall cultivation, {d) Co-operation of communities. (Consult U. S. Com. Rept. on Rocky Mt. Locust, 3 vols.. Farmers' Bulls. 691 and 747, U. S. Dept. Agr.; Circ. 5. Ent. Br. Dept. Agr., Can.; Cornell Bull, 378; Mich. sp. Bui. 83) 114 ECONOMIC ENTOMOLOGY J.ocusTiu.i; ILoNG-iioRNKD Grasshoppi'.ks ok Locusts) More Common Genera and Species A. Wingless or with rudimentary wings and wing-covers. B. Pronotum not extended over meso- and metanotum. — Ceuihophilus. BB. Pronotum extended over meso- and metanotum. — Thyreonotus. AA. Winged. B. Tegmina expanded in the middle. C. Tegmina much broadened in the middle, concave. — Cyrtophyllus. CC. Tegmina somewhat broadened in the middle, not concave. D. Ovipositor very small. — Microcentrum. DD. Ovipositor of medium size. — AmUycorypha. BB. Tegmina not expanded in the middle. C. Vertex of the head with a conical projection forward. — Conocephalus. CC. Vertex of the head without a conical projection. D. Ovipositor straight or very nearly so; insect small. — Xlphidium. DD. Ovipositor curved; insect large. E. Ovipositor curved sharply upward. — Scudderia. EE. Ovipositor sword-shaped. — Orchelimum. Species of CcutJiophilus: A. Fore femora about as long as pronotum. — C. maculatus. AA. Fore femora longer than pronotum. — C. brevipes. Species of Thyreonotus: A. Pronotum well rounded behind. — T. dorsalis. AA. Pronotum nearly square. — T. pachymerus. The members of this family are seldom of sufficient importance economically to require special treatment. The katydids, shield- backed grasshoppers, cricket-like grasshoppers, and meadow grass- hoppers belong here and are interesting objects of study. Recently it was found that two species of katydids {Sciidderia fiircata B runner and Microcentrum rlwmhifolium Sauss.) are injurious to oranges in California, often causing serious loss. (Bull. 256, Bur. Ent. U. S. Dept. Agr., 1915.) GRYLLiDiE (Crickets) Genera and Species A. Fore tibiae broad, fitted for digging (Fossorial Crickets). B. Insect small; antennre ten- to twelve-jointed. — Tridactylus. BB. Insect large; antenna? many-jointed. — GryUolalpa. CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS II 5 A A. Fore tibiae slender. IJ. Hind femora stout (True Crickets). C. Last segment of the maxillary palpi of the same length as the next to the last. — Gryllus. CC. Last segment of the maxillary palpi double the length of the next to the last. — Nemobius. BB. Hind femora slender (Tree Crickets). — (Ecanlhus. Species of Gryllus: A. Black field crickets. B. Ovipositor 13-14 mm. long; male more slender. — G. pennsylvanicus. BB. Ovipositor 18 mm. long; male stout. — G. abhrevialus. AA. Straw colored house crickets. — G. domeslicus. Species of Nemobius: A. Ovipositor longer than hind femora and straight; color blackish, arranged in longitudinal bars. — N. fasciatus. AA. Ovipositor shorter than hind femora and arcuate. — N. exiguus. ex- •b "^^-^ /"^d. Fig. 70. — Markings on basal segments of antenna) of CEcanihus: a, Qic. niveus b, CEc. anguslipennis; c, Qic. nigricornis; d, do. Species of QLcanlhus (Fig. 70); A. Antennae with one black mark on each basal joint. B. Black marks like small rounded dots. — QL. niveus. BB. Mark on first joint long and hooked, that on second oblong. — (E. anguslipennis. AA. Antennae with two black marks on the first basal joints. B. Antennae wholly black, also head, thorax and legs. Marks on first joint of antennx' generally connected at apex. — (E. nigricornis. BB. Pale greenish white; marks on antennae elongate, parallel, distinct. — QL. 4-punclalus. AAA. Antenna? without marks on first joints, wing-covers broad; head and first joints of antennae pink. — (E. latipennis. The Pennsylvania Field Cricket {Gryllus pennsylvanicus Burm.). — The field cricket is omnivorous and seldom does enough damage to merit special attention. It is fond of grain, however, and often enters barns destroying a considerable amount of grain. Adult. — A large black cricket existing in two forms — the commoner short-winged form in which the wings are rudimentary and the long- ii6 ECONOMIC ENTOMOLOGY winged form in which they project beyond the tip of the tegmina. The tegmina are deep black to grayish brown, in the male reaching the tip of the abdomen, in the short-winged female not quite so long and in the long-winged form slightly surpassing the tip of the abdomen. The ovipositor never exceeds the body in length. Length of insect 16-20 mm. (Fig. 71). Eggs. — Yellow, cylindrical, laid in the soil in late summer and autumn in Quebec, in June and July farther south. Nymphs. — In the north the nymphs hatch in early summer from hibernated eggs; in the neighborhood of Indiana they hatch in July and August and hibernate. Snowy Tree Cricket {(Ecanthus niveus DeG.). — Sometimes injures apple and plum trees by egg-punctures, and occasionally eats holes in the ripe fruit (Fig. 74). Adult. — Ivory-white tinged with green, 3^^ inch long; wing-covers nearly twice as long as abdomen; those of male flattened, crossed by oblique veins, semi-transparent and broader than body, those of female wrapped close about the body; ovipositor short, straight and tipped with black; maxillary palpi relatively long. July-October. Eggs. — Elongate, cylindrical, yellow, J-^ variL^'fieVdTrSef '(gX^5 i^^^ l^^SJ ^^^^ singly in punctures in the bark pennsyivanicus) . {After of smaller branches of apple, plum and peach, ^"^^^''•^ in the fall; hatch in May and June. Nymphs. — Feed on plant-lice and other insects. Black-horned Tree Cricket {(Ecanthus nigricornis Walker). — Con- sult Bull. 2,^S, N. Y. Ag. Exp. St.) Injures blackberry and raspberry canes by egg punctures, and carries spores of cane-hlight and other diseases (Figs. 72 and 73). Adult. — Greenish white; head and pronotum black or barred with black; body black beneath and yellowish-green above; antennae long, mostly black; wing-covers as in (E. niveus; head, thorax and legs mostly black. Probably feeds on flies. Eggs. — Similar to those of (E. niveus; laid in a row of punctures CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS II7 Fig. 72. — Black-horned tree cricket {CEcanthus nigricornis). Female above, male below. {After Lugger.) A Fig. 73. — Egg punctures and eggs in raspberry by the black-horned cricket {CE. nigricornis). Il8 ECONOMIC ENTOMOLOGY often 2 inches long, each row containing about 30 eggs; hatch in May and June. Nymphs. — Feed on plant-Hce and other insects; full grown late July and August. Control. — Prune out infested twigs and burn them. Other species of (Ecanthus deposit eggs in galls on willows, and in the stems of Helianthus, Solidago, etc. Fig. 74. — CEcanthus niveus ovipositing. (After Parrott.) ORDER THYSANOPTERA (THRIPS) (Consult Tech. Ser. No. 12, Pt. Ill, and No. 21, Bur. Ent., U. S. Dep. of Ag.) A. Female with a saw-like ovipositor, last segment of abdomen of female conical, that of male broadly rounded; wings usually present, the fore pair the stronger. B. Ovipositor curved upward; antennae 9-jointed; fore wings broad and rounded. MolothripidcB. — Genus Molothrips. BB. Ovipositor curved downward; antennae 7- to lo-jointed; wings usually narrow and pointed. — Thripida. Genera: Thrips, Eulhrips, Helio- ihrips, Anaphothrips. AA. Female without a modified ovipositor, last segment of abdomen tubular in both sexes; wings often absent, but when present similar in Btructu=re.=^t '^i'" Phlceothripidm. Genera: Phlosothrips, Trichothrips, Cryptothrips. CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS II 9 Thripid^ (Thrips) ♦ Grass Thrips (Anaphothrips striatus Osborn). — Feeds by sucking the juices of various grasses such as timothy, Kentucky blue, couch grass and oats. Adult. — Small, 3^f g inch long, yellowish or brownish-yellow; four narrow wings fringed with hairs; feet bladder-like; parthenogenetic; May-June. Hibernate. Eggs. — First brood laid in spring, hatching in 10 to 15 days; summer eggs hatching in 4 to 7 days. Nymphs. — Become full grown in spring in about 2 weeks, summer forms in 4 days. Life-cycle in 12 to 30 days. " Thrips injury on the leaves shows as minute dots or lines usually running parallel with the leaf veins and remaining white." Pear Thrips {Tceniothrips inconsequens Uzel). — (Consult Bull. 80, Part 4. U. S. Bur. Ent., 1909; Bull. 343, N. Y. Ag. Exp. St., 191 2; Bull. 15, Ent. Br. Dept. Ag. Can., 1918.) A pest in central California and British Columbia, along Hudson River and in Pennsylvania to pear, apple, cherry and plum. Chief injuries done by adults to the buds in spring (Fig. 75). Adult. — Minute, slender, dark brown, ^^5 inch long; wings fringe- like and flat along the back. Enters fruit buds in early spring. One brood a year. Eggs. — ^Laid by a sharp, curved, saw-toothed ovipositor beneath epidermis of fruit and leaf stems as the trees come into bloom, causing "bleeding," and giving the bud a shrivelled, scorched appearance when infestation is heavy. Nymphs. — Hatch out in blooming time and become full grown in about 2 weeks. They then drop to the ground and form a pupal cell some distance below, where they hibernate. The pupal stage is an inactive stage and lasts about 2 months before the adult appears. Control. — Spray early with kerosene emulsion or soap solution, or distillate oil emulsion, to which is added nicotine extract. Greenhouse Thrips {Heliothrips hcemorrhoidalis Bouche). — This in- sect injures the leaves of many greenhouse plants which first become spotted, then blotched and finally wilted. Drops of a reddish fluid, turning black, cover the leaves. (Consult Bull. 64, Pt. 6, Bur. Ent., U. S. Dept. of Agriculture.) I20 ECONOMIC ENTOMOLOGY Fig. 75. — Pear thrips {Tceniothrips inconsequens) : i. Adult; 2, eggs; 3 and 4, larvte; 5 and 6, nymphs or pupae; 7, head (side view) . All greatly enlarged. (^After Moulton, U. S. Bur. Enl.) CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 121 Adult. — One-fifteenth inch long; head and thorax dark brown, abdomen yellowish brown; antennae with 8 segments; 3 to 4 weeks for a generation; fore-wings with two, hind-wings with one longitudinal vein. Eggs. — Hatch in 5 to 8 days; laid singly in leaf tissue; colorless and bean-shaped. Nymphs. — Mature in 20 to 25 days. Onion Thrips or ''White Blast'' (Thrips tabaci Lind.). — Attacks a large variety of garden plants. Found on bulbs of onion in loose soil and at axils of leaves. Punctures the tissues and sucks the sap, giving the field a whitish appearance. Produces also scuHions or thick necks. Fig. 76. — Wheat thrips {Euthrips Iritici). Greatly enlarged. {After Folsom.) Adult. — One-twenty-fifth inch long, active, slender, yellowish tinged with black, two pairs of bristly narrow wings which fold along the back. Probably winters over in the rubbish on the ground; life-cycle about 3 weeks, hence several generations in a season. Eggs. — ^Laid singly in spring or early summer within the leaf tissue, Jf 00 i^ch long, elongate and curved; hatch in about 4 days. Nymphs. — Transparent at first, later greenish-yellow; mature in II or 12 days. Control. — Spray with solution of nicotine sulphate and whale oil soap (4 oz., 4 lb., 40 gal.) 122 ECONOMIC ENTOMOLOGY Wheat or Strawberry Thrips {Euthrips tritici Fitch). — The most common thrips and found on many cultivated plants. Injurious to strawberry, apple, peach and wheat. Several generations in a season (Fig. 76). Adult. — Small, J^o inch long, brownish yellow. Eggs. — Small, whitish, curved oblong; laid singly in lower part of calyx and in flower stalk of strawberry; hatch in 3 days. Nymphs. — Three moults; mature in 9 or 10 days. This thrips produces ''button" strawberries. Cow//-^?/.— rSpray with nicotine or kerosene emulsion. ORDER HOMOPTERAi Chief Economic Families A. Tarsi i or 2-jointed; antennae usually prominent; beak apparently arising from sternum. — Group Sternorhynchi. B. Tarsi i -jointed; adult male with beak and 2-winged; female wingless with body scale-like, or gall-like, or grub-like, and covered with waxy secretion. — Coccidce (Scale Insects), p. 123. BB. Tarsi 2-jointed; wings usually 4. C. Wings white, opaque. — Aleyrodida (White-flies), p. 151. CC. Wings transparent. D. Legs long and slender; antennae 3-7-jointed. — Aphidida (Plant-lice), p. 136. DD. Hind legs fitted for leaping; antennae 9 or lo-jointed. — Psyllidce (Jumping Plant-lice), p. 152. A A. Tarsi 3- jointed, antennae minute; beak evidently arising from mentum. — Group Auchenorhynchi. B. Ocelli 3; males with musical organs. — CicadldcB (Cicadas), p. 156. BB. Ocelli 2 or wanting; males without musical organs. C. Antennae inserted on side of cheek beneath the eyes. — FulgoridcE. CC. Antennae inserted in front of and between the eyes. D. Prothorax prolonged into a horn above the abdomen. — MembracidcB (Tree Hoppers), p. 157. DD. Prothorax not prolonged above the abdomen. E. Hind tibiae armed with two stout teeth and tip crowned with short stout spines. — Cercopidce (Spittle Insects), p. 153. EE. Hind tibiae with a double row of spines below. — CicadellidcB or the Jassoidea {Lea,i Hoppers), p. 154. ' The old order Hemiptera is here broken up into three orders viz.: Homoptera, Hemiptera and Siphunculata (see p. 94). CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 1 23 I. CoccidjE (Scale Insects) Chief Sub-families and Genera Chief S lib -families: A. Abdominal spiracles present on each segment; males with compound eyes; adult females with white waxy lamellae. — OrthezincB. AA. Abdominal spiracles absent; males with simple eyes. B. Concealed beneath a "scale," formed partly of larval exuviae, partly of secretion; abdomen ending in a "pygidium. " — Diaspina (P'ig. 79). BB. Naked or covered with a waxy secretion, but not beneath a "scale;" abdominal pygidium absent. ^ C. Extremity of abdomen cleft; anal orifice closed above by a pair of triangular plates, anal ring fringed with setae; waxy scale not separable from the insect. — CoccincE. CC. Extremity of abdomen not cleft; no anal triangular plates, anal ring without setae. — Dactylopince (Fig. 81). Chief Genera of the Diaspince: A. Scale of female circular to oval with central, sub-central, or sub-marginal exuvia. B. Scale of male resembling scale of female in color and texture; only slightly elongated. C. Pygidium with 6 groups of circumgenital gland-orifices. — Com- stockiella. CC. Pygidium with less than 6 groups of gland-orifices. D. Chitinous processes much elongated. — Chrysomphalus. DD. Chitinous processes smaller and shorter or wanting. — Aspidiotus (Fig. 79). BB. Scale of male white, delicate and carinated. C. Dorsal spinnerets irregular; exuvia usually sub-central. — Diaspis. CC. Dorsal spinnerets in distinct bands; exuvia terminal in 2d stage female and marginal in adult. — Aulacaspis. AA. Scale of female elongated with exuvia at one extremity. B. Scale of male similar to scale of female, but smaller; five groups of gland-orifices. — Lepidosaphes. BB. Scale of both sexes white, that of male small, with parallel sides and carinated. — Chionaspis. BBB. Scale of female brown, that of male white and carinated. — Hemi- chionaspis. Chief Genera of the Coccince: A. Naked or covered only by a filmy secretion. B. Flat or slightly convex; dermis alveolate. — Coccus. BB. Very convex, usually hemispherical; hard when mature. C. Dermis with coarse polygonal pitted areas. — Saissetia. CC. Dermis microscopically tesselate, or appearing smooth. — ■ Lecanium, 124 ECONOMIC ENTOMOLOGY AA. With a strong cottony secretion; secreting an ovisac; body more or less chitinous without dorsal patches of secretion. — Pulvinaria. Chief Genera of the Dactylopina: A. Female globular or reniform, in a hard shell; larva fringed with spines. — Kermes. A A. Female not as above; anal ring with eight hairs. B. Adult surrounded by secretion but dorsally naked. — Gossyparia. BB. Adult forming a cottony sac; caudal lobe long. — Eriococcus. AAA. Female with soft powdery oval unarmored body; anal ring with six hairs. B. Antennae normally with 8 segments, sometimes 7; tarsus not toothed. — Pseudococcus (Fig. 81). BB. Antennae normally with 9 segments; tarsus toothed. — Phenacoccus. Scale insects are typically bark-lice, being minute sucking insects covered with a mealy or cottony waxy secretion. Some, like the Mealy Bugs, secrete a cottony material; some, like the Lecaniums, secrete a waxy hard continuous layer which forms a protection for the back; while others, like the San Jose Scale and the Oyster Shell Scale, pos- sess true scale-like coverings, composed partly of a waxy secretion and partly of moulted skins, beneath which the insect lives. For a short time after birth Scale insects crawl about, but soon they settle on the bark or leaf and begin sucking the sap. After a few moults the females lose their legs, eyes and feelers. The male adult insect is, as a rule, an active 2-winged insect with legs, eyes, feelers, but no mouth. In most species the females lay eggs (oviparous), but in a few the young scale insects are born alive (viviparous), i.e., the eggs hatch within the body of the mother. (Consult Comstock's republished papers, Bull. 372, Cornell; the "Coccidae of Ohio" by Sanders; "Some Scale Insects of Mississippi" by Herrick; "The San Jose and other Scale Insects" by Lochhead; "Coccidae of Indiana" by Dietz and Morrison; and Bull. 6, Tech. Series, Div. Ent., U. S. Dept. Agr.) Hard Scales (Diaspin^) Following are the most common economic orchard forms: Oyster Shell Scale {Lepidosaphes ulmi Linn.). — (Consult Farmers' Bulletin 723, U. S. Dep. Ag.) A cosmopolitan insect of European origin and one of the most common pests of the orchard and of shade trees^and shrubs. Single-brooded in the North but double-brooded in the Middle and Southern States (Fig. 79). CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 1 25 Adults. — Female scale oyster-shell shaped, narrow, /'^-Jlo inch long, brownish-black; male scale smaller and ovate. Eggs. — Yellowish-white, laid in September-October under the female scale (50-60). Destroyed by a mite Hemlsarcoptes malus. Nymphs. — The eggs hatch in late May or early June, or shortly after the apple blossoms fall, into active 6-legged pale yellowish larvae, the females moulting twice and the males once. The exuviae are yellowish. Parasites. — Parasitized by Aphelinus, Mytilaspidis, Anaphes, and Chiloneurus and preyed upon by lady-birds, mites and birds. Fig. 77. — Female San Jose scale, mature female insect removed from beneath it. Greatly enlarged. {After Alwood.) Scurfy Scale {Chionaspis furfur a Fitch). — A native insect, occur- ring on pear, apple, gooseberry, and black currant. Adult. — Scales white; female scale ovate, 2-3 mm. long, male scale smaller (i mm.) and 3-ridged with parallel sides (Fig. 80). Eggs. — Purplish-colored; laid in the early fall and found under the female scale in winter. Nymphs. — These hatch about the middle of June and the female larvae moult twice. The male has one moult. As in the case of the Oyster Shell Scale there is but one brood a season in the North and two in the South. Parasites. — Parasitized by Ablerus clisiocampce How., a chalcid and preyed upon by Tyroglyphus malus and Chilocorus bivulnerus. 126 ECONOMIC ENTOMOLOGY San Jose Scale (Aspidiolus perniciosus Comst.). — China is probably the home of this scale. It became established at San Jose, Cal., about 1870, and was introduced into Eastern nurseries in the U. S. about 1886-7, and into Ontario about 1896. Occurs on orchard trees, bush fruits, and many perennials and annuals. On badly infested branches the scale presents the appearance of dark-grey scurfy patches, and on fruit there is often a purplish discoloration about the scale. Adult. — The female scale is circular, 3^5 inch in diameter, with a central exuvium surrounded by a yellowish ring. The male scale is Fig. 78. — a, Winged San Jose scale (much enlarged) ; h, young scale insect (enlarged 125 times). oval, twice as long as broad, with a long dark exuvium showing a nipple toward the small end of the scale. The San Jose scale winters in the half-grown state. Early in spring the winged males appear, and the females resume growth. The male moults thrice and the female twice. In early June the females begin to produce living young. The period of production lasts about six weeks during which time each female produces on an average 400 young. The females mature in 35 to 40 days, and the males in about 25 days after their birth. There are three or four broods in northern orchards (Figs. 77 and 78). Nymphs. — The half -grown scale is black, and shows a central nipple surrounded by one or two depressed rings. Parasites. — The following Lady-birds feed on the San Jose Scale: Chilocorus bivulnerus, Pentilia misella and P. suturalis. CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 1 27 The chief Chalcid parasites are FrospaUella perniciosa Tower, Aphelinus fuscipennis How., and A. diaspidis Kow., but the percentage of parasitism is too low for effective control. Fig. 79. — Pygidia of Aspidiotus. Showing the characteristic differences in five common species. Greatly enlarged. D, dorsal surface; V, ventral surface. (After Sanders.) Control. — Plant fumigated nursery stock; spray with lime-sulphur wash (sp. gr. 1.03) before the buds burst; spray with certain miscible oils (see Part IV). The three closely related species, Putnam Scale {A. ancylus Putn.) wintering in nearly full-grown condition and oviparous, the eggs 128 ECONOMIC ENTOMOLOGY hatching in June-July, tlic Forbes Scale (.1. forbcsi John.), and the Curtis Scale (.1. ostrecBj'ormis Curtis) (Fig. 79), are difficult to dis- tinguish from the San Jose Scale, and are also found in orchards. A comparison of the pygidiiim, or the fused posterior abdominal seg- ments, under the microscope enables one to identify the adults of these species. On the dorsal surface of the pygidium are the anal opening and the glands that secrete the wax of the scale. On the ventral sur- face are the vaginal opening and 4 or 5 groups of spinnerets (wanting in the San Jose Scale). The margin of the pygidium is modified into .1 B c Fig. So. — Three common orchard scales. A, San Jose scale; B, oyster-shell scale C, scurfy scale. lobes with thickenings, dorsal and ventral spines, and plates character- istic of each species (Fig. yg). Euonymus Scale {Chionaspis cuonymi Comst.) is a common pest of Euonymus in the Eastern United States. Two broods a season. Female scale elongate-oval, brown, with yellow exuvia, convex; male scale white, parallel-sided, 3-ridged, with yellow exuvia, much smaller than female scale. Rose Scale {Aulacaspis roscr Bouche). — Attacks rose, raspberry, blackberry, etc. Female scale snow-white, nearly circular, thin and flat, Jf 2 i^^ch in diameter; with two light yellow exuviae at margin; oviparous. Male scale shorter, narrower, 3-ridged. Hibernates in all stages, hence all stages may be found on one infested plant. Two or three broods a CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 1 29 year. Infested canes may become covered as if white-washed. Para- site: Aphelinus diaspidis How., a chalcid. Control. — (i) Trim out all badly infested canes before spring; (2) spray with whale-oil soap (i lb. to i gal. water) or lime-sulphur in early spring. Soft Scales (Cogging) Plum Scale, or European Fruit Lecanium (Lecanium corni Bouche). — This scale, also called the New York Plum Scale, is sometimes abundant in plum orchards. It occurs also on peach, apricot, pear, quince, currant, blackberry, ash, elm, etc. Adult. — Female scales conspicuous brown objects, *'like small halved peas," adhering to branches and twigs. Full grown in June. Male scales much smaller, flatter, more elongate, and of a whitish color; male insect delicate, with two whitish wings; emerges in May from scale. Eggs. — Deposited under the scale in early June; white; hatch in about a month. Nymphs. — Emerge from beneath the mother scale and crawl to the leaves in July; secrete much honey-dew. About the end of August or in September they begin to migrate from the leaves to the twigs and branches where they hibernate. In early spring (April) they begin feeding again and grow rapidly, maturing in June. Parasite. — Corny s fusca. Control. — Spray with a miscible oil (i to 15) before buds burst; spray about July ist with Black leaf 40 and soap. Terrapin Scale {Lecanium nigrofasciatum Perg.). — (Consult Bull. 351, Bur. Ent. U. S. Dept. Agr., and Circ. 88.) Attacks shade trees, such as maple, basswood and birch, and orchard trees, such as apple, plum and peach. A native insect. Adult. — Female nearly hemispherical, reddish, 1-7 inches long, mottled with radiating streaks of black conspicuous about the margin. The presence of a double mid-dorsal row of 25-4olowsubconical append- ages appearing like pores, extending from near the anal lobes to nearly above the sucking mouth-parts is quite characteristic. Adult of male a minute, delicate 2-winged insect with rose-red body marked with dark and with heavy brown thoracic band, appearing early in August; 130 ECONOMIC ENTOMOLOGY male scale smaller than female, elongate, slightly convex, and greenish white. Viviparous, young born June-July. One brood a year. Nymphs. — Female scales nearly full grown by autumn, and winter as such. Mature early in spring. Control. — A 20-25 per cent, kerosene emulsion or miscible oil ap- plied in dormant seasons destroys the hibernating females, or flour- lime sulphur just before the young migrate to the leaves. Coccophagus sp., a chalcid, is an important parasite. Cottony Maple Scale {Pulvinaria vitis L.). — Occasionally becomes a serious pest of shade trees, such as the soft maple, box-elder, bass- wood, etc. ^fi?w//.— Conspicuous on account of the cotton-like waxy masses projecting from beneath the brown scale of the female. Female scale "elliptical, convex on the back with a low rounded median ridge; pale green or whitish yellow, marked with black or brown." Male insect winged, with two long caudal filaments, and long antennae. Eggs.—MmMit, oval, pale yellowish; enclosed in the secretion of waxy threads; about 3000 eggs laid by each female, in June and July. Nymphs. — At first active and crawling, with six legs; later they settle and secrete a thin waxy covering on their backs. Females fertilized by the males in late summer. In autumn they migrate from leaves to twigs where they remain all winter. Parasites. — Coccophagus lecanii Sm., C. flavoscutellum Ashm. — chalcids. Control. — Spray in early spring with Black Leaf 40 and whale-oil soap. Golden Oak Scale (Asterolecanium variolosum Ratz). — A small, yellow, round, convex scale often coating twigs of oak. The nymphs appear in May- June. Cottony Grass Scale {Eriopeltis festucce Fonsc). — Often abundant on stems of grasses in the maritime provinces; forming conspicuous compact oval tufts of cotton wool, the egg-sacs. The eggs hatch in spring and the scales become full grown in July. Toward the end of July the eggs are laid in the cottony sacs. Elm Bark -louse {Gossyparia spuria Modeer). — The females are dark red, bordered with white wax; j^^o ir^ch long; arranged irregularly along cracks or fissures in the bark of trunks or limbs. The young appear in late June or early July and settle along the mid-veins of the leaves CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 131 and on the green tips of twigs. In Sept.-Oct. they migrate back to the twigs. Winter is passed as partly grown insects. Mealy Bugs (Dactylopin^) Greenhouse plants are often injured by Mealy Bugs, which are mealy in appearance and are able to move about freely. The scale is Orthe^ia msignis Ps.longisplnu5 "^ Kermes pubescens Fig. 81. — A, Pseudoccus cilri showing adult female, anal ring and penultimate segment (i), antenna of adult female (2). B, Pseudococcus longispinus, showing adtilt female, antenna (i), anal ring and penultimate segment (2). C, Kermes pubescens. D, Orthezia insignis. E, Pseudococcus trifolii, showing anal ring and penultimate segment (3), anterior leg of adult female (4), and antenna of adult female (5). {After Sanders.) absent and at maturity they secrete a cottony sack within which are deposited the cream-colored eggs. The following species are common: 132 KCONOMU' KN ri)M()l.(>('.Y I'^u;. S_'. lltniisflici iinl sutlr i,SiUsstMia lu'niisphaMicji) (Mi I\mh. Nadir. il si/.c* (.■l//(T l-'othfs.) Vic. S^. lliMuisphorioal sc.ilo. cnl.\r>;cil. {Alt(( us trijolii l-'orlxs). ()(< urs near (lie crown of second \v\\y icd ;ind while ( lovers in ( Inslers, ollen ;i,( ( oni- pauicd by anls. Two forms cxisl winlcr Jamilrs, li.ih lied from e^gs in llie fall, prodiu inj.-; larva' in 1 lie spring-;, some feed in j/; on I lie roots a, nd l''l( .. V> /\ . A s l> i (I i s I r II S( iilc. ( I I(niii( lii()ii;is])is uKi)i(!ii;lra!). Vv- inalc. scale, cnliirK^Jtl- {AJlcr I'Orlx-s.) Vu:. V>$. - Mah-r.calc lA \\n: A:;i)i(lisl,ra scale, cnl.-ii r.cd. {Aflc.r Forbes.) others on I lie leaves; and summer fcmdlcs, |)rodu( in^^ severaJ gen(;rat ions. Oviparous females lay eggs in the fall after mating with males (iMg. Si). Woolly Maple Leaf Scale {Phcnacoccus mcrirold Walsh and kiley). — A pest of maple trees, often confused with the Collony Maple Scale. Ovij)a,rous, ' f- to } f^ iiu h long, yellow, rounded oval. Other Greenhouse Scales Lemons, ( rotons, oleanders, ivies, etc. in greenhouses arc; frequently atta). i3P^' i^k^rl iii'/r'^^ Fig. 86. — Types of antenna^ of aphids: a, Chaitophorus: b, Aphis; c, Schizoneura; d, Pemphigus (apterous); e, Chermcs; f, g, scnsoria. Oleander or Ivy Scale {Aspuiiotus hcdcrce Vail.). — A circular, flat, grey or white scale, with a pale orange-colored centre. Occurs on oleander, ivy, box wood, orange, palm, cycad. Circular Scale (Chrysomp/ialus aoiiidum Linn.). — A circular dark brown scale with a grey nipple in a reddish brown ring. Occurs on Araucaria, citrus, oleander, l)egonia, and rubber plant. CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 135 Greenhouse Orthezia {Orthezia insignis Dougl.). — An ochreous to green insect, covered with plates of waxy secretion. Occurs on many j)lants (Fig. 81). Aspidistra Scale {Hemichionaspis aspidistrce Signoret). — Female scale l{o inch long; oviparous; light or dark brown with exuviae brighter; thin and delicate; somewhat oyster-shell shaped. Male \ y Fig. 87. — Front of head and cauda of aphids: a, Micros iphum cralcegi; h, Myzus (apterous); c, Myzus -{aXsite); d, Phorodon. scale white, 3-ridged, slender, edges parallel. Occurs on Boston fern, aspidistra, orange, orchids, Davallia (Figs. 85 and 86). Control. — On indoor plants for Mealy Bugs use Black Leaf 40 (i to 400) and soap (4 lb. to 50 gal); for Hard and Soft Scales use whale-oil soap (i lb. to 2 gal.) or a dilution of some good miscible oil to which Black Leaf 40 has been added. 136- ECONOMIC ENTOMOLOGY Spray with lime-sulphur, whale-oil soap, kerosene emulsions, miscible oils or whitewash when outdoor plants are infested. APHIDIDyE (APHIDS OR PLANT-LICE) Chief EcoNOsiiic Gener\ (Figs. 86-94) A. Front wings with four oblique veins; antennae generally 6-segmented. B. Media of fore wings twice forked (except Lachnus in part). C. Antennae of winged female 5-segmented. — Si pita. CC. Antennae of winged female 6-segmented. D. Cornicles mammiform; filament of sixth segment of antennae not developed. E. Fore wing with stigmal shading appearing as the stigma, extending to tip of wing. Large aphids occurring commonly on Quercus, Tilia^ and Platanus. — Longistigma. EE. Venation normal, except in Lachnus where media is sometimes unbranched or only once forked. Occur- ring usually on conifers, never on Tilia or Platanus. F. Flocculent species. Never on conifers. — Phyl- lapliis. FF. Not conspicuously flocculent as in F. Occur- ring on conifers. — Lachnus. DD. Cornicles variously shaped, seldom mammiform but if so the filament of sixth antennal segment developed. E. Large aphids \vith cornicles usually vasiform, body and appendages hirsute. Occurring on Populus and Salix. — Pteroco m ma . EE. Not as above. F. Cornicles short or wanting, usually tuberculate; Cauda bluntly rounded or knobbed. G. Cornicles appear as mere rings; wings held horizontal when at rest. — Moncllia. GG. Cornicles usually distinct; wings held slanting or roof-shaped over back when at rest. H. Body and appendages hirsute in which respect it approaches Ptero- comma but smaller and mostly leaf- feeders; hairs not knobbed; antennae noticeably shorter than body; gre- garious on host. — Chaitophorus. HH. Body not conspicuously hirsute; antennae varying in length often CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 137 noticeably longer than body; hairs on antenna) and body usually knobbed; most species living solitary or scat- tered on host. — Calliplerini (includes Myzocallis, Calliplerus, Euceraphis et al.).^ Fig. 88. — Types of cornicles among the aphids. Beginning from left, Aphis avence, A. brassicce, A. gossypii, Chaitophorus negundinis, Hyadaphis sp., Liosomaphis sp. FF. Cornicles short to very long but not tuberculate; Cauda not globular or knobbed. G. First antennal segment gibbous on inner side. Fig. 89. — Front of head and cauda of two aphids: a, Rhopalosiphum; b, Aphis. H, Frontal or antennal tubercles with a prominent tooth-like projection on inner side; cauda tapering. — Phorodon. * See Can. Ent., Vol. 42, No. 8. i.^S ECONOMIC ION lOMOl.OGY nil, I'lonlal liihi'icli's willioul t lu' pronii- iuii( toot I) like project ion; cau; antenna* sel- dom lonj^er than body; cauda tapering and knobbed. — R/tofxilo- si/) hum. II. Cornicles c>lin(hii a! or incon- spicut)usly swollen; antennir usu- ally lonj^cr than body; cauda ensiforni.- -M acrosi pituni. Mil. Mead with I'ronlal t ubcrcK's absent or slight. 1. C'ornicles distinctly cla\ate. — Siphocorync (llyadapliis). II Cornicles usually cylindrical and of moderate length; if clavate lhe>' are only slight 1\' swollen and (|uite small. j. Cornicles \ery short, nuu h shorter than cauda, slightly swollen; beak short ; antenna- shorter than hody.— IIyalop- Icms. }}. No{ as above, i.e., cornicles moderatel\- long, usually longer than cauda, cylindri- cal; antiMina- usuall\' as long as or only slightly shorter than iMxly. A phis. Ul{. Media of foic' wings oiuc forked or simjile. C. Media simple. I). Hind wings with two obliiiue \eins. Poiiphii^ns. ni>. Hind wings with but om- oblicjue \i'in. {']. Antenna" ()-segmenteil. — Tctromiini. \\\\. .\nteniKe 5 segmented. — llamaniclislcs. VA']K. AntiMUKc ,.; segmented. Ilorniophis. CC Media once forked. |). Cornicles present, an .\phis-like species. - Toxoph'ra. |)|). Cornicles \estigial or wanting. I''. Hind wings witli two obliciue veins. 'I'.riosotun. V.V.. Hind wings witli owe obli(|ue \-ein. Colopha. 1'^n;. (^o. I'^"onl of head o apliids: a. (Imilophorns; />, 11 yn dn phis. CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 1 39 AA. Front wings with three ()l)li(|uc veins, the media sim[)Ic (unbranched), radial sector merged with margin of stigma; antenna^ never more than 5- segmented. B. Antennae 5-segmented; wings at rest folded upright; galls on conifers. — Chcrmes. BH. Antenna; 3- or 4-segmented; wings at rest Hat on hack; galls on grape, hickory, etc., never on conifers. — Phylloxera. Sc*R+M*Cu* 1st A .5c Sc*R*MtCu*/stA 5c Fic;. 91. — Venation of Mucro- siphum. {After Patch.) Fig. 92. — Venation of Tuxoplera. (After Patch.) l^lanl-lice or Aphids are gregarious sucking insects, often abundant on many varieties of plants, and doing much injury. Three forms occur: i. sedentary wingless viviparous agamic females, 2. migra- tory winged vivi})arous agamic females, 3. sexual males and females — the females ()vi])arous and wingless and the males winged or wingless. 5c*R-^M^CutlstA sc Rs Sc*R*M*Ca*lstA Fig. 93. — Venation of Tclra- neura. {After Patch.) Fk;. 94.— Venation of Chcrmes. {After Patch.) Reproduction among the aphids may be represented diagrammatic- ally as follows: O— P~P— P—P— P— P— P— P( )0 ■ i ^ = P = P_P— p_P_p/ yo 9 where O represents the overwintering egg, P the vivij)ar()us agamic 140 ECONOMIC ENTOMOLOGY wingless form, and =P= the viviparous agamic winged form, and cf and 9 the sexual forms (Fig. 95). In general, plant-lice are soft-bodied and green, sometimes brown or black. The winged forms have four delicate wings with a few simple veins — the front pair much larger than the hind pair. The sucking beak is 3- jointed; the legs and antennae are long and the eyes promi- nent. In autumn the sexual females deposit eggs that hatch in the spring into females which are often termed "stem-mothers." These produce living females which in turn produce living females, and so on for several generations. As each female produces several young, and these mature in a short time, reproduction is very rapid. When autumn approaches and food supply becomes scarce a brood of winged males and wingless females is produced. The females produce the winter eggs. Some- times agamic females hibernate. There are many species of plant-Hce, some feeding on one variety of plant, but many are capable of feeding on two or more varieties. Some feed for a time on one host plant, then migrate to another for the sum- mer, finally returning to the first one in autumn. Some produce abnormal growths ^'"'paro^t^l'aphidT''^'" ^^lled galls, such as' the grape phylloxera gall, the cockscomb gall on the elm, the Cottonwood gall, the poplar gall, etc. Most plant-Kce excrete a sweet hquid called "honey-dew," which is attractive to ants, bees, wasps and other insects. On account of this honey-dew aphids are often attended by ants who guard them. Forbes has shown that the Httle brown ant {Lasius niger) has domesti- cated the Corn Root Aphis, which is cared for and controlled in all stages of its development. (Consult Bull, no, 112, 276 and Farmers' Bull. 804, U. S. Dept. Agr., and Bulletins by Parrott, Patch, Forbes, Herrick and Matheson.) Fecundity. — Regarding the powers of reproduction of aphids Web- ster and Phillips (Bull, no, U. S. Bur. of Entom.) cite the estimates of Huxley and Buckton. The former estimated that the tenth genera- tion alone of a single Rose Aphis, were there no deaths, would contain CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 141 more substance than 500 million stout men; the latter computed that in 300 days, or 15 generations of 20 each, there would be 20^^ indi- viduals, equal in weight to 1,638,400,000 men, supposing that 1000 aphids weigh i grain and i man weighs 2,000,000 grains. Another computer makes the possible number of individuals very much higher, viz., 210^^. It is believed that in the case of the Spring Grain Aphis or "Green Bug" {Toxoptera graminum) reproduction would not fall short of the figures given above as the average number of young pro- duced in Indiana by each viviparous female for 1907-8-9 was 28.2. It is conceivable, therefore, how this pest is able to devastate vast areas of grain fields within a few weeks. Professor Forbes of lUinois (Bulletin 130) also computes the fecundity of the Corn Root Aphis on the basis of a generation of 12 to 15 young in 2 weeks. If all the progeny lived and multipHed at this rate for a season they would reach 9,500,000,000. In the case of the Green Apple Aphis {Aphis pomi) A. C. Baker reports the average reproduction per insect for the entire season as about 40. As the stem-mother becomes mature about May ist in Vir- ginia, and there are from 9 to 17 generations, or an average of 13, re- production is very rapid. The potential number of green apple aphids in September from a single stem-mother would be 40^'^ = 670,088,- 640,000,000,000,000. J. J. Davis reports for the Oat Aphis {Aphis avence) 15 generations for Indiana with an average of 30 young for each female. The progeny of one stem-mother at the end of the season would be 30^^. The same writer gives for the Pea Aphis {Macrosiphum pisi) the average number of young borne by female of 16 consecutive genera- tions as 65. The progeny of a stem-mother at the end of the season would in this case be 65^^. Natural Enemies. — ^Lady-bird beetles, syrphid maggots, lace-wing larvae, many parasitic hymenoptera, nymphs of tree-crickets, harvest- spiders, birds. Control. — Spray with kerosene emulsion, whale-oil soap, tobacco extract, etc. Chief Economic Species COMMON CEREAL AND FARM CROP APHIDS Apple Bud or Oat Aphis {Aphis avence Fab.). — Sometimes called the European Grain Aphis; is often injurious to apple buds and appears 142 ECONOMIC ENTOMOLOGY before the other apple aphids. Stem-mothers appear early in May and are yellowish-green with three dark lines on back; progeny winged and blackish; migrate to grains and grasses in the second and third genera- tions, winged and wingless generations. Migrate back to apple in September where mating occurs. Males produced on the secondary host and females on the primary host. Beak short and stout; thoracic shield dark; cornicles short and flanged; cornicles, antennae and feet black. Clover Aphis {Aphis bakeri Cowan). — Sometimes attacks the apple in the middle West. Eggs are laid on the apple, the pink stem-mothers appear early and give rise to green winged and wingless forms. The former migrate to clovers and give rise to sevei*al wingless generations. In late autumn the winged forms fly back to the apple and hawthorn where the eggs are laid. Cornicles are short. Corn Leaf Aphis (Aphis maidis Fitch). — Bluish-green, with black legs, antennae and cornicles; a row of black dots on each side of back. Com Root Aphis {Aphis maidi-radicis Forb.). — Bluish-green lice on corn roots; attended by brown ant {Lasiiis niger). Spring Grain Aphis or Green Bug (Toxoptera graminum Rond.). — Infests cereals in spring; wingless form yellowush-green, with faint dark line along back; eyes black. Winged form larger, with darker thorax. Migrates to other regions and to grasses. Parasitized by Lysiphlebus tritici. Western Grain Aphis (Brachycolus tritici Gillette). — Is injurious to winter wheat in Montana. English Grain Aphis {Macrosiphum granarium Kirby). — Occurs on wheat, barley and the grasses, Agrostis, Bromus, Dactylis, Poa and Phletim and Cat-tail, widely distributed in the U. S. COMMON FRXHT APHIDS Apple Bud or Oat Aphis (Aphis avence Fab.). — See above. Green Apple Aphis (Aphis mali Fab. = A. pomi DeG.). — This aphis collects usually on the tips of tender shoots, on the under surface of the leaves, and when abundant attacks the developing fruit. Winters on tw^igs as black shining eggs which hatch just before leaf buds open; 3 12 i^^h long, pear-shaped; bright green; black, slender CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 1 43 cornicles; inhabits the apple throughout the season; winged females occur during summer. Causes curhng of the leaves to some extent, those of young trees suffering most. Several (10-15) generations Fig. 96. — Green apple aphis {Aphis pomi): a, alate or winged form; b, apterous or wingless form; c, oviparous female; d, male; e, antenna of winged form. in a season, and each generation shorter than 3 weeks; each mother produces about 70 young (Fig. 96). Rosy Apple Aphis {Aphis sorhi Kalt. = A. malifolice Fitch = A. pyri Boyer). — This shade-loving aphis collects around the flower buds, the developing fruits and on the under side of the leaves. It causes nearly all the curling of the leaves and the "cluster-apples." Larger than preceding; }y^ inch long. Wingless females blue; honey-tubes 144 ECONOMIC ENTOMOLOGY yellow tipped with black, long and tapering; body covered with a powdery substance. Winged females with black thorax and red ab- domen, honey-tubes long and black. Two small tubercles at end of abdomen; the late winged forms are migrants and have a black patch on abdomen, black bands across last segments of abdomen, and black spots on sides. Egg-laying females lemon-yellow, mate with migrant winged males. In this species also the males are produced on the secondary and the females on the primary host. After the third summer agamic generation this species deserts the apple for the plantain, but returns in autumn. (Consult ''Apple Tree Insects of Maine," Circ. 31, Bur. Ent., U. S. Dept. Agr.) Sweet Cherry Aphis {Myzus cerasi Fab.). — Eggs oval and black, laid around the buds and on bark of twigs and branches, hatching in late April. Stem mother globose and glossy black. First brood wingless viviparous, later broods winged and wingless viviparous; the winged form with head, thorax, cornicles and cauda black, and abdomen dark green to dark brown migrate to Lepidium where several broods of dark brown, wingless viviparous forms and darker winged forms are produced. The latter return to cherry when they and other resident winged forms produce viviparous females which are fertilized by migrant winged males from Lepidium. No males are produced on the cherry. Six to 14 generation are produced during the season in the Niagara district. Controlled most successfully in early spring, just before the buds burst, by spraying with lime sulphur and Black Leaf 40 (Ross, 48//? Rep. Out. Ent. Soc, 191 7). Clover Aphis (Aphis bakeri Cowan). — See above. Green Peach Aphis (Myzus persicce Sulz). — This general feeder is our most common greenhouse species. Under glass it reproduces vivi- parously from year to year. At first the young lice are pink, but next generation is bright green. Migration in third generation to garden crops (where it has been known as Rhopalosiphum dianthi Schr.) returning in autumn to peach. Currant Plant-louse (Myzus ribis L.). — A small yellowish plant- louse causing a curling and blistering of the leaves of currants with red discoloration of the upper surface. Wingless female light green and mottled; body covered with capitate hairs, and with two rows of spots on mid-dorsal surface. Winged forms darker and abdomen crossed by several bands. Migrates to Stachys and Galeopsis (Gillette). CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 145 Hop Plant-louse {Fhorodon humuli Schrank). — Migrates from plums to hop in the third generation; yellowish-green, with a prominent tubercle on head at base of each antenna, and another smaller tubercle on the base of each antenna. Apple Woolly Aphis {Schizoneura (= Eriosoma), lanigera Haus, americana Riley in part). — (Consult Bull. 256, Maine Agr. Expt. Stn., Fig. 97. — Forms of the woolly apple aphis: A, winged viviparous female; B, stem-mother; D, wingless viviparous female, summer form; E, male; F, pupa of fall migrant; G, oviparous female. All much enlarged. {After Baker, U. S. Bur. Ent.) 1916.) This native woolly aphis is frequently injurious to many vari- eties of apple trees, causing deformations both on the stems and leaves and on the roots. It occurs also on pear, hawthorn and mountain ash, and passes part of its life on the elm. The injury to the roots consists in the formation of hard fibrous enlargements resembhng knots or clubs, often causing the death of the affected part. Nursery 10 146 ECONOMIC ENTOMOLOGY stock is liable to infestation and severe injury. The injury to the branches is not so serious, but in cases of severe infestation it causes stunted growth and yellowing of the leaves. Colonies often collect at tlie axils of leaves, on water-sprouts, and at abrasions and wounds. The common form seen on roots and limbs is wingless, Jf ir^ch long, redcHsh-brown, and covered with a woolly waxy excretion (Fig. 97). The life-history of the trunk forms is as follows: Some winter near the base of the apple tree as immature nymphs; but those in the elm as eggs in crevices of the bark. The hibernating nymphs on the apple migrate to the branches in early spring, and a succession of parthenogenetic generations of apterous viviparous females appears throughout the season. From the eggs on the elm hatch out apterous viviparous stem-mothers in early spring about May 15th, the second generation is also apterous viviparous, but the third is winged and migrates to the apple, hawthorn and mountain ash where three generations are developed, two being apterous, and the third l)art apterous and part winged. 'i1ie winged form migrates back to the elm, and produces the wingless sexual forms. Each female lays one large yellow egg which winters on the tree. The wingless forms remaining on the apple give rise to another generation which winters over as immature nymphs. The injury to the elm leaves is characteristic — the formation of terminal leaf clusters or rosettes. S. americana produces leaf-curl. The winged forms are nearly black, the abdomen being rusty brown, the wings are clear and the antennae have annulations and are 6-jointed. The sexual forms are wingless, beakless, smaller than the agamic forms; the female J'20 i^^^h long, reddish-yellow, is larger than the olive-yellow male; the antennae are 5-jointed, and without annulations as in other apterous forms. The root colonies ordinarily remain underground throughout the year, and do less injury northward. Parasites. — Aphdinus niali, a chalcid; Fipiza radicum, a syrphid; lady-bird beetles. Control. — Spray thoroughly the aerial forms with kerosene emulsion, soap solution or tobacco decoction; dip roots of suspected nursery stock in same solution or fumigate with HCN; add tobacco dust to the soil. Black Peach Aphis [Aphis pcrsiccc-iiigcr Er. Sm.). — Black; lives CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 1 47 Oil roots, twigs and leaves. No migration. Of no economic importance in Ontario (Fig. 98). Mealy Plum Louse {Ilyaloplerus arundinis Fab.). — Has long narrow light green body with three longitudinal stripes; covered with a mealy powder; honey-tubes short and thick; winged females migrate in June to grasses and cat-tail and return in autumn. Variable Currant Aphis {Aphis varians I'atch).— Infests currants, gooseberries and llowering currants, causing curling of the leaves. The winged summer forms migrate to some unknown host, and return Ml Fk;. 98. — Black peach ai)his (winded female). {After Quaintance .) in the fall. The eggs are deposited on the twigs. The stem-mother is j)urplish-green with white honey-tubes. The winged form has a black head and body, with a dark green abdomen marked with black, while the wingless form is dark green, tan or dark brown. Green Gooseberry Aphis {Aphis sanborni Patch). — Green; honey- tubes white. Grape Phylloxera {Phylloxera vitifolice Fitch = vastatrix Planchon). — Four forms are recognized: (i) wingless leaf-gall form; (2) wingless root form; (3) winged form; {4) sexual form. I. Adult leaf-gall form is a wingless female, plump, orange-yellow. Fills gall with many yellow eggs which hatch in 3 days into females. Several generations during summer. The feeding puncture stimulates the growth of the leaf tissue so that a hollow gall is produced, opening on the upper surface. 148 ECONOMIC ENTOMOLOGY 2. Root form similar to that on leaf; often derived from leaf form; several generations in a season; yellowish and wingless, and forms nodules which break down and decay, often destroying the root. Yellowish oval eggs are laid on the roots. Larvae moult three times. Leaf-galls are most common on American grapes while root-galls are most common on European grapes. 3. Some of the root forms in late summer develop elongate long- legged winged females that fly to neighboring vines and lay 2-4 eggs beneath loose bark. 4. These eggs are of two sizes — the smaller producing males, the larger sexual females. These are wingless and minute. Each female lays one large egg from which hatch the following spring the leaf and root forms. Not destructive on "sandy soils. Control. — Spray in early spring with lime sulphur; use American varieties as stock. COMMON GARDEN APHIDS Cabbage or Turnip Plant-louse {Aphis brassiccEL.). — Often abun- dant on the under surface of leaves of cabbages and turnips, and very destructive in warm dry weather. A greenish, soft, pear-shaped insect covered with a whitish bloom. Mature forms have bkck head and eyes and dark cornicles; nymphs are pale green with black legs and antennae. Parasite, Aphidiiis rapce, a braconid. Aphis pseudobrassicae Davis. — Also occurs on turnip, radish, cab- bage, rape, mustard, etc., and is often mistaken for A. brassicce. Melon Plant-louse (Aphis gassy pii Glov.). — Occurs on the under surfaces of the leaves of melon, cucumber, squash etc., and also on other crops and weeds. Winter eggs have been found on purslane and straw- berry, A blackish-green insect. Apterous females with legs and antennae whitish, cornicles black and short; winged forms with a row of black spots on sides of abdomen, and spots on head and thorax. Bean Aphis (Aphis rumicis L.). — Occurs on the tips of horse and broad beans at time of flowering. When the lice are abundant the plants assume a sooty sticky appearance. Also on apple, dahlia, dock, shepherd's purse, pigweed, snowball and burning bush. This aphis is slaty blue or black, with white bands on the legs and often with waxy tufts. Called also the ''black fly," "collier" and "black dolphin." Strawberry Root Louse (Aphis forbesi Weed). — Bluish-green, on roots of strawberry; occurs also on leaves. Eggs laid on stems and CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 149 leaves. Ants carry lice to roots. Of no economic importance in Ontario. Pea Plant-louse (Macrosiphum pisi Kalt.). — Green; eyes red; legs long; migrates in August to clover fields where eggs are laid and first spring generation feeds. Parasites — A phidiusfletcheri Ash., Megorismus fletcheri Crwd., a chalcid. Potato Plant-louse {Macrosiphum s olanif olii Ashmesid). — Green or pink; migrates to the rose, where winter is spent. Feeds on a large number of plants. Green Rose Aphis {Macrosiphum rosce Linn.). — A large pale green aphis with dark antennae and the cornicles long and black. Occurs on roses. Black Chrysanthemum Aphis {Macrosiphum sanborni Gill.). — Occurs on chrysanthemums in greenhouses. A brownish-black pyri- form plant-louse. COMMON SHADE AND FOREST TREE APHIDS Negundo Plant-louse {Chaitophorus negundinis Thos.). — A serious pest of the ash-leaved or Manitoba maple in the West. Infested trees soon become covered with honey-dew in which a sooty fungus develops. Woolly Apple Aphis {Schizoneura lanigera) . — See above. Poplar Leaf Gall Louse {Pemphigus populicaulis Fitch). — Pro- duces a deformity at the junction of petiole and blade of cottonwood and aspen. Alder Blight {Pemphigus tessellatus Fitch). — A Woolly aphid, occurs on branches of alder. Winged forms migrate to the maple. Beech Tree Blight {Pemphigus imhricator Fitch). — A similar form on the twigs and leaves of beech. Sitka Spruce Gall Aphis {Chermes cooleyi Gillette), Western Hem- lock Woolly Aphis {Chermes funitectis Dreyfus), Sitka Spruce Green Aphis {Aphis abietina Walk.). — -Are important economic forms on the Pacific Coast of British Columbia. Spruce Gall Aphis {Chermes abietis Choi.). — Abundant locally on White and Norway spruces, producing pine-apple-like galls at base of terminal shoots. Each gall, % inch long, contains about 50 cells each holding from 8 to 12 nymphs. The life-cycle is briefly as follows: "Galls open about mid- August and fully grown pupae emerge and moult within a few hours becoming the winged form which deposits a ISO ECONOMIC ENTOMOLOGY cluster of 40 to 50 yellow eggs on a spruce needle. The eggs are extruded from the abdomen but the parent Chermes remains over them until dislodged after her death by wind or rain. The winged form often oviposits near the gall from which it emerges. A different species of host plant is never sought by this Chermes. In about two weeks the young "stem-mothers" hatch from these eggs and seek a protecting crevice in the surface of the spruce bud where they can spend the winter. These wingless forms develop in the spring and become full grown about the last of May when they lay a cluster of 140 or more eggs. From these eggs hatch the young that inhabit the gall and are known as the "gall generation" with which we started the cycle" (Patch). Spruce Gall Aphis {Chermes similis Gill.). — (Consult Bull. 173, Maine Agr. Exp. Stn.). Abundant locally on black, red, white and Norway spruces, producing loose terminal galls and scraggly deformed twigs. The galls open about July ist and the winged fiocculent mi- grants oviposit on spruce. Control. — Spray in early spring while trees are dormant with whale- oil soap (i lb. to 2 gal. water). Black Leaf 40 (i to 800) added to soap (i lb. to 4 gal. water). Pine Bark Aphis {Chermes pinicorticis Fitch). — A common enemy of cultivated pines, appearing as fiocculent white masses upon the green bark of the more tender parts. Control. — Spray in late April or May with fish-oil soap or kerosene emulsion. DOUBLE-HOST APHIDS Following is a partial list of double-host Aphids: Chermes abieticolens on spruce Pemphigus tesselatus Fitch on alder Pemphigus balsamiferae on cottonwood Eriosoma pyricola on pear Eriosoma lanigera on apple Eriosoma americana on plum Eriosoma ulmi on English elm Hyalopterus arundinis on plum Phorodon humuli on plum Aphis avense on apple Aphis sorbi on apple Aphis pruni on plum Aphis peril on oleander = Chermes pinifoliae on white pine. = Pemphigus acerifoliae Riley on maple. = Pemphigus betas on beets. = Eriosoma pyricola on elm. = Eriosoma americana in part on elm. = Eriosoma americana on Juneberry. = Eriosoma fodiens on currant. = H. arundinis on reed grass, cat-tail. = P. humuli on hop. = A. avenae on oats, cat-tail, etc. = A. sorbi on plantain. = Aphis cardui on thistle. = A. lutescens on milkweed. CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 151 Aphis bakeri on apple and hawthorn = Aphis bakeri on clover. Aphis brevis on apple and hawthorn = Aphis brevis on clover. Aphis euonymi on snowball and burning = Aphis rumicis on bean and dahlia. bush Macrosiphum illinoiensis on Viburnum = M. illinoiensis on grape. prunifoliae Macrosiphum solanifolii on rose = M. solanifolii on potato. Macrosiphum granarium on grains, rose, = M. granarium on cat-tail. etc. Aphis prunorum Dob. on plum, Ribes = Rhopalosiphum nymphaeae on Nym- phaea, Alisma, Sagittaria, Typha. Rhopalosiphum ribis on Ribes = R. lactucae on Sonchus. Rhopalosiphum caprese on willow = R, capreae on Umbelliferae. Myzus ribis on Ribes = M. galeopsidis on Galeopsis, Stachys and Leonurus. Myzus cerasi on cherry = M. cerasi on Lepidium. Myzus persicae on peach = Rhopalosiphum dianthi on garden plants. Rhopalosiphum pastinaceae on Lonicera = R. pastinaceae on Pastinaca. Hormaphis hamamelidis Fitch on witch = Hormaphis hamamelidis on birch. hazel Hamamelistes spinosus Shimer on witch = Hamamelistes spinosus Shimer on birch. hazel Tetraneura graminis on Ulmus = T. graminis on Leersia. Thecabius populiconduplifolius on = T. californicus on Ranunculus. poplar Chermes floccus on white pine = Chermes floccus on Red and Black spruce. Chermes cooleyi on Blue and Engelmann = Chermes cooleyi on Douglas fir. spruces Aleyrodid^ (White Flies) White Fly (Aleyrodes vapor ariorum Westw.). — (Consult Bull. 140, Conn. Agr. Exp. Stn.) Injurious both in adult and nymph stages sucking the juices from the under surfaces of the leaves. Often abundant in greenhouses, and difficult to control. Adult. — Wings pure white, covered with minute particles of wax; body yellow, 3^f e i^^^h long; antennae 6-jointed; beak 3-jointed; tarsus 2-jointed; eyes brown, in two pairs. Eggs. — Elongate-oval, J^foo i^^ch long, laid on the leaves; light green or white to dark; hatch in 1 1-14 days. Unfertilized eggs produce males only; each female usually lays several dozen eggs. 152 ECONOMIC ENTOMOLOGY Nymphs. — Three-one-hundredths inch long, yellowish when full grown; long waxen rods on back of "pupa." Life-cycle about 5 weeks. Control. — Fumigate at night with hydrocyanic acid gas (J.^ oz. potassium or sodium cyanide, i fl. oz. sulphuric acid, 3 fl. oz. water, for every 1000 cubic feet of space); spray or wash repeatedly infested leaves with whale-oil soap (ij-^ oz. to i gal. water). Citrus White Fly {Dialeurodes citri Ashm. = A. citri Riley & Howard). — A most serious pest of oranges and other citrous plants of the South. (Consult Tech. Ser. No. 12, Pt. V and No. 27, Bur. Ent., U. S. Dept. Agr.) PsYLLiD^. (Jumping Plant-lice) Pear Psylla (Psylla pyricola Fuerst). — A European pest introduced about 1832, and now widely distributed over the Eastern states and Canada. Adidt. — A dark reddish-brown bug, J{o inch long; abdomen with black bands; wings clear with dark veins and laid roof-hke over the body; when disturbed it hops and flies away. Eyes bronzy; hibernates on trunk in crevices, etc.; 4-5 generations each year. Eggs. — Orange-yellow, minute; Jl-fg inch long, pear-shaped; depos- ited in crevices of bark or along midrib of leaf; hatch in 2-3 weeks. Nymphs. — Broadly oval, flattened, yellowish bodies with crimson eyes; later reddish with black markings and conspicuous black wing pads; secrete honey dew; 4-5 moults. Natural Enemies. — ^Lady-birds, protracted periods of wet cold weather in spring, and long spells of hot dry weather in summer. Control. — Clean cultivation; bark scraped; spraying with Black Leaf 40 ( I pint in 100 gal. water) during warm days in early spring, late fall or after blossoming; spraying with lime-sulphur just before opening of blossoms. Bramble Flea-louse (Trioza tripunctata Fitch). — Occurs on black- berry, causing curling of the leaves and dwarfing of the shoots. Adult. — A small reddish-brown, jumping plant-louse, J^ inch long; wings with three yellowish-brown bands. October-May or June. Eggs. — ^Light yellow, deposited in June- July on blackberry. Nymphs. — Mature in September-October; young nearly pure whitc-^-ftv to a greenish white; older nymphs yellowish. classification and description of common insects 1 53 Cercopid^ (Froghoppers or Spittle Insects) (Consult I?Ull. 254, Maine Agr. Expt. Station) These insects commonly occur in meadows and are often conspicuous by the large number of frothy masses resembling spittle on the leaves of grass, clover and weeds. The injury done is difficult to estimate but it must be considerable in the aggregate. Philcenus spumarius and P. lineatus are common in meadows, and Aphrophora parallela Say on pines. Meadow Froghopper (Philcenus spumarius Linn.). — This insect feeds on oats and a wide range of plants, many of them weeds, but not on grasses. The injury is apparent in the formation of withered or dwarfed seeds. Adult. — Body elongate-oval, head bluntly angular, wing-covers extending well beyond the end of abdomen. Color pale grey to black, and the markings quite irregalar in form. Eggs. — Elongate-elliptical, one side straight, the other curved. Shell tough and hard; hibernate in dead stems or leaves in meadows. Nymphs. — Almost colorless; three ins tars; antennae 9- jointed. The viscid frothy masses excreted from anal opening and certain lateral glands on seventh and eighth abdominal segments. The masses are believed to be protective. Control. — Rotation of crops; early mowing to kill the nymphs; burning the surface dead grass to kill the eggs. Grass-feeding Froghopper {Philcenus lineatus L.). — This spittle insect is found almost exclusively on grasses, especially on timothy and red top, and undoubtedly does considerable injury. It causes withering of the stems and blasting of the heads. Adult. — Distinguished from P. spumarius by its longer head, and narrowed body with more nearly parallel sides. Front of head rounded- angular and as wide as thorax. Color grey with a whitish costal margin and a blackish border line. Eggs. — Hibernate; hatch late in spring. Nymphs. — Three or more ins tars; mature in July. 154 ECONOMIC ENTOMOLOGY Family Cicadellid^ (Leaf-hoppers) (Consult Bull. io8, Bur. Ent., U.S. Dept. Agr. and Bull. 238, 248, Maine Agr. Exp. Stn.) The Leaf-hoppers are divided into four fairly distinct sub-families, separated by means of the venation of the wings and by the head parts: (i) Bythoscopince occurring mainly on trees or shrubs, and including Idiocertis alternatus and the Clover Leaf-hopper (Fig. 99); (2) Cica- dellincB, including the Sharpshooter (Oncometopia undata) and Drcecula- cephala mollipes occurring in grass land; (3) Jassince, including the Shovel-nosed Leaf-hopper (Dorycephalus platyrhynchus) on wild rye Fig. 99. — The clover leaf-hopper (Agallia sanguinolenla) : a, adtilt; h, nymph, side view; c, nymph, dorsal view; d, face; e, elytron; /, female genitalia; g, male genitalia. All enlarged. {After Osborn and Ball.) {Elymus), the Inimical Leaf -hopper {DeUocephalus inimicus) on blue grass, the Destructive Leaf-hopper {Athysanus exitiosus) in grain fields, and the Six-spotted Leaf -hopper {Cicadula 6-notata) in oat fields; and (4) TyphlocybincB including the Apple Leaf-hopper {Empoasca mali) the Rose Leaf-hopper {Empoa rosce) and the Grape Leaf-hopper {Erythroneura comes). The presence of leaf-hoppers in very large numbers in meadows and pastures in late summer indicates that considerable injury is being done, and that they must be reckoned among insects of economic importance. Six-spotted Leaf -hopper {Cicadula 6-notata Fallen). — A small yellow form 4 mm. long with six black dots on the vertex and a double series of black arcs on the front. Occurs on oats, timothy, etc., producing spots on the leaves, whitish at first, then turning to brown or black. CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 1 55 Black Apple Leaf -hopper {Idiocerus fitchi Van D.). — A common pest in the Annapolis Valley but the injury is small. The eggs are laid in August and hatch from May 2 2d to June 13th. The duration of nymphal stage (5 moults) is about 50 days. Beet Leaf -hopper {Eutettix tenella Baker). — (Consult Bull. 66, Pt. IV, U. S. Bur. Ent.; Utah Bull. 155.) This native leaf-hopper causes the "curly-leaf" disease of sugar beets in the Western States and is therefore responsible for much loss. Found also on A triplex ^ Russian thistle, Sea-blite and Sarcohatus. One brood a year. Adult.- — Small, J^ inch long, pale yellowish-green to white, often straw-colored. June-August. Hibernates. Eggs. — Pale greenish- white, elongated, tapering at the end; inserted in the stems or large veins of leaf; hatch in about 2 weeks. Nymphs.' — White at first, becoming like the adult but wingless. Active. Duration 20-25 days, July-September. Grape Leaf -hopper {Erythroneura comes Say). — (See Bull. 215, Cornell Ag. Exp. St., 1904.) This bug is a very common pest in vineyards, and occasionally does considerable injury to the leaves which curl and turn brown. During the summer the nymphs feed on the under surface of the leaves and give them an unnatural spotted ap- pearance. The adults, mature in August, also do much harm. Feeds also on Virginia Creeper, Strawberry, etc. Adult. — One-eighth inch long; wings and back variably marked with yellow and red. Hibernates in nearby grass and wood-lands, and emerges about May ist. Eggs. — Three-one-hundredths inch long, semi-transparent, slightly curved and faintly yellow; deposited in June beneath the lower skin of grape leaves; hatch in 9-14 days. Nymphs. — ^Light yellowish-green with lemon-yellowish stripes on each side of the body; pass through 5 stages in 20-23 days; mature in July-August. Control. — Spray thoroughly with Black Leaf 40, tobacco extract or kerosene emulsion when young nymphs appear; clean culture. Apple Leaf -hopper (Empoasca mali Le Baron). — (Consult Bull. 108, Bur. Ent., U. S. Dept. of Agriculture, and Journ. Econ. Entomology, Vol. 2, p. 54; Vol. II, pp. 144-148.) Occurs also on beans, alfalfa, clover, potatoes, currants and gooseberries. Adult.- — Slender and cylindrical, J^ inch long; brilliant grass-green; 156 ECONOMIC ENTOMOLOGY white lines and dots between the eyes; a series of six whitish spots on front margin of prothorax, two whitish h'nes on mesothorax form- ing a letter H; three dots on scutellum; strongly convex above; front rounded; wings thin and uniform, folded close about the body; legs slender, hindmost larger; three or four generations each year. Adults may live 14-30 days. Hibernates. Eggs. — Autumn eggs laid in September under epidermis of apple, summer eggs under epidermis of petioles of apple, clover, etc.; hya- line, cylindrical. Nymphs. — Light green; feed on under side of leaves causing white spots, most injurious in May-June; five nymphal stages covering 22 days. Control. — Spray in spring with a mixture of Black Leaf 40 and whale- oil soap; collect adults by driving tanglefoot screens along the rows in bush-fruits. Rose Leaf -hopper (Empoa rosce Linn.). — ^Leaves of rose bushes and apple trees are often badly infested with the Rose Leaf-hopper, and all stages of growth may be readily found. Eggs are laid in July, and eggs are again laid in the fall beneath the bark of young wood of roses, blackberry, and strawberry runners, where they stay over winter. Migration from the roses occurs in June. Controlled by lime-sulphur and Black Leaf 40 during the early nymph stages (Consult Bui. 148 Oregon Ag. Exp, St.) ClCADID^ Periodical Cicada {Cicada septendecem Linn.). — (Consult Bull. 71, Bur. Ent., U. S. Dept. of Agr.) Often called the Seventeen-year Locust. Adults damage orchards and nurseries by making egg punctures in the twigs. Adult. — One and one-fourth inches long, black; abdomen banded with red; eyes red; veins red at base and along front margin; June; duration about 30 days. Dwarf forms also occur. Eggs. — Each female lays 300 to 500 eggs in punctures made by ovipositor in twigs and stems; eggs hatch in 6 to 8 weeks. Nymphs. — Burrow in the ground, feeding on juices of roots and humus of soil; moult probably 4 or 6 times at intervals of 2 to 4 years. In the spring of the seventeenth year they emerge and moult, changing to adults. A race or sub-species having a 13-year period CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 1 57 occurs mainly in the South. Over twenty broods have been recog- nized and deHmited. Control. — Prune off affected twigs in July and burn before the hatch- ing of the eggs; allow hogs the run of infested land during April and May; avoid pruning the orchard the year before a cicada year. N atural Enemies. — A digger wasp {Megastizus speciosus), egg parasites (cecidomyiid and chal- cid); mites; the English sparrow, catbird, robin, etc. The Dog -day Harvest-fly {Cicada tibicen Linn.). — Often oc- curs but is not of much import- ance economically. It is black and green, and white powdered underneath. Membracid^ (Tree-hoppers) Buffalo Tree-hopper (Ceresa bubalus Fab.). — (Consult Circ. 23, Div. Ent., U. S. Dept. Agric.) This bug is a common pest of or- chards and shade trees feeding on the sap of apple, maple, etc. It injures the trees by making longi- tudinal incisions in the bark, which become points of weakness (Fig. 100). Adult. — A grass-green bug, % inch long, with the pronotum greatly enlarged, and expanding laterally into two horns and pos-' teriorly into a long point. July- September. Eggs. — Dirty-whitish, cyHndrical, slightly curved, tapering toward outer end; Jf g inch long. Laid in the bark in batches of 6-12 in two Fig. 100. — Twigs showing egg punc- tures of the Buffalo tree-hopper. 158 ECONOMIC ENTOMOLOGY curved slits made by ovipositor. Egg-laying occurs in August and September; hatching the following May and June. Nymphs. — Covered along the centre of the back v^^ith numerous forked or barbed spines or projections, a pair to each segment. General feeders in or near orchards. Control. — Thorough cultivation of the orchard and destruction of weedy borders in May and June. ORDER HEMIPTERA ( = FORMER SUB-ORDER HETEROPTERA) Chief Economic Families^ (after Comstock) (Fig. loi) A. Antennae with 3-4 segments. B. Beak 3-jointed. Pig. ioi. — Fore wings of Heteroptera. i, Capsidae; 2, Pyrrhocoridae; 3, Lygaeidae; 4, Coreidae; 5, Nabidic; 6, Acanthidce; 7, Typical wing showing parts: m., membrane; cu., cuneus; e., embolium, co., corium; cl., clavus. {After Comstock.) ^ Other Hemiptera Families are of frequent occurrence, especially in or about water. For convenience of reference the common families (old Hepteroptera) are synopsized as follows: A. Short-horned Bugs. — Live in or near water; antennae short and concealed beneath the head. Families: Corisidae, Notonectidae, Nepidae, Belostomatidae, Naucoridae, and Galgulidae. AA. Long-horned Bugs. — Antennae at least as long as the head. B. Semi-aquatic Bugs. — Saldid^e, Veliidx, Hydrobatidae, Limnobatidae. BB. Land-hugs. C. Antennie 4-jointed. Emesidae, Reduviidae, Nabidae, Phymatidae, Aradidae, Tingitidae, Acanthiida^, Capsidae, Pyrrhocorida?, Lygaeidae, Berytidae, Coreidae. CC. Antennae 5-jointed. Pentatomidae, Cydnidae, Corimclaenidae, Scutelleridae. CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 1 59 C. Front legs with thick femora. — Phymatidm (Ambush- Bugs) P-43- CC. Front legs normal or slightly thickened. D. Body not flattened. — Reduviida (Assassin Bugs), p. 43. DD. Body flattened. E. Tarsus with 2 segments. — Aradida (Flat Bugs). EE. Tarsus with 3 segments, dorsum flat, beak short. — Acanthiidcd (Bedbugs), p. 167. KB. Beak 4-jointed. C. Ocelli absent. D. Membrane of front wings with about eight branching veins; cuneus absent and with two large cells at base. — Pyrrhocorida (Red Bugs). DD. Membrane of front wings with no branching veins; cuneus present and with one or two closed cells at base. — MiridcB or CapsidcB (Leaf Bugs), p. 163. CC. Ocelli present. D. Front legs fitted for grasping. — Nabidce (Damsel Bugs), P- 43- DD. Front legs normal. E. Membrane of front wings with 4 or 5 simple veins arising from its base. — Lygmda (Chinch Bugs), p. 161. EE. Membrane of front wings with many forked veins arising from a transverse basal vein. — Coreida (Squash Bugs), p. 159. AA. Antennae with 5 segments. B. Scutellum flat, narrowest behind; tibiae usually without spines. — Pentatomida (Stink Bugs), p. 166. BB. Scutellum convex, covering nearly the whole abdomen; tibiae strongly spinose; prothorax rounded in front and straight behind; scutellum margin furrowed. — Corimelcenidce (Negro Bugs), p. 167. BBB. Scutellum convex; prothorax not as above; scutellum with lateral margin unfurrowed. — ScutelleridcB. Coreida (Squash Bugs) Box-elder Plant Bug {Leptocoris trivittatus) . — ^Leaves attacked turn yellow and drop. Occurs in the West and is spreading eastward. Adult. — A blackish bug 3^^ inch long, with three broad red lines on the black thorax; veins of wings red, also edges of harder parts of wings; mature in autumn. Hibernates under rubbish or in crevices. Eggs. — ^Laid in spring and early summer on box-elder trees. i6o ECONOMIC ENTOMOLOGY Nymphs. — Also show bright red markings of adult. Very young forms are bright red; mature in less than 2 weeks. Control. — Collect bugs in sunny days in winter from trunks of trees; spray young forms with tobacco- soap solution. Squash Bug {Anasa tristis DeG.). — (Consult Cir. 39, Div. Ent., U. S. Dept. Agr.) Infests pumpkins and squashes. A suck- ing insect which should not be confused with the cucumber or squash beetle. Adult. — Dirty blackish-brown above and mottled-yellowish be- neath; J^ inch long; wings folded diagonally across the back; beak 4-jointed; ill-smelling (Fig. 102). Eggs. — Laid in clusters on the underside of leaves; red or bronze, smooth and shining; slightly flat- Hatching in 8-13 days. Nymphs. — When newly hatched they are red and green but later they become black like the adults but without wings and with propor- PlG. 102. — Squash bug {Anasa tris- tis): a, mature female; b, side view of head showing beak; c, abdominal seg- ment of male; d, same of female. {After Chittenden.) tened on two sides; }y^^ inch long. Fig. 103. — Nymphs of squash bug, showing five stages. {After Chittenden, U. S. Bur. Ent.) tionately longer legs and antennae, later developing wing pads and becoming more and more like the adult. Five moults occur (Fig. 103). CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS l6l Life-history. — ^It hibernates as an adult under rubbish, in out- buildings, etc. In spring the adult injures the young squash plants by sap punctures, and at that time lays eggs; nymphs reach maturity in July-August. Two broods in a season in the South. Control. — Spray with kerosene emulsion; trap the adults under bits of board; destroy the egg-masses; destroy the vines in fall; plant early squash plants among the cucumbers and melons as traps. Lyg^id^ (Chinch Bugs, etc.) Chinch Bug {Blissus leucopterus Say). — (Consult Bull. 95, 111. Agr. Exp. Stn.; Bulls. 15, 69; Circ. 113; Farmers' Bull. 132, Div. Ent., U. S. Dept. Agr.) A serious native Ameri- can pest, especially in the Central States to cereals and corn crops and to timothy meadows; widely distributed in the Eastern half of the Continent from the West Indies to Canada. Adult. — A black bug, J^ inch long; wings white and marked by a small black triangle on their outer margins; bases of the antennae and the legs are red. Short winged forms in the East and along the sea coast and Great Lakes. April-May, and August (Figs. 104 and 105). Eggs. — Cylindrical, -Jf 00 ii^ch long;squarer at one end; whitish at first, becoming amber-ed. in May, but in 10 days in August. Nymphs. — Four moults, the successive ins tars showing changes in size and markings, the first three often called the red stages. In the first stage it is pale red throughout with a yellow band across the base of abdomen; in the second stage the head and pro thorax become darker, the abdomen vermilion with pale yellow band; in the third stage the color is decidedly darker throughout, and in the fourth the red has disappeared, general color varying from black in front to dusky grey behind (Fig. 106). Life-history. — The bugs hibernate under rubbish, in thickets and in clumps of grass. In April and May females lay their eggs on the roots 11 Fig. 104. — Chinch bug: adult. (From Webster.) Hatch in 2-3 weeks l62 ECONOMIC ENTOMOLOGY or the bases of the stems of wheat and grasses. Eggs hatch in 2 or 3 weeks or less. The nymphs reach maturity in 6 or 7 weeks, when a migration occurs on foot to other plants. Eggs are laid on the stems and leaves of corn and the nymphs attain maturity in autumn. There are, therefore, two broods in a year. Pig. 105.— Chinch bug: adults of short-winged form. Webster.) Much enlarged. (After Control. — Clean up rubbish and burn the dried grasses in which the pest winters in late fall or early spring; place barriers of dust or oil or tar lines; plow furrow about fields to be protected; the use of muscardine fungus. Pig. 106. — The chinch bug: a, h, eggs; c, newly hatched larva, or nymph; d, its tarsus; e, larva after first molt; /, same, after second molt; g, last-stage larva; the natural sizes indicated at sides; h, enlarged leg of perfect bug; j, tarsvis of same, still more enlarged; i, proboscis, or beak, enlarged. {From Riley.) Parasites and Enemies. — Triphleps insidiosns Say, Milyas cinctus Fab., Agonoderus pallipes Fab., coccinellids, Reduviolus ferus, Pagasa fusca, Blechrus, Chrysopa, quail, frog, Sporotrichum glohulijerum Speg. CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 1 63 MiRiD^ = Capsid^ (Leaf Bugs) Four-lined Leaf Bug {Pcecilocapsus lineatus Fab.). — (Consult Bull. 58, Cornell Agr. Exp. St.) This bug is one of the most common in- sects found during summer on field and garden vegetation. It is oc- casionally destructive in flower gardens. Adult. — A greenish-yellow bug with two black spots on the thorax and four black stripes down the back; %o inch long; abundant in June and July. ^^^^' — White, laid on terminal twigs of currant and other bushes in the fall; hatch in the spring. Nymphs. — Red when young, but blacker when older, mature in about 20 days. They injure the tips of shoots and cause the leaves to curl up and become brown spotted. Currants, gooseberries, mint and sage are especially liable to injury. Control. — Spray with nicotine sulphate or other tobacco extracts, or kerosene emulsion. Tarnished Plant Bug (Lygus pratensis L.). — (Consult Bulls. 346 Fig. 107. — Tarnished plant hng (Lygus and 391, Agr. Exp. Sta., Cornell.) Pr^^'^^i^)- Wter Chittenden,) A very common insect, feeding on a wide range of plants. It causes the well-known injury to the buds of aster, dahlia and chrysanthe- mum, and to the buds and blossoms of orchard trees (Fig. 107). Adult. — Brownish, mottled with yellow and reddish. Head yel- lowish-brown, usually with three lines; prothorax bronzy brown, usually with four blackish spots in a row; scutellum brownish, usually with a Y-shaped spot. Wings bronzy brown mottled with yellowish- brown and reddish. Antennae dark brown; legs brown, tibiae banded near base and tarsi dusky. Under surface dark at centre with a lighter lateral stripe and a marginal brown band with yellow spots. Length ^^ to 3^^ inch. Hibernates. Eggs. — One-twenty-fifth inch long, flask-shaped, and obliquely truncate; deposited in stems, etc.; duration 10 days. Nymphs. — Five stages; active; feeding on juices of plants. Life-history. — Cycle completed in 25 to 30 days in late summer 164 ECONOMIC ENTOMOLOGY with probably four or five generations each year. Adults winter in sheltered situations; eggs laid in early spring and first nymphs appear in May. Broods not well distinguished, and insects to be seen from spring until fall. Control. — ^No effective remedy; spraying with nicotine sulphate, kerosene-soap emulsions and fish-oil soap is fairly satisfactory if ap- plied in early morning. False Tarnished Plant Bug (Lygus communis Knight). — (Consult Can. Ent. 48, 10 and Bull. 8, Nova Scotia.) A serious pest in pear orchards in New York State, causing knotty deformed and gritty fruit. Plum and quince are also injured. The Var. nova scotiensis injures apple. Adult. — Pale green to light brown; J^ inch long; two black rays on disk of pronotum; membrane of upper wing with three brown spots near tip of areole; legs and antennae long. Most commonly breeds on Cornus spp. Eggs. — Smooth and cylindrical, elongated, 0.8 mm. long; yellowish- white, translucent. Inserted in the bark of small branches July- Aug. ; hibernate, hatching during blossoming time. Nymphs. — Pale yellow at first, becoming greenish; feeding on the leaves; five stages, maturing about middle to end of June. They puncture the young fruits, often several punctures on one fruit, causing the fruit to fall or depressions and deformities in apples and grittiness in pears. Leaves, stems and blossoms are freely attacked. Dura- tion about 32 days. Carrier of European Canker and Fire Blight (Brittain). Control. — I. Spraying with Black Leaf 40 (i part to 1000 water) just after the petals fall. 2. Banding the trunks to prevent the bugs from crawling up. 3. Cultivation of soil up to July to keep down all plant growths. The Var. nova scotiensis (Green Apple Bug) occurs abundantly as an apple pest in Nova Scotia. It is more slender and much paler than the typical communis. Lygus invitus Say, according to Knight, breeds only on elm, and is not responsible for injuries to pear and apple. A very common capsid of meadows is Miris dolobratus L., a form long and narrow, % inch long; greenish, yellow with black markings; two black stripes extending from the eyes over the thorax. CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 165 Clouded Apple Capsid (Neurocolpus nuhilus Say). — A widely dis- tributed capsid, injuring apple trees and fruit in Ontario. Adult. — One-fourth inch long, larger and narrower i\vd^nLygus pra- tensis. Color variable, but dorsally mostly cinnamon brown to red- dish-black; has a dull felty appearance; ventrally light green. Basal joint of antennae stout, dark, and with clavate dark brown hair; second segment slender, elongate; legs slender with reddish bands. Eggs. — Curved, nearly colorless, with a glistening white cap. In- serted into tissues of new growth; egg-laying period July i5th-Sept. ist; eggs usually laid singly behind buds. Hibernate. Hatch about first week in June. Nymph.— This stage lasts from 3 to 4 weeks. At first nearly color- less, but later is green with dull reddish marks on back and sides. Control. — Clean cultivation, until end of June; spray the leaves thoroughly with soap and Black Leaf 40 soon after the nymphs hatch. Apple Red Bugs {Heterocordylus malinus Reuter and Lygidea mendax Reuter). — (Consult Cornell Bull. 291.) These bugs cause spotting of the leaves, and they puncture the fruit in June, causing deformation. Adults. — One-fourth inch long; Heterocordylus varies from red to black; wings red, black along inner edge and with an ovate black spot near outer margin; scutellum, legs and antennae black, dorsum covered with white, scale-like hairs; Lygidea is lighter colored and without hairs on back; head and pro thorax orange-red, scutellum orange-red in front and blackish posteriorly; wings with a band of orange-red along outer edges, legs darker yellow. Eggs. — Dull whitish, curved and slightly compressed, inserted into the bark of smaller branches; hatch soon after opening of leaves of fruit-buds. Nymphs. — At first red; five stages; Heterocordylus has dusky mark- ings on thorax and no fine short hairs on thorax. Control. — Applications of Black Leaf 40 (i pt. to 100 gal.) just before blossoms open, and just after falling of the petals. Hop Red Bug (Paralacoris hawleyi Knight). — This capsid is a pest of hops in New York. It stunts and deforms the vines and per- forates the leaves. Adult. — One-fourth inch long, black with hemelytra hyaline or pale yellowish, and cuneus reddish. July. 1 66 ECONOMIC ENTOMOLOGY Eggs. — One-fifteenth inch long, dirty white, curved and with two prominent white incurving hooks at micropylar end; smooth and glossy. Inserted in the bark or wood of hop poles, Aug.-Sept. Duration 9- g}'2 nionths. Hatch throughout June. Nymphs. — Five stages; duration about 30 days. Active. Enemies. — Apeteticus maculiventris, a Pentatomid; Reduviolus sub- coleoptratus, a nabid; and a species of Trombidium. Pentatomid^ (Stink Bugs) Harlequin Cabbage Bug {Murgantia histrionica Hahn). — A native of Mexico and Central America. Injurious in the Southern states but its ravages do not extend much farther north than New Jersey and Long Island. Also known as ''calico bug" "fire bug," and ''terrapin bug." Attacks cabbage, radish and turnip. Adult. — A moderate sized red and black plant bug, the markings running more or less transversely and alternating. In South active throughout the year; in North hibernates as adult. Eggs. — Resemble ''miniature white barrels bound with black hoops and with black spots set in for bung-holes." Usually laid in two rows, fastened by one end to under surface of leaf. Hatch in 2-11 days. Nymphs. — Like adults in markings; antennae with 4 joints; 5 instars, first instar glossy yellow; duration 2-10 weeks but shorter in the South. Probably 4 or 5 generations in the South and 2 or 3 in the North. Control. — Trap-crop of kale, rape, mustard, radish or turnip; clean farm practice; bounties for collections. Green Soldier Bug {Nezara hilaris Say). — (Consult Ohio Bull. 310.) In N. E. parts of U. S. and Canada; a general feeder, and a serious pest of the peach industry in Ohio. Adult. — Oblong-oval; bright green, finely punctate; edges of head, thorax and abdomen white-yellowish or rufous; % inch long. Hiber- nates. Eggs. — ^Light yellow; oval; circular cap with a row of short spine- like processes. Laid in clusters on leaves or fruits in June- July. Hatch in 7 to 8 days. Nymph. — Five instars; mature in 50-75 days. Injures by punc- turing the fruit. Parasites. — A Proctotrypid — Trissolous euschisti Ash. CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 167 In addition to the foregoing forms, among the more common northern plant-sucking species of this family are Nezara pennsylvanica a large green, flattened bug, ^^ inch long; Cosmopepla carnifex, shining black and spotted with red and orange, }i inch long; Leioderma ligata, a large broad form with a red margin and a red spot on the middle of its back. Among the blood-sucking species are Podisus spinosus, recognized by the conspicuous spine on each side of prothorax, and Brachymena spp. mostly large grey tree bugs; Perillus circumcindus which attacks the Colorado potato beetle. CoRiMEL^.NiD^ (Negro Bugs) Negro Bug {Corimelcena pulicaria Germer). — Feeds on strawberries, blackberries, raspberries and celery, imparting an unpleasant odor. Adult. — A small shiny black bug }/i inch long, with a white stripe on each side of body. Eggs. — Orange-yellow, oval; laid singly on the leaves; hatch in about 16 days. Nymphs. — Feeding on leaves and fruit. AcANTHiiD^ (Bed Bugs) Bed Bug (Cimex lectularius L.). — Adult. Reddish-brown, J^ inch or less in length; never fully winged but with wing pads; flattened; hiding in day-time in cracks but active at night; "buggy" odor. Eggs. — ^ White, oval, ^^q inch long; laid in cracks and crevices; each female lays about 200 eggs, 50 at a time. Nymphs. — -White at first but red after feeding; resemble adults but body more slender and head larger; 11 weeks to mature; one generation in a season. Control. — -Fumigate with sulphur or carbon bisulphide; wash floors thoroughly with soapsuds and spray with benzine. ORDER SIPHUNCULATA (SUCKING LICE) Chief Families A. Eyes large, convex, distinctly pigmented; beak short. — Pediculidce. AA. Eyes very indistinct or wanting; beak long. — Hcematopimdce. i68 ECONOMIC ENTOMOLOGY Pediculid^ (Consult Bull. 5, Div. Ent., U. S. Dept. Agr.; Bull. 48, Minn. Agr. Exp. St.) Most domestic animals at some time or other are liable to become infested with sucking lice which cause considerable irritation. The eggs or "nits" are attached to the hairs, and the lice by means of a beak suck the blood of their victims. Treatment consists in the application of tobacco water or Black Leaf 40 (i part to 1000 water), dilute carbolic acid, kerosene emulsion, sulphur and mercuric ointment, or an infusion of 4 oz. stavesacre and i oz. hellebore, or creolin solution. Two genera are of importance economically — Pediculus occurring on man, and Hcematopinus on domestic animals. Head-louse of Man {Pediculus capitis De Geer). — Whitish with faint dark markings on sides. Eggs (50) glued to hairs, whitish, hatch in 6 days and young become mature in about 3 weeks (Fig. 108). Body-louse of Man {Pediculus vestimenti LeBich) . — Similar in shape to preceding, but larger and at maturity with upper surface transversely banded with black. Eggs laid in the folds in clothing. Bacot {Parasitology, 1917) states that P. capitis and P. vestimenti may cross-pair with fertile offspring. He found that the average number of eggs per day was 3.7 for capitis and 6.4 for vestimenti. The egg period for the latter was estimated at 12 days, and 12 days more for the maturity of the female. "Allowing an average of 8 eggs per day, spread over a fertile period of 40 days we find that during her life a single female may. have 4160 offspring." A carrier of typhus fever. A common pest of army camps. Control Measures. — Change clothing as often as possible; wash infested clothing with a cresol soap made as follows: water 10 gal., Jeyes' Fluid ij^ oz., soft soap i}^ lb.; bathe body using cresol soap; place N.C.I, powder in shirt and trousers (naphthaline 96 per cent., creosote 2 per cent., iodoform 2 per cent.). Crab-louse of Man {Pediculus pubis = Phthirius inguinalis Leach). — Body as wide as long, with strong legs. Eggs glued to hairs. Mouth- F I G. 108.— Head louse {Pedi- culus capitis). En larged. CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 1 69 parts form a fleshy, extensible, unjointed beak. Tarsi with a strong curved claw. Control. — Cleanliness, sulphur and mercurial ointments. H^MATOPINID^ Hog-louse (Hcematopinus urius Nitzsch). — One-fourth inch long; broad abdomen, long head; grey with sides black. Horse-louse {H cBmatopinus asinilAnn.). — One-sixth inch long, half as wide, long and slender head with parallel sides. Short-nosed Cattle-louse {Hcematopinus eurysternus Nitzsch). — One-sixth inch long, half as wide; head rounded in front, as wide as long. Infests the neck and shoulders chiefly. Eggs white, hatching in 7-8 days; life-cycle 22-24 days. Each female lays from 35-50 eggs. Long-nosed Cattle-louse {HcBmatopinus vituli Linn.).— One-eighth inch long, one-third as wide; long slender head. Life-cycle from 25- 27 days. Dog-louse {Hcematopinus piliferus Burm.). — One- tenth inch long, abdomen wide, yellowish. VI. LEPmOPTERA (BUTTERFLIES AND MOTHS) ^ Common Families (Figs. 109-121) A. Antennae club-shaped at apex; wings at rest held erect; day-fliers. — The Butterflies {Rhopalocera). B. Butterflies with cubitus apparently 4-branched. — Papilionidce (Swal- low-tails), p. 174. BB. Butterflies with cubitus apparently 3-branched. C. Fore-legs normal. — Pieridce (Pierids), p. 175. CC. Fore-legs reduced in size. — LyccenidcB (Gossamer- wings). CCC. Fore-legs aborted, mere tippets. — Nymphalidce'^ (Four-footed Butterflies), p. 176. AA. Antennae clubbed but terminated by a hook; wings at rest usually held erect. — Hesperidcs (Skippers). AAA. Antennae not clubbed at apex; wings at rest held flat or folded like a roof over the body. — The Moths (Heterocera). B. Hind wings with one or two anal veins. — {Macrolepidoptera in part). C. Frenulum present. D. Subcosta and radius of hind wings connected by a strong oblique vein. — Sphingidce (Hawk Moths), p. 177. I Handlirsch groups the orders Mecoptera (Panorpatae) , Trichoptera and Lepidoptera under the Sub-class Panorpoidea. 2The Danaida family is now separated from the Nymphalidae on the basis of the bare antennae and forked base of subcostal vein. 170 ECONOMIC ENTOMOLOGY DD. Subcosta and radius of hind wings not connected by a cross vein. E. Cubitus of fore wings apparently 3-branched. F. Basal part of subcosta of hind wings joined to radius for a distance then bending sharply toward costal margin. — Geometrina (Geometrids), p. 204. FF. Basal part of subcosta of hind wings not as in F. — Notodontidm (Prominents), p. 198. Fig. 109. — Venation of a papilionid (Papilio) . {After Comstock.) Fig. no. — Venation of a pierid (Pieris). (After Comstock.) EE. Cubitus of fore wings apparently 4-branched. F. Subcosta of hind wings either separate from or joined for a short distance to radius. G. Ocelli absent; antennae pectinate; cubitus of hind wings apparently 4-branched. — Liparidce = LymantriidcB (Tussock Moths), p. 200. GG. Ocelli present; antennae mostly simple; CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 171 Fig. III. — Venation of a danaid {Danais). {After Comstock.) 2d A Fig. 112. — Venation of a saturniid {Anisota). {After Comstock.) Rz «3 Fig. 113. — Venation of a geometrid (Dyspteris). (After Comstock.) Fig. 114. — Venation of an arctiid (Halisidota) . (After Com- stock.) 172 ECONOMIC ENTOMOLOGY ,'Ri,-P^ A A ^ A Fig. 115. — Venation of a notodontid Fig. 116. — Venation of a noctuid {Noiodonta). {After Cotnslock.) (Agrotis). {After Comstock.) R.JiP^f^^ Fig. 117. — Venation of a lasiocampid {Malacosoma). {After Comstock.) A A Fig. 118. — Venation of a pyralid {Pyralis) . {After Comstock.) CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 1 73 cubitus of hind wings apparently 3- branched. — Noctuida (Owlet Moths), p. 184. R. R. Rz Pi^ Fig. 119. — Venation of a tortricid (Cacoecia) . (After Comstock.) 2dA id A Fig. 120. — Venation of Thyridopteryx. {After Comstock.) Fig. 121. — Venation of a cossid (Prionoxystus). {After Comstock.) FF. Subcosta of hind wings united with radius for a considerable distance; cubitus of hind wings apparently 4-branched. — ArctiidcB {T'lgti Moths), p. 181. 174 ECONOMIC ENTOMOLOGY CC. Frenulum absent. D. Cubitus of both wings apparently 4-branched. Hind wings with humeral veins. — Lasiocampidce (Tent- caterpillar Moths), p. 203. DD. Cubitus of both wings apparently 3-branched; tongue absent; tibia without spurs. — Saturniina (Silkworm Moths), p. 179. BB. Hind wings with usually three complete anal veins. (2 to 4 anal veins in hind wings of yEgeriidae). I C. Wings transparent; free from scales; fore wings narrow. — Mgeriidce (Clear- winged Moths), p. 216. CC. Small moths; wings covered with scales. — {Microlepidoplera). D. Subcosta and radius of hind wings fused or approximate. ^ — Pyralidina (Pyralids), p. 207. DD. Subcosta and radius of hind wings far apart. E. Second anal vein of hind wings forked at base. — ■ Tortriclna (Tortricids), p. 218. EE. Second anal vein of hind wings not forked at base. — Tineina (Tineids), p. 236. CCC. Large or medium-sized moths; wings usually covered with scales. — (Macrolepidoptera in part). D. Anal veins of fore wings partially fused; hind wings some- times with two anal veins. — Psychidce (Bag-worms), p. 207. DD. Anal veins of fore wings not fused. — Cossidce (Carpenter Moths), p. 237. Note. — The Geomctrina includes the following families: Ennomidae, Geometridae, Hydriomenidae, Sterrhidae and Monocteniidae. The Pyralidina includes the Pyraustidae, Pyralididae, Galeriidae, Crambidae, Phycitidae, Pterophoridae and Orneodidae. The Tortricina includes the Eucosmidae, Conchylidae and Tortricidae. The Tineina includes Tineidae, Yponomentidae, Plutellidae, Gelechiidae, Hap- loptiliidae, Lyonetiidae, Nepticulidae, Tischeriidae, Gracilariidae. (Consult Com- stock's Manual and Barnes and McDunnough's Checklist of Lepidoptera.) PAPILIONIDiE These butterflies are called ''Swallow-tails" and are readily recog- nized. The more common forms are the Tiger Swallow-tail {Papilio turnus, two forms), the Zehra Swallow-tail {Papilio ajax, three forms), the Green-clouded Swallow-tail (Papilio troilus) and the Black Swallow- tail {Papilio polyxenes) which feeds on celery and other members of the carrot family. Black Swallow-tail {Papilio polyxenes Fab.). Adult. — Wings black with two transverse rows of yellow spots on the hind wings; between the rows of yellow spots are several flashes of blue. Two broods, May and July. Wing expanse 3-4 inches. CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 1 75 Eggs. — Nearly spherical; honey-yellow changing in parts to reddish- brown; laid singly on leaves of food-plant; hatch in 5 to 9 days. Larva. — The Celery Caterpillar; mature form 2 inches long; green, each segment with a black band and spotted with yellow. Scent- horns orange. Chrysalis. — Dull grey, mottled with dull brown, roughened with larger projections pointing forward; swung in a loop of silk; summer chrysalis lasts from 9 to 18 days; hibernates. Control. — Hand-picking, or the application of arsenicals for large infested areas. PIERIDiE The more common butterflies of this family are the Cabbage Butterfly {Pieris rapes), the Grey- veined White {P. napi), the Check- ered White (P. protodice) the. Clouded Sulphur {Eurymus philodice) and the Alfalfa Caterpillar {Eurymus eurytheme). Cabbage Butterfly {Pieris rapcelAnn.) . — Introduced from Europe via Quebec about i860. Occurs throughout United States and Canada. The caterpillars first injure young plants, riddhng the outer leaves, later they attack the tender inner leaves where they are hard to poison, and which they render unsightly by reason of the abundant dark green excrement. Sometimes they eat into the centre of the head of cabbage where it is impossible to deal with them. Adult. — Wing expanse 2 inches, dull white above; fore wings with black tips and two spots in the female and one spot in the male. Two full broods and a partial third in the North, and more in the South. Life-cycle 3 to 6 weeks. Eggs. — Oval, yellow, ribbed, lengthwise and crosswise; laid singly on end on the leaves; hatch in 4 to 8 days. Larva. — The Green Cabbage worm; i3-^ inches long, velvety green with a narrow greenish-yellow band on back and on each side. A row of yellow spots. Matures in 10 to 14 days; feeds also on mustard and other crucifers. Chrysalis. — ^Three-fourth inch long, hght brown; attached and swung by a girdle of silk. Winters in this condition. Duration in summer 7 to 12 days. Enemies.- — Apanteles glomeratus, Pteromalus puparum, psipei wasps, ambush bug. 176 ECONOMIC ENTOMOLOGY Control. — Spray every week with arsenical solution; i lb. Paris Green, 4 lb. whale-oil soap, 40 gal. water before heads form and with hellebore or pyrethrum after; spray with salt-tobacco solution (i lb., I lb., 5 gal. water). Pieris napi Linn, is a native species, but not so abundant as P. rapce. Wings nearly all white. Alfalfa Caterpillar (Eurymus eurytheme Boisd.). — (Consult Bull. 124, U. S. Dept. Agr.) Common, and a serious pest of alfalfa in the West. Adult. — Yellow with the outer margins of wings black, dotted with white in the female. A black dot in the middle of the fore wings and a pale yellow spot in the middle of the hind wings. Two or more broods, March-April. Eggs. — Minute, ribbed and cross-lined, spindle-shaped; laid on the new growth. Larva. — Dark green, with a faint white line on each side; i inch long. Spiracles black and red. Strips the leaves leaving bare stalks. Pupa. — Yellowish-green, J^ inch long, suspended, head up, by two threads to the stalks of alfalfa, weeds and grasses. Parasites. — Tachinids — Phorocera and Forntina; also Apanteles, Pteromaliis and Tricho gramma. A bacterial disease. Control. — Pasture infested fields or cut when larvae appear in numbers; irrigate after cutting; disk in the fall; co-operation. NYMPHALIDJE This family includes a large number of common butterflies such as the Fritillarias or Argynnids; the Angle-wings or Vanessids, including the beautiful Red Admiral {Vanessa atalanta); the Painted Beauty {Vanessa virginiensis); the Cosmopolitan Butterfly {Vanessa cardui); the Mourning Cloak {Aglais antiopa); the Comma Butterflies {Poly- gonia f annus, P. comma, the "Hop Merchant," P. progne and P. inter- rogationis); the Purple Butterflies {Basilarchia arthemis, B. astyanax, B. archippus). Of these the larvae of the Comma and the Red Admiral feed on the hop. The ''Hop Merchant Caterpillar" often called the ''Spring Currant Caterpillar," attacks currants, gooseberries, hop, elm, basswood, etc. Generally two broods a year. They are brownish-yellow and marked CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 1 77 with black and yellow lines. On the body are numerous branched black tipped spines. The wings of the adult butterfly are reddish brown bordered with a darker brown. A silvery comma mark on surface of hind wings. The larvae of the Mourning Cloak Butterfly feed upon the leaves of willow, poplar, elm and dogwood and are interesting objects. There are two generations a year, the adults wintering over and appearing in early spring. The adults of the second brood appear in July. DANAID^ The monarch butterfly (Danais archippus Fab.) is a common insect but not of economic importance. Its larva feeds on milkweed. SPHlNGIDiE (HAWK MOTHS) The Hawk Moths are readily recognized both in the adult and the larval forms. The adults are strong fliers and are beautifully colored. They usually fly about dusk. The larvae are large and often ornamented with stripes, and usually have a horn near the hind end of the body. They feed on a great variety of foliage. Ordinarily they are kept under control by parasites and birds. When occasioning damage they are readily controlled by spraying with arsenicals and by hand-picking. Tomato Sphinx (Frotoparce quinque-maculata Haw.). Adult. — Ex- pands to 4 to 5 inches; wings ashy-grey with black markings; hind wings crossed by four blackish lines; abdomen with a black middle line with five yellow spots on each side; appears in June and July. Two breeds in the south. Eggs. — Laid singly on under surface of leaves; hatch in 4 to 8 days. Larva. — Three to 4 inches long; naked, dark-green with 8 V-shaped white lines on side; a black horn on tip of abdomen; feeds on leaves of tomato and tobacco. Pupa. — Dark-brown, about 2 inches long, sheath of proboscis forming a handle-like process; in the soil several inches below the surface. The Tobacco Sphinx (P. sexta) is very similar to the preceding, feeding on the same plants. It is more abundant in the South. The adult is brownish-grey instead of ashy-grey, with a distinct discal 12 178 ECONOMIC ENTOMOLOGY spot on the fore wings, and six spots on sides of abdomen instead of five. The larva has only seven oblique markings instead of eight V-shaped ones. Plixm Sphinx {Sphinx drupiferarum Sm. and Abb.). Adult. — Ex- pands 3 to 4 inches; body brown, wings purplish brown; fore wings with a whitish stripe on costal margin, a fawn colored stripe on outer margin and several black streaks; hind wings with two whitish wavy and an outer fawn colored stripe. June. Eggs. — ^Laid singly on the leaves of plum; smooth, oval, Jf 5 inch long; pale yellowish-green. Hatch in 8 days. Larva. — Three and one-half inches long, apple-green, with dark- brown lateral stripe. On each side are seven oblique white bands. Feeds on plum leaves. Pupa. — Reddish-brown, ij^ inches long, with a short tongue case; in ground all winter. Grapevine Sphinx {Ampeloeca myron Cram.). Adult. — Expands 2}^ inches; fore wings olive-grey with a curved oblique greenish-grey band, a discal point and a triangular spot. Body green. Two broods — June and August. Eggs. — -Round, 3-^0 ii^^h in diameter; yellowish-green. Larva. — A ''Hog Caterpillar," green with yellow dots; oblique yel- lowish stripes along sides; a white stripe with green margin from head to horn and seven pink spots along the middle; 2 inches long. Spine near tip of abdomen. Feeds on leaves of grape and Virginia creeper. Often infested with braconid parasites. Pupa. — -Formed in a loose cocoon of silk, spun under leaves at the surface of the ground. White-lined Sphinx (Celerio lineata Fab.). Adult. — Body and fore wings olive-brown; thorax with three parallel lateral white stripes; fore wings with a buff stripe from inner margin to apex; hind wings black with a reddish middle band. Probably two-brooded adults appearing in June and September. Larva. — About 33^^ inches long; color variable, yellowish-green with black spots or black with yellowish spots, with horn at tip of abdomen. Feeds on grape, apple, plum and on purslane, chickweed, etc. Pupa. — ^Light brown pupa formed in a smooth cavity in the ground. Other common Hawk Moths are: Abbott's Sphinx (Sphecodma ahbotti), Apple Sphinx {Sphinx gordius), Achemon Sphinx {Pholus CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 1 79 achemon), Pandorus Sphinx {Pholus pandorus) on Virginia creeper, Twin-spotted Sphinx {Smerinthus geminatus), Thysbe Clear- wing (Hcemorrhagia thysbe) on Viburnum, snowberry and hawthorn. SATURNIINA (GIANT SILK -WORM MOTHS) This super-family includes the following families: BombycidcB, HemileucidcB, Citheroniidce and Saturniidce. The larger number of commonly occurring forms belong to the third and fourth families which may be distinguished by the presence of two anal veins in the former and only one in the latter. CERATOCAMPlDiE (CITHERONUDiE) This family contains such magnificent forms as the Regal Moth {atheroma regalis) and Imperial Moth {Basilona imperialis), and the economic Oak-worm moths (Anisota) and the Green-striped Maple-worm moth {Anisota rubicunda). Green-striped Maple-worm {Anisota rubicunda Fab.). — The cater- pillar of this moth injures maples of all kinds, box-elder and oak. Usually two generations in a season. Adult. — A pale yellow moth with a dehcate shade of pink; wing expanse of female iM~2 inches; her body yellow and woolly and her head small with thread-like antennae. Male is smaller with plumose antennae. Eggs. — Pale green turning yellowish; 3'^5 inch in diameter. Each female may lay 150 eggs on the under side of leaves; hatch in 8-10 days. Larva. — A naked pale yellow green caterpillar, striped with dark green; armed back of the head on second thoracic segment with two long black horns, and along the sides and anal extremity with short black spiny projections. Two inches long in a month, when full grown. Four moults. Goes into ground to pupate. Pupa. — Dark brown, armed with little spines on margin of ab- dominal segments and on thorax; anal segment ends in a forked pro- jection. Duration two weeks. BOMBYCID^ Silk-worm Moth {Bombyx mori L.). — An Asiatic species, domestic- ated for its silk for many hundreds of years in Europe and Asia. Many l8o ECONOMIC ENTOMOLOGY races have been developed by selection differing in the color of the cocoons and larvae as well as the number of broods produced in a year. The main food plants are the white mulberry and the Osage orange. The moth is creamy white in color, and has a wing-expanse of about 1^4: inches. The lack of cheap labor in America has prevented the development of the silk-worm industry. SATURNIID^E The members of this family are often called the Giant Silk-worms and include several conspicuous forms such as the To Moth (Automeris io), the Polyphemus Moth (Telea polyphem^tis), the Luna Moth {Tropcea luna), the Fromethea Moth {Callosamia promethea) and the Cecropia Moth (Samia cecropia). A. Wings bluish-green with four eye-like spots; hind wings with long tails; front border of fore wings purple-brown; larva, pale bluish green with a pearl-colored head and two yellow stripes along the back; feeding on walnut, hickory, etc. — Tropcea luna L. (Luna moth). AA. Wings not green. B. Wings yellowish or brownish. C. With four oval, window-like spots, one near centre of each wing; a dusky band edged with pink along margin of wings; larva light green with an oblique yellow line on side of each abdominal segment, feeding on many forest and orchard trees. — Telea Polyphemus Cram. (Polyphemus moth). CC. With eye-like spots on hind wings only; ground color of wings of female purplish-red; that of male bright yellow; larva yellowish- green, edged with white on side, with many black-tippea branched spines; feeding on cherry, apple, elm, oak, etc. — Automeris ioh. (Io Moth). BB. Wings brown, never yellowish. C. With eye-like spots near apex of fore wings, and 4 crescent- shaped discal spots, one near the centre of each wing, white surrounded by reddish and black lines; thorax red, abdomen red and banded with black and white lines; larva bright green with four prominent coral-red and two yellow tubercles on thoracic segments, and smaller yellow tubercles on abdominal segments; feeding on fruit and shade trees. — Samia cecropia L. (Cecropia Emperor Moth). CC. With eye-like spots near apex of fore wings, discal spots angular'; in male color blackish and discal spots faint; larva bluish-green with rows of black tubercles, excepting those on second and third thoracic segments which are coral-red, and a yellow one on eighth CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS l8l abdominal segment; cocoon in a folded leaf. Feeds on leaves of fruit and forest trees. — Callosamia promelhea (Promethea Moth). These handsome moths are not of much importance economically. Their larvae are large, conspicuous and brilliantly colored, consequently are readily destroyed by birds. Many also are killed by parasites. Some attempts have been made to manufacture the silk of the cocoons of some species but it has been found that the cocoon cannot be profit- ably unwound on account of the large number of breaks in the thread. ARCTIIDiE (TIGER MOTHS) Woolly Bears. — Several interesting and common caterpillars may be conveniently grouped as ''Woolly Bears," on account of their hairy appearance. A few common forms are here considered. Yellow Bear {Diacrisia virginica Fab.). — Color of caterpillar vari- able; frequently yellow or straw color with a black interrupted line along each side of back, and a black transverse line between each segment; hairs long and yellow; uneven in length and not gathered into pencils. Cocoon is light and composed of hairs in which pupa passes the winter. Moth snowy- white; wings marked with a few black dots; three rows of black spots on abdomen. Hedge-hog Caterpillar {Isia isahella Sm. and A.). — An ''evenly clipped furry caterpillar, reddish-brown in the middle and black at either end." Passes winter as larva. Moth (Isabella Tiger Moth) has wings and body orange-buff, hind wings tinted with rose. Body with 3 rows of black dots. Salt Marsh Caterpilar (Estigmene acrcea Drury). — Body and head blackish with pale longitudinal stripes on the back; hair is dark brown; passes winter as pupa. Abdomen of moth orange; both wings white in female, hind wings orange in male; both marked with black dots. Six rows of black spots on abdomen, one on back, one on venter, and two on each side. Fall Web Worm (Hyphantria textor Harris). — Conspicuous by their webs or nests in autumn on orchard, shade and forest trees (Fig. 122). Adult. — Quite variable in markings; pure white, sometimes spotted with black; expands i J^ inches; femur of forelegs orange and legs and feet with touches of black. Eggs. — ^I aid in a flat cluster of about 400 on under side of leaf; golden-yellow, globular and pitted; hatch in about 10 days. l82 ECONOMIC ENTOMOLOGY Larva.— V^hcn young is pale yellow with two rows of black marks along the body, head black; hairs sparse; and when full grown is covered witli long whitish hairs arising from black and yellow warts; I inch long; spins webs and feeds within them; about five moults. Pupa.—Cocoon of silken web interwoven with hairs; pupa dark brown. Winter passed as j)upa. Fig. 122. — Fall web worm ^Hyphantria textor): a and h, caterpillars; c, pupa; d, adult moth. {After Howard, U. S. Bur. lint.) Life-history. — Hibernates as a pupa under rubbish, in crevices under walls, etc. Moths emerge in June; eggs hatch in about lo days and caterpillars mature in August and September. Two broods in some localities. Parasites. — Telenomus bifid us Riley, Meteor us hyphantricB Riley, Apanteles hyphantrice Riley, Limneria pall i pes Pro v., Tachina sp. CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 1 83 Control.' — Prune off and burn the webs ; spray with arsenical ; collect and destroy the cocoons. Hickory Tiger Moth {Halisidota caryce Harris). — (Consult Bull. 598, U. S. Dep. Ag.) Adult. — A yellow and brown moth, 2 inches wing expanse; fore wings long, narrow and pointed, ochre-yellow with five irregular transverse incomplete rows of spots. June- July. One brood a year. Distributed over the Northeastern States and the Eastern provinces of Canada. Eggs. — Blue and nearly globular a brown ring on upper surface; laid in patches of 100 or more on under side of leaf in early summer. Duration 15-16 days. Larva. — One and one-half inches long; gregarious at first; feeds on the leaves of hickory, butternut, apple and other trees; covered with dense and spreading tufts of white hairs, has a row of 8 black tufts on the back and two long slender black pencils on the fourth and tenth segments; head, feet and under surface of body black; upper surface of body white with black dots. Eight to nine feeding stages, and about a week as larva in the cocoon. Larvae feed gregariously during the first four stages. Duration 70-90 days. Pupa. — Cocoon greyish, oval, hairy, ^ inch long, found under boards and rubbish on the ground; pupa reddish-brown, caudal end with a transverse row of spines. Checkered Tiger Moth {Halisidota tessellaris Sm. and A.). — ^Like preceding species but tufts are yellow; two orange colored pencils on second and third segments; two white pencils on sides of third and eleventh segments. Spotted Halisidota (//. maculata Harris). — ^Larva with yellow tufts in the middle and black tufts at either end, and a row of black spots down the centre. Occurs on apple, maple, birch, alder, poplar, oak, etc. Cocoon is yellowish, oval and hairy. Parasites of Cocoons. — Scamhus pedalis, Theronia melanocephala, Amblyteles malacus. AGARISTIDiE (WOOD MOTHS) Eight-Spotted Forester (Alypia octomaculata Fab.). — A frequent feeder on the leaves of wild and cultivated grapes, and Virginia creeper in eastern U. S. and Canada, sometimes doing considerable injury. 184 ECONOMIC ENTOMOLOGY Adult. — General color a deep velvety blue black. Fore wings with two large circular pale yellow spots, and hind wings with two smaller white spots. Wing expanse ij^ inches. May-July. Single brooded. Larva. — One and two-fifth inches long; bluish-brown; head and cervi- cal shield bright orange with black spots. Each segment crossed with black, white and orange bands; eleventh segment with a prominent hump; legs black; base of prolegs orange. Full grown in early August. Pupa. — A chrysalis within a slight cocoon just below the surface of the ground. Hibernates. Parasites. — Wifit hernia 4-pustulata Fab. — A tachinid. Control. — Spray the larvae with arsenate of lead or pyrethrum. NOCTUID^ (OWLET OR MILLER MOTHS) According to their manner of feeding on plants the larvae of Noctuids may be classified roughly into: (a) Cutworms proper, feeding on roots Fig. 123. — Mouth parts of a caterpillar, the striped cutworm (Euxoa tessellata) : Ant., antennae; 01., clypeus; Lb., labium; Md., mandible; Mp., maxillary palpus; Lbr., labrum; Mx., maxilla; S., spinneret. of grasses and cutting off young plants at surface, (b) Army-worms, eating the leaves of cereal and other crops, (c) Climbing cutworms, feeding on buds of fruit trees, (d) Loopers and caterpillars, feeding on leaves of turnip, cabbage, celery and other plants, (e) Ear-worms, feeding on kernels of corn in the field. (/) Stalk-borers, feeding in tunnels made in stems, (g) Green Fruit-worms, feeding on the surface CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 1 85 of apple, etc. {h) Dagger Cater pillars j feeding on the leaves of many shrubs and trees, {i) Underwing Moths, some feeding on the leaves of trees (Fig. 123). {a) Cutworms Proper (Consult Bull. 95, 111. Agric. Exp. Station, 1904; Bull. 10, Div. Ent. Can., 1912) There are many species of cutworms that feed upon economic plants. They are mostly ''plump, soft-bodied, cylindrical caterpillars, dirty greyish or whitish, and variously spotted and striped" (Forbes). They are the larval stages of species of Noctuid moths, commonly termed "millers," and are night feeders. ''They are essentially grass and clover insects, and by far the greater part of them are bred in pastures and meadows." Life-history. — The majority of the species hibernate as partly grown larvae, and enter the ground to pupate m late June and early July. The adults — usually greyish nocturnal moths — -emerge in early August and lay their eggs in grass lands. Each moth may lay from 200 to 500 eggs, either in masses or singly. The larvae that hatch from these eggs feed on the roots of grasses until winter sets in. Feeding is resumed m the spring, when most serious injury is done, until their larvae pupate in June-July. Control of Cutworms. — Plow grass land in midsummer or early fall to prevent the female moths from egg-laying; late fall plowing of grass lands will destroy many of the hibernating cutworms; allow poultry and hogs upon cutworm land; use poison bait: bran 20 lb., molasses I qt., paris green or white arsenic 3^^ lb., water 23-^-3 gals. Natural Enemies. — Calosoma calidum, Ammophila luctuosa, Win- themia 4-pustulata. The following species are most commonly met with: Spotted Cutworm (Agrotis c-nigrum Linn.). — General color grey to brownish; a row of triangular black spots along each side of back; a pale line down the middle of back, a conspicuous whitish-yellowish stigmatal band, and a pale intermediate line; head and shield yellowish- brown; front feet pale brown and shiny, i3-^ inches long. Active in April and May in vegetable gardens (Fig. 124). W-marked Cutworm (Agrotis unicolor Wlk.). — General color pale brown; four rows of dark spots and often also with lighter lines along the back, resembling the letter W; sides of W-marks bordered with 1 86 ECONOMIC ENTOMOLOGY pale yellow; head pale brown with a wide black dash on each side; shield dark brown. Active in April and May in gardens and orchards (Fig. 125). Greasy Cutworm {Agrotis ypsilon Rott.).— General color dark greasy grey to black above and greenish-yellow below; a pale yellow line down centre of back, and three others on each side; tubercles black and shiny; head and shield dark brown; ij^ inches long. Active in May and early June on corn and garden vegetables (Fig. 125). Variegated Cutworm (Lycophotia margaritosa Haw.). — One and three-fourth inches long; color variable from grey to brown; body mottled with dark brown; a yellowish band along each side; a series of Fig. 124. — a. Spotted Cutworm, dorsal aspect; h, Spotted Cutworm, lateral aspect; c. White Cutworm; d. Dingy Cutworm; e, Black Army Cutworm, dorsal aspect; /, Black Army Cutworm, lateral aspect. {After Gibson, Bui. 10, Ent. Br. Can.) yellow dots or spots along the middle of back; two stripes of velvety black blotches bordered with orange and black curved dashes between the lateral yellow band and the middle of the back; head reddish-yellow and marked with black bands resembling slightly the letter H. Prac- tically an omnivorous feeder, its food plants including cereal root, forage, vegetable flowers and orchard trees. Active in May and early June in gardens. The eggs are laid in irregular masses upon the stems of plants; they are small, white, hemispherical and ribbed. The pupae are reddish-brown and about % inch long. Dark-sided Cutworm {Euxoa messoria Harris). — General color greyish; sides darker than rest of body; a dark line down middle of CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 1 87 back; tubercles blackish, each with a single hair; head and shield shiny and grey. Active in May and June on fruits and garden vegetables. Sometimes called the ''onion cutworm." Common Striped Cutworm (Euxoa tessellata Harris) . — This cutworm is 1 3^ inches long, grey, with a pale median dorsal line and three pale lines on each side. It feeds on most vegetable crops. One brood a year; passes the winter as half-grown larva, and is most destructive in June. The moths appear in July and August. Red-backed Cutworm {Euxoa ochrogaster Gn.). — With a broad reddish stripe down the back; head and shield yellowish-brown, the Fig. 125. — a. Red-backed Cutworm, dorsal aspect; h. Red-backed Cutworm, lateral aspect; c. Greasy Cutworm, dorsal aspect; d. Greasy Cutworm, lateral aspect; e, W-marked Cutworm, dorsal aspect; /, W-marked Cutworm, lateral aspect. {After Gibson, Ent. Br. Can.) former with two distinct black marks toward the centre. Along middle of back a pale stripe, and at each side a dark stripe borders the red of the back. Tubercles small and dark, each bearing a single hair. Moth variable in color and markings. Ground color of wings pale yellow to dark red; fore wings crossed by four or five irregular lines and marked with black; body grey or dull brown; active in May, June and July on corn (Fig. 125). Army Cutworm {ChorizagroHs auxiliaris Grote). (Consult Bull. 13, Entom. Branch, Ottawa.) Three varieties: C. auxiliaris y C. intra- i88 ECONOMIC ENTOMOLOGY ferens, and C agrestis are recognized as destructive to grain, alfalfa, beets and flax in the West in Montana and Alberta. The larvae begin to mature about the middle of May but pupation m earthen cells does not occur until the middle of June. The moths fly from June 15th- Sept. 30th and the eggs are laid from August 24th-October 15th in the soil in weedy summer-fallows. Porosagrotis delorata Sm. is injurious to wheat in June. In British Columbia Euxoa excellens Grote injures market gardens, and Neuria procincta Grote injures farm crops (Fig. 127). Glassy Cutworm {Sidemia devastator Brace). — Translucent whitish, tinged with bluish-green and without spots; tubercles brown, each with a single hair; head reddish-brown; neckshield brownish. Active in Fig. 126. — a. Moth of Glassy Cutworm {Sidemia devastator); b, larva. (After Gibson, Bui. lo, Ent. Br. Can.) May and early June on hay and garden vegetables. Diflicult to kill by poison bait on account of its underground feeding habit (Fig. 126). Yellow-headed Cutworm {Septis arctica Bdv.). — Pale smoky grey, with head and neck shield tawny-yellow; without spots, ij^ inches long. Active in July on cereal crops and vegetables (Fig. 127). Bronze Cutworm (Nephelodes emmedonia Gn.).— Large, 1% inches long, with alternate stripes of olive-bronze and yellowish, a pale stripe along the middle of the back, and two others on each side. Active in grass lands in April and May. Zebra Caterpillar (Ceramica picta Harris). — "Velvety black on the back; beautifully ornamented with two golden-yellow stripes on each side of the body, which are connected by narrow lines of the same color; CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 1 89 the head and feet reddish-brown" (Fletcher). Two broods, on cab- bages and turnips (Fig. 128). Fig. 127. — a, Moth of Yellow-headed Cutworm {Septis arctica); b, moth of Clover Cutworm {Scotogramma trifolii) ; c, moth of Pale Western Cutworm {Porosagrotis orthogonia); d, moth of Dingy Cutworm (Felia ducens). {After Gibson, Bui, 10, Ent. Br. Can.) Fig. 128. — The zebra caterpillar and moth {Ceramica picta). Clover Cutworm {Scotogramma trifolii Esp.). — Color varying from green to dark; a pale yellowish line along middle of back, a pinkish band bordered with white or pale yellow along each side, and between I go ECONOMIC ENTOMOLOGY these a broken yellow stripe; head pale yellow or green with white mottlings; under side greenish grey with spots and streaks. Damages peas, clover, root crops, lettuce, etc. August (Fig. 125). (b) Army Worms The Army Worm [Cirphis unipuncta Haw.). — (Consult Farmers' Bull. 731, U. S. Dep. Agr.; Bull. 9, Ent. Br., Dep. Agric, Can.) Army worms appear to be more abundant in a wet spring or summer following a dry season. Injurious in 1895-1896 and in 1914. Prob- ably a native of North America (Fig. 129). Adult. — A dingy yellowish-brown moth with a white spot on the centre of each front wing; wing expanse i3^^ inches, a row of small black spots near outer margins of wings with dark streaks. Eggs. — Minute white eggs laid in bead-like strings on grass leaves in the folded blades or under the leaf-sheaths. Hatch in 8-10 days. Larva. — A dark-colored cutworm, i J^ inches long; body striped with black and yellow lines; a narrow white stripe or line along middle of greenish-black back; lower stripe dark greenish-yellow; next, just above the spiracles, black; the lowest, just below the spiracles, light greenish- yellow, edged with white. Head greenish-brown with coarse black mottlings and with two curved blackish-brown bars; under surface greenish mottled with brown; looping gait until after second moult; duration 20-30 days. Parasitized by Winthemia 4-pustulata, A pan- teles militaris, Ichneumon canadensis, I. lactus, I. jucundus and others; by a bacterial disease; and preyed upon by Calosoma. Pupa. — A brown chrysahs in the ground; duration 12-15 days. Life-history. — There are two broods of the Army Worm moth each season. The insects usually pass the winter as half grown caterpillars. In the spring these mature and change to pupse, the moths appearing early in June. The May brood of caterpillars seldom does much harm. The female moths lay their eggs (about 700) on grass leaves from which caterpillars hatch in about 10 days. The caterpillars of this brood do most injury. The worms usually feed at night, consequently whole fields may be ruined before they are discovered. This July brood of caterpillars reaches maturity in about 25 days, and changes to pupae in the ground, the moths appearing again in about 2 weeks. These lay eggs for a brood of worms which appear in September, but are seldom injurious. CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS IQI Pig. 129. — Stages and work of the true army worm {Cirphis unipuncta) and some of its insect enemies: a, parent or moth; h, full-grown larva; c, eggs; d, pupa in soil; e, parasitic fly, Winthemia quadripustulata, laying its eggs on an army worm; /, a ground beetle, Calosoma calidum, preying upon an army worm, and, at right, Calosoma larva emerging from burrow; g, a digger wasp, Sphex sp., carrying an army worm to its burrow; h, Enicospilus purgatus, a wasplike parasite of the army worm, natural size. (U. S. Bur. Ent.) 192 ECONOMIC ENTOMOLOGY Control. — Plow the fields in late fall; plow three or four furrows in front of the advancing army and kill the woims that fall into the furrows; poison a narrow strip on the threatened side of field with Paris green or the poisoned bran mash. Black Army Cutworm {A grot is fennica Tausch). — General color brown; a series of velvety black marks along middle of back; a white line along each side, and a spiracular white band, reddish-brown in the centre; head yellowish-red; shield black; feet pale brown. May and early June. Attacks peas, clover, trees and some garden vegetables (Fig. 125). Fall Army Worm {Laphygma frngiperda S. and A.). — (Consult Farmers' Bull. 752, U. S. Dept. Agr.) Injurious mainly in the South but periodically appearing in the North. Feeds on grasses and cereal crops, cotton, alfalfa, cowpeas and other crops. Adult. — Wing expanse i)^ inches; front wings dark grey, mottled, and with a light grey spot near tips; hind wings white, with a pearly lustre, and edged with a brown line. Body ash grey. Eggs. — ^Light grey and minutely ribbed. Laid in clusters of 50- 200 on grass blades. Hatch in 2-4 days in South, but as long as 10 days in the North. Larva. — Newly hatched larvae with jet-black heads and white bodies. Full grown in 2 to 3 weeks; then striped, nearly naked and about ij^ inches long. Front of head marked with an invertied Y. Assumes the Army Worm habit when food becomes scarce. Pupa. — Golden-reddish at first but black later, living in an under- ground cell. Duration 10 to 14 days. In the Gulf States there are 5 to 6 broods annually, but in the north- ern probably not more than one. {c) Climbing Cutworms (See Bull. 104, Cornell Agr. Exp. Stn.^ 1895; Bull. 10, Ent. Br. Dept. Agr., Can.) Some species of cutworms are known to have a climbing habit, ascending not only fruit trees but also currants, gooseberries, tomatoes etc., to feed upon the leaves and fruit. Among these are: White Cutworm {Lycophotia scandens Riley). — One and three- fourths inches long, yellowish-grey with whitish spots; spiracles black. CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 1 93 Spotted-legged Cutworm {Porosagrotis vetusta Walk.). — One and one-half inches long; black spots on legs; feeding on peach buds. Dingy Cutworm (Feltia ducens Walk.). — Common; with wide buff- grey dorsal stripe; head and thoracic and anal shields dark brown. Feeds on garden crops (Fig. 124). {d) Noctuid Loopers Cabbage Looper (Aulographa brassiccB Riley) . — (Consult Bull. 33, Div. Ent., U. S. Dep. Ag., 1902, pp. 60-69.) Larva feeds on cab- bage and related plants (Fig. 130). Fig. 130. — Cabbage looper (Aulographa hrassicce). Showing a, adult; h, larva and pupa. Natural size. {After Chittenden, U. S. Bur. Ent.) Adult. — A brownish-grey "miller" moth; front wings transversely mottled with grey, white and black, and bearing a small silver- white spot on inner half; expanding ij^-^ inches; borders of wings scalloped. Egg. — Silvery-white or pale green, semi-globular, with radiating vertical ribs. Larva. — A pale green translucent looping caterpillar, obscurely marked longitudinally; prolegs absent from 6th and 7th segments; 2 to 4 weeks. 13 194 ECONOMIC ENTOMOLOGY Pupa. — Invested in a white gauzy silken cocoon spun on any con- venient object; one to three weeks. Winters as a chrysaHs. Life-history. — Probably two broods a year in Canada and north- ern States. Celery Looper {Autographa simplex Guen.). — (Consult Bull, t^t,, Div. Ent., U. S. Dept. Ag.) Slightly larger than the preceding species. Adult. — A "miller" moth with fore wings marked with grey and seal brown, silver mark hooked; wings expanded 2 inches; borders not scalloped. £g^. —Milky- white, flattened, globular; upper half grooved verti- cally. Larva. — A pale yellowish-green looping caterpillar; markings similar to those on A. brassicce; supra-spiracular spots black. Pupa. — Resembles that of A. brassicce.- — (Consult Bull. $$, Div. Ent., U. S. Dept. Ag.). Alfalfa Looper {Autographa calif ornica Speyer) . — Widely distributed over Western North America from Alaska and the Yukon south through B. C, Alberta, Saskatchewan, Manitoba to California, Nevada, Utah, Wyoming, Idaho, and Montana. Larvae destructive to the leaves and blossoms of alfalfa, clover, garden peas, cabbage, etc. Adult. — A brownish-grey moth, i]y^ inches wing expanse; fore wings light bluish-grey with rose and light markings— one shaped like the letter Gamma near the middle; hind wings dull brown. An active flier. Eggs. — Hemispherical, rounded at base, apex with rounded depres- sions; finely creased vertically; pale yellow. Duration 5-7 days. Probably laid on the leaves. Larva. — One and one-fourth inches long, dark green, cylindrical tapering toward the head; subdorsal line fine and wavy; two other lines in this area and a wide whitish stigmatal band. Tubercles white, setae white. Spiracles pale, black rimmed. Thoracic feet black, shiny. Three pairs of pro-legs on segments 9, 10, 13. Pupa. — Dark brown, % inch long. The cocoon is a thinly woven web of whitish silk spun among the leaves. Duration 10-14 days. Hibernates as pupa and adult. Probably two broods in B. C. and Washington. CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 1 95 Green Clover Worm {Plathypena scabra Fab.) (Consult Farmers' Bull. 982, U. S. Dept. Agric). A pest of alfalfa and the leguminous crops of eastern U. S. and southern Canada. Adult. — Variegated dark brown to black; wing expanse ij-^ inches, 2-4 generations a season. Hibernates. Eggs. — Circular, slightly flattened; green; about the size of a pin head. Female lays between 200-600 eggs in a few days singly on the underside of the leaf. Hatch in about four days. Larva. — Green, with a narrow white stripe and second fainter white line on each side; i^i inches long; only four pairs of pro-legs; 5 moults; restless and drops off the plant when disturbed. Mature in about 4 weeks. Pupa. — Yellow-brown or black, formed in a loose oval base or cocoon of debris webbed together; duration about 8 days. Some- times hibernates. Control. — Cut the crops when the caterpillars are most abundant; adopt clean culture; use hopperdozer in bad outbreaks. Hop Vine Looper or Snout Moth (HypenahumuliUsirns). — This noctuid sometimes does serious injury to the leaves of hop. Two broods a year. Adult. — A dark brown moth, i J^ inches wing expanse, with irregular and variable transverse markings on fore wings; palpi long, flattened, and projecting horizontally like a snout. July and August-September; hibernates. Eggs. — Pale green; laid on the under side of the leaves. Larva. — A semi-looper, lacking the first pair of prolegs; green; with two longitudinal white lines along the back, a dark green line between and an indistinct whitish line on each side; head green spotted with black piliferous dots. Spins a thin silken cocoon before pupating. Pupa. — Formed in the ground, in crevices in the poles, and in the leaves. Duration about 10 days. Control. — Spray or dust vines with arsenate of lead. (e) Com Ear Worm (Heliothis obsoleta Fab.) Adult. — An ochre-yellow moth with blackish markings, expand- ing about ij^ inches. Eggs. — Small yellow circular flattened disks, prettily corrugated by ridges radiating from the centre. 196 ECONOMIC ENTOMOLOGY Larva. — Variable in color, pale green or brownish caterpillar, ij^ inches long, often dark striped; head amber-yellow; legs black. Pupa. — In a small oval cell in the ground. Life-history. — In Canada there is one brood, perhaps two in some southern localities. The insect hibernates as a pupa. The moth emerges the following July, when eggs are laid on the silk of the ears. The young caterpillars feed upon the young kernels until fully de- veloped, when they descend to the ground and transform to pupae in small oval cells. Known in the South as the Cotton Boll Worm. (/) Stalk Borers Several species of Stalk Borers are injurious to various cultivated plants, such as hop vines, columbines, corn, potatoes, tomatoes, rasp- berries, asters, dahlias, and also to burdocks. The caterpillar lives inside the stem and makes a burrow by devouring the interior. As a result the plant often withers and dies. Before maturity it works its way down to the root where it changes to a pupa. The Stalk Borers have been placed in the genersiGortyna, Hydroecia snidPapaipema. Gortyna immanis occurs in hop vines; Papaipema purpurifascia in columbine; P. nitela in corn, dahlia, aster, potatoes, etc; P. cata- phrada in burdock; Gortyna micacea in rhubarb, corn, potatoes, etc. Garden Stalk Borer {Papaipema nitela Guen.). — This borer tunnels the stalks of potatoes, tomatoes, and other garden crops, and many weeds. Sometimes feeds on strawberry. One brood a year. Adult. — A mouse-colored noctuid moth, with outer third of fore wings paler and bordered within by a whitish cross-line. Late August. Eggs. — Grey, circular, with radiating ridge, J:5o inch in diameter; hatch in late May or early June. ■ Larva. — Mines in the leaf at first, then enters the stalk and tunnels it. Full grown about August; i inch long, purplish to light brown and marked with white stripes except on first four segments of ab- domen; head, neck-shield and anal-shield light reddish-yellow. Pupa. — Brown, formed in lower part of stalk. Duration about 2 weeks. Control. — Clean cultivation; removal and burning of old stalks. Potato Stalk Borer {Gortyna micaceaEsp.).- — A European insect, and a general feeder. Reported on rhubarb, corn, potatoes in N. S. and N. B. CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 1 97 Adult. — Ground color of fore wings light brown tinged with red, with a transverse darker median band. Hind wings dingy grey with a transverse light brown line. Aug.-Sept. Eggs. — Circular, finely ribbed and sculptured; slightly pinkish; laid on stems of couch grass. Larva. — One and three-fifth inches long; head chestnut-brown; tubercles pale brown with a stiff black bristle; spiracles shiny black; body color greyish tinged with pink. Pupa. — Brown, ^^ inch long. Duration about 3 weeks. (g) Green Fruit Worms (Graptolitha spp.) G. antennata Walker, G. laticinerea Grote, G. cinerosa, G. bethunei G. and R. and other species sometimes injure leaves and fruit of apple and forest trees in late May and early June. Ash-Gray Pinion {Graptolitha antennata Walk.). Adult. — Dull ashy-grey; fore wings with darker grey or greyish-brown markings. April and September; hibernates. Eggs. — Yellow, globular, ridged; laid singly on bark of smaller branches in early spring. Larva. — Light yellowish or apple-green naked caterpillar, i-i^^i inches long, with a cream-colored stripe along the middle of the back, a similar but wider stripe along each side, and mottled markings or stripes above the lateral stripes. Head glossy green, with white mottlings; legs whitish, prolegs greyish. May- June. Pupa. — Dark brown; often within a thin silken cocoon in an earthen cell in the ground. Duration 3 months, sometimes over winter. Control. — Spray with dilute lime-sulphur and lead arsenate before the blossoms open. Parasites. — Meteorus hyphantrice and Mesochorus agilis. Bethune*s Green Fruit Worm (Graptolitha bethunei G. and R.). — This fruit worm is a pest in many parts, and has been reported as most destructive in the Annapolis Valley, Nova Scotia. The color of the moth is quite variable, some moths being nearly white with darker markings, while others are much darker. Another species of Green Fruit Worm, Orthosia hibisci Guen., occurs at Geneva, N. Y. (//) Dagger Moths The larvae of several species of Dagger Moths may be found feeding on the leaves of shrubs and trees. The more common forms are the 1 98 ECONOMIC ENTOMOLOGY American Dagger Moth, the Raspberry Dagger Moth {A. impressa Walk.), the Smeared Dagger Moth {A. ohlinita S. and A.), the Grey Dagger Moth {A. populi Riley), and the Darkish Dagger Moth {A. morula Grote). They may be distinguished from the arctiid woolly-bears by the mode of distribution of the hairs. The hairs of the latter arise from tubercles in clusters, while they are scattered over the surface of the body in the Dagger-larvae. American Dagger Moth {Acronycta americana Harris). Adult. — Fore wings light grey with faint dark lines and dagger-like markings. Hind wings smaller, dark brown. Body similar in color to hind wings. Larva. — Two and one-half inches long when full grown; thickly covered with short pale yellow hairs, with a pair of long black hair pencils on first and third abdominal segments and a single one on the eighth; head black; body greenish- white above with a subdorsal and stigmatal black line; lower surface black. Common in September on elm, maple, oak, hickory, ash, poplar, alder and other trees. (i) Underwing Moths The Catocalas or Uhderwings are interesting Noctuids, the adult moths showing protective resemblance to the bark of trees. The larvae of some of the species at least feed on the leaves of trees, C. ultronia, C. grynea, on apple, plum, cherry; and C. relicta, C. car a, and C. concumhens on poplar, willow and birch, NOTODONTIDiE (PROMINENTS) Hand-maid Moths {Datana Spp.). — Several species of Datana occur on orchard and forest trees. Yellow-necked Caterpillar (Datana ministra Drury). — The larvae are gregarious, and are often injurious to the leaves of apple in late summer. Adult. — A russet-brown moth nearly 2 inches expanse; head and large spot on the thorax chestnut brown; fore wings cinnamon brown crossed by 3-5 darker brown lines; hind wings pale yellow. Early summer, June- July. One brood a year. Eggs. — In flat clusters of 70-100 on surface of leaf; white and round. CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 1 99 Larva. — Two inches long; head large and black; cervical shield dull orange; back and sides striped alternately with black and yellow lines; body thinly clothed with soft white hairs. Larvse occur in clusters and at rest their bodies assume a characteristic bow-form. When young they are chestnut brown. At maturity they descend to the ground and burrow to a depth of 3 inches. Larval stage 5-6 weeks. Pupa. — A naked brown object in the ground nearly an inch long. Control. — Hand-pick the clusters of caterpillars; spray the cater- pillars with an arsenical. Walnut Caterpillar (Datana integerrima G. and R.) is often destruc- tive on walnut, butternut, and hickory, and also on oak, beach, apple, and hawthorn. Adult. — A buff-brown moth with darker bands across the fore wings; i%-2 inches wing expanse. July-August. Eggs. — ^Laid in clusters of 100 or more on underside of leaves. LarvcB. — Caterpillars feed in clusters devouring the leaves; when nearing maturity they separate. Body black, with a loose covering of soft whitish hairs 2 inches long; when at rest they assume a bow-form. At moulting times they gather in large numbers on the trunks and larger branches. When mature they descend and enter the earth. Pupa.^A dark brown chrysalis; hibernates in this stage. Control. — Spray caterpillars with arsenical; collect the clusters of caterpillars. Red-humped Apple Caterpillar (Schizura concinna Sm. and Ab.). Adult. — Moth expanding ij^ inches; body light brown, thorax dark brown; fore wings greyish on outer margin and dark brown on inner, with a brown dot near middle, a spot near each angle and several longitudinal streaks along posterior margin. Hind wings brownish. June and July. One brood in the North. Eggs. — White, round, slightly flattened deposited in a cluster of 40-100 on the under side of leaf in July. LarvcB. — Body striped with yellow, black and white lines; a double row of black spines on back; head coral-red; a red hump on fourth seg- ment. Full-grown in late summer and fall, when they spin loose silken cocoons, mixed with rubbish, on the ground. Gregarious, attacking apple, pear, plum, cherry, and blackberry and some forest trees. Pupa. — Formed in fall and pass the winter and early spring in or on the ground. 200 ECONOMIC ENTOMOLOGY Control. — Spray with arsenate of lead; hand-pick or burn caterpillars with rag torch. LYMANTRHDiE (TUSSOCK MOTHS) G3rpsy Moth (Porthetria dispar Linn.). — A European insect intro- duced into the U. S. (Mass.) about 1869, now found in all the New England States. The larva feeds on a very large variety of plants — • forest, orchard and shade trees, especially oak, willow and apple, shrubs and even herbaceous plants. Conifers immune (Fig. 131). Adult. — Male brownish-yellow, slender, with feathered antennae; fore wings marked with zigzag darker lines; wing expanse ij^ inches; an active flier. Female white with zigzag dark lines and with slender black antennae; body so heavy as to prevent flight. Eggs. — ^Laid in July-August in irregular oval spongy masses of 400-500 in crevices and on convenient objects, and covered with tan colored hairs; hatching about May ist following. Larva. — A dark brown hairy caterpillar 2-3 inches long; 2 rows of red spots and 2 rows of blue spots along the back with a dim yellowish stripe between; body clothed with long black hairs. Full grown about July I St. Pupa. — ^Cocoon of silk loosely formed among the leaves; pupa con- ical and dark brown; i inch long. Duration 7-17 days. Parasites. — The following have been introduced: Anastatus bifas- ciatus and Schedius kuvance — chalcid egg parasites; Compsilura con- cinnata and Blepharipa scutellata on the caterpillar; Monodontomerus cereus, a chalcid pupa parasite; and Calosoma sycophanta. Control. — ^Treat the egg clusters with creosote; band the trees with burlap, etc. and spray; parasites. Brown Tail Moth {Euproctis chrysorrhcea Linn.). — ^Larva destruc- tive to orchard, shade and forest trees. Conifers immune. Probably introduced from Holland to Mass. about 1893 (Fig. 132). Adult. — A white moth, except that the abdomen is tinged with brown and tipped with a tuft of brown hairs, most conspicuous in the female. Both sexes are strong fliers and active at night in July. Eggs. — In brownish clusters of 150-300 on the leaves on the tips of the branches. Usually brown hairs are mixed with the egg mass. Eggs hatched by August 15th. Pig 131. -Different stages uf the yipsy moth (Porthetria dispar) Egg mass on center of twig; female moth ovipositing just below; female moth, Japanese variety, lower left; male moth immediately above; female moth immediately above; male moth with wings folded in upper left; male chrysalis at right of this; temale chrysahs again at right; larva at center. All slightly reduced. (After HoivaM and Fiske.) CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 201 Pig. 132. — Different stages of the brown-tail moth. Winter nest at upper left; male and female adults at lower right; another winter nest at upper right; male and female chrysalides above, male at left; full-grown larva in centre, somewhat reduced; young larvae at its left; egg-mass, the eggs hatching at lower left; female ovipositing on leaf; egg-mass also on same leaf. (After Howard and Fiske.) 202 ECONOMIC ENTOMOLOGY Larva. — Dark brown caterpillar ij^^ inches long with a sprinkling of orange; body covered with fine reddish-brown hairs; a row of conspicu- ous white hairs along each side; bright red tubercles on top of sixth and seventh abdominal segments. Full grown in June. Winter is spent as black quarter-grown larvae in colonies or nests of leaves bound firmly together by a silken web. Barbed hairs irritating to human skin. Pupa. — ^Loose cocoon attached to leaf; pupa brown, about ^ inch long. Duration about 20 days. Parasites. — Imported forms are: Pteromalus egregius, Apanteles lacteicolor, Meteorus versicolor, Zygohothria nidicola, Compsilura con- cinnata, Pales favida, Monodontomertis cereus; Calosoma sycophanta. Control. — Cut off and burn the winter nests before the caterpillars emerge in April; poison the caterpillars with lead arsenate before the middle of June; parasites. White-marked Tussock Moth {Hemerocampa leucostigma Sm. and Ab.). — A native insect whose larva is frequently injurious to fruit trees and shade trees. Adult. — Male winged and ashen-grey in color; fore wings crossed by wavy bands of a darker shade, with a minute white crescent near outer hind angle, a small black spot near tip of outer edge and an oblique blackish stripe beyond it. Antennas broad and feather-like. Females wingless with slender antennae, and of a light grey color. July- August. Eggs. — ^ White and nearly globular; 300-500 arranged in a three or four-layered mass and covered with a frothy substance. Hatch in May and June. Larva. — One and one-fourth to one and one-half inches long, bright yellow; head and two small protuberances on hinder portion of back bright coral red; four creamy tufts on back; two black plumes at front and one at the rear; black and dusky yellow stripes along the back and sides. Pupa. — Cocoons made of silk and hairs; pupa brownish, the male smaller than the female; 10-15 days duration. Life-history. — Eggs are laid in July and August and hatch in late May and early June; caterpillars full grown in a month; pupal stage lasts about 2 weeks, and the adults emerge in July and August to lay their egg-masses. But one brood in Canada and Northern United States. CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 203 Enemies. — Pimpla inquisitor, Chalcis ovata, Tachina mella; certain birds; red ants; certain dermestid beetles; certain fungi and bacteria. Control. — See under Antique Tussock Moth. Antique or Rusty Tussock Moth (Notolophus antiqua Linn.). — A European species often injurious in Nova Scotia, New England, and the West. Adults. — -Male has rust-brown wings, with two deep brown cross bands and a conspicuous white spot near anal angle of fore wings. Fe- male almost wingless with blackish body covered with yellowish- white hairs. Eggs. — Egg-mass laid on cocoon, but with no protective covering. ^ Larva. — Head black; first two tussocks on back are black at first but whitish on later moults when an additional pencil of long black hairs appears on each side of second abdominal segment. Pupa. — Female larger than the male. Control of Tussock Worms. — Collect and destroy the egg-masses; paint the egg-masses with creosote; spray in June with an arsenical; band trees with burlap or tar to prevent females from ascending. LASIOCAMPIDiE (TENT-CATERPILLAR MOTHS) Orchard Tent-caterpillar {Malacosoma americana Fab.). — Period- ically a serious defoliator of orchard and forest trees and occurring as far west as the Rockies. Adult. — A brown moth expanding ij^^ inches; fore wings crossed obliquely by two pale lines; female larger than male. Eggs. — A glistening brown mass (200-300) encircling the twigs, covered with a gluey froth. Each end of belt of eggs tapers; each egg J^5 inch long, elongate, thimble-shaped. Larva. — A hairy black soft velvety caterpillar, 2 inches long, with a white stripe down the back; on each side a row of blue spots; sides streaked with white or yellow lines; under side blackish. Caterpillars of a colony form silken tents at angles of branches and feed away from tents. Matures in 4-5 weeks. Pupa. — Cocoons formed under bark, in crevices, etc., elongated- oval; outer silk delicate and loose, inner part firm and close; a yellow powder within. Pupal stage lasts 2-3 weeks. Life-history. — Winters in the egg state; eggs hatch in May when the buds are beginning to open and the caterpillars reach maturity in June. 204 ECONOMIC ENTOMOLOGY Adults appear and eggs are laid in July. There is but one brood each year. Forest Tent-caterpillar (Malacosoma dis stria Hbn.) differs from the preceding in the following particulars: egg-mass is nearly square at the ends; caterpillars do not construct tents; line along the back is broken with dots; transverse lines on the wings of moth are darker than ground color. Parasites, — Pimpla conquisitor, P. inquisitor, Tachina mella, Anomolon exile. Calosoma and Podisus are predaceous enemies. Control. — Destroy the egg-masses; spray caterpillars with arseni- cal; burn off the tents; band trees with burlap or tar to prevent the caterpillars from ascending. GROUP GEOMETRINA (GEOMETERS) Chief Families (after Comstock) A. Media2 of the hind wings wanting, being represented merely by a fold in the wing. — EnnomidcB. AA. Mediaa of the hind wings present. B. Media2 of the hind wings arising much nearer to Mediai than to Medias. Wings usually green. — GeometridcB. BB. Media2 of the hind wings arising nearly midway between Mediai and Medias or nearer to Mediaa than to Mediai. Wings rarely green. C. Subcosta and Radius of hind wings extending distinctly separate from each other, except that they are connected by a cross vein near the middle of the discal cell. — HydriomenidcB. CC. Subcosta and Radius of hind wings approximated or coalesced for a greater or less distance. D. Subcosta and Radius of the hind wings closely approximated but not coalesced along the second fourth (more or less) of the discal cell. E. Radius and Mediai of hind wings separating at or before the apex of the discal cell. — EnnomidcB. EE. Radius and Mediai of hind wings coalesced for a considerable distance beyond the apex of the discal cell. — MonocteniidcB. DD. Subcosta and Radius of the hind wings coalesced for a short distance near the beginning of the second fourth of the discal cell, thence rapidly diverging. — Sterrhida. DDD. Subcosta and Radius of the hind wings coalesced to or beyond the middle of the discal cell. E. Fore wings with one or two accessory cells. — HydriomenidcB. EE. Fore wings without an accessory cell. — Monodeniida. CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 205 MONOCTENIIDiE Spring Canker Worm {Palceacrita vernata Peck.). — A widely distrib- uted insect from Canada to Texas, and from Maine to Kansas and California. Adults. — ^Male moth with thin brownish-grey silky wings, i inch expanse; fore wings with a row of light markings near outer margin and three transverse dark irregular bands; female moth wingless, 3^^ inch long, dull grey or brown with a dark brown stripe down the middle of the back. April-May. Eggs. — Yellowish-green, oval, 3-^5 inch long; laid in irregular masses of about 50 under loose bark, in crevices. Hatch in a month about the time of unfolding of the leaves. Larva. — Slender, cylindrical, i inch long, with only two pairs of pro- legs, with narrow longitudinal yellow-white lines, and a yellow stig- matal stripe along each side; ventral surface white. Mature in 4 to 5 weeks, when it drops to ground by a silk thread and enters to a depth of 2 to 5 inches. Pupa. — Cocoon an earthen cell lined with silk; pupa remains in it until following spring; light brown and pitted. Male pupa spined. Parasites, Etc. — ^Hymenoptera, Diptera and birds. Fall Canker Worm (Alsophila pometaria Harris). — Widely distrib- buted — -Eastern Canada, New England, New York, Ohio, California. Adults. — Male moth with darker, stronger wings than that of the spring Canker Worm ; fore wings crossed with two light bands ; hind wings darker. Female moth wingless, ashy-grey, no markings, an- tennae long. October-November. Eggs. — Brownish-grey, flower-pot like, outer end with a dark spot surrounded by a dark ring; laid in clusters of 100, in rows, each egg fastened on end and to the bark. Hatch in May, about the time of unfolding of the leaves. Larva. — Resembles in a general way that of the Spring Canker Worm, but has a broad dark stripe along the back and three pairs of prolegs near hind end of body. When disturbed or full grown it drops to the ground by a silken thread. It forms a cocoon in the ground. Matures in 4 to 5 weeks. Pupa. — Cocoon tough and contains more silk than that of Spring Canker Worm ; pupa stouter and spine of male pupa forked. 2o6 ECONOMIC ENTOMOLOGY Control. — Spray with arsenate of lead just after the leaves unfold; band trees with burlap in fall. ENNOMIDiE Pepper-and-salt Currant Moth {Amphidasis cognataria Guen.). — Injures leaves of currant, gooseberry, plum, Spirea and maple. Adult. — Body grey, with black dots; wing expanse 2 inches, grey with dark brown dots and two wavy brown cross bands on the outer third. May and August. Eggs. — Cylindrical, with surface marked with rows of hexagonal depressions; )^o inch long. Larva. — A geometrid or measuring caterpillar, 2 inches long; green to brownish-black in color, with indistinct green or yellow lines and spots. Full grown in July. Fupce. — Pupse dark brown, ^^ inch long, formed in the ground. Some change to moths in August, but others do not change until following May. Lime Tree Winter Moth (Erannis tiliaria Harris). — Occasionally injurious to the leaves of elm, basswood, hickory, apple, etc. Adult. — Male, with rusty-buff body and fore wings, and lighter hind wings. Female wingless, light brown to grey with markings. Oct.-Nov. Eggs. — Cream colored, cyhndrical with ends blunt-rounded. Hibernate. Larva. — A bright-yellow looper, with rust-colored head, and ten crinkled black lines along the back. Full grown larva i Ji -i M inches. June. Pupa. — July-Oct. Currant Span Worm (Itamera rihearia Fitch). Adult. — A pale yellowish geometrid moth with brownish spots, ij^ inches expanse; markings on wings variable and often with one or two cross bands. Mid-summer. Eggs. — ^Laid on twigs about July; hatch the following spring when leaves are full grown. Larva. — A yellow striped and black spotted looper, a little more than an inch long; full grown in 3 to 4 weeks. Pupa. — Formed just beneath the surface of ground; duration 2 to 3 weeks. One brood each season. Control. — Spray with arsenical or pyrethrum. CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 207 Mottled Umber Moth {Erannis defoliaria Clerck). — Destructive in plum and cherry orchards on the Pacific slope. A European insect, resembling the basswood or lime tree span-worm {Erannis tiliaria) . Adult. — Appears in November; female wingless, brown, with rows of brown spots; fore wings of male dull ochre-brown, crossed by two dark waved bands; hind wings pale and mottled with brown dots. Larva. — Active in June- July; a span-worm, with black stripes sepa- rated by reddish-brown stripes; spiracles in reddish-brown blotches. Bruce's Measuring Worm {Rachela bruceata Hulst). — Destructive in New York in 1886 and in Alberta in 1902-3. Adult. — Female wingless, 3^^ inch long, light brownish-grey; male winged, expanding ij^ inches, pale brownish. Oct.-Nov. Eggs. — Reddish-orange, oval, finely pitted; laid singly in crevices of bark; hatch in April. Larva. — Three-fourths inch long, apple-green, with three narrow yellowish- white stripes along each side of body; head and thoracic shield black; feeds 4 or 5 weeks in April and May, especially on blossom buds. Pupa. — ^Light brown in a slight silk-lined cocoon in the ground. One generation in a season. PsYCHiD^ (Bag- WORM Moths) Evergreen Bag Worm {Thyridopteryx ephemerceformis Haworth). — Occurs on conifers, red cedar and arbor vitae. Adult. — Female wingless, naked and grub-like; male with trans- parent wings. September-October. Eggs. — Deposited in a mass within a bag composed of silk mixed with bits of leaf and twig in September-October. They winter over and hatch in May- June. Larvce. — Feed on the leaves within bags which are gradually en- larged as they mature. Pupce. — Formed within the bags. Control. — Spray foliage with arsenical solution; gather cocoons and bags. PYR.\LIDINA GROUP Families (After Comstock) E. Wings not fissured. F. Hind wings without a fringe of hairs at base of Cubitus. 2o8 ECONOMIC ENTOMOLOGY G. Fore wings with fourth and fifth branches of Radius separate, the latter arising from the discal cell. — Pyraustidce. GG. Fore wings with fourth and fifth branches of Radius united at base. — Pyralididce. FF, Hind wings with a fringe of hairs at base of Cubitus. G. Radius of fore wings 5-branched. H. Maxillary palpi more or less developed but not triangular as in HH. — GalleriidcB. HH. Maxillary palpi well developed, appearing triangular; labial palpi long, straight and projecting forward. — CramhidcB. GG. Radius of fore wings 4-branched. — Phycitidce. EE. Wings fissured. F. Wings with less than five fissures. — Pterophoridce. FF. Wings with five fissures. — OrneodidcE. Pyralidid^ Meal Snout Moth (Pyralis farinalis Linn.). Adult. — A pyralid moth, I inch wmg expanse. Fore wings with base and tips dark brown, middle portion light brown, two wavy white lines crossing wings, bordering the middle portion; hind wings grey with two wavy whitish lines. Eggs. — ^Laid in masses; irregular. Larva. — ^Lives within a silken tube; dirty-grey, darker at both ends; head brownish-red. Pupa. — Brownish-red, in a cocoon. Clover Hay Worm (Hypsopygia costalis Fab.). — The caterpillars cause injury to stacked or stored clover, near the ground or floor, by webbing it together and contaminating it with excrement. Adult. — Small; ^5 inch wing expanse; wings silky, margined with orange and fringed with golden yellow; two large golden spots at the thirds of the fore wings, extending to hind margin as narrow lilac lines. Two straw colored lines on hind wing. Under surface of wings pale yellowish; head and legs straw colored; antennae and palpi pale orange. Two broods. June- July; August, Eggs. — ^Laid probably on growing clover heads. June and August. Larva. — ^Three-fourth inch long, dull brown; head, shield and anal plate black after last moult; segments much wrinkled and provided with several smooth shining areas each bearing a fine white hair. Hibernates. Pupa. — Honey-yellow; cocoon J^^ inch long, oblong-oval, white, silky, intermingled with excrement and bits of hay. CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 209 Control. — Remove old hay and if infested burn it; raise stack above ground a few feet on old rails, etc. Salt bottom of stack. Grape Leaf Folder (Desmia funeralis Hbn.). — Occurs on wild and cultivated grapes, and is widely distributed over the United States and Canada. Causes injury by skeletonizing the upper surface of leaves, while protected under their folds. Adult. — Wings expanded, %o inch, dark brown and bordered with white. Fore wings with two oval white spots; hind wings of male with one spot, of female spot divided. Body black, crossed by two white bands in female, one in male. Antennae of male knotted near the middle. Two broods; May and July-August. Eggs. — Minute, elliptical; laid singly on under side of leaf. Dura- tion 8-10 days. Larva. — One inch long when full grown; widest in middle; yellowish- green on sides; head and prothoracic shield light brown; sides of first two thoracic segments with light brown spots; six instars. Duration about 4 weeks. First brood matures in July, second in Sept.-October. Pupa. — Formed usually on the ground among fallen leaves. Dark brown; tapering posteriorly. Hibernates. Parasites. — Apanteles, Meteorus, Mesochorus, Exorista, Tachino- phyto and others. Control. — Spray with arsenate of lead shortly after blossoms have fallen. Purple-backed Cabbage Worm {Evergestis rimosalis Guen.). — Injuri- ous in the Maritime Provinces and Southern States to turnips and cabbages. Adult. — Small, wing-expanse % inch; fore wings pale satiny- yellow with a heart-shaped discal spot, two transverse wavy lines across middle of wings, a less distinct line near base and another near tip; hind wings silvery- white with a clear black margin. June and Oct.-Nov. Eggs. — Bright yellow; laid in masses of 20-40 on under surface of leaf; hatch in a week. Larva. — Three-fourth inch long; bristly, slender, tapering to each end; back purplish; head, anal plate and two spots on second segment black. July and Sept.-Oct. Full grown in 2 to 3 weeks. Pupa. — Winters as a chrysalis. Two broods in a season, the last brood being the more injurious. Probably three broods in the South. 14 2IO ECONOMIC ENTOMOLOGY Control. — Same as for imported cabbage worm (Pieris rapcB), p. 176. Sugar Beet Web Worm (Loxostege sticticalis Linn.).— Injurious in Manitoba, Saskatchewan and Alberta to alfalfa, turnips, rape, onions, peas, cabbage, and other garden plants; in the middle western states and the prairie provinces on sugar beets. A native of Europe and Northern Asia. Adult. — A purplish-brown moth, with darker and paler bands; wing expanse i inch. May and June. Eggs. — Broadly oval, Ylb inch long, pale green; laid in clusters (3-10) on the leaves. Larva. — One inch long, dark with a white stripe down the back and one on each side, marked with many black and white tubercles. In Colorado the first brood of larvae feed on pigweed and alfalfa in June; the second brood appears in July, and sohietimes injures beets; the third brood about middle of August is most injurious. Most of the larvae hibernate in the ground m long silken tubes. Pupa. — The pupa is formed in early spring in the silken tube. Greenhouse Leaf Tyer {Phlyctcenia ferrugalis Hbn.). — A serious pest in greenhouses to violet, rose, carnation, and other plants; and outdoors to beet, celery, lettuce, sweet pea and other plants. It ties up con- tiguous leaves by webs and feeds within, skeletonizing the leaves. Widely distributed. Adult. — A small moth, % inch wing expanse; fore wings light brown and with blackish cross lines; hind wings grey with darker margins. Eggs. — Translucent, oval disks, 1^2 inch long; laid in clusters of 8 to 12; hatch in 19-20 days. Larva. — Three-fourths inch when full grown; greenish white with a green line down the back and another on either side; head straw colored; mottled. Full grown in 3-5 weeks; feeds mostly at night. Pupa. — Formed within the webbed leaves. Control. — Spray or dip the plants in solution of arsenate of lead as soon as larvae are observed; hand pick infested leaves. Crambid^ (Close-wings) • Root or Sod Web Worms {Cramhus spp.). — In July and August many small greyish moths with closely folded wings and with project- CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 211 ing mouth-parts (labial palpi) are common on grass lands and collect in large numbers about lights. The caterpillars of these moths live in the sod in silk-lined burrows among the roots of the grass, feeding upon them. Corn is sometimes injured. Adults. — Several species; yellowish-white wings with silver stripes, bands, gold lines and other markings. Two broods. June-July. Eggs. — ^Laid in grass land in June- July and again Sept.-Oct.; oval, yellowish, ridged, 200 by each female; hatch in 6-10 days. LarvcB. — Color varying from yellowish- white to pink to reddish; surface tubercled with tufts of bristly hairs; form loose silken webs and feed on the roots; full grown in 5 to 7 weeks; }4 to % inch long. Hibernate in webs partly grown. PupcB. — Cocoons formed often in the larval webs; 12 to 15 days. Control. — Plow land early in autumn to prevent egg deposition; plow early in spring; use trap-lanterns to catch the moths. Cranberry Girdler {Crambus hortuellus Hbn.). — (See Bull. 554, Bur. Ent. U. S. Dep. Agr.) An injurious pest of cranberry vines, widely distributed in United States and Canada. Its host plants are certain grasses, Scirpus americanus, and cranberry. The moths appear in June, and eggs are laid on the trash covering the ground. These hatch in about 10 days. The larva feeds through- out the summer and fall; when full grown it is about half an inch long, with dark brown or black head, light amber colored thoracic shield and tip of abdomen, and sooty-white body bearing many long and short hairs black at the base. It forms cocoons in October-November, but pupates following spring. Duration of pupal stage about 3 weeks. The cocoon is composed of scraps of ground debris — bits of dead leaves, bark, twigs, fine roots, grasses and sand — held together by strands of silk. Its interior is lined with silk. Variable in shape, but usually enlarged at one end. Control.— FaW flooding after picking the crop; sanding; pruning. Larger Com Stalk Borer (Diatrcea saccharalis Fab.). — A serious pest of Southern corn fields, originally of sugar cane. The caterpillar feeds early in the season on the ''throat" of the young corn, destroying the growing tip, and later feeds as a borer in the lower stalk, where it hibernates. Adult. — A pale brownish-yellow moth, wing expanse of i}i inches, fore wings darker than hind wings and bear faint markings. Wings 212 ECONOMIC ENTOMOLOGY held close to body when at rest. First brood appears April ist to May 15th; and second brood May 15th to July ist. Eggs. — Flat, scale-like, circular, J 100 ii^ch long, placed in rows overlapping one another (2-25) on under side of a lower leaf; creamy white at first; hatch in 7 to 10 days. Larva. — Robust, dirty-white caterpillar i inch long, thickly covered with roundish dark spots each with a single bristle; head and thoracic shield brownish-yellow. Hibernating larva is unspotted. Summer duration 20 to 30 days. Pupa. — Light yellow changing to rich mahogany-brown, % inch long. Pupation in the stalk; duration 7 to 10 days. (Consult Farmers' Bulletin 634, U. S. Dept. of Agr.) Pyraustid^ European Com Borer (Pyratista nuhilalis Hbn.). — (Consult Bull. 178, Mass. Ag. Exp. St.) A pale yellowish or reddish brown moth of about I inch wing expanse, introduced from Europe into Massachusetts, whose larva bores into corn stalks. Its wild food plants are barnyard grass, foxtail, pigweed, and its cultivated food plants are corn, hemp, hops and millet. A possible serious enemy of corn. Galleriid^ Bee-moth {Galleria mellonella Linn.). — Known also as Wax-worm. Often a serious pest of bee-hives feeding on stored combs and honey, and combs occupied by bees. Adult. — Wings ashy-grey, hind part of fore wing bronze colored; body brown, about J^^ inch long. Appears April 15th to -May 15th, and again in July; lays her eggs in hives in crevices at night. Eggs. — Elliptical, J^o ii^ch long, pearly white — hatch in 12 days. Larva. — White; i inch long; feeds at night, and makes silk-lined tunnels in the comb. Pupa. — Formed in a tough cocoon on side of hive. Hibernates. Life-history. — In the north two broods appear — the first in May, the second in July-August, and under favorable conditions it requires only 6 weeks from egg to adult. Control. — Keep colonies strong; keep Italian bees; use well made hives, fumigate with carbon bisulphide. CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 213 PHYCITIDiE Apple Leaf Grumpier (Mineola indigenella Zeller). — A widely distributed moth but injurious mainly in the Central States on buds in early spring. Adult. — Wing expanse % inch; fore wings brown with patches and streaks of silver. Emerges in June. Eggs. — ^Laid in midsummer and hatch in about a week. Larva. — Three-fifth inch long when full grown; greenish brown, head and thoracic shield dark brown; young larva brown, feeding on leaves of tender shoots; construct crooked cornucopia-like cases of fras and silk. Winters as half grown larva. Injures the buds in spring. Full grown in June. Pupa. — Reddish-brown. Control. — Early spraying with arsenate of lead. Apple Leaf Skeletonizer {Psorosina hammondi Riley). — Sometimes injurious in Mississippi Valley especially on nursery stock, but not common northward and eastward. Adult. — A pyrahd moth, ^-2 mch wmg expanse; fore wings glossy, purplish-brown, marked with two transverse silvery grey bands. Two broods a season. May-June and August. Larva. — Small, 3^^ inch long, greenish or brownish, with 4 black shining tubercles on back behind the head, and with a broad darker stripe along each side of back. Feeding singly, or in groups, in July and Sept.-Oct., on upper surface of leaves under a silken web, skeleton- izmg them and giving them a rusty blighted appearance. Pupa. — Formed among the leaves in a slight cocoon; pale brown, J^ inch long. Mediterranean Flour -moth (Ephestia kuehniella Zeller) . A dull. — A pyralid moth, % inch wing expanse. Fore wings grey with transverse black zigzag lines; hind wings greyish white with a darker border. Both wings fringed. New generation every two months; lives about a week (Fig. 133). Eggs. — White, elongate oval; a female depositing as many as 200 eggs singly in flour, in cracks, and about machinery; hatch in about a week. Larva. — One -half inch long; white with fine black dots, sparsely cov- ered with hairs. Feeds within a silken tube and spins a silken web, 214 ECONOMIC ENTOMOLOGY matting the flour together and causing much damage. Full grown in 40 days. Pupa. — Formed in a cocoon; duration 11 days; cyHndrical, reddish- brown above and Hghter below; a cluster of small booklets at tip of abdomen. Control. — Fumigate with carbon bisulphide, carbon tetrachloride or hydrocyanic acid gas; or better still raise room to high temperature of 120-130° for 6 hours. Fig. 133. — Mediterranean flour moth {Ephestia kuehniella) : a, moth; b, same from side, resting; c, larva; d, pupa; e, abdominal segments of larva; a-d, enlarged; e, more enlarged. {After Chittenden, U. S. Bur. Ent.) Indian Meal -moth {Plodia inter punctella Hbn.). Adult. — A pyralid moth, 5^^^ inch wing expanse. Fore wings with outer portion red- dish-brown with fine transverse markings, the middle copper and the inner portion grey; hind wings grey. A new generation in about five weeks. Eggs. — Small, whitish; as many as 350 eggs laid either singly or in clusters; hatch in 4 days. Larva. — One-half inch long, whitish or pinkish, sparsely hairy. Pupa. — Cocoon elliptical-cylindrical. Gelechiid^ Angoumois Grain Moth {Sitotroga cerealella Oliv.). Adult. — A small moth like a clothes moth; % inch long; yellowish-grey. Hind wing dark grey, bordered with fine silvery fringe. Fore wing with a black dot between base and middle. Eggs. — Milky-white to pale red;3-^o iiich long; bottle-shaped; 60-90 eggs hatching in 4 to 10 days. CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 215 Larva. — Body white, densely covered with bristles, tapering slightly backward; head and antennae brown. Feeds within the kernel of grain. Pupa. — One-fifth inch long, brownish, ovate; eyes black. Formed within kernel. Peach Twig Borer (Anarsia lineatella Zeller). — Destructive to grape roots, peach and other trees in California and British Columbia and troublesome also in the East. Adult. — Dark grey; wings fringed with yellowish-grey, fore wing marked with blackish-brown spots or streaks; expands 3-2 inch; several broods each season. Eggs. — Yellowish- white, elongate-oval; laid on bark of new twigs near base of leaves; duration about 10 days. Larva. — One-half inch long; dull reddish-brown with dark-brown head; winters in silken cases beneath outer bark at base of new growth; first brood attacks young growth, second brood attacks tips and fruit, third brood the fruit. Pupa. — Reddish-brown, J^ inch long; duration 10-12 days. Control. — ^Lime-sulphur just after buds begin to swell. Palmer Worm {Dichomeris ligulella Hubner). — (Consult Bull. 187, Cornell Agr. Exp. Stn.) Adult. — A minute brownish-grey tineid moth, expanding % inch; fore wing sprinkled with black scales, and marked near middle with 4 black marks; hind wing fringed, dusky. July. Hibernates as adult. Eggs. — Probably laid in May, and hatch in 2 weeks. Larva. — Skeletonizes the leaf and eats holes in the young fruit of apple; a small caterpillar, J^ inch long; brownish-green; head light brown. Dorsal surface with two lateral and two dorsal whitish stripes. June. Pupa. — A small brown object attached to leaf by a few silk threads, duration 10 days. The Lesser Bud Moth (Recurvaria nanella Hbn.), a native of Europe, occurs in the eastern half of the United States and in Nova Scotia, and attacks the buds of apple trees. (ECOPHORID^ Parsnip Web Worm (Depressaria heracliana DeG.). — A European pest introduced about 1873, feeding on wild carrot and on wild and cultivated parsnips. 2l6 ECONOMIC ENTOMOLOGY Adult. — Greyish buff or pale ochreous, marked with fuscous spots; ^ inch wing expanse; July-August. Eggs. — ^Laid in May on leaves, stem and on sheath of inflorescence. Larva. — Pale yellow or bluish grey, marked with black tubercles bearing bristles; head and thoracic plate bluish black; J^ inch long. Larvae first web the flower-heads together and feed on the flowers and unripe seeds; they then enter the hollow stems and feed on the soft pith. Pupa. — Formed within the hollow stem in a silken cocoon. Dura- tion 2-3 weeks. Control. — Spray carefully the flower-heads as soon as webbing is observed with an arsenical. iEoERiiD^ = Sesiid^ (Clear Wings) Peach Tree Borer {Synanthedon exitiosa Say).- — (Consult Cir. 54, Div. of Ent., U. S. Dep. Ag.; Bull. 170, Cornell Ag. Exp. St.) A native insect occurring wherever peaches are grown east of the Rockies. Adult. — ^A slender dark-blue clear- winged wasp-Hke moth. Male moth with wings transparent and bordered with steel blue; expands I inch. Female moth with fore wings blue and clothed with scales; hind wings transparent resembling the male; a broad orange band about middle of abdomen; expands i^i inches. July-September. Eggs. — Minute, oval, yellowish-brown; and hexagonally sculp- tured; truncate at one end; deposited on the bark near surface of ground. Each female may lay from 300-400 eggs; hatch in about 10 days. Larva. — One inch long when full grown, robust, yellowish-white, with head and first segment white. Young larva bores into sap- wood at or below surface of ground, and continues feeding well into the fall, and after hibernating resumes feeding in spring, reaching full growth from July ist-September. Exudation of gum mixed with bits of bark and excrement. Pupa. — Cocoon-like cell elongated, made of grass and bits of bark attached with gum and threads of silk. Duration about 3 weeks. One generation each year. Control. — Probe or cut out the caterpillar in fall or early spring; mounding up the earth about base of tree in spring; protect trunk with paper or wire covering or netting (see Ohio Bull. 329). CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 217 Lesser Peach Borer {Synanthedon pictipes G. and R.).— This native insect occurs in most of the Northern States, in Ontario, and in some of the Southern States, and frequently does considerable injury. The larva bores as a rule above the soil level on the trunks and branches. Winter is passed as a larva, the pupa is formed in the canker or wound, and the moth emerges in June and July. About a month earlier than S. exitiosa. Attack by this insect usually follows mechanical and canker injuries. Imported Currant Borer {Synanthedon tipuliformis Linn.) . A dull. — A small clear- winged moth, J^ inch expanse; body black with a yellow band about the neck, and three yellow bands across the tufted abdomen; fore wings with a margin of blackish scales and a band about one-third from the tip. June. Eggs. — Small, brown, globular; placed in axils of leaves, or in cracks of the canes. Larva. — Bores into pith of cane and makes a long black tunnel in it; when full grown 3^^ inch long, yellowish; head brown; numerous tubercles on body. Half grown by winter; hibernates at bottom of burrow; full grown in May. Pupa. — Pupates in tunnel. Adult emerges in June. Control. — Cutting out and burning the old and affected canes in fall or early spring. Maple Sesian {Synanthedon acerni Clem.). — A serious borer in soft and hard maple shade trees. Adult. — A beautiful wasp-like moth, with transparent wings; body slender, yellow, banded trimmed with red, abdomen tufted. May- June. Eggs. — ^Laid in rough places on trunk. Larva. — A white caterpillar, }<2 inch long; head yellow; thoracic shield light yellow. Burrows mainly just below the bark, often in develop- ing tissue. Pupa. — Formed at surface. Control. — Apply soap-carbolic wash early in spring. Squash-vine Borer {Melittia satyriniformis Hbn.) . A dull. — A clear- winged moth, I J-^ inch wing expanse. Fore wings opaque, dark metallic olive-green. Hind wings transparent, veins and fringe black. Abdo- men with orange or black and bronze marks; legs orange; tarsi black with white bands. June- July. 2l8 ECONOMIC ENTOMOLOGY Eggs. — Oval, dull-red; J25 inch long; laid singly on stems of plant; hatch in 1-2 weeks. Larva. — Whitish, stout, i inch long; matures in 4 weeks; tunnels in the main stem. Hibernates in the north in a cocoon in the ground. Pupa. — Formed in tough silken cocoons in ground, in spring in North; pupa dark brown with a horn on head and hook-like spines on abdomen; Js i^^^ long. Blackberry Crown Borer {Bembecia marginata Harris) . — Occurs from Canada to New Mexico. Adult. — A clear- winged moth, 1} ^ inches wing expanse; fore wings with a transverse band on outer third; abdomen black, with four bright yellow cross bands; last segment of female yellow, of male black mixed with yellow. Aug.-Sept. Eggs. — Oval, reddish-brown, He i^^ch long; laid singly on under side of leaves, about 140 by each female. Larva. — At first white with a brownish head, hibernating under bits of bark or just below surface of ground. In spring bores into root girdling it; hibernating again in its burrow; in second spring bores upward, and becomes full grown in July. Pupa. — Reddish brown, ^4 inch long, 25-30 days; formed in burrow near surface of cane. Empty pupal skin usually protrudes from open- ing when moth emerges. Control. — Remove infested canes during spring and fall when thinning and pruning, and burn them. ToRTRiciNA Group Eucosmidae Apple Leaf Sewer {Ancylis nubeculana Clemens). ^ — (Consult N. Y. State Mus. Bull. 124; Bull. 435, U. S. Dept. of Agr.) Generally distributed over the Northern States and Canada. Adult. — A small white tortricid moth with brown markings; wing expanse % inch. May- June. Eggs. — ^Laid in June on under side of leaf; flat, oval-shaped, flanged, minute, yellow; hatch in 8 days. Larva. — One-half inch long; yellowish-green; head yellow; thoracic shield darker with a black dot on each side; each body segment with pale tubercles bearing a single hair. Hibernates in folded leaves on CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 219 the ground. Full grown in April. Total feeding period 5-6 months. Spends the first 3 or 4 weeks of its life under a silken covering on the under side of the leaf, afterward within a succession of folded leaves. It folds the leaf along the mid-rib and forms its nest within. Pupa. — Dark yellowish-brown, but head, eyes and wing shields black mottled with yellow. Duration about 10 days. Fig. 134. — Codling moth. A, adult moth with wings expanded; B, egg much enlarged; C, half of worm-eaten apple; D, cocoon with empty pupa.shell protruding; E, cocoon with pupa enclosed; F, leaf and apple showing eggs of a codling moth; G, caterpillar or "apple worm" enlarged; H, a, young apple just after petals fall; h, cup beginning to close; c, too late to spray. {Montana Ag. Exp, St.) Codling Moth (Carpocapsa pomonella Linn.). — This European insect is probably the most destructive of apple insects and is practically cosmopolitan (Fig. 134). Adult. — A small greyish-brown moth, % inch expanse; fore wings crossed by alternate irregular transverse waxy bands of brown and grey, and with a large dark brown spot in the inner hind angle; hind wings 220 ECONOMIC ENTOMOLOGY light silky brownish-yellow, darker toward the fringed margin. Flies at night, about 1-2 weeks after the petals fall. Sometimes emerges as late as July ist in northern districts. Eggs. — A minute thin scale-like white object, 3^5 inch in diameter, at first transparent but later with a blackish streak. Each female deposits 60 to 75 eggs, mainly on the leaves i to 3 weeks after the blossoms fall; hatch in 5-10 days, or from 3 to 4 weeks after petals fall; 60 to 80 per cent, of larva? enter the young fruit at the calyx end. Larva. — At first whitish with distinct black tubercles on the body and black head; later the tubercles less distinct. When full grown larva Fig. 135. — Larvne and pupa? of the codling moth in the bark. is ^4 inch long, whitish or pinkish, head dark brown, tubercles indistinct, thoracic and anal shields light brown. INIatures in 3-4 weeks. Winters as a larva within a white, tough, silken cocoon (Figs. 134 and 135). Pupa. — ^Pale brown; }2 inch long, back armed with transverse rows of minute spines; within a cocoon; duration of spring pupa? about 21 days, of summer pupae about 15 days (July 3oth-August 14th in Maine). Life-history. — Winters as a full grown larva within a cocoon on the trunk, under bark, etc.; about the time of apple blossoming the larva transforms to a pupa, and the moth emerges 15 to 22 days later. The eggs are laid singly on the leaves, stems, and even fruit, where they hatch in 7 to 10 days. The young larva feeds for a short time on the leaves, but finds its way to the fruit which it enters usually at the calyx end. It then makes its way to the core. When full grown in 3 to 4 CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 2 21 weeks it makes its way out of the apple Ijy a round hole and finds a place under bark, etc., to make its cocoon. When a second brood occurs Fig. 136. — Chart showing life-history of the codling moth with suggested times of spraying and banding in Utah. {After Hagon.) Fig. 137. — The proper time to spray for the codling moth. the moths emerge throughout August, and the second brood larvae enter the apples chiefly from the side. In Northern New England and 222 ECONOMIC ENTOMOLOGY o u w w H O Q O U 1 1 o* "" ' Ov On 0) >. c o p c w X o O Ti 000 C 0\ ro rj- o\ •c o X! +-> < ^ Ov t-t -2 cj5 O M u (/5 ° o Id 13^3 1-1 0\0\ ■M +J +-• ■*-» M u ca • e s c52 c3 o Si'-- o\ rt o\ t- • -J CX3 rt C/2C2 M Kmo cyj -• U PhP4 K O 2 ^1 V 00 0) 6 (U 0) in 'tn rOsO M ^ 00 c •n 3^ ft^ o 3 3 f^ ^ >4-l 5? ^ 'to 1 (»'tn 1 C '% u > O o o 1 M 3 ajr^ l>.ob t- o 1 :? 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J_C^ 3 4> c? 3 3 3 3 41 ->t»^3 ■— > ■> i— > — > ^05 ^-^ ^— V 1 "^ 1 ^ tn o 2"^ ^ tn •'-s^ n'^ (v 5 >0 3 C U5 O o t>o M "^ rt •^ >> M 1^ rt '^ >> 3 =1 2 3 ^2- ^00 CX?\PO 3 3-^ ^ «« ^-^ S^: 4J Pi 3 J3 1— i"— >^-' ►-> »— »-~^ r— jf-^ l^ » 1— > 1 O cfl a \ M f^ M (N t^ 1 i^ 1 M 1 O 4) a;--j C o 3 00 c S-^^-t ^S ^S 2 to ^ , 44^^ 3 1 — > 3 3 3 3 3 3 :s4 ^^ ""* ^_^ c B 1 <« 1 (A ,L <" i, <" 1 _o N S >. t- >, M >> N '^>' t^ M >« 'u ft w "^ <^ rt w rt IT) ClS "^ N rt (S M ft TO .— • 1-1 cij C c^ 1-^ ft < o3 S4^ 5! 3 N 5t 3 N S 3 3 >. 13 ffi a X u 3 o o -J C O o O <; a 1 C c i2 ) E X I- C 2 t/- w t c 2 > a X ' X 4. :z p p 1— ii _p 't7 p >-: i 1 CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 223 Hammar, 19 10 Hammar, 191 1 •d c rt Jenne, 1908 (3 broods) Os M d" in a S (N 1 00 f*5 M M M M . -d 1 1; (N ^ 4 a SO < ^00 1 w >> bb July 22- Aug. 16 (13.6 days) ."d »5 M 1 00 M 3 3 -d ."d ^ ;3 (N 1 ^ IN M >> Co .— ' 3^ -i June 29- Sept. 14 (25-29 days) 1 t- c :3 ;- rt IN 00 U < .00'^ M >, M rt lu-d So a 3 June 19- July 14 (6-7 days) 1 00 1^ So IN ^^ . 1 <" 'tn >, 1 1 M t^ OS kr-l *=5 1 Apr. 15- June 3 (26 days) 1a 1 >, "d >rH 3 00 mm™ rt i i Cl Q 1 t is V a "5 Q 1 > C lU ai > «3 4 t, i-i OlJ tS) -d l-H (U '0 pq C C c 224 ECONOMIC ENTOMOLOGY Canada, with the cxccplion of Soulhcni Ontario, llicre is but one brood a year, with a very small percentage transforming to make a partial second generation, but further soutl\ there arc two or even three broods. Parasites, Etc. — Trichograniiiia prctiosa, Tromhidium on eggs; Pimpla annulipes, Macrocentnis dcJicatus, Ascogaster carpocaps^, ItopJcctis marg'niaius, Ilypostcna variabilis and TacJrinopJiyto on larva^; Pig. 138. — Bud moth, i, Adult moth; 2, larva; 3, pupa (dorsal view); 4, pupa (ventral view). {After DuPorte.) some beetles {Tenehr aides cortical is) two species of ants, Lasius niger and Solenopsis molesta, woodpeckers and chickadees. (Consult Bull. 142, Cornell Ag. Exp. St.; Bull. 41, 80, 97, 115, 189, 252, n. s., Div. Ent., U. S. Dep. Ag.; Bull. 187, Ont. Dep. Agric.) Control. — Spray with arsenical just after the blossoms fall, and again in 3 weeks; destroy fallen fruit; band trees about July ist; fumigate fruit-houses with sulphur to kill the moth (Fig. 136 and 137). CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 225 Bud Moth (l^mdocera ocellana D. and S.j. -(Consult Jiulls. 50 and 107, Corncllj. — The caler})illar of this molh sometimes does serious injury to the unfolding flower and leaf buds of the af>})le and other orchard trees. Introduced from Europe, and occurs from the Atlantic to the Pacific. Adult. — A small moth with broad yellowish-white bands across ash colored fore wings; % inch exj)anse; lives 2-3 weeks. P^merges in June and July and deposits eggs (Fig. 138). Eggs. — Flattened, disk-shaped, transparent; laid singly or in clusters on the under surface of the leaves; hatch in 7-10 days. Pig. 139. — Seasonal history of the bud moth in Quebec. Larva. — Full grown larva J^ inch long, chestnut brown sparsely clothed with light colored hairs borne on darker tubercles; head, legs and thoracic shield dark brown or black, smooth and shining. Full grown in June. Winters as half-grown larva in small oval silken cases on bark of twig. Emerges in spring when buds are expanding and bores into the bud and feeds for 6-7 weeks, latterly on the leaves tying them together. Pupa.— Light brown ; ij^^ inches long; two rows of short blunt back- ward pointing spines on back of abdomen; in a thin closely woven silk 15 226 ECONOMIC ENTOMOLOGY cocoon within a tube of tangled leaves. Pupal stage lasts about lo days. Life-history. — Hibernates as a half-grown larva, and matures in June; pupal stage lasts lo days and moth emerges in July to deposit eggs. Young caterpillars feed on epidermis of under side of leaf and on green tissue within a silken tube for protection. Toward the end of September they leave their silken tubes and form oval silken cases on the smaller twigs near the buds, where they hibernate (Fig. 139). Fig. 140. — Pea moth: a, a full grown "worm" or caterpillar (enlarged); b, adult moth with wings expanded (enlarged); c, adult moth with wings closed; d, a group of five peas injured by the caterpillar of the pea moth. Parasites.— Pirn pla conquisitor, Bassus earinoides, Trichogramma pretiosa {Pentarthron minutum), Opius sp., Microdus laticinctus. Control. — Spray with arsenate of lead when buds are expanding, when the leaves are expanded, and before and after blossoming. ArgyroploceconsanguinanaW2i\^^vci.\s another bud pest of occasional importance. Pea Moth {Laspeyresia nigricana Steph.). Adult. — A small grey moth % inch long. July (Fig. 140). CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 227 Eggs. — ^Laid in the growing pod; hatch in about 2 weeks. Larva. — A small whitish slightly hairy caterpillar with pale brown head and thoracic shield; about 3-^ inch long when full grown, feeding within the pod on the green peas. Pupa. — In a small oval cocoon in the ground near the surface. Life-history. — Early in July the moths emerge from cocoons in the ground, and begin egg-laying; larvae hatch out in about 2 weeks. About the end of July the larvae emerge from the pods and spin small oval cocoons near the surface where they remain all winter. Control. — Sow early varieties; sow very late; deep fall plowing of infested land; spray after blossoming with soap and Paris green and repeat in 10 days. Lesser Apple Worm (Laspeyresia prunivora Walsh). — (Consult Bulls. 68, Part V, and 80, Part III, Bureau of Entomology.) The early work of this worm is similar to that of the Codling Worm, only nearer the surface on the flesh just under the skin; the young larvae hatched in August often eat on the surface of the fruit. Two broods in the Northern States, and one in Quebec and northern Ontario. Adult. — Ground color of fore wings brown with pale rusty-red patches, and with grey, yellowish-white and blue oblique lines; hind wings dusky grey at base, shading to black at apex. Appears in early June a,bout the same time as the Codling Moth, and again in August. Eggs. — Glistening white, minute, flat, oval, and covered with net- work of irregular ridges. Deposited on both sides of leaves, but on upper surface of fruit, stems, etc; hatch in 4-6 days. Larva. — Full-grown larva }i-}i inch long; reddish flesh-colored above, lighter below; head brown; thoracic shield yellowish, transparent; anal plate brownish, with a brownish comet-like structure on the caudal curvature, and with an anal fork; mature in June and July. Many of the second brood larvae enter the fruit on the side. Time in fruit 2-4 weeks; larva in cocoon before pupation 7-8 days. Larvae of second brood winter over. Pupa. — Pupation in spring; cocoon densely lined inside with whitish silk; pupa brown, 3^^ inch long; pupation stage about 10 days. Empty pupal case usually attached to cocoon. Control. — As for Codling Moth but spray again in August; destroy hawthorns in vicinity. 2 28 ECONOMIC ENTOMOLOGY Laspeyresia molesta Busck. — A new species found injurious to peach in District of Columbia. Clover Seed Caterpillar (Laspeyresia inter stinctana Clemens). — (Consult Bull. 134, 111. Ag. Exp. St.) Injures heads of red clover, white clover and alsike. AdidL — A silky dark brown moth, expanding about J^ inch; fore wings with 8 or 9 silvery markings along the front margin, and 2 curved markings on hind margin forming two crescents when wings are closed; hind wings dark brown with pale fringes. Probably three broods each season. May- June ; July ; Aug.-Sept. Eggs. — At first green, later yellowish- white ; slightly flattened orbicular; hatch in 5 or 6 days; laid on young clover heads, or on young stems and leaflets near the base. Larva. — One-third inch long; dirty- white to orange; head dark brown and polished; thoracic shield yellowish or dark brown with a clear me- dian line; dorsal tubercles arranged in 2 pairs and bearing hairs; body with several pale stiff hairs. Mature in 4 to 5 weeks. Pupa. — Brown, 3^^ inch long. Cocoon oval, white, silken, usually with bits of flower tissue and excrement attached. Spun in a clover head or at surface of ground. Duration 14 to 30 days. Control. — Cut and store the clover crop early in June; do not allow clover to run for more than 2 years. Grape Berry Moth {Polychrosis viteana Clemens). — (Consult Bull. 223, Cornell and Bull. 293, Ohio). A serious grape pest causing wormy grapes. Adult. — A purplish-brown tortricid moth, ^2 inch expanse; wings leaden-blue with dark spots. Two broods. Eggs. — Minute, whitish and scale-like, laid on stems of flower clusters or later on the green berries; hatch in 4-8 days. Larva — Mature caterpillar, % inch long, dark green to purplish; head light brown; thoracic shield black; body covered with many faint spots bearing whitish hairs; 3 weeks. Pupa. — Formed in a thin silk cocoon in a piece of leaf; light green- ish-brown. Duration 10-14 days. Life-history. — In June- July the moths appear and lay their eggs in the blossoms and on young grapes. The young larvae feed on the blossoms and young berries, webbing the clusters together. They mature in 3 weeks and pupae are formed in cocoons made from bits CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 229 of leaf and lined with silk. Moths emerge in 10 to 14 days in early August. The eggs of second generation are laid on the berries, and the larvae feed on the pulp and seeds. Sometimes there is a third generation. Winter is passed in the pupal stage. Control.— Spra,y with arsenate of lead, 4 lb., Bordeaux 2:3 : 50, and 2 lb. dissolved soft soap just after blooming; in August, when the berries are half-grown, or about 7 weeks after the grapes bloom, use 6 lb. arsenate of lead. ToRTRiciD^ (Leaf Rollers) Fruit Tree Leaf Roller {Cacoecia argyrospila Walker).— (Consult Bull. 311, Cornell, Bull. 250, Ont. Dep. Ag.) A serious enemy of the apple east of the Rockies. It attacks also pears and plums, and some shade and forest trees. Fig. 141. — Egg-masses of fruit tree leaf roller. Natural size. (After Caesar.) Fig. 142. — Fruit tree leaf roller: a, female; b, male. Naturaljsize. (After Caesar.) Adult. — Front wings mottled with a rusty-brown shade and silvery- white markings, hind wmgs light ashy brown without markings, % inch wing expanse. Early July; one brood each year (Fig. 142). Eggs. — Attached to upper side of twigs in small oval, flat, greyish varnish-covered patches, about 100 eggs in each egg- mass, in July. Hatch as buds are opening. Hibernate (Fig. 141). LarvcB. — At first are black-headed and green; tie together the young leaves and blossoms with a silk web, later cut large irregular cavities 230 ECONOMIC ENTOMOLOGY out of young fruit. Injured fruit falls or is deformed. The leaves are also badly injured. Full grown in three weeks; about i inch long; light green; head, thoracic shield and legs brown to black. Pupa. — Formed within a rolled leaf, brownish; duration about 10 days. Control. — Spray with lime-sulphur (32°) and lead arsenate (3 lb. to 100 gal. water) about May 15, June i and June 15; use Scalecide (i to 15) just before leaf-buds burst to destroy the eggs. Cherry Tree Tortrix {Caccecia cerasivorana Fitch). — A pest of cultivated and choke cherries. Adult. — A tortricid moth, expanding about an inch; front wings ochreous yellow with irregular brownish spots and many transverse pale blue bands. July-August. Eggs. — ^Laid in flat gluey-covered masses on twigs mainly near the ground; hibernate; hatch in spring. LarvcB. — ^Lemon-yellow, 5^^ inch long; colony forms nest enclosed in silk web. Mature in July. PupcB. — Formed within the dirty ugly nest. Duration 10 to 14 days. Pupal skms project from nest. Control. — Cut out and burn the nests before the moths emerge. Oblique Banded Leaf Roller [Caccecia rosaceana Harris) . — Injurious to leaves and buds of orchard trees and small fruits; widely distributed. Adult. — A yellowish-brown tortricid moth with three oblique dark bands across the fore wings; bell-shaped with wings folded; hind wings pale yellow. End of June. Eggs. — ^Laid in flat patches on the bark where they winter. LarvcB. — Roll up and fasten together the young leaves within which they feed; % inch long; yellowish-green; head and thoracic shield brown- ish-black; two broods, one feeding in May- June, the other in July- August. Pupa. — A dark brown object formed in its silken shelter in folded leaves. Control. — Spray with arsenate of lead in early spring and July. Caccecia scmiferana occurs on apple. The Large Aspen Tortrix {Caccecia conflictana Walk.) occurred in destructive numbers in Manitoba in 191 6-1 7 on aspen poplars, although it is usually a rare insect. According to Criddle the adult emerges in July and lays flat masses of eggs on the leaves. The caterpillars eat CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 23 1 holes in the leaves and spin much silk. About the end of July they go into hibernation resuming feeding in the spring and pupating in July. The natural means of control are hymenopterous parasites, birds, and sudden climatic changes in early spring. Lesser Apple Leaf Roller (Peronea minuta Rob.). — Sometimes inju- rious in Eastern nurseries, causing the leaves to become folded and brown; also a pest of cranberry bogs. Adult. — Small, % inch wmg expanse; fore wings of summer brood bright orange colored; of the autumn brood slaty-grey. Two or three brooded. Hibernates. Eggs. — Minute, disk-like, yellow; laid on unfolding leaves. Larva. — Feeds within a folded leaf for 3 to 4 weeks. Broods work in May, July and September. Pupa. — Small, J^ inch long, brown; head with a knob-like projection; within a silken web or cocoon. Duration 7 to 10 days. Spruce Bud Worm (Harmologa fumiferana Clem.). — (Consult Bull. 210, Maine Ag. Exp. St. and Hewitt's Reports.) A destructive pest of spruces in Northern United States, Eastern Canada, Manitoba and Vancouver. Adult. Fore wings brown, varied with short dark brown striae; hmd wings dark fuscous. July. Eggs.— Vale green, scale-like, fiat; laid in patches overlapping each other. Hatch in about 10 days. Larva. — When young pale green with a yellowish tint; head dark brown, thoracic shield amber with two dots on posterior margin; hairs half as long as thickness of body Jf i^ich long. Just before last moult uniformly rust-red brown, and head and shield black. Full grown larva with thick stout body tapering from middle to end; head not quite so wide as body, and dark brown. Feeds on needles of terminal shoots, often separating them at base and spinnmg a silk thread about them and the bud scales. Hibernates among the terminal shoots, becoming full grown the following June- July- Pupa. — Thick; thorax swollen; pale brown color striped with brown; antennae and legs dull tan color. Parasites. — Winthemia fumiferance, Pimpla inquisitor and P. con- quisitor^ Meteorus trachynotus, Conoblasta fumiferance, Mesochorus diversicolor, Epiurus innominatus. 232 ECONOMIC ENTOMOLOGY Strawberry Leaf Rollers (Ancy/is (om plana Im()Ii1 dndCacoecia ohsole- lana Walker). ^ — ^Thcsc Iwo lortricids oflcii do injury to strawberry leaves by rollin^ij a!i(l destroying them. 'I'hey may be controlled by spraying the phmls with a solution of lead arsenate (5 lb. to too gal. water) witliin a week after the lirst aj)|)earance of the Moths. IIkliozkud^-: Resplendent Shield Bearer {Coptodisia sp/endoriferclla Clem.). — Sometimes a serious |)est in orchards. Found from Maine to Minnesota. AiInJt.-'A small brilliantly colored golden-headed moth; fore wings leaden grey and lustrous at base, outer portion golden with silver and dark brown streaks; hind wings rich grey with long yellowish fringe; antenna' brown tinged with gold. May June. yt/,'^'.v.— Laid on lea\'es. Larva. — Small, ' s inch long, legless, light yellowish brown; head dark; makes 'an irregular dark blotch mine ' .^ inch in diameter, in the leaf. When full grown in July it cuts out a portion of the mine and forms a seed-like yellowish shield, which is attached to bark. A second brood in Se])tember, and in October the seed-like i)ui)a case is formed. Pupa. — In an o\al, disk-shaped seed-like case. Hibernates. Diamond-back Moth {PlutcUa macidipcnnis Curtis). — A widely distributed insect in U. S. and Canada. The cater|)illar occasionally attacks the leaves of turni[)s and cabbages, and does considerable injury. Adult. — A slender moth of a general ashy-grey color with white marks on the back, diamond-shai)ed when wings are closed; J5 inch wing expanse. Kggs. — ^Minute, scale-like, greenish white or yellowish, laid singly on lower surface of leaves. Larva. — A minute, active, dull green caterpillar with si)in(lle-shaped body and with a wriggling motion when disturbed; mature form pfo inch long; feeds on the lower surface oi the leaves; effects visible in July. Pupa. Slender, yelU)wish, ' j inch long, enclosed in a beautiful white lace like cocoon on the surface of the leaves. CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 233 Probably two or more broods in a year in Canada; seven broods at Rocky Ford, Colorado. Control. — Broadcast 2 to 3 cwt. ground lime per acre on appearance of moths on a dewy morning. Brush off caterpillars. Spray the caterpillars with kerosene emulsion, care being taken to get the solution on the under surfaces of the leaves. Yponomeutid^ Apple Fruit Miner {Argyresthia conjugella Zeller). — Occurs in western portions of Canada and the U. S. Adult. — One-half inch spread; fore wings purplish-grey mottled with brown, with a row of small white and brown dots on front margins and a broad white interrupted band. May-June. Larva. — Pinkish-white; J^g inch long; burrows in all directions through fruit. Also on wild crab. Pupa. — In white cocoon with open pattern, under bark or leaves. White Cedar Twig Borer (Argyresthia thuiella Pack.). — Causes a rusty appearance on white cedars along the Ottawa. Adult. — A small pearly white moth with costal and apical brownish spots; head and thorax white; antennae white with brown rings. Latter half of June. Larva. — Slender, olive green, brownish at anal end; head black and shining; thoracic shield piceous; 3^^ inch long before winter sets in; hibernates in mines made in the young twigs; renews growth at end of May and is J^ inch long when full grown in June. Pupa. — No cocoon; formed in the mines. The Apple Ermine Moth {Vponomeuta malina) and the Cherry Ermine Moth (Yponomeuta padella L.) are destructive orchard pests in Europe. They reached the U. S. in 1914 on nursery stock imported from France into New York State, and were discovered in shipments of ornamental shrubs and fruit seedlings into New Brunswick in 191 7. The moths are small, about ^^5 inch wing expanse; fore wings white with black dots; hind wings grey and broadly fringed. The caterpillars are about ^^ inch long and vary in color from pale to greyish or greenish brown. The moths fly during July and August; the eggs hatch in the fall and the young larvae hibernate beneath the scaly covering formed by the egg-masses. 234 ECONOMIC ENTOMOLOGY Haploptiliid^ Case Bearers. — Two species of Case Bearers are found in apple orchards: the Cigar Case Bearer, and the Pistol Case Bearer. They do most injury to the young buds and blossoms. I. Cigar Case Bearer {Haploptilia fletcherella Fernald). — (Consult Bull. Q3, Cornell Ag. Exp. St.; Bull. 80, Pt. II, Bur. Ent, U. S. Dep. Fig. 143. — a. Cigar case bearers and their work on apple leaves; b, pistol case bearer and its work on young fruit. Natural size. {After Caesar.) V2 inch; wings Ag.) Adult. — A small greyish moth, expanding broadly fringed. June-July (Fig. 143, a). Eggs. — Delicate light lemon-yellow; pitted; cylindrical; laid singly on under sides of leaves; hatch in ia-14 days, about July 15th. LarvcB. — Orange colored; head black; feed as miners for 2-3 weeks within the leaf, then later in curved cases on the leaves. About CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 235 September 15th they migrate to the twigs where they hibernate in their cases. About April 15th they attack the young buds, etc.; about the end of May they make their characteristic cigar-shaped cases, within which they feed on the leaves. About the end of June they change to pupae. Pupa. — ^Light brown; duration about 10 days. 2. Pistol Case Bearer {Haploptilia malivorella Riley). — (Consult Bull. 124, Cornell Agric. Exp. St.) The life history of this species is very similar to that of the Cigar Case Bearer, the habits of the larvae differing to a slight extent (Fig. 143 h). Adult. — -A minute moth with brownish, heavily fringed wings and covered with white scales, head and thorax white; abdomen whitish; all parts dotted with brown scales. June- July. Eggs. — Cinnamon-rufous; like inverted tea-cups with strongly ridged sides; July; egg stage lasts about a week. Larv(B. — Never miners; make cases as soon as they begin to eat. In September they migrate to twigs where they pass the winter in small pistol-shaped cases. In spring they attack the buds and make irregular holes in the leaves. About the beginning of June they change to pupae. Pupa. — Pupal stage lasts about 2 weeks. Control. — Spray with arsenate of lead in early spring just before the blossoms open and in July. TiscHERiiD^ (Leaf Miners) Apple Leaf Miner {Tischeria malifoliella Clemens). — The larva forms trumpet- shaped blotches under the surface of the leaves. Adult. — A minute moth expanding }i inch; wings broadly fringed. Fore wings shining dark brown with a purplish tinge; hind wings grey; head and antennae dark brown. May. Eggs. — Small, greenish-yellow, blister-like, elliptical, J^o i^^h long; attached to surface of leaf. Hatch in 8-10 days. Larva. — A miner within the leaf; mature in 3 weeks. Larvae of last generation hibernate in the fallen leaf. Pupa. — Pupa formed within the leaf. Duration 8-10 days. Two or three generations each season. 236 ECONOMIC ENTOMOLOGY Lyonktiud/E (Lkaf Skeletonizers) Apple Leaf Bucculatrix (BiiccuJatrix pomifoUcUa Clemens). — (Consult lUill. 214, Cornell.) Adult. A small moth, '4 inch expanse; fore wings whitish tinged with pale yellow and dusky brown. Hind wings broadly fringed. Appears when leaves unfold. Eggs. — Laid in May, singly on under side of apple leaves; elliptical, /GO X M25 inch, greenish, iridescent; surface rough. Larva. — One-half inch long, cylindrical, tapering at both ends; dark greenish-yellow, with reddish tinge on anterior segments, active. Full grown in July. Pupa. — Cocoons dirty white, slender, ' | inch long; six ]:)rominent longitudinal ridges; oblong, tapering at both ends; fastened to twigs in groups, in September-October, etc. Hibernates in this stage. Birch Leaf Skeletonizer {Bucculalrix caiiadoisiscUa Chamb.). — A serious pest of birches, skeletonizing tlie leaves. Adult. — A small brown moth, about j 3 inch long; wings crossed with fine white bars. Z«rz;a.— Slender, green; head brown; tapering slightly toward both ends. It spins a small round white moulting cocoon on the twigs or leaf, and later spins a yellowish ribbed elongate cocoon within which it pupates. Control. — By parasites and by spraying with arsenical solution. TlNEID/E (TlNEIl'is) Clothes Moths. Three injurious species of Clothes Moths are rec- ognized in America: (i) Case-making Clothes Moth, (2) Webbing or Southern Clothes Moth, and (^0 'rai>estry Moth. I. Case-making Clothes Moth {Tinea pclUonclla L.). — So-called because the larva makes a true transportable case. (Consult Circ. 36, Bur. Ent., U. S. Dept. Agr.) Adult. — A small tineid moth ex])anding '2 inch; head and fore wings greyish yellow; hind wings gre}'ish white and silky. June- August. Eggs. — Minute whitish, ])laced directly on food material; hatch in about TO davs. CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 237 Larva. — A dull white calerf)illar with head and upper part of neck segment brown; living within its case; feeds on woolens, carpets, furs, feathers, etc. Pw/>a.— Formed within larval case; duration aljout 3 weeks. One generation a year in the North. 2. Webbing or Southern Clothes Moth {Tineola biselliella Hum.). — Two or more broods in the North; more common than the preceding in the North. Adult. — Fore wings pale ochreous. Female larger than the male; lays 40-50 eggs. Eggs. — ^Laid among the threads of the cloth; hatch in 7 days. Larva. — Constructs no case, but spins a silky cobwebby path wherever it goes; full grown in 10 or more weeks. Feeding all months of the year on woolens and furs. Not readily poisoned. Pupa. — Cocoon stage 2 or more weeks. 3. Tapestry Moth {Trichophaga tapetzella L.). — Rarer and slightly larger than either of the preceding. Adult. — Head white, basal half of fore wings black; outer half creamy and grey; hind wings pale grey. Expanse % inch. Larva. — Burrows in food materials, lining them with silk — no other protection than the galleries or burrows it makes. Feeds on carpets, horse blankets, tapestries, felting, furs, skins and woolen upholstering of carriages. Control. — Give clothes or carpets a thorough beating, spray with benzine and expose to sun for some hours, and repeat frequently. C0SSID.E (Carpenter Moths) Leopard Moth (Zeuzera pyrina Linn.). — A serious pest of shade trees in the East, especially of elm and maple. A native of the old world. Adult. — A white moth with blue and black markings; female much larger than male and a feeble flyer. Male with pectinate antennae; wings semi-transparent and white with black markings; thorax with six large and one small black spot. Eggs. — Oval, salmon-colored, deposited either singly or in a large mass in crevices of bark; hatch in about 10 days. Larva. — White or pinkish, over 2 inches long when full grown; numerous dark tubercles with hairs on body; head, thoracic and anal shields brown. Bores along the pith, eating the wood at intervals, 238 ECONOMIC ENTOMOLOGY with an occasional opening for the removal of fras, which is soon closed with a web of silk. Both large and small limbs when attacked fre- quently break off. Nearly full grown by second winter. Pupa. — Formed in the burrow in May of second year. Control. — Prune away and burn the smaller injured twigs or branches; inject carbon bisulphide into the openings of burrows and seal with wax or putty. Carpenter or Goat Moth {Prionoxystus rohinice Peck.). — The cater- pillar bores into maple, oak, ash, willow and locust trees, often producing deformities. Adult. — A large moth, wing expanse of female 3 inches, of male 2 inches. Color dark grey mottled with light grey. Front wings of male darker, and hind wings ochre yellow. June and July. Eggs. — Oval, Jfo inch long; each female lays several hundred eggs; dirty whitish with one end black; finely reticulated, sticky. Laid in crevices about injuries. About July ist. Larva. — A large white caterpillar suffused with rose red, 23^^ inches long; head brownish, jaws prominent and black; thoracic shield dark brown in front; each segment with several minute brownish tubercles, each bearing a hair; spiracles brownish; a dark-colored dorsal line; under side of larva greenish white; bad smelling. Pupa. — Brownish, i}/'^ inches long; dorsal surface of abdominal segments with rows of tooth-Hke processes. Formed in a loose cocoon at ends of galleries. Duration 2 weeks or longer. The life-cycle is beUeved to occupy 3 years. Control. — Trim away deformities; inject CS2 into borings and close holes with putty or cement. Nepticulid^ Serpentine Leaf Miner {Nepticula pomivorella Pack.). Adult. — A minute, purphsh-black tineid moth; head tufted; reddish-yellow; June. Larvcs. — Small, dark-green caterpillars Jfo inch long. Make a narrow serpentine mine beneath surface of leaves of apple and pear, first half of mine broader than second half. In late autumn the larvae find their way to twigs by means of silken threads, where they spin small oval brown cocoons }i inch long resembHng Lecanium scales. In May they transform to pupae. Pupa. — Bright green. CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 239 ORDER DIPTERA (FLIES) Sub -orders and Groups A. Adults without a frontal lunule; pupa and adult escape from larval skin through a T-shaped opening at anterior end. — Sub-order Orthorrhapha. B. AntenniE long, with more than five joints. — Nematocera Group (Fig. 144, A). BB. Antennse short, usually 3-jointed; first anal cell narrowed. — Brachycera Group. (Fig. 144) A A. Adults with a frontal lunule; pupa and adult escape from larval skin through a circular opening at anterior end. — Sub-order Cyclorrhapha. Fig. 144. — Antennas of common Diptera. A, Xiphuria (Tipulidae). B, Sargus (Stratiomyiidae). C. Stratiomyia (Stratiomyiidae). D, Culex (Culicidae). E. Tabanus (Tabanidae). F, Leptis (Leptidas). G, Chrysops (Tabanidas). H, Anthrax (Bombyliidas). /, Dasyllis (Asilidae). J, Bibio (Bibionidae). A", Gonia (Tach- inidce). L, PolUnia (Muscidae). Chief Families of the Nematocerous Orthorrhapha: A. A distinct V-shaped suture on back of thorax; legs long and slender. — Tipulida (Crane Flies) p. 242. A A. No V-shaped suture on thorax. B. Veins and margin of wings fringed with scales. — Culicidce (Mos- quitoes), p. 243. BB. Margin of wings not fringed with scales. C. Anal veins wanting; Media vein wanting; tibiae without spurs. — Cecidomyiidce (Gall Gnats), p. 245. CC. Anal veins present and Media vein at least represented by a fold. Costal vein does not extend beyond tip of wing. 240 ECONOMIC ENTOMOLOGY D. Abdomen slender; wings narrow; antennie pulmosc in the males; wing veins slrong near costal margin. — Chiro- nomidce (Midges), p. 252. DD. Abdomen short and thick; wings broad; antenna; short and non-plumose. — Simuliida' (Black Flies), p. 251. Chief Families of the Brachyccrous Orlhorrhapha (Figs. 146-149); A. Antennic of five or more segments, those beyond the second more or less united. (Fig. 144, E). «2*J 3d A Fig. 145. — Venation of a tipulid (Tipula). (After Comstock.) Pk;. 146. — Venation of a tabanid {Tabanus). {After Comstock.) B. Alulcts large, third joint of antenna; without a style or bristle. — Tabanid(C (Horse Flies), p. 252. BB. Alulets small; branches of Radius crowded together near the costal margin. — Slraliomyiidcc (Soldier Flies). AA. Antennie of four or live segments but the third joint not ringed. B. Antennae long, clavate, 4-jointed; branches of Radius curving toward costal margin. — Midaidce (Midas Flies). Fig. 147. — Venation of Dixa. (After Comstock.) Fig. 148. — Venation of an asilid (Erax). (After Comstock.) AAA. Antennie of three segments; Radius four-branched. B. Vertex of head hollowed out between the eyes; palpi present. — Asilidce (Robber Flies). BB. Vertex of head not hollowed out; alulets small; beak prominent. — BomhyUidw (Bee Flies). Chief Families of the Cyclorrhapha (Figs. 151 and 152): A. Adults non-parasitic; maxillae covered by upper lip; Radius 3-branched. B. With a spurious longitudinal vein between Radius and Media; front convex between the antenna;. — Syrphidcc (Flower Flies), p. 250. CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 241 BB. With rudimentary ni()uth-[)arts; |)al[)i wanting; antennae with dorsal arista. — (Estridce (Hot FHes), p. 254. BBB. With well developed mouth-parts; palpi present; head with a suture above the antenna;. — Superfamily Muscoldca. C. Alulets small; eyes of males not contiguous; thorax without com- plete transverse suture. — (Acalyplrale Muscids.) R4 i£ Mit^ Fig. 149.— Venation of a leptid (Leptis). (After Comslock.) Fig. 150. — Venation of a syrphid {Eristalis) . {After Comstock.) D. Subcostal or auxiliary vein ending in the costa and distinctly separate from Radius I, or first longitudinal, which usually ends near the middle of the wing. Anal cell present. E. Oral vibrissas present; front bristly; R. nearly half the wing length; cross veins not close together; yellow or brown. — Scalophagida (Dung Flies). Bz*5 Fig. 151. — Venation of Thereva. {After Comstock.) Fig. 152. — Venation of a muscid {Musca). {After Comslock.) EE. Oral vibrissaj absent; eyes large; first posterior cell (R5) closed or narrowed in the margin; proboscis and ovi- positor greatly lengthened. — Conopidce (Thick-headed Flies). DD. Subcostal vein absent, vestigial or incomplete; Radius I usually ending in costa before middle of wing. E. Discal and basal cells united; Anal cell absent. — Os- cinida (Grass Stem Flies), p. 260. 16 242 ECONOMIC ENTOMOLOGY EE. Discal and second basal cells separated; anal cell complete. F. Oral vibrissae present. G. Arista long plumose or pectinate above. — DrosophiUdce (Pomace Flies), p. 260. GG. Arista bare, pubescent or short plumose; front bristly as far as middle, usually light colored. — Agromyzidce (Leaf-miner Flies), p. 262. FF. Oral vibrissae absent. G, Subcostal vein abruptly bent forward before the tip of Radius I; anal cell angular. Wings pictured. — Trypetida (Fruit Flies), p. 264. GG. Subcostal vein more or less fused with Radius I; all three basal cells distinct, anal cell not produced; antennae more or less elongate and decumbent. — Psilida (Rust Flies), p. 262. CC. Alulets or calypters large; eyes of males often contiguous; thorax with complete transverse suture. — Calyptrate Mtiscids. D. Cell Radius 5 closed or more or less narrowed at the margin of the wing. E. Antennal bristle bare. — Tachinidce (Tachina-flies), p. 278. EE. Antennal bristle bare near tip. — Sarcophagidct (Flesh- flies). EEE. Antennal bristle pubescent or plumose to the tip. F. Dorsum of abdomen bristly; legs elongate. — DexiidcB. FF. Dorsum of abdomen not bristly except at tip. — MuscidcB (House-flies), p. 268. DD. Cell Radius 5 widely open. — Anthomyiida (Root-maggot flies), p. 273. AA. Adults parasitic; upper lip enveloped by maxillae as by a sheath. — Pupipara (Sheep-ticks, etc.), p. 279. (Consult Tech. Series, No. 22, Bur. Ent., U. S. Dep. Ag. on "The Structure of Certain Dipterous Larvae, etc.," by N. Banks, 1912) TIPULIDiE (CRANE FLIES) Meadow Maggots {Crane Flies or Leather Jackets). Adult. — ^Large mosquito-like flies with very long thin legs, long slender bodies, narrow wings and thread-like antennae. A transverse V-shaped suture on the back of middle portion of the thorax (Figs. 145 and 153). Larva. — When full grown about an inch long, dirty brown, and footless; of a tough leathery texture; cylindrical; tapering in front and blunt behind. CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 243 Pupa. — No puparium; occupying small cells near the surface of the ground in a vertical position. Broods. — There are two broods each season. Larvae winter over and change to pupae in late May. Adults soon appear and deposit eggs from which hatch the maggots. These change to pupae and adults in September when eggs are laid for a fall brood. The maggots hatching from these eggs winter over. Control. — Early fall plowing, draining, and rotation of crops. A Fig. 153. — Tipula. A, Larva; B, cast pupal skin; C, imago. Slightly reduced. {After Folsom.) CULICID^ (MOSQUITOES) Key to The Common Genera A. Palpi in both sexes at least almost as long as the proboscis. — Anopheles. A A. Palpi in both sexes less than one-half as long as the proboscis. — Aedes. AAA. Palpi in the male at least nearly as long as the proboscis; in the female less than one-half as long. — Culex. This family includes several important economic genera, comprising many hundreds of species. The more important of these are Culex pipiens, C. pungens, Anopheles maculipennis , and Stegomyia fas data = Aedes calopus. House Mosquito [Culex pipiens Linn.). Adult. — A slender-bodied, delicate fly with gauzy wings, the veins bearing minute scales; deep yellowish to dark brown; legs and beaks not banded; abdomen with narrow whitish bands at the base of each segment. Hibernates as adult (Fig. 154). 244 ECONOMIC ENTOMOLOGY Eggs. — ^Laid at night or early morning on the surface of standing water in masses of 50 to 400. Hatch in about 24 hours. Larva. — ^Large head with a pair of mouth-brushes and a tube at opposite end of body for breathing, not over four times as long as broad; antennae of moderate length with a branch about the middle, bearing a tuft of hairs. Full grown in a week; dirty white, or yellowish. Pupa. — A hunched object, floating just below the surface of the water. Duration i to 3 days. Number of broods limited only by conditions of temperature and moisture. Fig. 154. — The common house mosquito: a, male; b, female. {U. S. Bur. Ent.) Malarial Mosquito {Anopheles maculipennis Meign.). Adult. — Differs from Culex in being much larger, more slender and with larger legs; wings longer, and more or less spotted with brown or black, and carried flat on the back when not in use; palpi or mouth-feelers as long as the beak in both sexes. (In Culex the palpi are short in the female.) A common malaria carrier. Eggs. — ^Laid singly on surface of water; hatch in 24 to 48 hours. Larva. — ^Larva Hes flat on surface; tube very short; at first black or CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 245 grey, usually banded with white; later color harmonizes with sur- roundings. Full grown in 7 to 10 days. Pupa, — ^Like that of Culex but with shorter, more trumpet-shaped breathing tubes; duration about 2 days. Other species of Anopheles are: A. punctipennis and A. crucians. The Salt Marsh Mosquito (^^^e^^6?//za7aw5Walk.), the Swamp Mos- quito {A. syhestris Theo.) and the Irritating Mosquito {Mansonia per- turbans Walk.) are commonly met with and are annoying. On the western prairies the genus Aedes is most abundant. The eggs are laid in late summer and hatch out the following spring in the water of the melting snow. There is but one brood a year. The most common species are A. spenceri Theob., A. fletcheri Coq., and A. cur- riei Coq. CECIDOMYIIDiE (GALL MIDGES) Hessian Fly (Mayetiola destructor Say). — (Consult Ent. Bull. 11, Dep. Ag., Ottawa; Bull. 116, Ont. Dep. Ag.; Cornell Bull. 194; and Fig. 155. — The hessian fly {Mayetiola destructor): i, adult female; 2, mature larva; 3, puparium or " flax-seed "; 4, seed of flax. Enlarged about 8 times. {After Criddle, Ent. Bid. 11, Dep. Agric. Can.) bulletins by Webster and Marlatt.) An introduced pest from Europe and one of the most serious enemies of growing wheat. Distributed over the wheat regions of United States and Canada. Attacks also oats, barley, rye, Agropyron spp., Bromus, Elymus and Agrostis (Fig. 155)- Adutt. — A small dusky 2 -winged fly, }<8 inch long, about half the size of a common mosquito; the female with a dull reddish tinge and larger than ihe male; legs long; wings smoky-black, covered with fine black hairs and obscurely fringed. 246 ECONOMIC ENTOMOLOGY Eggs. — Spindle-shaped, reddish and i to 50 inches long; hatch in 4 to 12 days. Larva. — A footless maggot, clear-white except for a greenish stripe down the middle; last stage of larva passed in "flax-seed" covering, and having a peculiar "breast-bone," a horny forked structure. Pupa. — Pupa case deep rich brown, like small "flax-seeds;" pupa rosy colored and with a pointed beak. Broods. — Two generations in fall wheat regions, and one in spring wheat regions. Criddle reports a supplementary summer brood in Manitoba, the adults appearing from late June up to middle of August. Pupae develop which winter over. Webster (640) is of the opinion that the Hessian Fly is two-brooded even in spring wheat sections. Female lays a few, to 50 or more, eggs on upper surface of leaf about last week in August, first week in September or later, according to latitude, altitude and longitude; maggots hatch in about 4 days and move down the leaf to the stem where they embed themselves within the leaf -sheath. In about 3 weeks they change to "flax-seed" but remain as larvae until the following May, when they change to pupae. The flies emerge a few days later to lay their eggs for a new spring brood on the leaves of spring cereals. The maggot stage lasts until the third week in June, and the "flax-seed" stage until the third week in August or later, when the flies emerge (Fig. 156). Parasitized by Folygnotus, Merisus, Eupelmus, Tetrastichus, and Entedon, all Chalcids. Control. — ^Late seeding in fall on well prepared seed-bed; trap- strips; destruction of all volunteer wheat; destruction of "flax-seeds" at threshing; co-operation. Plowing the wheat stubble deeply immedi- ately after harvest. (See Part IV). Clover Seed Midge (Dasyneura leguminicola Lintner). — (Consult Bull. I 34, 111. Agr. Exp. Stn.). A widely distributed pest of red and white clover fields. Alsike, mammoth and alfalfa are uninjured. Adult. — A minute 2-winged fly, J^-f 2 inch long, with red abdomen and long reddish-brown legs and antennae; head and thorax black; wings transparent with dusky hairs. April-May and July-August. Eggs. — Very minute, orange, smooth and transparent. Laid in green flower-heads, hatch in about a week. Larva. — A footless orange maggot, Jf ii^^h long, and with nine pairs of respiratory tubercles and a sternal spatula. CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 247 ^ b ^ s 8 O a a > c! o o Xi m a u ^ ^ I I I P^ 248 ECONOMIC ENTOMOLOGY Pupa. — Cocoon oval, ^^2 iri^h lon^, made of silk threads; pupa pale orange; eyes brown; two short tubercles on front of head. Life-history. — There are two broods each year. Eggs are laid in May in the forming llower-heads. At the end of June and early July (June 20 to |ul\' S in Illinois) the maggots mature and drop to the ground to pupate. The adult flies emerge when the second crop of clover comes into bloom (July 15-Sept. i) and lay their eggs among the blossoms. The maggots leave the ripe heads in autumn, and pass the winter in the ground. In May the adult flies emerge to lay their eggs. Affected florets do not expand then" ])etals and remain fresh and pink until after maggot leaves the bud, eventually fadmg and withermg without opening. Natural Enemies. — Tetrastic/ius, A nopcdius, Triplileps. Cputrol. — Cutting or ])asturing clover before the 20th of June. Clover Leaf Midge {Dasyneura trifolii Low.). — A serious pest of white clover, affected leaves folding ui)on a midrib with maggots enclosed . .!^5 inch long; dull yellowish- white; narrow; ovoid. Larva. — Dr. Cooper Curtice of Washington believed that the eggs were licked into the mouth and the maggots bored through the wall of the oesophagus, whence they gradually made their way to the tissues along the back, causing warbles. Miss Ormerod, of England, on the other hand maintained the popular belief that the eggs were laid on the back, but Carpenter of Ireland, and more lately Dr. Hadwen of Canada, have proven fairly Pig. 162. — The striped warble fly {Hypoderma lineatmn). Enlarged. {After Hadwen.) conclusively that the eggs may be laid on almost any part of the body of the animal, and that the maggots bore into the skin where lesions and swellings are produced. They finally make their way to the back where the warbles are formed. Full grown maggots are greyish-white and nearly an inch long. When mature they make their way out through the minute opening, drop to the ground and bore an inch or so below the surface, where they change to pupae. Four stages of larva; duration 9-10 months. Pupa. — Puparium dark brown. Duration 3-6 weeks. CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 257 The Ox Warble Fly {Hypoderma bovis DeG.).— This bot-fly is also European and is found in several provinces of Canada and in several states. It is more dreaded by cattle than lineatum, and causes much panic due largely to the insect's persistence and manner of egg-laying. More robust than H. lineatum. Body hairs yellow, except those on scutellum and base of abdomen which are yellowish-white, and at apex Fig. 163. — The ox warble fly {Hypoderma bovis). Enlarged. {After Hadwen.) of abdomen which are bright lemon yellow (see Table given above for structural differences between hovis and lineatum) (Fig. i63)<. The adults of H. hovis appeared in B. C. from May 31st to August 2d as extremes (Hadwen). Carpenter says that most of the maggots emerged from May 2 7 th to June 1 7 th. The pupal period has an average duration of about 35 days varying according to temperature. One egg is laid at a time, often when the cattle are running, besides not 17 258 ECONOMIC ENTOMOLOGY SO many laid about the hoof as with lineatum. SwelHng is more rounded and more raised than that of lineatum j and exudes less serum. Control. — When practicable dip every lo days and treat the larvae with arsenic. Remove the larva from the warble in spring. Larvae of a species of Hypoderma have been obtained from the backs of horses. BoT Flies These flies are probably of European origin but little is known of their introduction. Horse Bot Fly {Gastrophilus intestinalis DeG. = equi Fab.). Adult, — A large brownish hairy bee-like fly, % inch long; head brown with 1 Fig. 164. — Larvae of horse bot flies: i, G. hoemorrholdalis; 2, G. intestinalis; 3, G. nasalis. (After Dove, Bur. Ent., U. S.) three rows of black spots; wings with dark spots or bands; abdomen brown with spots and conical. July-August. Eggs. — Yellow, conical, attached by female without alighting to hairs of fore-legs, shoulders and under side of body; Jf g inch long; hatch most readily lo to 15 days after deposition, with the aid of warmth, friction and moisture. Larva. — ^Licked into the mouth of the horse, thence into the stomach, where it attaches itself to the wall. Remains in stomach 8-10 months. CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 259 In spring it escapes in the droppings to the ground and bores an inch or two below the surface where it pupates (Fig. 164). Pupa. — Duration 30-40 days. Chin or Nose Flies {p. nasalis Linn. andG. hcBmorrhoidalis Linn.). — These flies are a serious annoyance to horses in the West. They have bands of whitish, black and orange-red on the abdomen. The eggs of G. nasalis are yellowish; laid on the hairs of the throat. Parker (191 6) records the egg-laying of G. hcemorrhoidalis, the red- tailed bot fly. The egg is black, barnacle-like and stalked, and is in- FiG. 165. — An effective leather fringe device to protect horses from the nose and red-tailed bot flies. {After Dove.) serted on the hairs of the lip and nostrils by the stalk. The "striking" of the fly causes a sharp pain and excites a nervous uncontrollable fear in the horse. Control. — Administer three or four 4-oz. doses of turpentine, followed finally by an ounce of powdered aloes; stable horses in day time; groom carefully so as to kill or remove the eggs; use fly-nets of loosely dangling cords for G. equi, and wire-screen muzzles, leather nosebands cut into narrow strips or provided with canvas flaps for G. nasalis and hcBmorrhoidalis (Fig. 165). 26o ji:co:N()Mi(" iin roMoi.ocY Sheep Bot Fly ((Ksirus ovis Linn.). Ad nil. A dull-yellow lly a liHK" lar^iT (Ikiii IIu- lloiisc-lly and covered with niiiuile s|)ols; alxlonien wilh live rin^s, velvety and varie^jjated with daik-hrowii and straw color. Antenna' small; eyt's purplish-hrown; ocelli three on top of head; no tnoiith; win^^s Iransparenl extendiii}^ beyond body ;alulels large cover- iiij^f the poisers. June August. Egl^s. — Deposited in nostrils of slieep; hatch ahiiost at once. A^/rM— Maggot works its way up the nasal passages until it readies the frontal sinuses, the cavities between and above the eyes. There it attaclies itself and feeds on (he nuu us present. Young is creamy- while, with two brown spots, spiracles on last segment ; full grown mag- got darker, |)arlicularly |)osleriorly ; two small hooks on head; small rounded si)ots on sides of each segment. When mature, maggot i)asses down the nasal passages and falls to (he ground, which it enters to i)upale. Pupa. I'uparium smooth, hard, and black, tapermg toward head; duration 40 50 days. Control.— ~A\)\)\\ tar to llu> nose; furnish a shed for the sheep or a plot of plovvi'd or dust\' ground. DROSOPHILIDiE (POMACE FLIES) Pomace Fly {Drosophila (impclop/iila Loew.). 'Phis small lly breeds in decaying or over-ripe fruit, and is a common pest about fruit-stores. It is also susi)ected of being a t\i)hoid transmitter. The adult is a small light brown lly with bright-red eyes; the maggot is white and about '1 inch long; the pui)a is yellow or brown with two long horn- like breathing tubes at anterior end. The front tarsus of the male has a comb of black si)ines on its upi)er side near the tip. OSCINID^ (GRASS STEM MAGGOTS) Wheat Stem Maggot (/l/'^^^^ l*'ii^'' 'i'^;//rf)/.--Siiiiimci-falI()w ^rass lands; prevent volunteer growth in aiitiinin. PSlLIDiE (RUST FLIES) Carrot Rust Fly {I\sil(i roscr Fab.). — This fly is a native of Europe, and (he larva frc(|ncMi(ly docs considerable injury to the roots of carrols, celery and ])arsnii)s. Adii/ir One-six ill imh lonu:, dark green, sparsely clothed with yellow iiairs; eyes black, and head and legs ])ale yellow. 7'J/,'i,'.v.- Deposited by female about roots of host through cracks in (he ground. Lonm. — Maggot dark brown, '^ fo inch long, slender, truncate al ])osterior end; segments well marked, head small. 7*///>(/.- ru])arium dark brown; anterior segment obli(iuely trun- cate; \^ incli long; puj)ation in the earlh. Life-history. — (Consult Fletcher's Reports and Bull. ^^^^, V. S. Div. Ent.) Winters as larva or pupa; adults appear early in the season; summer generations devclo]> in 3 or 4 weeks (Curtis); both flies and maggots found throughout the warmer months; number of broods uncertain. Control. Spra\' the carrots four or fi\e times at intervals of a week or (en days with keiosene emulsion, (he fust a])])lication at the time of dunning; spread the earth in which carrots have been stored in the poultry yard; sow late and practice rotation of crops. AGROMYZIDiE (LEAF MINER FLIES) Marguerite Fly {Phytomyza chrysanthcml Kowz.). — (Mass. Agricul- tural Isxperiment Station, Hull. 157.) Attacks comj)ositous plants and is especially injurious in the greenhouse. Occurs in the Northern States, and has done considerable injury in B. C. .[diilt. — A small greyish fly V12 ii^^'^^ h)ng, with a yellow stri})e on eaih side of abdomen; face yellow; antennae black; legs black with >ellow markings; rather inactive. Average length of generation about 3^^ days; several generations a season in greenhouse. 7^'.i,'.v. - Laid singly in incisions between llesh and skin of leaf. Hatch in 5 days. Larva. — Burrows in the leaf, producing irregular whitish lines or CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 263 patches, often causing withering, also preventing flowering or reducing the number of blossonas. Matures in about 17 days. Pupa. — Formed in larval mine. This stage lasts about 14 days; puparia dark brown. Control. — A solution of Black Leaf 40 and Soap applied at intervals of 10 or 12 days, as soon as first signs of operation of the insect. Asparagus Miner (A^romyza simplex Loew.). — (Consult Bull, 66, Part I, U. S. Bur. Ent.) Injures asparagus stalks, the maggot mining beneath the epidermis, sometimes girdling the stem. Adult. — A black two- winged fly; eyes and head prominent; wings clear with },{^ inch expanse. Probably two generations, June and August. E^gs. — White; deposited just beneath epidermis of stalk. Larva. — Milk-white; 3^ inch long; footless, truncate posteriorly and tapering anteriorly. Pupa. — Puparium flax-seed-like, red, 3-^ inch long; attached to slits in epidermis of asparagus stalk near ground. Control. — Pull up and burn infested stalks in spring; destroy volunteer trap plants in late June. Com or Spike-homed Leaf Miner {Cerodonta dorsalis Loew.). — (Consult Bull. 432, Bur. Ent., U. S. Dept. Agr.) This leaf-miner has a wide distribution in the U. S. and feeds on a wide range of cereal and grass plants. Three generations at least in Indiana. Adult. — One-twelfth to j^fo ii^ch long; proboscis, palpi, front, antennae, legs, mesonotum and abdomen mostly yellow. Punctures the leaves, in some of which an egg is laid. May in Indiana, but active throughout the year in Pasadena, Cal. Eggs. — Elongate, kidney-shaped, rounded at each end. Color opaque white; 3-^o ii^ch long. Hatch in 3-12 days. Larva. — Dirty- white; % inch long; slender, nearly cylindrical; mouth-hooks black; body segments plain; posterior ends truncate; mines in the leaves and stem of host plant, frequently killing the parts affected. Full grown in 9-24 days. Pupa. — White at flrst, turning yellow and dark later. Duration 9-24 days. Hibernates (in Indiana). Control. — (i) Summer fallowing, (2) fall plowing, (3) burning dry grasses along fence lines, roadsides, etc. in late fall and early spring. 264 ECONOMIC ENTOMOLOGY TRYPETIDiE (FRUIT FLIES) Common Genera (after Williston) : A. Bristle on each side of front with a terminal leaf-like appendage. — Ceratitis. A A. Front without such bristles; wings with colored markings not reticulate; scutellum not with six bristles; fourth longitudinal vein not conspicuously curved forward at its extremity. B. Distal portion of wings marked with two hyaline indentations. Sepa- rated by a curved or arched brown projection from the brown oblique cross-band; body short; abdomen as broad as thorax; antepenultimate section of fourth vein curved. — Epochra. BB. Wings not marked as in B. C. Coloring of body generally light, never black; cross-bands on wings nearly transverse; cross-veins but little oblique. — Trypeta. CC. Coloring of body black; wings with four very oblique black cross- bands; cross- veins not approximated; scutellum with 4 bristles, yellow. — Rhagoletis. Mediterranean Fruit Fly (Ceratitis capitata Wied.). — (Consult Circ. 160, U. S. Div. Entomology.) Probably a native of the East Indies. The appearance of this destructive insect in Hawaii has alarmed the fruit-growers of the Pacific coast, and quarantine restrictions have been enforced. It already occurs in Africa, Europe and Asia, in Australia and in Brazil, and attacks nearly all kinds of fruits. Adult. — An active fly about size of house-fly, ochre yellow color; eyes reddish purple; a blackish blotch in centre of forehead where two stout black bristles arise; thickened basal antennal joints yellow, terminal segments black; dorsum of thorax convex, yellowish- white marbled with shiny black blotches. Wings broad and semi-opaque with extreme base blotched with ochreous or brownish yellow, the rest of the basal area marked with black; beyond a broad, irregular, trans- verse ochreous band blotched at extremity; another similar blotch inside of costal vein. Abdomen oval, with fine scattered bristles on upper surface, and two rather broad transverse silvery white bands on basal half. Num- ber of broods depends on temperature and food supply. Eggs. — Glistening white eggs placed beneath skin of ripe fruit by sharp extensile ovipositor. Eggs not all deposited at once. Larvce. — Begin feeding at once on the pulp, when mature (2-3 weeks) they leave the fruit and enter the ground, changing to puparia. Pupa. — Duration 12-21 days. CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 265 Control. — Cleaning up and destruction of all fallen fruits; covering trees with netting; using a poison bait spray (Berlese and Mally). Currant Fruit Fly {Epochra canadensis Loew.). — (Consult Bull. 264, Maine Agr. Expt. St.) A common pest on currants and gooseberries in Canada and the Northern States, and confined to the Canadian, Transition and Upper Austral zones. Adult. — Pale yellowish, slightly smaller and more delicate than the house fly; eyes green, legs yellow, wings cross-banded; active and restless. May and June. Mating period 33 days; preoviposition period 6-10 days. One brood a year. Eggs. — Elongate, oval, whitish, }y<25 J^ich long; placed under skin of fruit by long ovipositor. Female may lay about 200 eggs. Hatch in 4-7 days. Larva. — Burrows within the fruit, destroying seeds and kernel. Infested berries show discolored spots, become deformed and usually fall early. Matures in 3 weeks; J^ inch long, white with black mouth- parts. Leaves the fruit and enters the ground to pupate. Pupa. — Puparium broadly oval and straw colored, in the ground. Hibernates. Duration lo-ii months. Control— KWo^ poultry to run , ^^c- l^l'-^ ^^^fJ^ white-banded ^ •' cherry fruit fly. Much enlarged. among the bushes to pick up fallen {After Caesar.) infested fruit; spray bushes with a sweetened poison of sodium arsenite and diluted molasses to kill adult flies at intervals of a week beginning early in May. A heroic but effectual method is to pick entire crop of fruit and destroy it before the maggots emerge. White-banded Cherry Fruit Fly (Rhagoletis cingulata Loew.). Adult. — A small blackish fly, smaller than the House-fly, % inch long, expanding ^^ inch; pale yellow spot on hinder part of thorax and a yellowish stripe along each side of thorax; head yellow, eyes gold-green; legs yellow, abdomen crossed with 3 or 4 white bands. Wings with four brown cross bands, and a black spot at tip. June (Fig. 167). ^^Z^' — Egg-laying begins about 11 days after emergence of flies. 266 ECONOMIC ENTOMOLOGY Eggs inserted under the skin of cherries; small, glistening white; ellip- tical; hatch in about 5 days. Larva. — One-fourth inch long, white or cream-colored, cylindrical, tapering. Twelve to 22 days in fruit; destroys the pulp. Leaves the cherry when full grown. Pupa. — Puparium formed just beneath the surface of the ground; brown; hibernates. Black -bodied Cherry Fruit Fly {Rhagoletis fausta O. S.). — (Consult Bull. 227, O. A. C, 1915.) Adult. — Larger than preceding; black with- out white cross-bands on the abdo- men; head, eyes and legs similar to those of cingulata but bands on wings darker and differently arranged (Fig. 168). Eggs and Larvce. — Similar to those of cingulata. Pupa. — Puparium cream or straw colored. Control. — Spraying with sweet- ened arsenate of lead solution (2 to 3 lb. arsenate of lead (paste), 40 gal. of water and i gal. of cheap molasses) when the flies begin to emerge about June loth, and again 10 to 12 days later. Apple Maggot or Railroad Worm (Rhagoletis pomonella Walsh). — (Consult Rep. Maine Ag. Exp. St., 1889; Cir. loi. Bureau of Ent., U. S. Dep. Agr.; Bull. 171, N. H. Ag. Exp. St.; Bull. 324, Cornell Ag. Exp. St.; U. S. Dep. Ag., Bull. 9.) This maggot is a serious pest of apples in N. E. districts. It is probably a native species, and occurs widely in both the United States and Canada on apple, crab- apple, haw, and huckleberry. Perhaps most common on sweet and sub-acid varieties of apple. Adult. — A small fly, a little smaller than the house-fly; blackish, with yellow head and legs; eyes green; 3-4 white bands (3 in male and 4 in female) across the abdomen; wings marked by four dark irreg- ular bands. July and later, each female capable of laying 300-400 eggs; uses sharp ovipositor to puncture the skin of the fruit. Pre- oviposition period may be as short as one week or less, but usually longer than a week (Fig. 169). Fig. 168. — A female black-bodied cherry fruit fly. Much enlarged. {After Caesar.) CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 267 Eggs. — Elliptical, yellowish, pedicellate, J'30 ^^^^ lo^^g) l^-id singly just under the skin of the apple; hatch in 4-10 days. Larva. — A small plump white legless maggot, J^ inch long; mouth- parts with a pair of small black rasping hooks; caudal end truncate; Fig. 169. — A female of the apple maggot fly {Rhagoletis pomonella). (After W. H. Brillain.) M uch enlarged. makes soft discolored trails and corky strands in the pulp; full grown in 4-6 weeks, or when the infested fruit is ripe. Infested apple usually falls, and larvae leave the fruit i to 4 weeks later to enter the ground (Fig. 170). Fig. 170. -A parasite of the apple maggot {Biosleres rhagolelis) . W. H. Brillain.) Enlarged. {After Pupa. — Puparium just beneath the surface of the ground in which the pupa rests all winter, and in some cases the following year. Some flies emerge in September from early pupae. 268 ECONOMIC ENTOMOLOGY Life-history. — Hibernates as pupa in the ground; adults begin to emerge in July, and appear irregularly later; maggots hatching from the eggs tunnel in the flesh of the fruit, sometimes close to the surface. They mature in 4-6 weeks, and make their way out of the apple to the ground, the time (i to 4 weeks) depending on variety of apple — a short time (3 days) in early apples. Infested fruit usually falls. There is but one generation each year. '' Some forms require an extra year for the pupal stage" (O'Kane). Control. — Apply arsenical or poison-bait spray in early July for adults; collect fallen apples; allow hogs the run of the orchard. Records Locality Emergence of adults Oviposition Larval period Second brood adults Authority Ithaca. N. Y. . . Durham, N. H.. June IS 1910, July 9 1911, June 26 1912, June 28 1913, July 10 1912, July 6- Aug. 20 i9iS,July 27 —Sept. 29 1916, July 18 -Sept. 18 July 4 July 4- Sept. 18 July 20 July 27-Sept. II July 25-Sept. 12 July 4 (12-32 days) 30 days more or less Some flies emerge in Sept. None Illingworth O'Kane. Ross Ont. Windsor. N. S... 4 weeks + None Brittain MUSCIDiE (MUSCIDS) Common Genera (Figs. 171 and 172): A. Proboscis long, slenc^er, directed forward, adapted for piercing; arista pectinate (rays on one side only). B. Palpi nearly as lohg as proboscis. — Hamatohia (Lyperosia). BB. Palpi much shorter than proboscis. — Stomoxys. A A. Proboscis not elongate; labclla fleshy and not adapted for piercing. B. Arista plumose; hypopleura? with a vertical row of bristles; eyes bare; vibrissal angle distant and above oral margin. C. Thorax and abdomen with depressed yellow woolly hairs among the bristles; sternopleurals arranged i : i. — Pollenia. CC. Thorax and abdomen without such hairs; sternopleurals arranged 2:1; mesonotum distinctly striped; bright metallic. — Chryso- myia. BB. Arista plumose; hypopleurae without a row or tuft of bristles. CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 269 C. Last section of fourth vein (Mi+j) with a rounded angle.— M usca. CC. Last section of fourth vein curved forwarrl, often sh'ghtly, beyond J^nf 6as,e ~» — - — • ^Transverse suture , ^ a. idc. ...pj^s.. ._ e.dc » -• — V....e-^9. :m ta — • — sa. •Oce/far u^q. idc anterior dorso centrals .idc ■■ inner •• ia 'intraalar h liumerals p.h post " :>cace//um )p(jQ posterior dor^so centrals ''pidc ■' inner •• i.a. intraalar pra prealar = anterior sa sa supra alar - AL ower squama. = '^^'Xsquamula thoracal is I sa.-'l^^^^^ squama, = ■ ^{squamula a/aris Vertical -Ocelli Ybltals -Antenna y/drissal ridges Oral margin Vibrissa _ Palpus ■Proboscis Fig. 171. — Dorsal aspects of the thorax, and frontal aspect of the head of a muscoidean fly, with designations of the parts commonly used in taxonomic work (.After Riley and Johannsen, Comslock Pub. Co., Ithaca, N. Y.) its middle or at the tip, the cell broadly open; the first longitudinal vein (Ri) ending beyond the middle of the wing.—Muscina. BBB. Arista plumose; hypopleuraj and eyes as in B; vibrissal angle near oral margin. 270 ECONOMIC ENTOMOLOGY ('. Mc'SoMoliini llatLciicd bcluiul Llic Iransvcrsc suture; posterior dor- socTiilral and acrostichal bristles inconstant and uncfjually developed. — riwrniia. CC. Mesonotum not llattcncd l)eliind tlie transverse suture; posterior dorsocentral and acrostichal bristles well developed and constant. J). Cheeks hairy; third lonj?i(udinal vein (K41&) spinulose at base only.-- Call ip/iora. 1)1). CMieeks bare; third longitudinal vein (R41-1.) spinulose. — Lucilia. •Transverje sutur ,Post alar callus Propleura Front coxa Haltere Hind coxa Middle coxa Fir.. 172 — Lateral view of the thorax of a niuscoiilean lly, with designations of the parts commonly used in ta.xonomic work. (Aflir Riley and Johannsen.) House-fly {Must a domestica Linn.). — A cosmopolitan insect dangerous lo luiinan life. A carrier for typhoid fever, tuberculosis, (l)'senlery and other diseases (Fi^. i7.0- Adult. — A two-winged lly with four black lines on back of thorax; brislle of antennai feathered; vein ending near lij) of wing distinctly elbowed; no bristles on abdomen except at the tip. Mouth-i)arts used for sucking not for piercing, retractile; mouth-j)arts and feet specially adapted for carrying micro-organisms. Each foot with two claws and two sticky pads. Egg-laying begins 10 14 days after adult emerges from i)uparium (Fig. 174). Eggs. — Minute, glistening white, long ovoid, J^ inch long. Laid in irregular small clusters. Each female la>'s about 120 eggs at a time CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 27 1 and may lay several times; hatch in about 8 hours in midTSummer. Laid in horse manure, i>ig manure, and to a less extent in other manure, human excreta, in decaying grain, moist bran, moist mixtures of hay and grain from feed troughs, in excreta-soiled straw, decaying kitchen refuse, rotting fruits, vegetables, in ensilage. Fig. 173. — The common house-fly (Musca domestica). Puparium at left; adult next; larva and enlarged parts at right. All enlarged. {After Jloward.) Larva. — At first glistening white; two moults; duration about 5 days; yellowish when full grown, slender in front and truncate behind; a large hook above the mouth; active. Develops in horse manure and other filth in substances more or less alkaline. Pupa. — Puparium nearly cylindrical, dark chestnut; duration 3-4 days. Duration of life-cycle 10-14 days. Prob- ably seven to ten generations develop be- tween April 15th and October loth. Jt hibernates as larva or pu[)a in the South but pro]>ably more commonly as adult in the North. (Consult Howard's and Hewitt's books on ''House Flies.") Stable Fly {Stomoxys calcitrans Linn.). — Occurs in stables, yards, shady groves, dwellings, etc. Adult. — Resembles house-fly, but has piercing mouth-parts; bright golden tinge at front end of median, light stripe on thorax; six black lines on thorax; dorsal surface of abdomen with a number of nearly round dark spots. Bite severe but not poisonous. A carrier of disease; breeds in moist straw and hay. Fig. 174. — Extremity of tarsus: e., empodium; p., pulvillus in A, Jiihiu; Ji, Musca. 272 ECONOMIC ENTOMOLOGY Eggs.. — Laid in an irregular heap of about 100 on manure and gar- bage; similar in form to those of House-lly; hatch in 2-3 days. Larva. — Similar in form to that of House-fly, but more trans- lucent in appearance. Duration 10-20 days. Pupa. — Duration 6-20 days; puparium reddish-brown, elongate- oval, Js inch long. This fly occurs in the open, but often enters houses; breeds rapidly in oat-straw and other organic refuse. Winters as pupa! or larva. Control. — Apply 0.62 lb. borax to every 10 cu. ft. (8 bushels) manure, on removal from stables, with a flour sifter or fine sieve, particularly about the edges of the pile, and sprinkle 2 or 3 gal. water over the heated manure; use fly-traps. (Consult Farmers' Bulls. 540, 734 and 851, U. S. Dep. Agr., 1913.) Horn Fly {Hccmatobia serrata Rob.-Desv., Ly per osi a irritansLinn.). — (Consult Circ. 115, Bur. Ent., U. S. Dep. Agr.) Introduced into U. S. about 1886 from Europe, and has spread rapidly since. Adult. — Similar in shape and color to House-fly, but about half as large. June-September. Eggs. — Laid singly in fresh cow manure in day time, irregular, oval, light reddish brown. Egg-laying begins soon after adult emerges. Larva. — White, J^ inch long; full grown in 4-6 days. Pupa. — Puparium dark brown, eflipsoidal, J^ inch long; pupal stage lasts 5-10 days. Probably 6-8 generations in a season. Control. — (i) Killing the maggots by the introduction into the man- ure of limfe and other drying and destructive agents; (2) application of creolin compounds in the form of spray, or kerosene emulsion solution, or a mixture of 3 2 g^^- ^^h oil, ^ 2 P^^^^ coal oil, 4 tbspfls. crude carbolic acid applied with a cloth rubbed over the parts attacked. The main factors limiting the number of the common flies are: (a) The destruction of the larvae and pupae by braconid and chalcid parasites; (b) The lack of food for the larvae; (c) The enemies of the adults; {d) Weather conditions — oppressive sultry weather; cold, wet and windy weather; acting on the adults, and preventing the emergence of adults from the pupae. CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 273 The Screw-worm Fly (Chrysomyia macellaria Fab.) occurs as far north as Canada but is of importance economically in the south- western States as a pest of stock. The adult is larger than the house-fly, of a dark bluish-green color, with three distinct black stripes on the thorax. The eggs are laid in irregular masses upon dead animals and in wounds. The maggots bore into the carcass or fiesh, often causing death. (See Farmers' Bull. 857, U. S. Dep. Ag.) Blue Bottle or Green Bottle Flies. — Two or three common species of these flies occur which are also known as Blow, Green or Blue Bottle Flies. Meat Fly, or Blue Bottle, or Blow Fly (Calliphora vomitoria Linn.) . — - A large blackish fly with bluish abdomen and black spines on the thorax. Its eggs are laid on meat and dead animals, and each female may lay 400 to 600 eggs, which hatch very soon after deposition. Duration of a gen- eration 22 to 23 days. C. erythrocephala Meig. is another common species with a pre-oviposition period of 12-17 days, an active larval stage of 3-4 days and a pupal stage of 7-9 days. Green Bottle Fly (Lucilia c(Bsar Linn.). — Similar in habits to Meat Fly, with pre-oviposition period of 1-3 weeks, active larval stage of 2-5 days and a pupal stage of 5-16 days. Hibernates as larva and pupa. Phormia regina Meig. is a large black fly seen in early spring in houses, and breeds in garbage. Large Blue Bottle Fly {Cynomyia cadaverina Desv.) frequents pantries. Lays eggs on meats — smoked, uncured and cooked. Pre- oviposition period i to 3 weeks, larval period 5-40 days, and pupal stage 1-8 weeks. The Cluster Fly (Pollenia rudis Fabr.) and Muscina stahulans Fall. are also dangerous as disease carriers (see Part I). The former is found in early spring and late autumn crawling sluggishly about, often collecting in large numbers in and about houses. It has short curly yellow hair on dorsum of thorax. Probably breeds in manure and garbage. ANTHOMYIDiE (ANTHOMYIDS) Root Maggots (Phorbia spp.). — Three spec'es of root maggots are commonly injurious to root crops — Cabbage Root Maggot, Onion Maggot and Seed Corn Maggot. Cabbage Root Maggot {Phorbia brassicce Bouche). — A widely dis- tributed insect, introduced from Europe. 18 274 iicoNoMU' i;n lOMOl.OC.Y l»l;i( kisli, rnllu 1 hro.id hands on hark ol" (horax and a dark siripc alon^ hai k (>r ahdoiucn; a iiiinihci ol" slilT hairs on hody and Ic^^s; cyrs iimI- * \ i^ 1 % . I''n.. I'/S- Male el llu- f.ibliar.i" i""i>l inar.f.ot. Hv. I'liiIarjM'tl alxuil, .{ I.imcs. (1'IhUo by J. v. Witil.viCitilli. Mli-r iiih.siHi untl Tichi-nu-, Unl. i.'., I'.nt. I>r. l)■•• I'^-nlarKi'tl aboul. .i I iim>s. (I'liolo hy J. r. WaiLsicorlh.) AjUr ilih.soii ami lirlin-nr. Hid. l->, hint. Br. l>l'; ''iii''; sliowiu}.^ arraiiK<*m<',nt of flr;;liy tuln;r(.l«;s and central spiracle:;. All nnii h (tnl;u>M;(|. (Ajicy (iilr.un and 'J't't:ltU|)aria in the soil. In 15 days or so the adults appear in late June and July to lay eggs for a se(ond brood. The imnibcr of broods is uii((i "single-j)ly tarred felt" j)aj)er disks when young plants are set out; use cheese doth frames as screens; |)l.'uil trap-crops; api>ly white hellebore or j)yrethrum either as dust or as solution; use carbolic wash; use corrosive sublimate solution (4 oz to 50 gal. water). Jn the case of the last three insecticides, treatment should be made when the plants are set out and repeated once a week for 5 weeks. Jinemies. — Baryodma onlarionis, a Staj>hylinid; Colhonaspis gilleUci Wash., a ('ynipid; and 'rrombidlum sj)p. (Consult Ikill. j2, Va\\.. lir. 276 ECONOMIC ENTOMOLOGY Dep. Agr. Canada, 1916; Bull. 419, N. Y. Agr. Exp. Stn.; Cornell Univ., Bull. 78.) Onion Maggot (Phorbia ceparum Mg. = Hylemyia anfiqua Mg.). Adult. — Slightly larger than Cabbage Root Maggot Fly; body and legs with many black bristles; back of thorax of male with four indistinct dark colored bands; abdomen with a distinct blackish band down the middle; May- June. Probably three broods a year. Pre-oviposi- tion period about 10 days (Fig. 180). Fig. 179. — Onion maggot {Phorbia ceparum), female and head of male. Eggs. — Cylindrical, white, distinctly ridged; groove not so deep or long as in P. brassicce; duration 3 to 4 days. Larva. — White, cylindrical, rounded, truncate at posterior end; % inch long; central tubercles of blunt end single-pointed, with a pair of additional tubercles. Duration 2-3 weeks, occasionally 4-5 weeks. Young larva works its way down within the sheath of the plant to the forming bulb, in which it feeds. Pupa. — Puparia formed in soil or in outer layers of onion. Found iJ^-3 inches below the surface. Summer duration about 2 weeks; hibernates. CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 277 The Barred-winged Onion Maggot {Chaitopsis (jenea Wied.) is also injurious to onions (Michigan). Control. — Apply poisoned bait spray composed of sodium arsenite and molasses to kill adults; apply hellebore, pyrethrum and carbolic wash. Seed Com Maggot (Fhorbiafusciceps Zett.). — (Consult Bull. 12, Ent. Br. Dep. Agric. Can.). Injurious frequently to beans, peas and corn. Adult. — Smaller than Onion Maggot Fly, 3^:5 inch long; bands on back of thorax indistinct, those on abdomen distinct; inner side of pos- terior tibiae of male with a row of short bristly hairs. Body of female pointed, eyes widely separate. June- July. Eggs. — ^Laid on or about the seed in the soil, or on the seedhng. Larva. — Smaller than Cabbage Root Maggot or Onion Maggot, 3-:^ inch long; whitish, cylindrical, footless, blunt at caudal end and pointed at the head. Caudal tubercles simple, rather close together with a trace of additional tubercles. Feeds mostly on the seed. Pupa. — Puparium }i inch long, light brown to dark reddish-brown; duration 12 days. Number of generations not yet known. Injury seems most severe when a wet period follows immediately after planting the seed. Control. — Difficult. Use mineral fertilizers; carbolic acid emulsion. Raspbeny Cane Maggot (Fhorbia rubivora Coquillet). Adult. — A grayish-black fly, smaller than the house-fly. April. Eggs. — White, elongate, H5 inch long, laid in the axil of young leaves at the tip of shoot. Hatch in a few days. Larva. — Maggot bores into the pith of the shoot, and tunnels downward, making a tortuous path. About halfway down it girdles the wood beneath the bark. It continues burrowing downward and becomes full grown in June. Wilting occurs in May. Pupa. — Formed at lower end of burrow in June and July. Control. — Cut off and burn the wilting canes as soon as observed. Beet Leaf Miner {Pegomyia vicina Lintner). — It is sometimes de- structive to beets in late fall. Whitish blotches are formed on the leaves. There are several generations each year, and the winter is passed in the pupal condition under fallen leaves or in the soil. The eggs are placed on the lower side of the leaves, and the maggots mine in the leaves; life-cycle about a month. Control. — Pick and burn infested leaves where practicable; use 278 ECONOMIC ENTOMOLOGY spinach as a trap crop; plow deep and harrow as soon as crop is removed. Lesser House-fly {Homalomyia canicularis Linn.). — This fly is smaller than Musca domestica, and may be observed in houses in early summer. As an Anthomyiid it can be readily distinguished from the true muscids by the venation of the wings. In this species the middle tibiae are without a tubercle. The larva, 3^:5 inch long, is markedly different from that of Musca. It has a flattened body with a double row of spiny processes. It lives in waste vegetables and animal matter, and no doubt is responsible Fig. 180. — The little house-fly {Homalomyia hrcvis). Female at left; male next, with enlarged antenna; larva at right. All enlarged. {After Howard.) for the transmission of certain diseases. It becomes full grown in about a week, sometimes prolonged to 3 or 4 weeks. The Little House Fly {Homalomyia brevis Rond.) occurs about outbuildings and breeds in human excrement. It acts, no doubt, as a disease carrier (Fig. 180). The Latrine Fly {Homalomyia scalaris Fab.) is also under suspicion as a carrier of contagion. Middle tibiae with a tubercle. TACHINID^ (TACHINA FLIES) These flies are useful in that the larvae or maggots are parasitic within the bodies of injurious caterpillars. The female tachina fly lays her eggs upon the caterpillar or upon the leaves of the food plant, and the maggots on hatching bore their way through the walls and CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 279 live within the body until full grown. Tachina flies resemble house- flies but are usually more bristly and hairy. The bristles of the antennse are entirely bare. They are frequently found about flowers and rank vegetation. Besides caterpillars, such as army-worms and cutworms, locusts, leaf-eating beetles and other injurious forms are kept under control by tachina flies. HIPPOBOSCID^ (SHEEP TICKS) Sheep Ticks {Melophagus ovinus Linn.) are wingless, brownish flattened blood-sucking insects belonging to the sub-order Pupipara. They are often very injurious to lambs in spring after shearing time. Sheep should, therefore, be dipped twice after shearing in some good "dip," of which several kinds are on the market. (See Farmers' Bull. 798, U. S. Dep. Agr.) Life-history. — Each female produces 5 to 8 nearly full grown larvae which become brown puparia in about 12 hours. Eggs are not pro- duced. The adult tick emerges in 19-24 days after the deposition of the pupa, and reaches sexual maturity 3 or 4 days later. In 8 to 10 days after fertilization the female deposits the larva. ORDER SIPHONAPTERA (FLEAS) Pulicidae (Fleas). — (Consult Farmers' Bull. 897, U. S. Dep. Ag.) Two species of fleas are found infesting houses: the Human Flea (Pulex irritans) most commonly found on the Pacific Coast, the Cat and Dog Flea (Pulex serraticeps) in the eastern part of the continent. Fleas are most numerous in sandy regions and in rainy seasons. Htiman Flea (Pulex irritans Linn.). — Secretes itself in bedding and clothing, and attacks its human victims at night. Adult. — Body compressed; wingless; legs long and stout; tarsi 5- join ted, and mouth-parts adapted for sucking; antenna small, eyes simple. Eggs. — ^Laid in dust or lint under carpets and other out-of-the-way places, whitish and ovoid; in summer hatching in 4 to 6 days. Each female lays 8 to 12 eggs. Larva. — ^Lives and feeds in dust or Htter; slender, worm-like, footless, sparsely haired; fuU grown in summer in about 11 days, but may be prolonged to several months. 28o ECONOMIC ENTOMOLOGY Pupa. — Formed where larva lives, often enclosed in a small silk cocoon, covered with dust. Duration about 12 days in warm con- ditions, but may be more than a year under unfavorable conditions. Cat and Dog Flea {Pulex serraticeps Gerv. = Ctenocephalus canis Curtis). Adult. — ^Like that of House Flea but with a comb of spines on border of head and pronotum. Adheres quite closely to its host. Eggs. — ^Laid loosely among the hairs of host; small white and oval; hatch in about 2 weeks. Collect on mats. Larva. — At first white, footless, maggot-like; head pale yellow; feeds on decaying particles of animal and vegetable matter; matures in summer in about 12 days. Pupa. — Duration 12 to 16 days in summer in a cocoon. This flea may be found in winter in any of the stages. Several broods each season. Control. — Bathe the animals frequently in a 3 per cent, creolin solution (4 teaspoonf uls to a quart of water) ; provide them with sleep- ing mats and have these mats beaten or shaken regularly once a week; keep the kennel clean; dust fresh pyrethrum thoroughly among the hairs of the animals and on the floors; remove carpets or mats and give floors a thorough cleaning with soapsuds and later with benzine; dust powdered alum upon the carpets, etc. Treatment of bites with a 3 per cent. carboHc acid solution, menthol, camphor or carbolated vaseline will allay the irritation. COLEOPTERA (BEETLES) Chief Groups of Beetles A. Head of the ordinary form, not prolonged into a narrow beak; maxillae divided; palpus flexible, usually 4- join ted; larvae rarely without legs. — Tyue Beetles (Fig. 181). B. All tarsi with the same number of segments. — Isomera. C. Fourth and fifth tarsal segments not grown together. — Pentamera (Fig. 182). D. First three ventral segments of abdomen grown together; most with thread-like antennae. — Carnivora or Fredaceous Beetles. DD. First ventral segments of abdomen not grown together. E. Antennas club-shaped. — Clavicornia or Club-horns (Fig. 183). EE. Antennae serrate. — Serricornia or Saw-horns {Fig. 184). CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 28 1 EEE. Antennae lamellate. — Lamellicornia or Leaf-horns (Fig. 183). CC. Fourth and fifth tarsal segments grown together; antennas bead-like. — Phytophaga or Plant-eaters (Fig. 184, A). ^•13 Fig. 181. — Ventral aspect, of a carabid beetle {Galerita janus) . i, Prosternum; 2, proepisternum; 3, proepimeron; 4, coxal cavity; 5, inflexed side of pronotum; 6, mesosternum; 7, mesoepisternum ; 8, mesoepimeron; 9, metasternum; 10, ante- coxal piece; 11, metaepisternum; 12, metaepimeron; 13, inflexed side of elytron; a., sternum; an., antenna; c, coxa;/., femur. (After Folsom.) CCC. Tarsi 3-jointed; antennae clavicorn. — Trimera Coccinellida, p. 281. BB. Fore and middle tarsi 5-jointed and hind tarsi 4-jointed. — Heteromera. A A. Head often prolonged into a beak; maxillae undivided; palpi rigid and not more than 3-jointed; larvae legless. — Rhyncophora or Snout Beetles, p. 328. 282 ECONOMIC ENTOMOLOGY Chief Families of the Carnivora Group: A. Legs adapted for running; terrestrial; antennae ii-jointed. B. Antennae inserted on front of head above the base of the mandibles. — Cicindelidce (Tiger Beetles), p. 284. BB. Antennae inserted on sides of head between the base of the mandibles and the eyes. — CarabidcB (Ground Beetles), p. 285. A A. Legs adapted for swimming; aquatic. B. With only two eyes. — DytiscidcB (Diving Beetles). BB. With four eyes. — Gyrinidce (Whirligig Beetles). y^^^^mm/ Tib, Fig. 182. — Tarsi of coleoptera. A, Leptinotarsa; B, fore leg; D, Tenehrio, hind leg. Coccinella; C, Tenehrio, Chief Families of the Clavicornia Group: A. Legs fitted for swimming; aquatic. — Hydrophilidce (Water-scavengers). AA. Legs not fitted for swimming; terrestrial. B. Elytra short. — Staphylinidce (Rove Beetles). BB. Elytra as long or nearly as long as body. C. Abdomen with 5 ventral segments. — Dermestidce (Larder Beetles), p. 291. CC. Abdomen with 6 or more ventral segments. — Silphidce (Carrion Beetles), p. 293. CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 283 Chief Families of the Serricornia Group (Fig 184) : A. Head inserted in thorax up to compound eyes. B. First two segments of abdomen fused together on ventral side. — BuprestidcB (Metallic Wood-borers), p. 300. BB. First two segments of abdomen not fused. — Elateridce (Click Beetles), p. 293. AA. Head not inserted in thorax up to compound eyes. B, Head normal or bent, but partially covered by the margin of thorax. C. Elytra flexible; body elongated and flattened. — Lampyrida (Fire Flies). CC. Elytra firm; body not much flattened. — Cleridce (Checkered Beetles). ^ Fig. 183. — Forms of antennae of beetles, 1-9, clavate; 10, 12, 13, lamellate; moniliform. (After Leconte and Horn.) II. BB. Head bent nearly at right angles to thorax; size small— Ptinidcs (Death Watch Beetles, etc.), p. 327. Chief Families of the Lamellicornia Group: A. Antennae elbowed; lamellce fixed. — Lucanidce (Stag Beetles), p. 318. AA. Antennae not elbowed; lamellae not fixed. — ScarahczidcB (Leaf Chafers), p. 302. Chief Families of the Phytophaga Group: A. Body and antennae short. B. Front of head prolonged into a broad, quadrate, beak; elytra short; seed eaters. — Bruchidce (Pea- weevils), p. 319, BB. Front of head not prolonged into a beak; elytra long; leaf-eaters. — ChrysomelidcB (Leaf Beetles), p. 306. AA. Body and antennas long. — Ceramhycidce (Long-horned Beetles), p. 320. Chief Families of the Heteromera Group: A. Head with distinct neck; body soft and elytra flexible. — MeloidcB (Blister Beetles), p. 325. AA. Head without distinct neck; body wall hard. — Tenehrionida (Darkling Beetles), p. 328. 284 ECONOMIC ENTOMOLOGY Chief Genera of the Rhyneophora Group: B. Beak short and broad; anteniiit short, gcnicuhite and ckibbcd; tibia* often with several teeth externally; head narrower than prothorax; ej'es oval, emarginatc or divided; first tarsal joint much shorter than combined length of the others. — I pidec (Bark Beetles), p. 339. BB. Beak usually long and well developed; palpi small and concealed; antennae usually clubbed; tibine without teeth externally; submentum produced into a gular peduncle. C. Dorsum of last segment of male divided transversely. D. Mandibles with a scar on anterior aspect. — Otiorhynchidce, P- 3?>^- DD. Mandibles without scar on anterior aspect. — Curculionidce (Curculios), p. 329. CC. Dorsum of last segment of both sexes undivided; tibix not serrated. — Calandrid(C (Clrain Weevils), p. 337. ^^113 Fig. 184. — Serrate antennae and modifications: i, serrate; 2, pectinate; 3, bi- pectinate; 4, flabellate; 5, plumose; 6, 7, 8, irregularly serrate, approaching the clavicorn type. {After Leconte and Horn.) CICINDELIDiE (TIGER BEETLES) Tiger beetles, both adult and larvae, are predaceous, feeding upon caterpillars and other unwary insects. The adults are active, alert creatures, and are most commonly observed on sandy grounds and roads. They are brilliantly marked with metallic colors. The larvae live in vertical burrows and there lie in wait for their prey. They have . strong jaws and large dirt-colored heads, and the fifth abdominal segment bears a hump with two backward-curved hooks which serve to anchor their owners in the burrows. The majority of the species belong to the genus Ciclndela, and the most abundant forms are C. sexguttata Fab., C. vulgaris Say, C. repanda Dej., C. hirticollis Say, and C. punctulata Oliv. CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 285 CARABIDiE (GROUND BEETLESj Common Genera (after Leconte and Horn) : A. Middle coxal cavities entirely closed by the sterna (Fig. 185). B. Head with two punctures above the eye, each bearing a single bristly hair. C. Margin of elytra interrupted at posterior end and with a distinct internal fold; three basal joints of antenna glabrous. D. Last joint of palpi as long as or longer than the next to the last and cylindrical. — Plcrostichus. DD. Last joint of palpi shorter than the next to the last. — Amara. CC. Margin of elytra not interrupted posteriorly and without an internal fold. D. Penultimate joint of labial palpi with but two bristly hairs; elytra truncate at tip; front tibiae slender; tibial spurs short, head constricted behind the eyes. — Lebia. Pig. 185. — Prosterna of beetles. A, Coxal cavities (CC) confluent and open behind; B, coxal cavities Separated and open behind; C, coxal cavities separated and closed behind. (After Wickham.) DD. Penultimate joint of labial palpi with a number of bristly hairs in front and always longer than last joint; first antennal joint elongate; head elongate-oval, prolonged behind the eyes. — Galerita. BB. Head with but one bristle-bearing puncture above the eye. C. Elytra truncate at apex; mandibles with a bristle-bearing punc- ture in outer groove; hind coxse often separated. — Brachinus (Bombardier Beetle). CC. Elytra always entire; mandibles without a bristle-bearing puncture; hind coxa? contiguous. D. Antennae with only two basal joints glabrous; black, front tarsi of male dilated and with two rows of small scales beneath; first joint of hind tarsus not longer than the two following. — Harpalus. AA. Middle coxal cavities not entirely closed by the sterna (Fig. 185). B. Hind coxae not separated; labrum not forked; third joint of antennae cylindrical. — Carabus. BB. As in B, but third joint of antennae compressed. — Calosoma. 286 ECONOMIC ENTOMOLOGY Ground beetles are common insects and, with two or three exceptions, prey upon injurious forms and do not feed upon fruits, leaves or seeds. (See Part I, Beneficial Insects.) Following are the species most com- monly met with: Some Common Carabids Murky Ground Beetles: Pterostichus lucuhlandus Say. — Color usually green or bluish, not polished; length 10-14 mm.; thorax widened posteriorly; striae of elytra Fig. 186. — A carabid beetle {Pterostichus lucuhlandus) . {After Gibson and Treherne, Ent. Bui. 12, Dep. Ag. Can.) smooth; 4 dorsal punctures; legs usually reddish; under surface punc- tured; three basal joints of antennae distinctly carinate; basal impressions of thorax double (Fig. 186). Galerita janus Fab. — Black, clothed with short hairs; length 17- 22 mm.; legs, palpi, thorax and base of antennae reddish-brown; head black, strongly constricted behind; prothorax half as wide as wing- covers; elytral striae fine not punctured. Lebia grandis Hertz. — ^Length 9 mm.; head and thorax reddish-yel- CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 287 low; under surface and legs pale brownish-yellow; abdomen black; elytra dark blue and deeply striate; antennae pale; head finely wrinkled; tarsal claws comb-shaped; tibial spurs short; thorax but little wider than head and much narrower than elytra. Harpalus caliginosus Fab. — Pitchy black, length 21-25 mm.; an- tennae and tarsi reddish-brown; legs black, thorax broader than long, narrow in front, as broad as base of elytra nearly square; elytra deeply striate and without a dorsal puncture on third interval, and sinuate at tip. A seed-eater. Harpalus pennsylvanicus Dej. — Black, length 13-15 mm,; antennae and legs reddish-yellow; under surface reddish-brown to piceous; sides of thorax gradually curved; region of basal angles strongly de- pressed, densely punctate; mentum toothed. Metallic Ground Beetles : Calosoma scrutator Fab. — (Searcher). Length 28-30 mm.; disk of thorax blue; margins reddish-bronzed, sides and angles rounded; legs blue, abdomen green and red; elytra metallic green with red margin, striate, punctured; third joint of antennae compressed. Calosoma calidum Fab. — (Fiery Hunter). Length 22 mm.; black above and below; elytra black with six rows of golden spots, deeply striate and finely punctate; head and thorax finely rugose; third joint of antennae compressed. Calosoma sycophanta Linn. — A European form imported to combat the Gypsy and the Brown-tail moths. Both larvae and adults are predaceous and freely climb trees in search of their prey. The eggs are deposited in the earth and the mature larvae seek the earth again and construct pupal cells. The adult beetles emerge late in the spring. They are about an inch long, and of a beautiful green color. (See Bull, loi, Bur. Ent., U. S. Dep. Ag.) COCCINELLIDiE (LADY-BIRD BEETLES) (Consult Bull. 181, Conn. Agr. Exp. St. and "Coleoptera of Indiana.") Lady-bird beetles are essentially feeders on plant-lice and scale insects; both as adults and larvae; hence are of great economic impor- tance. (See Part I, Beneficial Insects.) Common Lady-birds: Two-Spotted Adalia (Adalia bipundata Linn.). — Wing-covers red with a black spot in the centre of each; thorax black-margined with 288 ECONOMIC ENTOMOLOGY yellow; head black with two yellow spots between eyes; legs and under side of body black. Feeds on plant-lice. Common. Egg stage lasts about a week, larval stage about 3 weeks, and the pupal stage about a week. One-eighth to one-fifth inch long (Fig. 188). Twice-stabbed Chilocorus {Chiloconis hivulnerus Muls.). — Wing- covers black with a red spot near centre of each; head, thorax and legs black; under side of thorax black, and abdomen red. Larva spiny; pupa black and spiny. Feeds on scale insects and plant-lice (Fig. 188). Two-spotted Hyperaspis {Hyperaspis signata Oliv.). — Wing-covers black with a red circular spot and a smaller yellowish spot on each; thorax Fig. 187. — The 15-spotted lady-bird in all its stages. Enlarged about 3 times. {After Brilton.) and head black. In male the head and margins of thorax yellow. Larva white and woolly. Feeds on cottony maple scale. Spotted Megilla {Megilla maculata'DeG. = Megillafuscilabris Muls.). — Wing-covers red with six black spots on each; thorax red with two triangular black spots; head black with a red median stripe; legs and under surface of body black. Larva blackish with white lines and black spots. Feeds on plant-lice. One-fourth inch long. Pitiful Lady-bird (Fentilia misella Lee). — Black, small. Feeds on San Jose Scale (Fig. 189). Convergent Lady-bird (Hippodamia convergens Guer.). — Wing- covers reddish yellow with six black dots on each; thorax black with CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 289 Fig. 188. — Lady-bird beetles: a, a 2-spotted lady-beetle (Adalia bipunctata); b, the convergent lady-beetle {Hippodamia convey gens) ; c, the g-spotted lady- beetle (Coccinella g-notata); d, twice-stabbed lady-bird (Chilocorus bivulnertis); e, the 5-spotted lady-beetle (C. $-notala). {After Briiton.) Pig. iSQ.—Pentilia misella LeC: a, beetle; b, larva; c, pupa; d, blossom end of scale infested pear, showing beetles and their larvae feeding upon the scales, all greatly enlarged. {After Howard and Mariatt. Bull. 3, Div Ent., U. S. Dept. Agric.) 19 290 ECONOMIC ENTOMOLOGY margins yellow and two oblique yellow dashes; head black with yellow between the eyes; legs and under surface of body black. Larva yellow with black spots and cross bands. Feeds on plant-lice, etc. One-fourth to one-third inch long (Fig. 188). Thirteen-spotted Lady-bird {Hippodamia ly punctata Linn.). — Wing-covers reddish-yellow marked with 13 spots; thorax black with yellow margins; head black with yellow mouth-parts. Under surface of body and femora black; tibias and tarsi yellow. Feeds on plant-lice. Fig. 190. — The squash lady-bird beetle {Epilachna borealis). Five-Spotted Lady-bird {Coccinella ^-notafa). — Wing-covers red with five black bands; thorax with front lateral margins yellow; head black with two yellow spots between the eyes; legs and under surface black. Feeds on plant-lice. One-fourth to three-eighth inch long (Fig. 188). Nine-spotted Lady-bird {Coccinella g-notata Herbst.). — Wing- covers reddish-yellow with 9 black spots; thorax black with front mar- gin or red yellow; head red or yellow; legs and under surface black. Larva with black markings on thorax and white markings^on abdomen. Feeds on plant-lice. One-fourth to three-eighth inch long. CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 29 1 Fifteen-spotted Lady-bird {Anatis 1 $- punctata 0\\y.). — Wing-covers reddish yellow with 8 spots on each; thorax black with wide white lat- eral margins with a black spot in each, and two whitish spots at poste- rior margin; under surface of body black with yellowish margins; femora black, tibiae and tarsi brown % inch long. Larva large, black with sharp spines on each segment. Feeds on plant-lice. Three- eighth inch long (Fig. 187). Squash Lady-beetle {Epilachna horealis Fab.). — A native insect occurring in the east as far north as Canada. The adult and larva of this lady-beetle feed on the leaves of cucumbers. The adult is orange- yellow with four black spots on the thorax and seven on each wing- cover. The larva is yellow and armed with six rows of forked black spines. The adults hibernate in large colonies beneath leaves on the ground (Fig. 190). DERMESTID^ (LARDER AND CARPET BEETLES) Larder Beetle (Dermestes lardarius Linn.). — Sometimes a pest in meat pantries, and where skins and feathers are kept. Adult. — Dark brown, J^ inch long, oval; a pale yellowish-brown black-dotted band across the front half of the wing-covers. Hibernates. Eggs. — ^Laid on meat, or in crevices near the food. Larva. — One-half inch long, brown above, white below and covered with long brown hairs; feeding on surface of meat at first, later burrowing into it and pupating there. Control. — Trap or collect the beetles; clean the pantry thoroughly; wrap the hams very closely; fumigate the pantry. Buffalo Carpet Beetle (Anthrenus scrophularm Linn.). — A serious pest of carpets and woolens. Introduced from Europe, where it is principally a museum pest (Fig. 191). Adult. — A stout oval beetle, ^q inch long, with black, white and red mottled wing-covers. Winters normally out of doors, under bark of trees, and other shelters. In spring it visits the flowers of spiraeas, cherries, etc. Probably two generations in the North. ^SS^' — ^Laid in convenient places on carpets or other woolens. Hatch in a few days. Larva. — A stout active grub, J^ inch long, covered with stiff brown hairs, forming tufts at the sides and at the end of body. Develops 292 ECONOMIC ENTOMOLOGY rapidly, but may be retarded by cold weather or by lack of food. Normally six moults; feeds on woolens. Pupa. — Yellowish, formed within a larval skin. Control. — Use rugs; remove and beat the carpets, and spray them with gasoline; scrub the floors with soap and water; spray floors with gasoline, and fill the cracks with putty. Black Carpet Beetle {Attagenus piceus Oliv.). — Introduced from Europe. Injury done by the larva. Adult. — A small black oval beetle, smaller than the Buffalo Carpet Beetle, }{q inch long. Eggs. — White, broadly oval; laid about the edges of the carpet or on woolens. Fig. 191. — Bufifalo carpet beetle (Anthrenus scrophularioe): a, larva, dorsal view; b, pupa within larval skin; c, pupa, ventral view; d, adult. All enlarged. {From Riley.) Larva. — A reddish-brown active grub, }i inch long, with a long bushy tail of reddish hairs; body cylindrical with closely appressed hairs. Pupa. — Duration 6-15 days; clothed with a coat of whitish hairs. A museum pest; a house pest feeding on woolens, carpets and feathers. Probably requires 2 years for life-cycle. Raspberry Byturus (Byturus unicolor Say). Adult. — A small brown dermestid beetle, 3^^ inch long; body covered with pale tawny hairs. May- July. Feeds on young leaves and buds. Eggs. — ^Laid in June on the unripe fruit, one egg on a berry and at- tached by one side to one of the carpels. Larva. — A small white plump cylindrical grub, J^ inch long; each CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 293 segment marked crosswise with a broad yellow band and many short white hairs. Feeds on heads bearing the berries. Pupa. — Yellowish, formed in an earthen cell in the ground, where it winters. Control. — ^Spray with arsenate of lead, 3-4 lb. to about 40 gal., where beetles first appear. SILPHIDiE (CARRION BEETLES) Spinach Carrion Beetle (Silpha bituberosa Lee). — The shiny black active flattened larva of this dull black beetle destroys the leaves of spinach, pumpkin, squash, beet, etc. at night. Eggs are laid in June and the grubs mature four or five weeks later. The adult beetles winter under clods, etc. S. opaca L. is also an injurious species in the West. ELATERID^ (CLICK BEETLES, WIREWORMS) Common Economic Genera (After Leconte and Horn) : A. Hind coxal plates suddenly dilated about the middle, the outer part much narrower than the inner. B. Prosternum very broad, sutures straight, side pieces of mesothorax reaching the middle coxae. — Cryptohypnus. BE. Prosternum of moderate width; sutures double and not excavated in front; third joint of antennae longer than second.— Dr aster ins. AA. Hind coxal plates gradually dilated on the inner side. B. Clypeus or front convex and truncate, its edge higher than the labrum, mouth inferior and applied to the prosternum in repose. Side mar- gins of thorax bent downward in front. — Agriotes. BB. Clypeus or front flattened; mouth horizontal or anterior. C. Front margined; tarsal claws with comb-like teeth. — Melanotus. CC. Front not margined. D. Tarsi simple, filiform. — Corymhites. DD. Tarsi with the second and third joints lobed beneath. — Asaphes. WiREWORMS The larvse of click beetles are known as ''Wire worms" of which several species are injurious to the roots of cereal crops. Perhaps the most common are Agriotes mancus, Drasterius elegans, Asaphes de- 294 ECONOMIC ENTOMOLOGY coloratus, Melanotus communis, Cryptohypmus abbreviatus, and Corym- bites spp. (Consult Bull. 156, Bur. Ent., U. S. Dep. Ag., 1915.) Adults. — Slender oval hard beetles (the ''click" or "snapping" beetles) with serrated antennae, mostly brownish in color, sometimes black or greyish, or even metallic. In Agriotes mancus Say, the " wheat wire worm," the thorax is very convex, coarsely and densely punctate, and the front or clypeus convex. It is dull brownish yellow, dusky beneath, sparsely pubescent, and about 3^^ inch long. Diasterius Pig. 192. — Agriotes mancus. (After Forbes.) Pig. 193. — Melanotus crihulosus, {After Forbes.) elegans Fabr. is dull reddish brown, about J^ inch long, sparsely pubes- cent, head black, a median black spot on thorax, a black spot in front of middle of each wing-cover, and a black cross-bar near the apex. Asaphes decolor atus Say is shining black, about half an inch long, with hind angles of thorax divergent. Melanotus communis Gyll. is about J^ inch long, dull brown, and with a more or less distinct median im- pressed line on basal half of thorax (Figs. 192-195). CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 295 LarvcB. — Slender, cylindrical, yellowish or reddish-brown, wire-like grub, mostly vegetable feeders, in the ground; more than an inch long when full grown. Require 2 to 5 years to reach maturity. Pupa. — A soft white body resembling the adult in form, in a pupal cell in the ground. Fig. 194. — Drasterius elegans. (After Forbes.) Agriotes mancus Say {Wheat Wirew or m). — Mating takes place in April and May, and eggs are laid immediately in grass lands. The larvae feed for 2 full years, pupating in July. The pupal stage lasts from 2 to 3 weeks in the pupal cell about 5 inches below the surface. Larvae have been reported feeding on the roots of wheat, corn, turnip, cabbage, cucumber and carrot; on potato tubers and on corn seed. 296 I'XONoMic 1';ni"()M()1,()(;y The ^rul) of Agriotcs manciis is cylindrical, jxilc brownish-yellow, iii^'hly polished, with two black ])ils on last segment which tapers gradually to a brown point, and about an inch long when full grown. Mclano/iis spp. {Corn, W irrwornis). Vhc larva: si)end 2 to 5 years ill the soil, and feed on corn, ana.— White. Control. — ^Spray hop vines with whale-oil soap solution (i to 5); collect by means of tarred shield and feather duster. LUCANIDJE (STAG BEETLES) Stag Beetle {Lucanus dama Thunb.). Adult. — A large brown lamellicorn beetle; male with large sickle-shaped mandibles and a smooth broad head; the female with smaller mandibles and a narrower, rough head. July-August. Eggs. — ^Large, globular, white; laid in crevices of the bark near the roots. CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 319 LarvcE. — ^Like white grul)s; live in decaying wood. .^ Pupa. — In an oval cocoon made of fragments of wood. BRUCHIDiE (PEA AND BEAN WEEVILS) Pea Weevil {Bruchus pisorum Linn.). Adult. — A small brownish black beetle, % inch long, with characteristic black and white markings; sides of thorax notched; abdomen projects beyond the wing-covers. Two black spots on uncovered portion of abdomen; an- tennae ii-jointed; hind femora thickened and prolegs with two spines. A native of the old world (Fig. 208). Eggs. — Yellow, 3-^0 iiich long, spindle-shaped. Larva. — White fleshy wrinkled grub, about 3.^ inch long when fully grown; 3 pairs of minute legs. Pupa. — White, becoming brown after thresh- ing or fumigating; thorax with notched sides; formed in the pea. Life-history. — Adult winters over and eggs are laid on the forming pods. The larva bores through the wall of the pod and enters the seed, where it feeds and grows. The pupal stage lasts about a week. Mature adults develop in August, the majority remaining in the mature seed all winter. Several grubs may inhabit a single seed. Control. — Fumigate peas with carbon bisulphide ; drench seed with kerosene; store the peas over for a season in tight sacks before planting; raise the temperature to i45°F. to kill the weevils. Bean Weevil {Bruchus obtedus Say) . A dull. — A small brown beetle, about J^ inch long, with wing-covers shorter than the body, and ''marked with ten impressed and dotted longitudinal lines which are broken up into pale yellow dashes and dark brown spots" (Fletcher); body covered with short silky hairs; tips of abdomen, antennae and legs of a reddish tinge; antennae enlarging toward the tip. Probably a native of Central or South America. Fig. 208. — Pea weevil: a, the grub; b, the pupa, under surface; c, the pupa, upper sur- face; d, the adult weevil. 320 ECONOMIC ENTOMOLOGY Eggs. — Cylindrical oval grey objects, I150 irich long; laid on or in the young pods or stored beans; hatch in 5-20 days. Larva. — A small whitish fleshy wrinkled 'grub; matures in 11-42 days. Pupa. — White and delicate; enclosed in an oval pupal chamber within the bean; duration 5-18 days. Life-history. — The larva enters the seed, where it feeds and grows until autumn when it changes to a pupa, and a little later to the beetle. Propagation may take place for several generations in the dry beans. Control. — Fumigate with carbon bisulphide or superheat as for pea weevil. CERAMBYCIDiE (LONG-HORN BEETLES) Common Economic Genera: A. Thorax margined; labrum united with clypeus; body broad and depressed. — Prionince. B. Antennae ii-jointed; body elongate, parallel. — Orthosoma. BB. Antennae 12-20- jointed; body stout, broad. — Prionus. A A. Thorax not margined; labrum free; body oblong and cylindrical. B. Front tibiae obliquely grooved on inner side; last joint of palpi pointed at tip. — Lamiince. C. Elytra spined; size small. — Psenocerus. CC. Elytra not spinose; large size. D. Scape of antennae with an apical scar; body elongate. — Monohammus. DD. Scape of antennae without apical scar. E. Tarsal claws divaricate and simple. — Saperda. EE. Tarsal claws divaricate and cleft. F. Eyes not divided; thorax cylindrical. — Oberea. FF. Eyes divided; thorax with blunt tubercle on each side and marked with four black spots. — Tetraopes. BB. Front tibiae not grooved; last joint of palpi not pointed at tip. — CerambycincE. C. Base of antennae partly enveloped by the eyes; front coxae not conical; eyes finely granulated; scutellum rounded behind; tibial spurs large. D. Head small; process between hind coxae rounded. E. Thorax transversely excavated at sides and with three yellow cross bands. — Cyllene. EE. Thorax not excavated at sides and without yellow cross bands. — Plagionolus. DD. Head large; process between hind coxae acute. — Clytus. CC. Base of antennas not enveloped by the eyes; front coxae conical. — Desmocerus. CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 32 1 Round-headed Apple-tree Borer {Saperda Candida Fab.). — This beetle is a common native pest of the mountain ash, apple, quince and pear in orchards east of the Rocky Mountains (Fig. 209). Adult. — A pretty beetle, ^ inch long, with long grey antennae; head and under side of body silvery white, upper surface light yellow- ish-brown and with two longitudinal white stripes extending through thorax and wing-covers; legs grey. Appears mostly in May, June and July, usually in day-time. Eggs. — Embedded singly in incisions in the bark, near the base of the trunk, and covered with gummy substance; pale rust-brown, oval, 3-^ inch long; hatch in 2-3 weeks. A female may deposit 15-30 eggs. Larva. — Full-grown larva is a yellowish fleshy cylindrical legless Fig. 209. — Round-headed apple-tree borer: a, b, larvae; c, female beetle; d, pupa. {Chittenden, Cir. 32, Bur. Ent., U. S. D. A.) grub, % to ij^ inch long; head small and dark; body tapering from the thorax backward. Matures in 3 years. Works in bark and sap- wood the first year forming broad, irregular, circular galleries beneath the outer bark; bores deeper in the second year, and in the third year bores upward into the solid wood and outward to the bark, and in May of the fourth year transforms to a pupa, the winter being spent in the pupal chamber. Pupa. — ^Lighter than larva, with transverse rows of minute spines on the back. Duration about 3 weeks. Control. — Probe or cut out grubs in fall; apply a carbolic alkaline 21 32 2 ECONOMIC ENTOMOLOGY wash in early June to trunks; apply protectors to trunk; spray with arsenical to kill adult. Woodpeckers destroy large numbers of the larvae. Saperda tridentata Oliv. is the well-known elm-borer. The grub girdles the tree by burrowing under the bark. Raspberry Cane-borer {Oberea himaculata Oliv.). Adult. — A slender black cerambycid beetle, }/^ inch long; prothorax yellow, with two or three black spots; antennae long, body cylindrical; June. A native American insect. Eggs. — ^Large, elliptical, yellow. Egg placed in pith of tip of cane in a slit between two ring-like cuts about an inch apart. Hatches in a few days. Larva. — A dull yellow grub with a small dark-brown head; i inch long; body cylindrical and segments connected. Burrows downward in the pith, often opening at surface of stem. Hibernates near base of stem as a larva. Pupa. — Formed in burrow in spring. Perhaps this insect requires two years to complete its stages. Wilting occurs in July-August. Control. — Cut off and destroy the wilted canes as soon as observed. Giant Root Borer {Prionus laticollis Drury) . A dull. — A large pitchy- black, long-horned beetle ; thorax with three teeth on margin ; wing-covers thickly punctate. Larva. — ^Two to three inches long; yellowish- white; a small, horny, reddish-brown head with hard dark jaws; three years; matures in June- July, boring into roots of black berry, grape, apple, and cherry. Locust Borer {Cyllene robinics Forst.). — Heartwood of infected trees shows longitudinal galleries often so numerous as to give honey- combed appearance to the wood. Adult. — A black long-horned beetle, with three straight yellow bands across thorax and five broken or irregular yellow bands across wing-covers; % inch long; found on golden rod in August-October. Eggs. — Snow-white; deposited in the fall in crevices in the bark of black locust trees; hatch in 8-10 days. Larva. — Makes winding tunnels deep into the wood; matures in less than a year; ^ inch long, dull white, somewhat flattened and club- shaped. Winters as a young larva in the soft inner bark. Pupa. — Formed in July-August and stage lasts 4 or 5 weeks. CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 323 Three-fourth inch long, stout, flattened, yellowish; dorsum of head and first six abdominal segments with chitinous points. Control. — Badly infested branches should be cut out and burned in winter or spring. Spray infected trunks and branches with kerosene (1:2 of water) in late fall after leaves have fallen to kill the young larvae in the bark. Fig. 210. — The hickory borer (Cyllene picla) on dead or dying hickory. Cyllene picta Drury bores in hickory and elm. Adult is velvety black with many pale yellow lines across the thorax and elytra (Fig. 210). Sugar Maple Borer {Plagionotus speciosus Say). — Apparently healthy trees are attacked. Adult. — -Nearly an inch long; black marked with yellow. Antennae 324 ECONOMIC ENTOMOLOGY and eyes reddish black; legs yellow; under side of body reddish-yellow, variegated with brown. Thorax black with two yellow spots on each side; wing-covers black with yellow tips, a yellow spot on each shoulder, a yellow curved band, a zigzag yellow band forming the letter W, a median yellow band arching backward, and a black curved band and spot on the yellow tip. June- July. Eggs. — Deposited in summer in slits in the bark of larger limbs. LarvcB. — Whitish, flattened legless grubs with brownish mouth- parts, excavating shallow burrows^ often several feet long, in inner bark and sapwood, and often girdling the tree. When full grown about 2 inches long. Pupa. — Formed in the end of the burrow. Control. — Examine trees for "sawdust" and probe the burrows to kill the grubs. Oak Twig Pruner {Elaphidion villosum Fab.). Adult. — A slender, dark brown beetle, ^^ inch long, sparsely covered with whitish hairs; tips of wing-covers with two teeth. July. Eggs. — Laid on smaller twigs, between the twig and the leaf stalk. Larva. — At first it makes burrows in the wood under the bark; later channels at centre of twig, and finally a deep circular groove which causes twig to break off. It usually changes to a pupa in the severed twig, but sometimes part of the larval and the pupal stage is passed outside of the twig. Control. — Fallen twigs containing the grubs should be promptly gathered and burned. Pine Wood Borers {Monohammus spp.). — Several species of Mono- hammus are well known as pine and spruce wood borers. They are large insects with long legs and long antennae. The following species are common: M. scutellatus Say, a bronzy-black form, M. confusor Kby., a brown form and M. titillator Fab., rare in the North. Logs are preserved from their ravages by putting them in water or by covering the log piles with -a thick layer of spruce or balsam boughs. MELOIDiE (BLISTER BEETLES) Blister Beetles. — (Consult Bull. 43, Div. Ent. U. S. Dep. Agric, 1903; Bull. 10, 111. Agric. Exp. Stn., 1900; 42d Rep. Ont. Ent. Soc.) Blister Beetles are characterized by a long cylindrical soft body CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 325 and flexible wing-covers, and by a rounded head joined to a small thorax by a slender neck. The adults are leaf-feeders, and are gre- garious. As larvae they feed on the egg-masses of grasshoppers and are, therefore, beneficial. Each female lays 500-600 eggs in a cavity in the soil in late summer and the eggs hatch in about 10 days. The larva on hatching from the eggs is long-legged, large-headed and active (the triungulin stage); and on moulting it assumes the second stage (carabidoid) with short legs and relatively smaller head. After another moult it assumes the third stage (scarabaeidoid), and with the fourth moult is formed the coarctate larval stage (winter stage). In the spring another moult occurs before the pupal stage is entered. On account of their habit of traveling sometimes like army- worms blis- ter beetles are often called "army beetles." Seven species of Blister Beetles of economic importance are found in Canada and the Northern States. 1. Black Blister Beetle {Epicauta pennsylvanica DeG.). — Uni- formly black and J^ inch long; one of the "Aster Bugs" of the florists; serious pest of garden vegetables and flowers; occurs from June to October. 2. Grey Blister Beetle {Epicauta cinerea Forst.). — Uniformly grey; J^ inch long; a pest of beans, potatoes, vetch and alfalfa; occurs in July and August. 3. Striped Blister Beetle {Epicauta vittata Fab.). — One- third inch long, with four black stripes on back; the "old-fashioned potato-bug;" a general feeder; occurs from June to September; eggs laid on plants or upon the ground. 4. Margined Blister Beetle {Epicauta marginata Fab.). — Of a gen- eral black color except that the wing-covers are margined with grey; a general feeder; occurs from July to October. 5. Ash-grey Blister Beetle {Macrobasis unicolor Kby.). — Uniformly ash-grey; feeds on beets, potato and legumes; occurs in June and July. 6. Spotted Blister Beetle {Epicauta maculata Say). — With a black body which, excepting small areas on the wing-covers, is covered with grey hairs. Attacks beets, cabbage, spinach, beans and clover in the Western provinces. 7. Western Blister Beetle {Cantharis nuttalli Say). — Three-fourth to one inch long; head, thorax and body metallic golden green; wing- 326 ECONOMIC ENTOMOLOGY covers variable in color — -purple, green or coppery. Often destruc- tive in the West to leguminous crops. June-August. Control. — -Spray with arsenical solution. CUCUJIDiE Saw -toothed Grain-beetle (Silvanus surinamensis Linn.). — A widely distributed beetle, feeding on stored grain and their products, and on starchy goods (Fig. 211). Adult. — -A minute flattened chocolate-brown beetle; margins of thorax with six tooth-like projections; Jfo inch long; two grooves in thorax; head and thorax finely punctate; wing-covers punctured and lined. There may be four generations in a season. Lary^.— Flattened, with transverse, rectangular, yellowish, chitinized spots above; 6 legs; active. Fig. 211. — The saw-toothed grain-beetle {Silvanus surinamensis): a, adult; h, pupa; c, larva— all enlarged; d, antenna of beetle. {After Chittenden.) Pupa. — White, occasionally enclosed in a delicate cocoon made of particles of food. OSTOMATIDiE = TROGOSITID^ The Cadelle (Tenebroides mauritanica Linn.). — Feeds on stored grain and also on other injurious grain insects. Adult.—Axi elongate oblong depressed beetle, nearly black; elytra longitudinally ridged; head and thorax finely punctate; }i inch long; found in granaries. CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 327 Eggs. — Small, white, much longer than broad; hatch in about 10 days. Larva. — Fleshy, slender, J-^ inch long, dull white with a dark brown head and pro thorax; two dark horny points at posterior end. Pupa. — -White; formed in a burrow in wood. PTINIDJE (DEATH-WATCH AND DRUG STORE BEETLES) Apple-twig Borer (Amphicerus bicaudatus Say). — (Consult Farmers' Bull. 70, U. S. Dep. Agr.) Adult. A cylindrical ptinid beetle, J^ inch long; dark brown above and black beneath; front of thorax with minute rough points; male with two little horns in front, two near the ends of wing-covers. Mature in the fall. Bores in early spring into twigs of apple, grape, pear, etc. Eggs. — Laid in May in dead roots of smilax, or in dead shoots of grape. Larya. ^Develops during summer, transforming to pupa and beetle in fall. Other more or less important forms belonging to this family are: the Drug Store Beetle (Sitodrepa panicea Linn.) which infests such drugs as ginger, rhubarb, licorice, peppermint and seeds; also flour, breakfast foods, chocolate, black pepper, coffee, dried beans and peas; also books and manuscripts; the Cigarette Beetle {Lasioderma serricorne Fab.) which infests tobacco in every form, pepper, ginger, rhubarb, rice, figs, yeast cakes, etc.; and the Death Watch (Anobium tesselatum) which occurs in timbers and tunneling in woodwork of houses. LYCTIDiE (POWDER POST BEETLES) Several species of Lyctus bore into dry stored sap wood, and are known as Powder Post Beetles. The adult insects are small, slender, dark brown beetles. Eggs are laid in the wood, and the grubs tunnel in every direction through the wood. In a short time the interior of the infested material may be reduced to powder. Control. — In house furniture remove and burn any replaceable infested parts; paint rest of infested surface with kerosene, giving several applications as long as boring dust appears. TENEBRIONIDiE (DARKLING BEETLES) Yellow Meal-worm {Tenebrio molitor Linn.). Adult, — A darkling beetle, % inch long, somewhat flattened; head and thorax finely 328 ECONOMIC ENTOMOLOGY punctured; wing-covers ridged lengthwise; April- June. One genera- tion each year; nocturnal. Eggs. — White, bean-shaped, J^q ii^ch long; deposited in the meal. Larva. — Cylindrical, waxy and slender; i inch long, resembling wireworms; yellowish, darker at each end. Mature in 3 months. Pupa. — Duration about 2 weeks. The Dark Meal-worm (Tenebrio obscurus Fab.) is dull pitchy black and has similar habits to the preceding. Control. — Subject infested rooms to a temperature of i2o°-i25°F. for 6 hours; fumigate with hydrocyanic acid gas or carbon bisulphide. Confused Flour Beetle (Tribolium confusum Duval). Adult. — A small, shining, reddish-brown beetle, },i inch long; flattened, oval; head and thorax finely punctate; wing-covers ridged lengthwise and sparsely punctate. Eggs. — Minute, white, hatching in 6 days. Larva. — Cylindrical, wiry, yellowish- white, % inch long; mature in 24 days. Pupa. — White, matures in 6 days. CURCULIONIDiE (WEEVILS) Common Economic Genera: A. Claws simple, pygidium not exposed. B. Antennae straight, club annulated, claws toothed, gular peduncle broad. — Ithycerus. BB. Antennae elbowed, rostrum with distinct scrobes, gular peduncle long; front coxae contiguous. C. Mandibles usually emarginate, 2-toothed at tip. — Phytonomus. CC. Mandibles bi-emarginate, 3-toothed at tip. D. Lateral angles of first ventral segment uncovered. — Lixtis. DD. Lateral angles of first ventral segment not visible. — Fissodes. A A. Claws appendiculate, toothed or cleft (except in Tyloderma). B. Ventral sutures straight, hind angles of prothorax rectangular or rounded, prosternum short, broadly emarginate; eyes rounded, distant. — A nthonomus. BB. Ventral sutures more or less curved. C. Beak received in or upon the breast in a pectoral groove confined to prosternum; beak long; tarsi dilated; front coxae contiguous. — Conotrachelus. CC. Pectoral groove extending into the mesosternum, sharply limited behind; front coxae not contiguous; metathoracic epimera distinct, mesosternum feebly emarginate. — Tyloderma. CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 329 CCC. Characters similar to CC, but mesosternum is deeply emarginate. Claws simple and divergent; ventral segments 2-4, equal; sutures straight. — Cryptorhynchus. Poplar and Willow Borer {Cryptorhynchus lapathi Linn.). — (Consult Cornell Bull. 388.) An introduced beetle from Europe, infesting poplars, willows and alders from N. Dakota to Maine and Quebec. Adult. — A sooty-brown snout-beetle, 3^^ inch long, spotted with grey; be^k curved and as long as head and thorax; body thick and punctured on the surface; ends of wing-covers, sides of pro thorax and two oblique bands on wing-cover light grey. After emerging the adult feeds by puncturing the bark of young tender shoots. Mating and egg- laying occur 10-14 days after emergence. July-October. Eggs. — Cream colored, oval; laid in holes made in bark of branches 2-4 years old. Hatch in 18-25 days, in August-November. Larva. — Burrows in the cambium until nearly full grown, then in the wood; a soft yellowish fleshy cylindrical footless grub with a pale brown head and darker mouth-parts; 3^^ inch long. Mature in June. Pupa. — When ready for pupation the larva enters older wood and makes a pupal chamber (i to several inches long) which is filled with fras. Pupa whitish-yellow, with brown spiracles; small spines scattered over dorsal surface and a pair of strong incurving brown spines at tip of abdomen. Duration 10-18 days. Control. — Spray trees with arsenate of lead every fortnight between July 15th and September ist; apply carbolineum to nursery stock in early spring; cut out grubs from moderately infested trees; cut down and burn badly infested trees during winter or before July ist. Plum Curculio (Conotrachelus nenuphar Herbst.). — This snout- beetle is a widely distributed native insect and is a serious pest of plums, pears, apples and peaches, cherries and apricots on account of its punctures and the dropping of infested fruit (Fig. 212). Adult. — A stout snout-beetle, J-^ inch long, brownish, and marked with grey and black; four black-ridged tubercles on the wing-cover; hibernates and emerges just before the fruit buds open. Feeds to some extent on the buds, but mostly on the young fruit as soon as it is set. Female begins to lay eggs in the young fruit as soon as it is formed. Lives about 2 months, laying 100-300 eggs. Makes two kinds of punctures in the fruit: egg-punctures and feeding-punctures. 330 ECONOMIC ENTOMOLOGY Eggs. — Oval, white; laid in cavities made by the snout of the beetle; protected in the hole by a crescent-shaped slit. Hatch in 4-6 days. Deposition occurs mostly in June but continues through July and August. Larva. — Whitish footless grub, mature in about 15 days; it then bores out of the fruit and enters the ground where it forms an earthen cell and remains for 2 weeks before pupation. Infested fruit drops prematurely (except cherries). Pupa. — White; formed in a small cell 1-2 inches below the surface, duration about 10 days; first adults emerge about 10 weeks after the apple blossoms. Fig. 212. -Plum curculio: a, larva; b, adult; c, pupa. (Chittenden, Cir. 73, Br. ofEnt., U.S.D.A.) Life-history. — Insect hibernates as a beetle under rubbiSh, etc., and emerges early to feed on buds, etc.; eggs deposited in young fruit; larvae tunnel in the fruit for about 20 days, then enter the ground to pupate; pupa stage lasts about 10 days; adults emerge to puncture the ripening fruit, and hibernation begins about first frosts. Larvae only in fruit that has fallen. Punctures produce gnarling of fruit. The beetles that emerge during the summer deposit no eggs. Control. — Spray thoroughly with arsenate of lead (3 to 40 gal.) as leaf buds are opening, and again before and after the blossoming pe- riod in the case of the apple. In the case of plum and cherry the applications should be made after the blossoms fall. Practice clean cultivation and remove rubbish. Apple Curculio {Anthonomus quadrigibbus Say). — (Consult Bull. 98, 111. Agr. Expt. Stn.; Cir. 120, Bureau of Ent., U. S. Dept. Agr.) CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 33 1 Sometimes injurious. Adult beetle distinguished from Plum Curculio by following characters: (i) more reddish-brown; (2) snout much longer and borne directly in front of the head; (3) wing-covers with four prominent humps; (4) abdomen more robust; (5) crescent- shaped mark absent. The life-history much the same as that of the Plum Curculio, except that the pupal stage lasts about a week. Beetles feed but little after they emerge in summer. Larva a hump-backed footless white grub, 3-^ inch long. Control. — Spray with lead arsenate (3 lb. to 40 gal.) just after the blossoms fade, and at intervals of 10 days; gather promptly fallen fruit; jar the trees and collect beetles. Clover Leaf Weevil {Phytonomus punctatus Fab.). Adult. — "A stout, oval, brown, finely punctured curculio," about J^ inch long; pro thorax narrower than abdomen; beak about ij^ times as long as the head, stout and curved. Eggs. — Yellow, oval and pitted. Larva. — A green, footless grub with a brown head, and a whitish stripe edged with black-red along the middle of the back, tapers to each end; lies curled in the ground. Hibernates. Pupa. — Cocoon is oval and the pupa has "a yellowish-green head, small black eyes, and a dark green abdomen." Life-history. — One brood a year, and winters as a partially grown larva. In spring it resumes its growth, and reaches maturity in June. Pupal stage beneath the surface does not last long, and adult beetles emerge in June and July. Eggs laid in September and October, and the grubs are partially grown when winter comes. Control. — Plow under infested fields after second season so as to destroy early stages of insect. The Lesser Clover Leaf Weevil {Phytonomus nigrirostris Fab.). — More injurious in Canada than the preceding. Adult. — Brown on emergence, later becoming green; snout black; thorax rounded with two dorsal brown stripes; length 3 to 4 mm. Eggs. — Ovoid, greenish, reticulate, placed beneath epidermis of leaf sheath; hatch in yl^ to 8J^ days. Larva. — Greenish straw-color; head light brown; pale dorsal stripe. Feeding on tender leaf buds beneath sheath, or in flower heads where it destroys the florets; 17-20 days. 332 ECONOMIC ENTOMOLOGY Pupa. — In an oval open mesh cocoon usually in flower head; about 7 days. Life-history. — Hibernating adults come forth as soon as clover appears in spring. Egg laying commences immediately and extends over several weeks. One generation, but all stages found during the summer. Alfalfa Leaf Weevil {Phytonomus posticus Gyll.). — (Consult Farmers' Bull. 741, U. S. Dep. Ag.) A European beetle, introduced about 1904 into the West, puncturing the stems and eating the leaves of alfalfa. The larvae also feed on the tender growths, causing the tops to appear white. Adult. — A dark brown snout-beetle, %6 i^ich long; body covered with black and grey hairs; hibernates in crowns of alfalfa or under grass, rubbish, etc.; oviposits in April and June. Eggs. — Small, oval, shiny, yellowish; laid in punctures in stems of alfalfa; April-July, hatch in 10 days. Larva, — A green, worm-like grub, J^ inch long, tapering toward both ends; head black; a light stripe down the back. May-July. Pupa. — Cocoons globular and composed of network of white threads; spun in dead leaves or rubbish on the ground; duration 1-2 weeks. Control. — Disk alfalfa fields in early spring and cut about middle of May when most of eggs have been laid; use a bush-drag to kill the weevil; collect the weevils; destroy weeds and rubbish; spray in April with arsenite of zinc solution (4 lb. to 100 gal.); pasture or graze in- fested fields after eggs are laid. A Clover Leaf Weevil {Tychius picirostris Fab.) is injurious to some extent to clover heads on the island of Montreal. The adult is a black curculio Jf inch long, and is an introduction from Europe where it attacks the flower heads of red clover, plantain and Genista. Strawberry Weevil {Anthonomus signatus Say). — (Consult Cir. 21, U. S. Dep. Ag., Div. Ent.) Adult. A small weevil, Jfo inch long, from black to dull red, marked with a dark spot on each wing- cover. Snout half as long as body, slender and curved. Hibernates July-May (Figs. 213 and 214). Eggs. — ^Laid in buds in spring; hatch in 6-7 days. Larva. — Feeds on pollen and harder parts of buds. Matures in 3-4 weeks. Pupa. — Formed in a cell in the bud; duration 5-8 days. Injury CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 333 is done also when the egg is laid; then the female cuts the stem of the bud. Fig. 213. — Strawberry weevil (Anthonomus sig- nalus). Enlarged. {After Riley and Chittenden.) Fig. 214. — The strawberry weevil: a, h, plant showing work on bud and stem; c, outline of egg; d, larva; e, head of larva;/, pupa; g, bud opened to show egg and punc- tures. {After Chittenden.) Control. — Plant mostly pistillate varieties; plant only stamina te varieties as trap-crops; cover beds with muslin. Cotton Boll-Weevil {Antho- nomus grandis Bob.). — (Consult Bulletin 51, and Farmers' Bull. 344, Bur. Ent., U. S. Dept, of Agriculture.) A serious pest of cotton in the Southern States. Adult. — A small brownish weevil, 3^^ inch long, with two teeth at tip of femora of forelegs; female lays about 140 eggs. Hibernates in sheltered situ- ations (Fig. 215). Eggs. — Small, oval, white; hatch in about 3 days. Larva. — A white, footless grub with brown head; matures in 7 to 12 days (Fig. 216). Pupa. — Soft, white; stage lasts 3-5 days. Average duration of Fig. 215. — Cotton boll- weevil: a, beetle, from above; h, same, from side. About 5 times natural size. {After W. D. Hunter, U. S. Bur. Ent.) 334 ECONOMIC ENTOMOLOGY generation about 43 days and there are probably not more than four or five generations in a season. Life-history. — "The egg is deposited by the female weevil in a cavity formed by eating into a cotton square or boll. The egg hatches in a few days and the footless grub begins to feed, making a larger place for itself as it grows. During the course of its growth the larva sheds its skin at least three times, the third moult being at the formation of the pupa, which after a few days sheds its skin, whereupon the trans- formation becomes completed. These immature stages require on the aver- age between 2 and 3 weeks. A fur- F I G . 216 .—Cotton boll-weevil: ther period of feeding equal to about larva at left, pupa at right About o^C-third of the preceding develop- 5 times natural size. {After Hunter.) ... mental period is required to perfect sexual maturity so that reproduction may begin" (Hunter and Pierce). Strawbeny Crown Borer {Tyloderma fragarice Riley). Adult. — A small dark snout-beetle, J:5 inch long; head and thorax black; each wing-cover with 3 black spots. Hibernates. Eggs. — Probably laid in the crown. Larva. — Small white grub mining out interior of the crown; J^ inch long; legless; head yellowish-brown. Matures in August. Pupa. — Formed in the larval cavity. Adults emerge in late summer and fall. Potato Stalk Borer {Trichobaris trinotata Say). — Burrows in the stalks of potatoes. Adult. — A snout-beetle, K inch long, dull black to light grey; three black spots at union of pro thorax and wing-covers; snout curved and as long as prothorax. Front of prothorax orange-yellow. Hibernates in burrows in the old stalk. Eggs. — Small, oval, pearly white; laid singly in punctures in stalks. Larva. — Yellowish- white; head light brown; legless; % inch long. Burrows in the stalks. Pupa. — At first yellowish- white, later dull brown; }i inch long, en- closed in oval greenish cocoon of fras; duration about a month. CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 335 Control. — Burn all the old stalks and rubbish as soon as crop is harvested. The Black-snouted Rose Beetle {Rhynchites bicolor Fab.) occurs chiefly in the Transition zone and injures roses by puncturing the flower buds, and blackberries and raspberries by puncturing the fruit. Bronze Apple-tree Weevil {Magdalis cenescens Leconte). — Young apple trees are sometimes severely injured in B. C. and the Pacific States. Adult. — A slender, blackish-bronze weevil, J^ inch long. April- August. Feeds on the leaves. Eggs. — Smooth, shining, yellowish-white; 1 aid in holes in the bark. Larva. — A plump, legless, white grub, 3^^ inch long; burrows under the bark. Pupa. — Formed in the spring. Grape Curculio {Craponius incequalis Say). — (Consult Bull. 730, U. S. Bur. Ent.) This snout-beetle is one of the worst pests of the grape in the Upper Austral Zone, East of the Rockies, the adult feeding on the leaf in the spring and fall and the larva feeding on the pulp and seeds of the fruit. Adult. — A short, robust, chocolate-brown, snout-beetle about 3^^ inch long. Thorax and elytra with prominent acute tubercles, and body and elytra clothed with minute whitish scales. Eggs. — Oblong-elliptical, smooth, opaque, yellowish; deposited in cavities in the fruit during July and August. About 250 laid by each female. Hatch in 6 days. Larva, — A legless, fusiorm, curved grub; white with light brown head; J:^ inch long; body sparsely covered with short fine hairs; mature in 10-12 days. Pupa. — Short, stout, yellowish- white; eyes and tip of beak reddish; occupies a small spherical cocoon formed of earthen grains and lined with a delicate membrane. Duration about 18 days. Natural Enemies. — Certain members of the following ant genera: Solenopsis, Camponotus, Myrmica, Lasius, and Cremastogaster. Also the parasites Anaphoridea and Microhracon. Control. — Spray with arsenicals on the first appearance of the beetles, and again in 2 weeks. 3>?>^ ECONOMIC ENTOMOLOGY OTIORHYNCHIDiE (SCARRED SNOUT-BEETLES) Strawberry Root Weevil {Otiorhynchus ovatus Linn.). — Adult, A small brownish-black snout-beetle; J^ inch long. June and August- September (Fig. 217). Eggs. — Female lays about 50 eggs in 4 to 1 5 days in the soil. Hatch in 21 days. End of June to end of August. Fig. 217. — Strawberry root weevil (Otiorhynchus ovatus) and its grub. Treherne, Bui. 8, Div. Ent., Dept. Agric, Can.) {After Larva. — A small white grub % inch long; feeds on roots of straw- berry, clover, timothy, rhubarb, rumex; lasts about 7 months. Winters partly grown. Pupa. — Four to eight inches below surface; lasts from 21 to 24 days. May- June. Control. — Rotation of crops as two- and three-year plantations suffer most; thorough cultivation; growing of suitable varieties; use of chickens. The Black Vine Weevil or the Cyclamen Borer {Otiorhynchus sulcatus Fab.). — Occurs from the Atlantic to the Pacific in Northern U. S. and Canada, and is injurious to roots and crown of strawberry, also to Gloxinia, Cyclamen, Primula, Maiden-hair fern "n greenhouses. Adult. — A black beetle, % inch long, with patches of yellowish hairs on the wing-covers. Wing-covers joined together and wings absent. CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 337 It appears in April and May and attacks the foliage of various plants; nocturnal. Larva. — ^Legless, white to flesh colored, usually curved; head brown, body thickest at the middle; ^^ inch long and lives in the soil and at- tacks roots of Cyclamen y Adiantum and Gloxinia. Feytaud, of France, reports parthenogenetic reproduction of this insect, and considers it probable that males appear sporadically. The females deposit more than 150 eggs, and reproduction is very rapid. Control. — The adults may be caught at night by shaking them from infested plants; the grubs in the soil are not readily controlled. Peach Leaf Weevil {Anametis granulatus Say). — This weevil is about 14 inch long, dark brown, oval, robust, densely covered with greyish scales. It sometimes damages peach, pear and apple trees by eating at night the buds and bark. Widely distributed. CALANDRID^ (GRAIN WEEVILS) Granary Weevil {Calandra granaria Linn.). — Adult. A snout- weevil, J^ inch long, convex, brown; thorax punctate; wing-covers Pig. 218. — Grain and rice weevils: a, adult of grain beetle {Calandra granaria)', h, larva; c, pupa; d, adult of rice weevil (C. oryzx). {After Chittenden.) ridged lengthwise. Four or five generations in a season, each requir- ing about 40 days (Fig. 218). 22 33^ ECONOMIC ENTOMOLOGY Eggs.— Minute, white, deposited in cavity of kernel. Larva. — Small, robust, whitish, legless; one larva to a kernel of wheat, but several in corn. Pupa. — White, clear and transparent. Control. — Superheat for 6 hours at i2o°-i2 5°F.; fumigate with hydrocyanic acid gas or carbon bisulphide. The Rice Weevil (Calandra oryzce) is also of economic importance, espe- cially in the South (Fig. 218). Com Bill-bugs (Sphenophorus spp.). — Adults. Snout-beetles, dull black, surface marked with small pits and narrow grooves; irregularly oval and rounded; 3^^-J^ inch long; hibernate under rubbish; single brooded (Fig. 219). Eggs. — ^Laid in May and June in roots and stems of grasses. Larva. — Thick-bodied, oval, footless grub, with a hard brown head; feeding in corn stem or in root bulbs of grasses; June-August. S. maidis. — Does injury to corn Fig. 219. — The maize bill-bug both as grub and adult. The grub {Sphenophorus maidis). Pour times burrows in lower part of stalk, and the enlarged. ^ ' adult occupies the burrow. Other species make holes and slits in the leaves of corn. SCOLYTID^ OR IPID^ (BARK-BEETLES) Three common Fruit Bark-beetles are Eccoptogaster rugulosus, PhthoropUoeus liminaris and Anisandrus pyri, which may be dis- tinguished by the following characters: A. Venter of abdomen with caudal part bent abruptly upward. Antennal club flat and marked by angulated sutures. — Eccop- togaster rugulosus (Fruit-tree Bark-beetle). AA. Venter of abdomen normal, regularly curved. B. Antennal club lamellate, of three separate, laterally pro- duced segments ; head visible from above. — PhthoropUoeus liminaris (Peach-tree Bark-beetle). CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 339 BB. Antennal club globular; truncate at tip, head deeply im- bedded in prothorax whose anterior margin is nearly horizontal and invisible from above. — Anisandrtis pyri (Shot-hole Borer). (Consult Farmers' Bull. 763.) Fruit Tree Bark-beetle {Eccoptogaster rugulosus Ratz.). — Intro- duced from Europe; occurs in most states east of the Rockies. This small beetle, also called the Shot-hole Borer, injures fruit trees by puncturing the bark, and burrowing in the bark and wood, causing the death of twigs and leaf buds (Fig. 220). Adult. — A small black scolytid beetle 3-fo ii^ch long, with the tips of wing-covers and parts of the leg reddish. May- June and August. Pig. 220. — The fruit tree bark beetle (Eccoptogaster rugulosus): a, adult or beetle; b, same in. profile; c, pupa; d, larva. All enlarged about 10 times. (Chittenden.) Eggs. — Deposited in little pockets in the brood gallery or chamber between the bark and sapwood; hatch in 3 to 4 days (Fig. 221). Larva. — Matures in 4 to 5 weeks. A minute legless grub Jf iiich long; whitish; head small, larger in front than behind. Larval burrows 3 or 4 inches long, filled with reddish dust-like fras and at first at right angles to brood chamber. Pupa. — Pupa formed in a slightly enlarged chamber; duration 7 to 10 days. Adults make their way out through little round holes in the bark. Life-history. — Cycle in about i3^^ months; two generations in a season in the North and more in the South. Second brood larvae winter in the trees. Said to attack preferably unhealthy trees. Parasitized by Chiropachys colon Westw., a chalcid. Control. — Remove and destroy dead or dying trees before May or June; apply a protective wash of whitewash and carbolic acid in June and August. 340 ECONOMIC ENTOMOLOGY Peach-tree Bark-beetle (PMhorophlocus liminaris Harris). — (Consult Farmers' Bull. 763, U. S. Dept. Ag.) This native borer cuts its tunnels between the bark and the wood of peach and cherry. Two broods a year. Common in wild cherry in some localities. Adult. — Brownish-black, J^o irich long; head large and visible from above; antennal club lamellate, of three separate laterally produced segments. Breeds in weak and dying limbs, but in fall bores a *h Fig. 221. — Galleries of the fruit tree bark beetle on twig under bark: a, a, main galleries; b, b, side or larval galleries; c, c, pupal cells. Natural size. (Ratzeburg.) Fig. 222. — Shot-hole borer (Anisandrus pyri). {After Swaine, Bui. 14, En^. Bur. Can.) holes in healthy limbs from which much sap exudes following season. Hibernates. Eggs. — Small, white; 80 to 160; laid in niches along sides of egg- tunnel or brood chamber in spring. Hatch in 17-20 days. Larvce. — White; head yelowish, mouth-parts dark; mature in 25-30 days. Form galleries off the egg-tunnel. Fupce. — Formed in enlarged end of larval galleries; adults appear through holes cut in the bark above the pupal cells; duration 4-6 days. Shot-hole Borer (Anisandrus pyri Peck). — This borer cuts round, black tunnels deep into the wood; in small branches or stems one divi- sion of the tunnels partially girdles the wood (Fig. 222). Adult. — Cylindrical, black, J^ inch long; antennal club globular CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 341 and truncate at tip; pronotum strongly bent downward in front so as to be nearly vertical. Male wingless, smaller than female, and with a curious, humped back. June. Eggs. — ^Laid free in galleries in June. Fig. 223. — Clover root borer {Hy- lastinus obscurus). Natural size at right. {After Webster, U. S. Bur. Ent.) Fig. 224. — Larva or grub of the clover root borer. En- larged. {After Webster.) Larvce. — Feed on fungus growing on walls of tunnel; mature late in season. Pupce. — Formed in tunnels and adults emerge through entrance hole cut by mother beetle. Clover Root Borer {Hylastinus obscurus Marsh). — Adult. A small dark brown cylindrical hairy scoly- tidid beetle, Jfo ii^ch long; wing-covers coarsely punctate (Fig. 223). Eggs. — Minute, white, elliptical and shining. Larva. — A white stout footless grub with yellow head and brown mouth-parts; J^ inch long (Fig. 224). Pupa. — White, with a pair of spines at top of head, and another at tip of abdomen (Fig. 225). Life-history. — There is but one brood each year. The adult winters in the clover roots, and lays her eggs during May and June in the crown or on the sides of the root. The larvae tunnel the root, and mature in July; the pupae transform to adults be- fore October ist. Control.— Vliiw up infested clover fields after the hay is taken off; break up clover sod after taking one crop. Forest Bark-beetles {Dentroctonus spp. chiefly). — (Consult bulletins Fig. 225. — Pupa of the clover root borer. Enlarged. {After Webster.) 342 ECONOMIC ENTOMOLOGY by Hopkins and Swaine.) Reference can be made here to only a few of the economic wood-boring beetles that do an immense amount of injury to the forests of the United States and Canada: 1. Dendrodonus horealis Hopk., Attacks spruce of the western forests in Alberta and British Columbia. 2. D. brevicomis Lee, Western yellow pine. 3. D. engelmanni Hopk., Engelmann's spruce of the west. 4. D. monticolcB Hopk., Western pines (Figs. 226 and 227). 5. D. miirrayana Hopk., The lodge-pole pine of the West; not injurious. 6. D. obesusLec, The Sitka spruce. Fig. 226. — The wes- Fig. 227. — Larva of Dendrodonus monlicolce. tern pine borer {Dendroc- {After Swaine, Bui. 14, Eni. Bur. Can.) tonus monticoloe. {After Swaine, Bui. 14, Ent. Bur. Can.) 7. D. piceaperda Hopk., Eastern spruces. 8. D. pseudotsugce Hopk., The Douglas fir and western larch. 9. D. simplex Lee, Larch (Eastern). 10. D. valens Lee, Pinus and Picea. 11. Dryoccstes confusus Sw., Alpine fir of British Columbia and Alberta. 12. Polygraphiis rujipennis Ky., Spruces throughout Canada. 13. Pityokteines sparsus Lee, Balsam fir in the east. The bark-beetles are small (1-9 mm. long), brownish or black, and usually cylindrical beetles. One group, the Ambrosia bark-beetles make their tunnels in the wood whose walls are stained black by the growth of the fungus Ambrosia which nourish them. The other group — the true bark-beetles — make their tunnels in the bark or between the bark and the wood. CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 343 The systems of tunnels show much variation in shape but are often distinctive of the individual species. They may be simple longitudinal, simple transverse, irregular elongate, irregular short, forked, radiate, cave, pith or ambrosia. In some forms the egg-tunnels originate from a small cavity, the nuptial chamber, at the base of the entrance hole. The eggs are laid in niches along the sides of the egg-tunnels, and the larvae make slender mines leading away from the egg-tunnels. At the ends of these mines are the enlarged pupal cells. The adult beetles, in emergence, bore round holes through the bark. With most of the destructive bark-beetles, there is but one brood, or a partial second one, each season. They pass the winter as adults and larvae in the dying trees entered by the parent adults early in the same season. , ,, • While most of the bark-beetles breed in dying and dead trees, some species attack sound trees. The latter are, therefore, called ''primary" and the former ''secondary" enemies. Some species, how- ever, fall into both classes as they are known to attack both sound and dead and dying trees. Natural Control. — Several natural factors operate in checking the development of bark-beetles. These are (a) weather conditions, such as cold and wet seasons; {b) certain hymenopterous and mite parasites; {c) certain predaceous beetles; {d) wood-peckers; and {e) certain para- sitic fungi. „^ Control Measures. — Epidemic and sporadic outJ;;treaks often occur in spite of the operation of the natural control factors mentioned above, especially in districts swept by fires, or subjected to careless lumbering operations where much "slash'' is left. If, however, the slash is burned in winter or the trees injured by fire are cut during the first winter after the fire, and got into water or sawn before spring opens, most of the beetles will be destroyed, if the slabs are burned. The cutting and barking of infested trees, with the burning of the bark during winter or early spring, may be adopted as a control meas- ure. Sometimes cutting and charring the bark will be found sufficient to destroy the beetles. Hymenoptera (Ants, Bees, Wasps, et al.) Principal Groups and Families A. Trochanter with two segments; female with ovipositor. B. Abdomen sessile or joined broadly to thorax. 344 ECONOMIC ENTOMOLOGY C. Tibia of forelegs with two apical spurs; female with saw-like ovipositor. — Tenthredinidm (Saw-flies) (Fig. 228), p. 345. CC. Tibia of forelegs with one apical spur; female with ovipositor fitted for boring. — Siricidce (Horntails), p. 350. BB. Abdomen joined to thorax by slender petiole or stalk. C. Fore wings with few or no cross veins, hence with no closed cells. D. Ovipositor issuing before the apex of the abdomen; anten- FiG. 228. — Venation of a tenthredinid (Janus). (After Comstock.) Fig. 229. — Venation of the honeybee. (After Comstock.) naj elbowed and with one or more ring-like segments next to last. — ChalcididcB (Chalcis Flies), p. 353. DD. Ovipositor issuing from the apex of the abdomen; antennae straight, or if elbowed without ring-like segments. — Proct- olrypidcB, p. 351. CC. Fore wings with one or more closed cells. Fig. 230. — Venation of an ichneu- monid. (After Comstock.) Fig. 231. — Venation of a braconid. (After Comstock.) D. Fore wings without a stigma; antennae with not more than 16 segments and sira.\ght.~Cynipidce (Gall Flies), p. 351. DD. Fore wings with a stigma; antennae with more than 16 segments and straight. E. Fore wing with vein between Media i and ist Media 2 wanting. — BraconidcB (Braconid Flies) (Fig. 231), p. 352. EE. Fore wing with vein between Media i and ist Media 2 present— I chneumonida; (Ichneumon Flies) (Fig. 230), P- 352. AA. Trochanter simple; female usually with a sting. CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 345 B. Fore wings without closed submarginal cells. C. Abdomen and antennae long; body smooth and black. — Pele- cinidcB, p. 352. CC. Abdomen and antennaj short; body colored and often sculptured. — ChrysididcB (Cuckoo Flies). BB. Fore wings with one or more closed submarginal cells. C. Abdominal stalk normal. D. First segment of the tarsus of the hind leg more or less compressed, at least on inner side, and often thickly hirsute. — Group Apoidea (Bees) (Fig. 229), p. 356. DD. First segment of the tarsus of the hind leg more or less cylindrical, neither markedly broadened nor hairy. E. Fore wings folded once lengthwise; antennae usually clearly bent at an angle; pronotum extending back so as to touch or reach above the tegulae. — Group Vespoidea (Wasps), p. 356. EE. Fore wings not folded lengthwise; hind angles of pronotum remote from and below the tegulae. Ab- domen appended or pedunculate, oval or broadest anteriorly, gradually tapering posteriorly. — Group Sphecoidea (Digger and Mud Wasps), p. 356. CC. Abdominal stalk formed of one or two knots or scale-like rings; antennae flagellum-like. — Group Formicoidea (Ants), p. 359. The classification given above is deemed sufficient for the purposes of this book, but recent monographs show a breaking up of many of the old families into new ones, with new groupings. (See Hymenoptera of Connecticut, Bull. 22, State Geol. and Nat. Hist. Survey, 1916.) TENTHREDINID^ (SAW-FLIES) Currant Stem Girdler {Janus integer 'Norton).— Adult. A slender black saw-fly with yellowish legs; male smaller than female, with abdomen brownish-yellow. Abdomen in female is half reddish-orange and half black. May. Stem girdled by female. Eggs. — Deposited in pith of cane; elongate-oval, yellowish-white, 3^^5 inch long. Laid in May and June; hatch in about 11 days. Larva. — One-half inch long, straw color; head darker yellow; thoracic segments broadest; tip of abdomen with a horny brown bifid spine. Tunnels in the pith. Winters in a silken cocoon. Pupa. — Formed in April; white. Wilting of cane occurs in May. Control. — Cut off and burn infested canes 8 or 10 inches below the girdled part, in June or fall. 346 ECONOMIC ENTOMOLOGY Imported Currant Worm {Pteronus ribesii Scop.). — Adults. Four- winged saw-flies, J^^ inch long; female with light yellow abdomen marked with black; male smaller and darker; May and July. Eggs. — Laid in rows on leaves along the mid-ribs; hatch in 4 to 10 days. Larva. — At first the caterpillar is whitish and with white head; after first moult the body is green with black spots on side of body. When full grown, % inch long, they lose their black spots and descend to ground to pupate. Two or three weeks. Pupa. — Formed in an oval brownish silken cocoon on the surface of the ground. Pupa of second brood winters over. Life-history. — Two broods a year; adults emerge in spring and again in July. Broods overlap. Control. — Dust or spray with hellebore or with an arsenical poison. Larch Saw-fly {Lygceonematus erichsonii Hartig.). — (Consult Bull. 10, Div. Ent. Dep. Ag. Can.) A serious pest of larch introduced from Europe. Adult. — A large thick black saw-fly, with second, fifth and part of sixth abdominal segments bright red. April-May. Eggs. — ^Laid in slits in terminal shoots June-July; white, cylin- drical, tapering at each end; J^q ii^ch long; hatching in 8-10 days. LarvcB. — Feeding on leaves in June-July; mature in 20 days when they descend to ground and spin cocoons; hibernate. Full grown larvae with jet-black head and glaucous green body. About each segment, except second, double parallel rows of minute dark dots; five moults. Pup(B. — In dark brown, oval, elongated cocoons, % inch long, beneath the surface. Parasites. — Pteromalus nematicidus Pack., a chalcid, and Mesoleius tenthredinidis, an ichneumonid. Birch Saw-fly {Hylotoma pectoralis Leach). — Defoliates birches in Quebec and Prince Edward Island, while Fir Saw-fly {Lophyrus ahietis Harr.) and Abbott's Pine Saw-fly {L. abbotii Leach) do damage to firs and pines respectively. Raspberry Web Worm {Pamphilius fletcheri MacG.) — Injurious in New Brunswick. Adult. — Three-eight inch long; head and thorax black with white markings. Abdomen of male black with a broad median transverse CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 347 yellowish band; abdomen of female with front third black and remainder reddish-yellow. Middle of June. Larva. — Smooth, bright green, }^ inch long, feeding within a tent formed by webbing together the terminal leaves. Hibernates. Dock False Worm {Ametastegia glahrata Fallen = Taxonus nigrisoma Norton). — (Consult Bull. 265, Bur. Ent. U. S. Dep. Ag., 1 91 6.) The green worm-like larva of this saw-fly often burrows into apples to hibernate. Its natural food plants are dock and related plants. Four broods a yea". Elm Saw-fly {Cimhex americana Leach). — Feeds on leaves of elm, willow, poplar, maple and basswood. Adult. — A saw-fly with head and thorax black; body steel-blue with three or four oval yellowish spots on each side; wings smoky brown; legs bluish-black; tarsi yellowish; antennae short and knobbed. May. Eggs. — Elongate or oval, flattened, clear; laid in the leaf. Larva. — Three-fourths inch long; yellowish-white, coiled, with a black stripe along the middle of back; 8 pairs of prolegs; legs greenish-white. Matures in July-August, and forms a tough, coarse silken cocoon at base of tree where it hibernates. Pupa. — Formed in spring in cocoon. Parasite. — Opheltes glaucopterus Holmgr., an ichneumon. Raspberry Saw-fly {Monophadnus ruhi Harris). — (Consult Bull. 150, N. Y. Agr. Expt. Station, Geneva.) Adult. A saw-fly, J^ inch long; female with body black, with segments of abdomen from 2 to 6 yellowish-white, and under side rusty brown; male black with shoulders yellowish- white; May. Eggs. — Pear-shaped, yellowish-white, J^o i^^ch long; inserted under upper cuticle of leaf; hatch in 7 to 10 days. Larva. — At first pale yellowish-green; covered with whitish spiny tubercles; mature larva % inch long, green, covered with barbed spiny tubercles, brown on back and white on sides; feed for 10 days, then enter soil and form small, brown, oval cocoons. Hibernate in cocoons. Pupa. — Formed in May, and lasting a few days. Strawberry Saw-fly {Harpiphorus maculatus Norton). — (Consult Bull. 54, Mo. Agr. Expt. Station.) Adult. A black saw-fly with a row of light spots on sides of abdomen; J^ inch long; May. Eggs. — Inserted beneath epidermis of leaf; hatch in 2 weeks. Larva. — Slug-like, J^ inch long, yellowish with a pale stripe along 348 ECONOMIC ENTOMOLOGY the back; coiled when at rest; 8 pairs of prolegs; full grown in a month; entering soil and forming a cocoon. Hibernates. Pupa. — Formed in May. Rose Saw-fly Slug (Endelomyia roses Harr.). — This insect is often injurious to the leaves of roses. The slug-like larvae eat the upper surface of the leaves. The pupae are found in the ground. There are two broods each year; June and August. Cherry Saw-fly Leaf Miner (Profenusa collarisMsLcG.). — (Consult Bull. 41 1, N. Y. Ag. Exp. St.) This insect has been injurious to cherries in New York State for several years. It produces blister-like areas on leaves. The adult is a small saw-fly 3^^ inch long, appearing in May, and the larva passes part of its existence in the leaf as a miner and in the ground in an earthen cell. Pupation occurs, in late April or early May. Plum Web-spinning Saw-fly {Neurotoma inconspicua Norton). — Forms ugly nests in the leaves of plum and cherry. Adult. — A saw-fly, J^ inch long; wings hyaline with a faint fuscous band behind stigma; body, coxae and tarsi black, legs reddish. May- June as leaves expand. Eggs. — Smooth, elongate, yellow; deposited in two or three rows along mid-rib of under surface of leaf. Hatch in about 8 days. Larva. — Three-fourth inch long, grey above and yellow or pinkish below; head yellow; thoracic shield and anal segment black; full grown in a month; feeds on leaves under webs. Passes the winter in an earthen cell 6 inches below the surface of the ground. Pupa. — In early spring pupa forms near the surface. Pear Slug {Eriocampoides Umacina Retzius, Caliroa cerasi Linn.). — (Consult Circ. 26, Div. Ent., U. S. Dept. of Agriculture.) The slug-like larvae of this European insect are often found feeding on the surfaces of the leaves of pear, plum and cherry. Adult. — A glossy black saw-fly, 3^-5 inch long; wings with a smoky band across the middle. May and June, and August. Two genera- tions in the North but one along the Lower St. Lawrence. £g^5.— Deposited beneath the upper surface of leaf in a cut made by ovipositor; hatch in 2 weeks. Larva. — At first white with yellowish-brown head; later, darker with brownish-black head; body covered with slime like a slug; anterior portion of body enlarged; 7 pairs of prolegs. Full grown in about CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 349 25 days; Y^ inch long with orange-yellow dry body and light colored head; enters the ground for a week where it forms a cell. Pupa. — Formed in a cell in the ground, 1-2 inches below surface; duration i week. Pupae of last brood hibernate, but some larvae do not pupate until spring. Parasite. — Pentarthron minutum. Control. — Readily controlled by arsenicals or tobacco-soap solu- tions, or by dry hellebore or air-slaked Hme. Fig. 232. — Western wheat-stem saw-fly (Cephus occidentalis) : c, adult. {After Criddle, Ent. Bui. 11, Dept. Agric. Ottawa.) Rose-slugs. — Three species infest the rose, the American Rose- slug {Endelomyia cethiops Fab.), the Bristly Rose- worm (Cladius pectinicornis Fourcr) and the Curled Rose-worm (Emphytus cinctipes Nort.). They vary from J^-M inch in length. Western Wheat-stem Saw-fly {Cephus occidentalis R. and M.). — (Consult Ent. Bull. 11, Dep. Agric, Ottawa.) A native of N. America, 350 ECONOMIC ENTOMOLOGY probably with species of Agropyron as its host plants. A serious pest in the West on wheat and rye (Figs. 232 and 233). Adult. — A shiny black 4-winged fly, J-^ inch long; abdomen with three prominent yellow rings; legs yellow. Female with a short stout horn-like ovipositor. It rests head downward on the stems of grasses, with its wings very close together over the body. June 10- July 10. Eggs. — Minute, white, cylindrical. Larva. — Dull yellowish-white, J^-J^ inch long; first two segments swollen; end of abdomen with a short blunt projection. Always occurs within the stem. Bores downward in the stem, reaching base Pig. 233. — Full grown larva of the western wheat-stem saw-fly {Cephus occidentalis) {After Criddle, Bui. 11, Ent. Br. Can.) about August ist and cutting the stems through level with ground; remains all winter in stub until following May. Pupa. — Formed in May in stub inhabited by larva. Control. — I. Plough infested stubble 5 inches deep in fall, with attention at least to worst infested fields. 2. All infested grasses, such as western rye grass, timothy and the prairie grasses next to growing crops should be cut between July loth and August ist. SiRiciD^ (Horn-tails) Pigeon Tremex (Tremex columba Linn.). — Injures elm and maple. Adult. — Female a large 4-winged fly, 2 inches long, with a prominent yellow horn at end of abdomen; head and thorax reddish-black, ab- domen cylindrical, dark brown, with seven yellowish band-like mark- ings; male smaller, without horn. June-August (Fig. 234). Eggs. — Oblong oval, jointed at ends, 3^^o i^ch long. Larva. — ^Large, soft, yellowish, cylindrical, with six true legs and a horny point at end of abdomen; boring into wood. Parasitized by CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 351 Thalessa lunator, a slender, brown and yellow, wasp-like Ichneumon with a long delicate ovipositor. Pupa. — Formed in burrow within a cocoon made of silk and chips. Cynipid/E (Gall-flies) The injury done by Cynipids to economic plants is not serious, being confined mainly to oaks and roses. (Consult Felt's Key to American Insect Galls). Eggs are laid in the leaves, stems and roots, and soon gall-like en- largements are formed as a result of the stimulus of the larvae. The galls are closed and are very varied in shape. The Mossy Rose-gall on Sweet- brier, produced by Rhodites rosce Linn., is many-celled and consists of a number of hard kernels embracing the stem, covered with reddish-green mossy filaments. The Pithy Blackberry-gall, pro- duced by Diastrophus turgidus on blackberry canes consists of an elon- gated, many-celled, ridged, woody, reddish-brown gall. Pithy Blackberry-gall Fly {Dias- trophus turgidus Bass.). Adult. — Black, 1^2 i^ich long; feet and antennae red; four wings, transparent and almost without veins. Early summer. Larva. — White, J^fo ii^ch long, mouth-parts and spiracles reddish; hibernates in cells of gall. Pupa. — Formed in spring. Control. — Cut out and burn infested canes during the winter. Several species infest oaks, viz., Amphiholips spp., Holcaspis spp., Andricus spp., and Cynips spp., each producing its characteristic gall. PROCTOTRYPIDiE (PROCTOTRYPIDS) The members of this family, or rather the group Proctotrypoidea, are the smallest of insect parasites. They are usually black and without Fig. 234. — Pigeon tremex {Tremex columba): A, adult; B, larva (with parasitic larva of Thalessa attached). Natural size. {After Riley.) 352 ECONOMIC ENTOMOLOGY metallic lustre. Sometimes they occur as secondary parasites on primary parasites. The larvae live within other insects, often within insect eggs and sometimes within larvae or pupae. The larvae of Polygnotus develop within the digestive tract of gall midges, and Trichacis in the nervous system of the same midge. Telenomus is a common form infesting the eggs of many butterflies and moths. Ano- pedius is parasitic on the clover seed midge and the wheat midge, and Platygaster on the Hessian-fly. The eggs of Proctotrypids are "ovate, with a peduncle at the end." The neuration of the wings shows great diversity. As a rule the hind wings are veinless. In some sub-families the veining of the fore wings resembles that of the Braconids and the Chrysidids and Scoliids, and in others the Chalcids. (Consult Ashmead's Monograph of the N. A. Proctotrypidae and Brues' Serphoidea in Hymenoptera of Connecticut.) Family Pelecinid^ Pelecinus obturator Drury is a long black hymenopter (female 2-2^:5 inches long), parasitic on white grubs {Lachno sterna). It is sometimes grouped with the Proctrypids under the Serphoidea. ICHNEUMONIDiE (ICHNEUMON FlIES) These insects form an important group of parasites upon injurious forms. The females lay their eggs either within or upon the host larva, and the maggots feed within the host until maturity, feeding upon its blood by osmosis through the skin; in some cases, by attacking muscle tissues and the fat body, and getting air, probably by attach- ment to the tracheae. Cocoons are often spun on the back of the host, from which emerge the adults. Some common genera are Ophion (light brown with compressed abdomen), parasitic on Polyphemus larva, Thalessa (with a long flexible ovipositor) on Pigeon Tremex, Pimpia conquisitor on the pupae of tent-caterpillars, the cotton-worm and the Brown-tail, P. inquisitor on tussock caterpillars (see Howard's Insect Book), and Trogus parasitic on chrysalids of Papilio. Braconids (Braconid Flies) (Figs. 235 and 236) Braconids are, as a rule, smaller than the Ichneumons, but like the latter are valuable parasites. Aphidius and Lysiphlebus parasitize CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 353 plant-lice, Apanteles tomato worms, cabbage worms and others, Micro- gaster Grape Sphinx caterpillars; Meteorus Fall Web-worms. Braconid flies are wasp-like, brownish or yellowish-black, and about J^ inch long. Fig, 235, — A tomato worm (Phlegethontius sexto), bearing cocoons of the parasitic Apanteles congregatus. Natural size. (After Folsom.) Fig. 236. — Bassus earinoides. A braconid parasite of the budmoth. Much enlarged. Chalcidid^ (Chalcid Flies) (Fig. 237) The great majority of Chalcis-flies are beneficial as parasites on injurious insects. They are minute metallic insects with stout heads 23 354 ECONOMIC ENTOMOLOGY and bodies. They are recognized by the branched single vein of the fore wings. Their larvae attack many species of caterpillars. Among the more common forms are Pteromalus puparum on the pupae of the White Cabbage Butterfly; Aphelinus on scale insects; M onodontomerus (Breus on the Biro wn- tail and Gypsy Moths; Tricho gramma on many caterpillars, and Coslopistha nematicida on the Larch Saw-fly. Tetra- stichus, Dibrachys, Coccophagus, Scutellista, Prospaltella, Eupelmus and Aphycus are other valuable economic forms. The four following species are injurious: Wheat Joint Worm (Isosoma tritici F tch.). — (Consult Farmers' Bull. 132 and 1006, U. S. Dept. of Agric.) Adut. A minute black 4-winged ant-Hke fly; J^ inch long. May. Injurious in the East on account of the larva living in the stems of wheat, sucking the juices and causing a swelling in the stem. Infested plants contain one or more hard woody cells in the stem just above the second or third joint from the ground, in which live the larvae or grubs. On nearing maturity the stems fall" or break at the places of injury. Eggs. — Small, white, round-oval. Inserted in daytime, singly at a place, in the stem by the sharp ovipositor, but of en as many as 15 into one stem. Each female may lay as many as 70 or more eggs. Hatch in about 14 days. Larva. — A yellowish- white maggot, J:5 inch long, tips of jaws brown, 3 to 4 moults; full grown in 3 weeks; hibernates in wheat straw; forms cell in stem. Most of the larvae change to pupae late in Autumn. Pupa. — Yellow to black; 3^:5 inch long. Parasites. — Ditriponotus aureoviridis, Homoporus chalcidephagus , Eurytoma holteri parva, Eupelmus epicasta Walk., all chalcids. Control. — Rotation of crops; burning and deep plowing under of stubble when practicable, or harvesting of stubble in spring, collecting with horse-rake and burning; preparation of good seed-bed. Wheat Straw Worm {Isosoma grande Riley). — A pest west of the Mississippi; adults emerge in April-May from stubble and lay eggs, and the larvae eat the forming heads of wheat. Adults appear again in June and lay eggs above the upper joints. Larvae pupate by October and winter is passed in the stubble. Species of Isosoma (Females) (after Howard) A. Mesonotum smooth, polished, shining. — grande. A A. Mesonotum rugulose; abdomen longer than thorax. CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 355 B. Pronotal spot minute. — hordei. BB, Pronotal spot large, distinct. C. Second abdominal segment longer than fourth and fifth together. — secale. CC. Second abdominal segment shorter than fourth and fifth together. — tritici. Apple Seed Chalcid (Syntomaspis druparum Boh.). — An introduced insect from Europe. Well distributed in the Northern States. Causes deformities and corky discolored streaks in the fruit when repeated puncturing occurs. Adult. — A wasp-like chalcid, bright green with bronzy reflections; legs brownish-yellow; wings clear hyaline. Female }^ inch long, with long slender ovipositor; male smaller than female. June-July. Eggs. — Elongate-oval, one end prolonged into a slender twisted pedicle, yellowish-white. Laid in the seed and hatch in 6 to 8 days. Larva. — Spindle-shaped and curved; 3^^ inch long; five instars. Feeds on the soft kernel until September, then hibernates in the hollow seed until spring. Pupa. — Dark greenish when mature; dura- Fig. 237. — Pentarthron tion about 4 weeks. . T S; Lti'olh.^^"- Control. — Collect and destroy apples lying under the trees. Clover Seed Chalcid (Bruchophagus funebris Howard). Adult, — A minute black four- winged fly, J-f 2 ii^ch long. Egg. — Elliptical with a slender tube, whitish and smooth. Larva. — A white stout footless maggot, }i5-}y{2 iiich long. Pupa. — Dark and less than Jf 2 ii^ch long. Life-history. — This insect usually winters over in the seed as a well-developed larva; the pupal stage is rather short, and the adult lays her eggs in May and June. The first of the adults of this brood appear in July and August, but some do not come out till the following spring. There is much overlapping of stages and the number of broods is difficult to determine. Folsom traced as many as three generations per year, with a possibility of four. 356 ECONOMIC ENTOMOLOGY Group Vespoidea (Wasps) The true wasps are divided into the SoHtary Wasps (EumenidcB) and the Social Wasps {Vespidce). The former have similar habits to the Digger Wasps (see below), forming burrows in the earth, in wood or on twigs of shrubs. In the latter class two genera are common, Polistes with a spindle-shaped abdomen, and black ringed with yellow, and Vespa, the common hornet or yellow- jacket. The paper nests attached to buildings, trees or in the earth are constructed from bits of wood made into a pulp, and are provisioned with spiders or insects. The nest of Polistes consists of a single comb, attached by a short stem, but that of Vespa consists of several layers of combs with a papery covering. The White-faced Hornet is well known as the maker and owner of the large paper nest. It provides its young with noxious larvae, and un- doubtedly does much to control insect life. Occasionally, however, it may injure grapes or peaches by eating holes in them. The life-history is quite similar to that of the Bumble Bee — males, females and workers (undeveloped females) making up the colony. Only the females sur- vive the autumn and hibernate. Group Sphecoidea (Digger Wasps) The Digger Wasps contain a large number of families. (See Com- stock's Manual of Insects and Hymenoptera of Connecticut.) They are solitary and store their nests with paralyzed insects or spiders. The nests vary in structure; some are made of mud attached to ceilings of buildings, some made in the pith of elder, sumach, etc., and others in sandy banks. The more common genera are Tiphia, Peloposus, Sphecius, Stigmus and Trypoxylon. Group Apoidea (Bees) The bees are grouped into two families, the Andrenidce (Short- tongued bees) and the Apidce (Long-tongued bees). In provisioning their nests with honey or pollen, or both, which they collect from flowers, bees are of great economic importance in the cross-fertilization of many flowers. (See Part I.) Most of the Andrenidce are miners and make their nests in the ground. They are sohtary, each female making her own nest, but CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 357 frequently the nests are close together. Some of the more common genera are Andrena, Halictus and Prosopis. To the Apidce belong the Leaf-cutter bees (Megachile), Carpenter bees {Ceratina and Xylocopa), Guest-bees (Psithyrus), Bumble Bees (Bombus) and Honey Bees (Apis). The Leaf-cutter bees (Megachile) make tubular cells out of nearly semi-circular pieces of leaves cut from rose bushes and various plants. These cells are placed in burrows made either in the ground or in soft wood. The Mason Bees (Osmia) construct nests of clay and sand in stone walls, old fence posts and trunks of trees. The cells are composed of sand, earth or clay mixed with pebbles or bits of wood, all glued firmly together. (See Mantcals of Comstock and Kellogg, and Sladen's "Humble bee" for details regarding the habits of bees.) Social Habits of Bees. — Bees show a gradation from solitary forms like Ceratina, Prosopis, Andrena and Halictus to colonial forms like the bumble bee and honey bee. This gradation may be repre- sented as follows: A. Solitary bees. B. Queen dies after egg-laying and providing food for larvae. C. Nests quite apart. — Prosopis, Ceratina. CC. Nests in colonies, but females work independently. — Andrena, Anthrophora, Osmia. CCC. Females hibernate in companies. — Xylocopa. CCCC. Two or more females use a common hole or refuge. — Halictus, Panurgus. BB. Queen survives to see the brood and watch over the nest. — Species of Halictus. AA. Social Bees. B. Fertilized female hibernates alone. — Bumble Bees. BB. Permanent societies with perfect combs. — Honey Bees. Biunble Bees (Bombus spp.). — From an economic standpoint Bum- ble Bees are of importance as agents in pollination of red and other clovers. The over-wintering queen starts her nest in the spring usually in a deserted mouse's nest. She places in it some pellets of pollen and nectar and on them in a wax cell lays her first eggs. Next she constructs a ''honey-pot" for holding the honey collected at the entrance to the nest. The larvae feed on the pollen, and when full grown — about 11 days after the eggs are laid — form silken cocoons in which they spend their pupal period of about 11 days. The first 3S8 ECONOMIC ENTOMOLOGY brood are small workers who relieve the queen of further work except that of egg-laying. Later broods are large workers and the last brood consists of males and females. In the autumn all succumb except the young queens. The males and females of Bomhus are reared after the workers near the close of the summer, and mating occurs then. The number jof workers is relatively small, 300 in some of the underground-dwelling: species to 60 in some of the surface-dwelling species. The more common species are B. horealis, B. terricola, B. ternarius, B. pennsylvanicus, B. vagans, and B. fervidus. Honey Bee {Apis mellifera Linn.). — There are three kinds of in- dividuals — queen, drones and neutral workers. The queen is the mother of the colony and lays the eggs; the drones are males and relatively few. A colony at the beginning of the season contains 30,000 to 40,000 workers. Honey. — Obtained from nectaries of flowers by workers and carried in the honey sac in the abdomen. Nectar is stored in cells and the surplus water is evaporated by currents of air to 10 to 12 per cent. Finished product is stored in wax cells about the brood chambers. Wax. — Made from honey and sugar. Gorged workers hang in dense masses and plates of wax appear beneath the abdomen in about 24 hours. The wax is then transferred to the mouth and there masti- cated with a fluid excreted by the cephalic glands. Twenty pounds of honey are required to make i pound of wax. Propolis. — Obtained from buds and used to strengthen the cells. Brood. — Egg hatches in 3 days. The grubs are nursed by workers on fluids from the mouth; later they are fed on pollen, honey and water; after 5 days the grub spins its cocoon, and 13 days later the winged bee emerges. Duration of Stages. — Egg Larva Pupa Total Queen 3 days 3 days 3 days S}4 days 6 days 5 days 7 days 15 days 13 days 15K days 24 days 21 days Drone Worker The queen grub is fed on royal jelly — the nutritious fluid excreted by the nurses. CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 359 Swarming. — As the queen lays about 1000 eggs per day a time arrives when a prosperous colony tends to be overcrowded. The workers then rear new queens and the old queen collects several thou- sand workers about her and emerges to found a new colony. This phe- nomenon is known as swarming. Frequently a hive may swarm twice or thrice during a favorable season. The expert apiarist may save much worry and trouble by inducing swarming artificially. Fertilization. — The queen is fertilized by a drone during the nuptial flight, when her spermathecae are filled with spermatozoa. She usually mates but once, and the sperms are sufficiently numerous to fertilize the thousands of eggs which produce workers. The queen may also lay some, relatively few, unfertilized eggs which produce drones. Characteristics of the more Important Races of Honey Bees- F. Phillips) (Dr. E T>„^„ Color of ^^^® abdomen Disposi- tion Quality as a producer Cappings of comb honey Remarks German Black Cross Poor White First race introduced into America. Italian Yellow stripes Gentle Best Fairly white Most popular race. Carniolan .... Grey Gentle Good White Some advocates in the United States. Caucasian Yellow grey Gentlest known Good White Recently introduced. Good for amateurs. Banat Black Gentle Good White Recent. Cyprian Yellow Vicious Good Watery Now practically abandoned in United States. GROUP FORMICOIDEA (ANTS) Family Formicid^ (Consult Howard's Insects, Wheeler's Ants and Formicoidea in Hymenoptera of Connecticut) Three classes of individuals occur in an ant colony — males, females, and wingless workers, the last being undeveloped females. 360 ECONOMIC ENTOMOLOGY The males and females mate in the air, after which the males die and the females tear off their wings. They then build small cells and com- mence egg-laying. These eggs and their larvae are first tended by the queen but later by the workers. The larvae are white and legless, and at maturity spin egg-shaped cocoons. How queens are developed is not known, but they and the workers may live for many years. The food of ants is quite varied, but is usually of animal origin, especially nectar and dead insects. On the whole ants are beneficial. As to general habits ants may be classified into: 1. Hunting ants which prey upon insects, other ants, etc. 2. Slave-making ants which capture other species and make slaves of them. 3. Honey ants which collect honey and store it in certain members of the colony — mostly western forms. 4. Leaf-cutting ants which bite off bits of leaves, take them to their nests, and grow fungi upon them — mostly tropical forms. 5. Harvesting ants which collect and store seeds for food supply in underground granaries — mostly southern forms. The colonies or nests occur either in the ground or in decaying wood, and consist of irregular cavities that intercommunicate. Often above the nests are dome-shaped hills in which the eggs are hatched, and the legless larvae and pupae nurtured. Ants belonging to the sub-family Camponotince are stingless, and here belong the genera Lasius, Camponotus and Formica. Those belong- ing to the sub-family Myrmicince are stinging ants, including the genera Solenopsis, Tetramorium, Monomorium, Cremastogaster, and Myrmica. House and lawn ants may be classified, according to origin, into: 1. Tropical old-world ants, represented by the little red ant or Pharaoh's ant (Monomorium pharaonis Linn.), the crazy ant (Pre- nolepis longicornis Latr.), a related species Prenolepis vividula Nyl. and Plagiolepis longipes Jerden. 2. Introduced tropical new- world ants, represented by the Argentine ant {Iridomyrmex humilis Mayr.), and Prenolepis fulva var. pubens Fovel. 3. Native Temperate N. A. ants, represented by the thief ant (Solenopsis molesta Say), the carpenter ant (Componotus herculaneus, var. pennsylvanicus DeG.), the little black ant (Monomorium minimum Bckley), the American lawn or corn ant (Lasius niger var. americanus CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 36 1 Emery), and the European meadow ant or pavement ant {Tetramorium ccespitum Linn.)- The three last mentioned species are also fre- quenters of gardens and lawns (Fig. 238). House Ants {Monomorium pharaonis Linn.). — (Consult Circ. 34, Farmers' Bull. 740, U. S. Dep. Ag.; Wheeler's Ants.) These are the little red ants that have their nests in the wall, or beneath the flooring, Fig. 238. — The little black ant {Monomorium minimum): a, male; h, pupa; c, female; d, same with wings; e, worker; /, larva; g, eggs; group of workers in line of march below. All enlarged, the lettered illustrations all drawn to the same scale. {After Marlatt, U. S. Dept. Agric.) and are nuisances about houses. The black ant {M. minutum) and the pavement ant {Tetramorium ccespitum) are also occasionally found in houses (Fig. 239). Adults. — Worker neuters, winged males and females, and wing- less females constitute an ant colony. 362 ECONOMIC ENTOMOLOGY Eggs, — Laid in immense numbers by the solitary queen mother; minute, oval, whitish; cared for by the workers. Larvae. — Fed by workers. FupcB. — White, cared for by workers; egg-Hke but much larger than the true eggs. Fig, 239. — The little red, or Pharaoh's ant (Monomorium pharaonis): a, queen or female; h, worker. Both drawings enlarged to the same scale. {After Marlatt.) Control. — Destroy nests with hot water or carbon bisulphide; dust with sodium fluoride; trap ants in sponges soaked in sweetened water or in a syrup poisoned with arsenate of soda. Formula: sugar, i lb.; arsenate of soda, 125 grains; water, i qt.; boiled and strained. Lawn or Com Ant (Lasius niger var. americanus Em.). — This ant, which is very abundant in the corn-growing districts of the Central CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 7,6^ States, is closely associated with the corn-root louse or aphid (Aphis maidiradicis Forbes). Forbes has shown very interestingly how the ants carry the eggs of this aphis into the underground galleries of their nests on the approach of winter, tend them carefully, and in the spring carry the young aphids to suitable weeds, transferring them later to the corn plants. In the control of this aphid, therefore, the best method is to plow and harrow in the autumn infested fields so as to break up the ants' nests, to destroy the weeds that may serve as temporary food-plants, and to practise crop rotation. NEAR RELATIVES OF INSECTS INJURIOUS TO PLANTS AND ANIMALS Crustaceans, Arachnidans and Myriapods belong also to the great Branch of Animals called the Arthropoda, hence are here termed "near relatives" of insects. Class Crustacea Sow Bugs, Pill Bugs or Wood Lice. — Sow bugs cause considerable injury both indoors and outdoors to young growing flower and vege- table crops. They occur in dark moist conditions, near dwellings such as cellars, outhouses; about walls, cisterns, water barrels; under boards, stones and rubbish; in green- houses and rockeries. They usually feed at night. They are sometimes injurious in mushroom beds and to the roots of strawberries. The eggs are laid in early summer. The in- cubation period varies with the different species — in Armadillium vulgar e Latr. about 70 days. The young are carried in a pouch formed of modified plates on the abdomen of the female. Other species are Porcellio Icevis Latr., A. quadrijrons, and Oniscus asellus Linn. They have seven pairs of legs, and antennae which are 7-jointed (Fig. 240). Control. — Cleanliness about outhouses, potting houses, etc.; the use of baits of sliced potatoes covered with a thin coating of Paris green, or Paris green, sugar and flour (1:2:2), or of bran-Paris-green- molasses-orange juice; sprinkling or spraying with kerosene emulsion; Fig. 240. — Por- cellio Icevis, a common sow bug. (After Essig.) 364 ECONOMIC ENTOMOLOGY sprinkling Paris green on the floor of greenhouses and covering it with damp boards; trapping by means of inverted flower pots containing damp hay or moss; flushing crevices, edges of greenhouse beds, benches and ground beneath with hot water or steam; fumigation with NaCN or KCN (J^-J^ oz. of cyanide to every 100 cubic feet of space). Class Arachnida ORDER ACARINA (MITES AND TICKS) Abdomen unsegmented, sometimes with annulations; without a deep constriction between cephalothorax and abdomen; legs usually well developed; body more or less depressed. Chief Families and Genera EriophyidcB = Elongated annulated forms. Eriophyes — on plants. ArgasidcB = Argus, Ornithodoros — on birds and mammals. IxodidcB = Ixodes, Dermacentor, Rhipicenlor, Mar gar opus, Boophilus, Amhlyomma — on mammals. Dermanyssidce = Liponyssus, Dermanyssus — chiefly on birds. Gamasid(B = Lcelaps — on Arthropods and mammals. TarsonemidcB = Pediculoides, Tarsonemus — on man and grain and other plants. TyroglyphidcB = Tyroglyphus, Rhlzoglyphus — on dried fruits and bulbs, and man. SarcoptidcB = Psoroptes, Sarcoptes, Chorioptes — producing itch on mammals and birds. TetranychidcR = Tetranychus, Bryohia — on plants. Trombidiidce = Trombidium. Harvest mites. (Consult Handbook of Medical Entomology,hy Riley and Johannsen, pp. 259- 273). Family Dermanyssxd^ (Poultry Mites) (Consult Bulls. 553 and 801, Bur. Ent,, U. S. Dep. Agric.) A most common form is the Chicken Mite (Dermanyssus gallincB DeG.), a flattened, elliptical mite, with 8 legs, J^o ii^ch long, distinctly reddish after feeding. The eggs are oval, smooth and pearly white, and laid in cracks and crevices of the wood or straw of the nests and roosts. They hatch in 48 hours at summer temperature and young mites become mature in less than 10 days. They are most active at night. The young larva on hatching is white and has 3 pairs of legs. In about 24 hours CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 365 it moults and this nymph (first stage) with 4 legs moults in about 24 hours forming the second stage nymph which moults into the adult. Control. — (a) Cleanliness and sunhght, as mites thrive best in damp, dirty houses; {h) remove droppings and all old nesting material; {c) clean and scrub or wash with water all the perches, roosts, nests, floor and walls; {d) spray or paint these with a 5 per cent, cresol, crude petroleum, or with 3 parts kerosene and i part crude carbolic acid, or with kerosene emulsion. Two or three applications are necessary at intervals of a few days. When houses are whitewashed 4 oz. crude carbolic acid should be added to each gallon of whitewash. It is often advantageous to scatter a mixture of three parts of dry slaked lime and one part sul- phur with the doors and windows closed. Family Argasid^ Spinose Ear Tick {Qmithodoros megnini.). — Found attached to the ears of domestic animals and jack rabbits. Occurs in the south- western U. S. as far north as Nevada and Oregon and is often trouble- some. Treated by an injection of a mixture of two parts pine tar and one part cotton-seed oil into the ears. (Consult Farmers Bulletin 980, U. S. Dept. Ag.) Family Sarcoptid^ (Scab and Itch Mites) The Poultry Itch Mite {Sarcoptes mutans Robin) produces "scaly- leg" of fowls, turkeys, etc. It may also attack the comb and beak. The disease is contagious. The mites bore under the scales of the foot and leg and burrow deeper and deeper into the tissue, setting up an irritation, frequently a lameness, and sometimes causing the loss of some of the toes. Control. — (i) Oil of carraway (i part to 5 parts white vaseHne) rub- bed into leg and foot every few days; (2) bathing in warm soapy water and applying sulphur ointment or naphthaline mixed with 9 parts lard, or 5 per cent, creolin or zenoleum, or vaseline and zinc ointment. Itch Mite of Man {Sarcoptes scabiei Latr.). — This pest burrows under the skin where eggs are laid. In about a week the eggs hatch and the young mites become mature in about 4 weeks. The lesions 366 ECONOMIC ENTOMOLOGY and blisters formed are very irritating, and the disease may spread rapidly. Sheep Scab Mite (Psoroptes communis var. ovis Furst). — This mite burrows under the skin of sheep forming large areas of crust called scabs. From these areas, commonly confined to the neck, back and rump, the wool falls away. The disease is contagious. Each female lays 15-24 eggs which hatch in 2-3 days; the young mites mature in 15 days. (See Farmers' Bull. 713, U. S. Dept. Agr.) Family Ixodid^ (Ticks) Cattle Tick {Mar gar opus annulatus Say). — In the Southern States this tick causes large losses as the agent responsible for the Texas Fig. 241. — Rocky mountain spotted fever tick {Dermacentor venustus) : i, unengorged female; 2, unengorged male. (^Year Book, U. S. Dept. Agric.) Cattle Fever. It is a dark 8-legged creature. The engorged female drops from cattle to the ground and lays its eggs. The young ticks (seed ticks) on hatching crawl up nearby herbage and drop on the backs of cattle as they brush by. Attached to the skin they feed until they become mature. Rocky Mountain Spotted Fever Tick {Dermacentor venustus Banks). — This tick, with others, is able to transmit the so-called "Spotted Fever" of man in the Rocky Mountain states. It is possible that the ground squirrel of the region serves as a reservoir of the virus. The CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 367 disease is probably transferred through the saHvary secretion of the tick. Dr. Hadwen reports cases' of "tick paralysis" of man and sheep in British Columbia due to the bites of this species (Fig. 241). D. variahilu Say is a widespread form occurring on dogs, cattle horses and man, but apparently is of little economic importance. Family Tetranychid^ (Red Spiders) "Red Spider" {Tetranychus himaculatus Harvey). — (Consult Bull. 416, U. S. Dep. Agr., 191 7; Bull. 79, Mass. Ag. Exp. St.) A common pest on roses, violets, carnations in greenhouses; cucumbers in the vegetable garden; and on many outdoor perennials; and a serious pest in Western Colorado on fruit trees, in Central California on hops, and in the Southern States on cotton. Adult. — Color of female variable— rusty green, amber, yellowish, but more often brick red, with pigment blotches on the sides; legs pale amber; palpi pale salmon; body oval, pear-shaped, J^o i^ch long; color of male rusty salmon, body J70 inch long. Eggs. — Spherical; clear becoming opaque; 50-100 eggs laid by each female over a period of 7-12 days. Incubation period varies with the temperature — -3-17 days. Laid singly on the under side of the leaves. Larval stage. — Six-legged, round and colorless; duration 2-17 days. First Nymphal Stage. — Eight-legged, oval, darker in color; duration 2-4 days. Second Nymphal Stage. — Females only have this stage; elongate; duration 13^^-13 days. Feeding is done by means of sharp, slender, lance-hke mouth-parts thrust into the leaf, producing spotting. The fine webs spun on the under surface of the leaf are probably protective. Reproduction is both sexual and parthenogenetic. Control. — Spray with water; with lime-sulphur, nicotine sulphate and miscible oil, linseed oil emulsion or fish oil soap, potassium sulphide, kerosene emulsion; dust with finely resublimed sulphur; clean culture or eradication of weeds which harbor mites during winter. Clover Mite {Bryohia pratensis Carman). — This is a small red mite about Koo inch long which injures the leaves of clover, apple and other orchard and forest trees by puncturing the tissues, causing them to become yellowish and sickly. The winter is passed in the egg 368 ECONOMIC ENTOMOLOGY stage, and the small round red eggs can be readily recognized in the crotches of fruit trees. There are several generations in a season. In autumn it sometimes invades houses. Family Eriophyid^ (Blister Mites) (Consult Bull. 283, N. Y. Ag. Exp. St.) Pear-leaf Blister Mites {Eriophyes pyri Pgst.). — This introduced mite is responsible for the reddish or yellowish blisters on the leaves ■^ \ ls t \ Fig. 242. — Pear-leaf blister mite (^Eriophyes pyri). {After Nalepa and Parrott ) of pear and apple. These bhsters turn brown later in the season, and badly infested leaves drop. Nursery stock is often badly injured. The mites Hve in colonies beneath the epidermis, forming blister- like galls. Within these galls the minute oval white translucent eggs are laid and hatched, and the young mites grow to maturity. They then leave by a minute opening on the lower surface and go to new CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 369 leaves where new blisters are started. The winter is passed as eggs beneath the bud scales. The adult mite is white, elongate, 4-legged, K25 inch long (Fig. 242). Control. — Spray with lime sulphur, wash before leaf buds open. In addition, the following Eriophyids occur in orchards: Epitri- merus pyri Nal. and Phyllocoptes schlechtendali Nal. on apple and pear, Eriophyes phloeocoptes Nal. on plum, and Phyllocoptes cornutus Banks on peach. Family Tarsonemid^ Cyclamen Mite (Tarsonemus pallidus). — This mite is reported from many scattered sections as destructive to cyclamens. It destroys the flowers and flower buds, and all stages may be found there. Attacked flowers become distorted, streaked and flaccid and die prematurely. In many cases they die before opening. Infested leaves curl. The adult mita is pale brown, Jf 25 inch long; the eggs are oval and trans- lucent. Control. — Spray plants with nicotin and soap solution when the younge plants are transferred from flats to pots, and every 10 days thereafter. Fig. Class Diplopoda 243. — a common milliped. {After Folsom.) Millipeds. — Millipeds are often termed "thousand-legs," "galley- worms," or "false wireworms." They sometimes occur in rich garden soils containing much refuse organic matter, and do considerable injury. They attack plants grown from seed, and also gnaw holes in potatoes, strawberries and bulbs (Fig. 243). The eggs are laid in holes in the soil in the spring, and it requires about 2 years for the young forms to reach maturity. They are night-feeders. The most common injurious forms belong to the Families Julidce and PolydesmidcB. Julus canadensis is dark brown or black above with sides spotted with yellow, and is from i to 2 inches 24 370 ECONOMIC ENTOMOLOGY long. Jtdus virgatus injures lettuce and /. coeruleocinctus the fruit and roots of strawberries. The young millipeds have only three pairs of legs. Spirobolus is from 3 to 5 inches long. Polydesmus canadensis is a deep brown flattened form. Oxidus gracilis is a common pest of greenhouses, sometimes occurr- ing in millions in an abundant supply of decaying vegetable matter. It attacks sprouting seeds, and burrows into the decaying spots of roots. In color it is chestnut-brown marked in parts with lemon yellow. Gos- sard says that the whitish eggs are laid in April and May in the soil in masses of from 100 to 300 or more and hatch in about 20 days. So far as known there is but one generation a year. Control. — (i) Trap with slices of beet or potato; (2) mix thoroughly with the soil tobacco dust, gas lime (3 tons to acre in fall), or soot; (3) give the soil a thorough drenching with kerosene emulsion or two or three light dressings of nitrate of soda (100 lb. to acre). BRANCH MOLLUSCA Class Gastropoda Garden Slugs (Limax spp.). — Garden slugs are moUusks and not arthropods, but may be treated here. They are frequently injurious in moist situations to garden and greenhouse produce. They dislike sand, sawdust and ashes as these dry up the secretion of mucus. They spend the winter in the ground encased in their own slime. Some species, however, winter in greenhouses and remain active through- out the year. They are active at night, and feed upon green succulent leaves, mushrooms and ripe fruit. There are three common injurious species: L. maximus, L. agrestis and L. flavus. Slugs differ from snails in the apparent absence of a shell, but in reality the shell is reduced to a thin horny plate embedded in the mantle. The eggs are large, round, transparent, yellowish, occurring in gelatinous clusters under boards or refuse. They hatch in spring and the slugs become half grown by fall. The adults may live several years. Blackbirds, toads, moles, centipeds, and poultry destroy slugs and snails. Control. — (a) Trapping by placing out shingles or boards is quite effective. Examine the traps every morning and crush the slugs col- CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 371 lected under them, (b) Liming the soil is also useful, (c) If slugs have collected on the plants dust them with a mixture of lime 5 parts and fresh hellebore i part. Providing the hellebore is fresh this is very- effective and does not injure the plants, (d) Use the bran-arsenic- treacle mash as for cutworms, (e) Broadcast salt at night in misty weather. (/) Use poultry. (See Farmer's Bull. 959, U. S. Dept. Ag.) Nematodes or Eelworms Common Eelworm {Heterodera radicicola Greef). — Eelworms, although not closely related structurally to insects may be considered here in connection with them. They are common pests of roots and underground parts of plants, producing root-knots, galls or rough warty surfaces. Tomatoes indoors and potatoes outdoors are often injured, especially when grown on sandy soil. The males are micro- scopic in size and resemble miniature eels, hence the name eelworms. The females are glistening pearly white and pear-shaped or rounded, about half the size of a pin head. Life-history.— The eggs are oval-shaped and are produced by the females in great numbers in the knots or galls. They hatch in a short time and the young eelworms seek new quarters and feed upon the roots of plants producing the characteristic deformities. They may pass the winter in their host; or it may be on other plants. The young forms may even encyst themselves in the soil. The following plants are liable to be severely injured by Nematode attacks (Gilbert, Farmers' Bulletin 625): Soy bean, beet, carrot, celery, cow pea, crimson clover, cucumber, lettuce, peach, potato, squash, tobacco, tomato, watermelon; less severely: alfalfa, asparagus, Lima bean, cabbage, sweet clover, cotton, onion, garden pea, radish, spinach, strawberry, vetch. The following plants are largely immune: barley, corn, grasses, oats, rye, wheat, and cow peas (some varieties). Control. — Infested soil in greenhouses may be sterilized by steam, carbolic acid (1:20) or formalin; mix the soil intimately with gas- lime; rotation of crops; summer fallow; plant clean nursery stock. PART IV THE CONTROL OF INJURIOUS INSECTS The effective control of injurious insects demands a knowledge of the habits of the insects themselves so that they may be attacked at the most vulnerable point. As insects differ greatly in their habits and life-history, methods of control must also differ greatly, not only with regard to individual insects but also with regard to the crops that are attacked. For example, it is obvious that insects that live mostly in the ground and injure roots must be controlled in a different way from insects that feed on foliage. Moreover, insects that attack the cereal crops of the farm cannot profitably be treated in the same way as insects that attack the fruit and leaves of garden or orchard crops. It has been said that the aim of the economic entomologist should be the control of injurious insects at a profit. It may not be possible to achieve this aim in all cases, for insects must be controlled sometimes for esthetic reasons, not entirely for the losses they cause. Moreover, recent investigations go to show that many so-called minor insects if left untreated simply because it does not pay to treat them, may turn out to be harmful in some indirect way. The term "at a profit" used above is rather indefinite. It is sometimes impossible to say whether the control of injurious insects is profitable or not for there are many factors to be considered. A con- trol, seemingly unprofitable from the money standpoint for a particular year, may be profitable from the standpoint of the health of the trees and of future production of fruit. Moreover, orchardists recognize the cumulative effect of continuous spraying. Factors of Insect Control The factors operating in the control of noxious insects may be grouped as follows: I. Climatic. — The range and number of insects are strongly influenced tiy temperature, rainfall, winds, etc. (see Part I). 373 374 ECONOMIC ENTOMOLOGY 2. Food Supply. — An important regulator of insect life (see Part I). 3. Parasites. — Protozoa, bacteria, fungi and insects. 4. Predatory Animals. — Birds, insects, snakes, toads, annelids, etc. 5. Cultural or Preventive Methods (see below). 6. Artificial or Remedial Methods (see below). The first four factors are, however, almost wholly beyond man's control. Methods of Control The main practical methods of control of injurious insects may, therefore, be grouped into two general classes : (a) Cultural or Preventive Methods — those practices of culture or of handling the crop that prevent, or interfere with, the development of injurious insects; and (b) Artificial or Remedial Methods — those which deal with injurious insects when they appear by the use of poisonous or contact substances, or other artificial means. A. CULTURAL OR PREVENTIVE METHODS For most farm crops Cultural Methods are the only practicable methods. They are essentially Preventives. The most important cultural methods are the following: I. Rotation of Crops. — The growing of crops year after year on the same land permits many insects which feed on the roots to develop and multiply. On the other hand, a good crop rotation makes it impossible, or very difficult, for an insect to pass through its life stages without being seriously disturbed and its food supply destroyed. (a) Some rotations are preferable to others when wireworms and white grubs are abundant. For example, where corn is the chief crop a rotation of clover, corn, oats is better than forage grasses, corn, oats. Professor Forbes, of Illinois, advises plowing the grass in early fall, and sowing clover either with barley, wheat, or rye. The clover is allowed to stand 2 years and is followed by corn or roots. As certain crops such as clover, barley, wheat and rye are not so liable to attack as corn, potatoes, mangels and oats they are better adapted to follow sod. (b) Moreover, if sod infested with white grubs is broken up early, sown to turnips or rape, and pastured with hogs in late summer and THE CONTROL OF INJURIOUS INSECTS 375 autumn most of the white grubs will be destroyed by the hogs. As the grubs burrow deeply at the approach of cold weather it is not advisable to pasture hogs late in the season. Clover is seldom attacked by white grubs, hence is useful as a "starvation" crop before planting to corn, potatoes or mangels. (c) Where the clover root borer is injurious in second year clover fields, the sod should be plowed up after the first season. 2. Good Cultivation. — This involves careful treatment of the soil, the crop, and its products. It means careful attention to the waste products and the waste places which are breeding places for many injurious insects. It means the adoption of deep, late fall plowing under certain conditions, which practice is one of the best methods of dealing with wireworms, white grubs, cutworms and grasshoppers. It means high fertility of soil, and good drainage of the land so that vigorous healthy plants, capable of resisting the drains of insect attacks, are grown instead of poorly nourished plants which are more likely to succumb. Timely plowing, planting, and harvesting are often effective against some of the worst insects of the farm. For example, two or three fall plowings destroy large numbers of maturing wireworms and white grubs; early plowing of grass in August destroys the eggs and larvae of cutworms and grasshoppers. Late sowing of fall wheat prevents Hessian-fly injury; and early cutting of the first crop of clover destroys the first brood of the clover seed midge and thus saves the clover seed of the later crop. The destruction of rubbish, screenings, stubble, dead stalks and weeds deprives many hibernating insects of resting or breeding places. Such insects are Hessian-fly ''flaxseed," chinch bug, clover hay worm, tarnished plant bug, squash bug, stalk borers, etc. Cutworms endeavor to lay their eggs in August and September on weeds and grasses. Consequently if the land is kept free from weeds and the grass is fed or mown few cutworms will appear the following spring. The application of fertilizers, such as nitrate of potash, barnyard manure, wood-ashes, and tobacco dust, is often advantageous in forcing the growth of plants that are attacked, and in repelling insects. 3. Co-operative Measures. — Co-operation among the farmers of a district is required for the successful control of certain insects such 376 ECONOMIC ENTOMOLOGY as the Hessian-fly, the pea-weevil, the codling moth, the San Jose scale, the plum curculio, the apple maggot, grasshoppers and many others (Fig. 244). 4. Natural Enemies of Insects. — {a) Farmers and fruit-growers can do much to encourage the presence of insectivorous birds among the crops. These birds are most important in keeping injurious insects under control. Fig. 244. — The San Jose scale. {After Alwood.) ' (b) Frequently, too, hogs and poultry can be utilized to advantage in destroying white grubs, cutworms, grasshoppers, asparagus beetles, etc., in infested fields. (c) Lady-bird beetles, ground beetles, and other predaceous insects should be protected as far as possible (see Section relating to the Utilization of Parasites, p. 401). 5. Restriction and Exclusion of Foreign Insects. — It has been fre- quently pointed out in the preceding pages that many of the most THE CONTROL OF INJURIOUS INSECTS 377 destructive insects are imported forms. Until recent years no effort had been made to exclude foreign insects, but now a rigid inspection of plants which may harbor dangerous pests occurs at the ports of entry. In some cases plants are subjected to fumigation with hydro- cyanic acid gas. That such restriction and exclusion are very important is evident in view of recent experiences with the brown-tail moth, the white Ermine moth, the Mediterranean fruit-fly, and others. On the other hand it is advisable to import foreign species that prey upon other foreign insects already here as was done in the case of the gypsy moth and the cottony cushion scale. B. ARTIFICIAL OR REMEDIAL METHODS Artificial methods may be conveniently classified as follows: 1. The application of poisons against biting insects. 2. The application of contact substances against sucking insects. 3. The use of poisonous gases. 4. The application of repellent substances. 5. The use of protectors. 6. The use of traps and trap crops. 7. The use of ditches. 8. The use of hopperdozers, etc. 9. Collecting, digging out, jarring, etc. 10. High and low temperatures. I. The Application of Poisons for Biting Insects (Consult Farmers' Bull. 908, U. S. Dep. Ag.) The three essentials of a good insecticide are: (a) Efectiveness against insects. {h) Cheapness, both with regard to material and application, (c) Harmlessness with regard to insect hosts. With regard to Efectiveness , an insecticide must be applied: {a) In the proper manner. {h) At the proper time. When the application of the insecticide is made in the form of a spray some form of pump is necessary. In small yards and gardens 378 ECONOMIC ENTOMOLOGY cheap hand-pumps are usually sufficient; but for orchards pressure- pumps, operated either by hand or by power, are essential. With or- chards over 5 or lo acres or with high trees power-pumps or sprays, capable of giving a high pressure of 150 to 200 lbs. are now generally used. An important feature of all spray pumps is the agitator for keeping the chemicals in the tank well stirred. Moreover, it is very essential that the spraying be done thoroughly and at the proper time. Thoroughness of spraying, while largely a matter of personal atten- tion, is secured with greater convenience with a pump of high pressure and with suitable nozzles, extension rods and hose, so that every part of the plant, the tips of the twigs as well as the larger branches, is drenched. The proper time of application is determined by the habits of the insect, and herein lies the value of a knowledge of the life-history of the insect. Fig. 245. — Knapsack sprayer. Pig. 246. — Bucket force pump. SPRAYING EQUIPMENT Outfits for spraying may be classified as follows: 1. Atomizer sprayer, useful for treating individual plants. 2. Bucket with force pump, convenient for small areas (Fig. 246). 3. Knapsack or compressed air sprayer, operated either by hand or by compressed air, useful in greenhouses, stables, poultry houses, etc. (Fig. 245). THE CONTROL OF INJURIOUS INSECTS 379 4. Hand-cart sprayer, a small barrel mounted on a hand cart and operated by a hand -pump. Useful in gardens. 5. Barrel sprayer, with force pump operated by hand. Useful in small orchards and gardens. 6. Tank sprayer, with pressure pump operated either by hand, com- pressed air, traction gearing, gasoline motor, or liquid carbon dioxide. Fig. 247.— An up-to-date spraying outfit in an apple orchard, using the "spra-gun." {Courtesy of the Friend Manufacturing Co.) In orchard spraying every outfit should be provided with a spray-tower so that the tips of the branches may be treated properly (Figs. 247 and 248). Other accessories are strong hose, able to withstand a pressure of about 300 lbs. per square inch, half -inch hose being commonly used; and extension rods with drip guards and cut-ofs. 38o ECONOMIC ENTOMOLOGY The essentials of a good nozzle are: 1 . Simple in construction, adjustable, light and free from projecting parts. 2. Not liable to dribble on account of wearing of packing or springs. 3. Easy to clean. 4. Not liable to clog. 5. Giving a uniform spray when pressure is constant. 7T- ' ■■./. -^'"- --i^*';---' .-m*^^ C;.;■■•^^■:^^v■■:■V^, , sp>-.:f "Vii'' ii «5^..-, s4 .,..#■<' ■> Fig. 248. — Spraying large orchard and shade trees by means of a tank platform and two lines of hose. y- i ^ NOZZLES Three types of nozzles are used in spraying operations— the Bor- deaux, Vermorel and Disk. The Bordeaux nozzle has its opening adjustable by means of a stop-cock so that various forms of sprays can be employed. The spray is made by a straight stream hitting a lip and breaking up into a fan-shaped spray. It is well adapted for vineyard work where Bor- deaux and arsenicals are used. When clogged it can be readily cleaned by reversing the stop -cock. ''Perfecto," "Niagara," ''Seneca" are trade names. The Vermorel nozzle has a central opening in front of a chamber, into which the Hquid enters at a tangent. It gives a fine cone-shaped THE CONTROL OF INJURIOUS INSECTS 38 1 spray but is very liable to clog. A needle operated by a spring can be used to clean the clogged nozzle. It is unsuited to large orchards or with large outfits. ''Buena," ''Cyclone," ''Eureka," ''Dewey," ^'Spramotor, " "Vapor Mist" are trade names. The Disk nozzle, known under several trade names, has been evolved from the Vermorel for modern power outfits. It is larger and has a disk plate at the orifice which may be changed when desired. The chamber is broad and flat and the liquid enters it by two spiral grooves. As a result a strong rotary motion is given to the liquid which breaks up into a fine spray as it leaves the large opening. It is the most satis- factory nozzle at the present time. Trade names are "Friend," "Cy- clone," "Jumbo," "Atomic," "Mistry," "Power," "Simplex," "Tiger," "Whirlpool." The "Nusystem" or "Spra-gun" Nozzle is an improved form of the Disk. It has a large chamber, entered by several spiral grooves, at one end of a heavy brass rod, and an adjuster at the other end. Near this end is an opening for attachment to the hose (Fig. 247). COST OF SPRAYING The cost of spraying depends on: (i) the materials used, (2) the location and size of the trees, (3) the outfit and (4) the rate of pay for labor. Many carefully kept records are now available for comparison, but the following cases will suflice here : Case I. — Cost of spraying 500 20-year-old apple trees in Okanagan Valley, B. C, averaged 8 cents per tree. Case 2. — In Dr. Hedrick's experimental lo-acre orchard, Geneva, N. Y., about 30 years old, the cost of spraying averaged per year for 10 years 41.8 cents per tree for 2-7^ sprayings. Case 3. — Five-year average cost of spraying eight orchards in Indiana, the trees being from 18 to 23 years of age, a first dormant spray with lime-sulphur, and four other summer sprays mostly with lime-sulphur and arsenate of lead; 41 cents per tree, $16.89 P^^ ^cre, and 17.98 gal. per tree (Bull. 194, Purdue Univ. Agr. Exp. Stn., 1916). Case 4. — Cost of spraying in New Hampshire (labor and material, arsenate of lead and Bordeaux) iij^ cents per tree per application. Case 5. — In 1916 the average cost of spraying eleven widely separated orchards in Massachusetts was 52 cents per tree, and the 382 ECONOMIC ENTOMOLOGY average profit was $4.50. These results are interesting as they were obtained from farmers under ordinary farm conditions. DUST SPRAYING During the last 6 or 7 years there has been a revival of dust spraying, especially in New York State. Professors Reddick and Fig. 249.- — A liusl sprayer in uperaUun in an orchard. {Courlesy oj Ike Niagara Sprayer Co.) Crosby of Cornell University carried out a series of experiments from 1911 to 1917 with dust sprays against insects and fungous diseases of the orchard. Different mixtures were used: 1. Sulphur, 80 per cent.; arsenate of lead, 20 per cent. 2. Sulphur, 40 per cent. ; arsenate of lead, 10 per cent. ; finely ground gypsum, 50 per cent. THE CONTROL OF INJURIOUS INSECTS 383 3. Sulphur, 40 per cent.; arsenate of lead, lo percent.; hydrated lime, 50 per cent. In every case the sulphur was finely ground so that it could pass through a 200-mesh screen. The results were very staisfactory, comparing very favorably with those obtained from the liquid spray. The cost of the materials in dust spraying, however, was high, but the cost of labor was lower than in liquid spraying. The only objec- tion, at present, to the complete substitution of the dust method for spraying is that there is no known dust preparation that will kill scale insects, or that is effective against aphis, pear psylla or red bugs. The dust method makes it possible to protect the orchard at critical times, as a large orchard can be treated in about one-fifth of the time required by liquid spraying (Fig. 249). POISONS FOR BITING INSECTS (Consult Farmers' Bull. 908, U. S. Dep. Ag.) The most important poisons used for the destruction of biting insects are (a) Paris green; (b) arsenite of lime; (c) arsenate of lead; {d) arsen- ate of lime; (e) hellebore; (/) sodium fluoride. When leaves or other portions of plants, dusted or sprayed with suitable quantities of these substances, are eaten by insects the latter are poisoned. As a rule, better results are secured by spraying the plants than by dusting them; sometimes, however, it is impracticable to spray and resort must be had to dusting. (a) Paris Green.^- — Pure Paris green, 3Cu(As02)2-Cu(C2H302)2, composed of 58.65 per cent, arsenious oxide, 31.29 per cent, copper oxide, and 10.06 per cent, acetic acid, is soluble in ammonia but only slightly soluble in water. In commercial forms there is usually a small amount of free arsenious acid, so that it is necessary to add lime to prevent injury from the burning of the fohage. The amount of lime used should be at least equal to that of the Paris green, but when it is added to Bordeaux mixture the excess of lime renders the addition of lime unnecessary. One pound of Paris green is suflScient for an acre of potatoes. Paris green particles are heavy and sink readily in 1 Paris Green first came into use as an insecticide about 1870 in the early effort to control the Colorado potato beetle, and lead arsenate was first used in Massachusetts about 1892 as a safe chemical against the gypsy and brown tail caterpillars. 384 ECONOMIC ENTOMOLOGY water. The finer the particles the longer they remain in suspension, consequently it should first of all be made into a thin paste in a small amount of water, and after it is in the barrel it should be kept in suspension by a mixer. // cannot he used with lime-sulphur solution. The usual formula employed is: Paris green, i lb.; best stone lime, I to 4 lb.; water, 160 gal. imperial or 200 gal. U. S. measure. The Paris green is made into a paste with water and stirred into the lime- and-water mixture. When used as a dry application for the potato beetle, i lb. of Paris green is thoroughly mixed with 20 lb. cheap flour, air-slaked lime or finely sifted land plaster. {h) Ar senile of Lime. — White arsenic (AS2O3), combined with washing soda or sal soda (Na2C03) and quick hme (CaO), is frequently used on account of its cheapness. The combination is made as follows: Dissolve I lb. white arsenic and i lb. sal soda in i gal. of water by boiling in an iron vessel for 20 minutes. Add this while hot to slake the hme; then add 2 gal. of water. Use 2 qt. of this to 40 gal. of water. AS2O3 + NasCOa + Ca(OH)2 = Ca(As02)2 + CO2 + 2NaOH; or rather AS2O3 + NasCOa = 2NaAs02 + CO2; 2NaAs02 + Ca(0H)2 = Ca(As02)2 + 2NaOH. {c) Arsenate of Lead. — This insecticide is preferred by many fruit growers to Paris green since it adheres better to foliage, is less likely to do injury, and no lime is required in standard preparations. The commercial form consists of a mixture of the neutral triplumbic arsenate [Pb3(As04)2] and the acid plumbic hydrogen arsenate (PbH- ASO4). The neutral product may be prepared by dissolving acetate of lead (11 oz.) and arsenate of soda (4 oz.) in 120 gal. water. The reaction is as follows: 3Pb(C2H302)2 + 2Na3As04 = Pb3(AsOi)2 + 6NaC2H302. When lead nitrate is used instead of lead acetate more of the acid arsenate is formed. For fruit trees 2 lb. of arsenate of lead (paste) to the barrel (40 gal.) of water is the usual strength. For the Potato Beetle 4 lb. (paste) or 2 lb. (powder) to the barrel should be used. Acid brands are apt to burn the leaves. Commercial arsenate of lead is put up- in the paste, the usual form, and the powder form of which but half the amount is required. The former contains about 15 per cent. AS2O5; the latter has about ZZ P^r THE CONTROL OF INJURIOUS INSECTS 385 cent. AS2O5, but does not remain well in suspension. The powder form is used in dust spraying. Sometimes a gallon of molasses is added to 40 gal. of the solution with good effect against fruit-flies, rose-chafers and grape root-worm beetles. Arsenate of lead can be used safely with the lime-sulphur mixture for summer sprays. {d) Arsenate of Lime. — 'Recently arsenate of lime or calcium arsenate has given good results against certain chewing insects. It may be prepared according to the following formula: Stone lime (90 per cent. CaO), 55 lb.; sodium arsenate (dry pow- dered), 65 per cent. AS2O5, 100 lb.; water, 26 gal. 2Na3AsOi + 3Ca(OH)2 = Ca3(As04)2 + 6NaOH. The lime is slaked in a small amount of water; while slaking is taking place the sodium arsenate, dissolved in hot water, is poured in; sufficient water is added to prevent burning. The calcium arsenate formed in this way contains about 18 per cent. AS2O5. The killing action is about equal to that of lead arsenate, perhaps a Httle slower, when used at the rate of 2 lb. to each 50 gal. of water. It can be used with lime-sulphur as a combined insecticide and fungi- cide. It can be prepared more cheaply than lead arsenate.^ Arsenate of lime, when used alone as a spray, is liable to burn the leaves, but when used in combination sprays with Bordeaux mixture, lime sulphur, and sodium sulphide ("Soluble sulphur," " Sulphocide ") it is as safe as any other arsenical and probably the cheapest of all insecticides. {e) Hellebore. — This substance is sometimes used as a substitute for arsenicals on fruit which is nearly ripe. It may be applied dry or liquid; dry with five parts of flour or air-slaked lime, Hquid at the rate of i oz. of hellebore to 2 gal. of water. Although an internal poison to insects it is harmless to man in the quantities named. It is too expensive for use on large areas. (/) Sodium Fluoride. — Acts both as a poison and a contact substance. Applied as a fine powder or dust pure or mixed with flour or lime. Effective against ants, cockroaches, etc. ^Some chemists maintain that arsenate of lead, when added to Bordeaux, is converted into arsenate of lime; hence it is more economical to add arsenate of lime in the first place. 25 386 economic entomology 2. The Application of Contact Substances Against Sucking Insects (Consult Farmers' Bull. 908, U. S. Dep. Ag.) The main substances used as Contact Insecticides against sucking insects are: (a) Lime-sulphur wash; (b) whale-oil soap; (c) kerosene emulsion; (d) tobacco decoction; (e) miscible oils; (f) pyrethrum; (g) lime dust; (h) commercial sodium fluoride; (i) carbolic acid emulsion, (7) other substances. (a) Lime-sulphur Wash. — This wash first came into use in the control of the San Jose scale on dormant wood where its beneficial effects were evident also against other insects and against certain fungous diseases. It cannot be used on potato leaves. It is prepared in two forms — ^home-made Hme-sulphur wash and commercial Hme-sulphur wash, diluted for use on dormant wood and on summer foliage as required. I. Home-made Preparation (Boiled). — ^Lime (best), 20 lb.; sulphur (flowers), 15 lb.; water, 40 gal. (imperial).^ II. Concentrated Formula (Stock Wash). — Lime, 50 lb.; sulphur 100 lb.; water, 40 gal. (imperial) or 50 gal. U. S. measure. Heat water (20 gal.) to near boiling and add the fresh lime. While slaking is in progress add with frequent stirrings the sulphur which has been made into a paste. Add water to make up to 40 gal. and boil for an hour replacing the water lost by boihng. Strain through a 20-mesh screen, and place in storage barrels. By means of a lime- sulphur hydrometer the amount of dilution can be determined for each spraying. "For use before buds burst" dilute to sp. gr. 1.03; ''before blossoms burst" 1.009; and ''just after blossoms fall," 1.008. To get the amount of dilution divide the reading after the decimal point of the stock solution by the reading after the decimal point of the solution desired. For example, if the hydrometer reading of the stock solution is 1.3 and that of solution to use "before buds burst" is 1.03, the amount of dilution is 30 divided by 3 = 10. That is I gal. of stock solution makes 10 gal. of spray (Fig. 250). Some recent experiments go to show that the lime-sulphur applica- ^The capacity of a barrel is expressed in all cases in imperial gallons (40); sometimes the equivalent in U. S. measure (50) is also given. THE CONTROL OF INJURIOUS INSECTS 387 tion 10 days or 2 weeks after the blossoms fall should be diluted to a sp. gr. of 1.005 o^ account of the tenderness of the apple pedicels. The amount of spray liquid varies with the size of the tree. A thrifty 9- or lo-year-old tree on the average requires i3^^ gal. for the dormant spray and i gal. for each of the later sprays. A 30-year-old tree requires 5 gal. for the dormant spray and 4 gal. for each of the later sprays. In boiling Hme and sulphur to- gether according to the formulae given above, two sulphides of cal- cium (CaS4 and CaSs) and the thio- sulphate of calcium (CaS203) are formed. These are soluble in water. If too much lime is used a sediment will form. Only the best stone lime should be employed, and the boiling should not be too prolonged as in- soluble compounds are formed. 3Ca(OH)2+ iiS = CaS4 + CaSs +CaS203 + 3H2O. When the hydrometer has the Baume graduation marks ranging from o to 36° the mixture for^^the San Jose scale (dormant stage) should test between 4.5° and 5° Baume^ and for the summer spray- ing about 1° Baume (Fig. 250). The following table of dilutions of lime-sulphur has been calculated for both hydrometer graduations : C oncentrate d Pig. 250. — Diagram of hydrometer in use. i, For concentrated solutions and graduated from 1.21 to 1.32 specific gravity, with surface of liquid indicated at a-b; 2, for diluted solu- tion and graduated from i.oo to i.io specific gravity, with surface of liquid indicated at c-d. (After Corby.) 388 ECONOMIC ENTOMOLOGY Specific Degrees Baum6 To make a dormant spray testing 5° Baume or 1.03 sp. gr. For i gal. of lime-sul- phur use gal. water For I gal. of lime-sulphur use following gallons of water, to make a summer spray testing gravity 1 .009 1 .008 1 .007 1.006 1. 005 sp. gr. sp. gr. sp. gr. sp. gr. sp. gr. I. 318 35 9K 34 39 44 52 62 1.306 34 9 33 37 43 50 60 1-295 33 m 32 36 41 48 58 1.283 32 8H 30 343^ 39 46 55H 1 .272 31 8 29 33 38 44 53K 1 . 261 30 7M 28 31M 36 423^ 51 1.250 29 7H 27 30 35 403^ 49 1.239 28 7 26 29 33 39 47 1 .229 27 6K 24 27K 32 37 45 I. 218 26 634 23 26 30 35 43 1.208 25 6 22 25 29 33 K 40 1. 198 24 53^ 21 24 27 32 39 1. 188 23 sK 20 223^ 26 30 37 1. 179 22 5 19 21 25 29 35 1 . 169 21 4H 18 20 23 27 33 1 . 160 20 4M 17 19 22 26 31 1. 151 19 4 16 18 21 24 29 1. 142 18 3^ 15 17 19 223^ 27 I 133 17 3^ 14 153^ 18 21 26 1 . 124 16 3 13 143^ 17 20 24 1. 115 15 2% 12 13 IS 18 22 III. Commercial Wash. — Commercial washes are now sold which are quite reliable. Directions are given as to dilution. Usually they test about 1.290 sp. gr. or 33° Baume. Lime-sulphur when used at summer strength acts also as a stomach poison, but more slowly than arsenate of lead. Flour-paste as a ''sticker" is often added, especially in summer sprays (8 lb. flour boiled into a thin paste in 8 gal. of water, mixed with 160 gal. of lime-sulphur). It is to be noted that Lead Arsenate, not Paris green, is to be used with the Lime-sulphur Wash. When Paris green, a copper-aceto compound, is added to lime-sulphur the copper is attacked and free soluble arsenic is liberated in quantity sufficient to kill foliage. IV. Lime-sulphur (Self-boiled). — Prepared by slaking 8 lb. best stone lime in a small quantity of cold water; while slaking 8 lb. of THE CONTROL OF INJURIOUS INSECTS 389 finely powdered sulphur are added with constant stirring, also sufficient water to prevent burning. Then add water to make 40 gal. This liquid is a mixture of lime and sulphur, for little combination takes place, and is a good fungicide against brown rot of stone fruits. It is not used to any great extent by fruit growers. Sulphur and Lime. — Flowers of sulphur and hydrated lime in equal parts, when blown upon citrous trees, keep in control red spiders and mites. Recent experiments in Nova Scotia show that arsenate of lime is preferable to arsenate of lead as a poison with Hme-sulphur solutions. When standard arsenate of lead is added to lime-sulphur a double decomposition occurs with the formation of lead sulphide and a crude arsenate of lime, 5 per cent, of which is soluble. When the soluble sodium sulphides, such as "soluble sulphur," '"sulfocide," "spra sulphide," etc., are used in combination with arsen- icals of copper, lead and zinc soluble arsenical salts of sodium are formed which are unsafe as apple sprays. However, when used with arsenate of lime ar^d water-slaked lime (3 lb. soluble sulphur, ij-^ lb. arsenate of lime and 5 to 10 lb. water-slaked hme) no injury results to apple foliage. In Nova Scotia it has been found that when the common poisons are added to Bordeaux mixture their killing power is usually decreased by about 50 per cent. Sodium arsenate, however, retains its power after its addition to Bordeaux if prepared as follows: Dissolve I lb. sodium arsenate in water and with this solution slake 5 lb. of fresh stone Hme and make up to 20 gal. Dissolve 4 lb. blue- stone in another 20 gal. of water and pour the two together. Sodium sulphide, on the other hand, increases the kiUing value of poisons. With the advent of high power sprayers complaints have come in regarding injury to and drop of the leaves and fruit of trees sprayed with the summer strength of lime-sulphur, especially with the later sprayings. This result is due to the destructive action of the lime- sulphur on the contents of the leaf-cells. Experiments showed that when the upper surface of the leaves only was sprayed no drop of leaf or fruit ensued, but when the spray was applied to the under surface much drop followed. This result does not follow the appHcation of sodium sulphide or Bordeaux. 390 ECONOMIC ENTOMOLOGY The "spray gun" may be safely used, however, at a high pressure by the long distance method of spraying in which only the upper side of the leaves becomes wet. Bordeaux frequently causes ''russetting" of the fruit, and for this reason fruit growers began the use of the summer strength of lime- sulphur. The latter, however, causes a drop of the fruit, and the soluble sulphur-slaked lime-arsenate of lime combination is recom- mended as being free from injurious effects. A modification of the 4:40:40 Bordeaux formula is now recom- mended in Nova Scotia for the later sprayings in apple orchards: 2 lb. bluestone, finely pulverized; 10 lb. lime; 40 gal. water. Many evidences point to the conclusion that in mixtures of Bor- deaux and arsenious compounds the lack of injury to foliage is due to the formation of a copper-arsenide compound rather than to the sup- posed neutralizing action of the lime. Soluble Sulphur. — A patent preparation containing about 60 per cent, soluble sulphur and 40 per cent, inert matter. It is used as a substitute for hme and sulphur. Its value has not yet been definitely determined on account of conflicting reports by growers. It has the merit of being easily handled. {b) Whale-oil Soap. — Potash whale-oil soap of a good grade, when dissolved in warm water at the rate of 2 lb. to a gallon of water, makes an excellent spray for early spring treatment of or- chards — just before the buds swell. It is also valuable as a summer treatment against aphids and pear psylla, but it should be diluted: I lb. of soap dissolved in 4-6 gal. of warm water. The soap has an invigorating effect on the tree, but the cost prohibits its use in orchards on a large scale. Against scale insects on palms, rubber plants, cycads, and oleanders in conservatories whale-oil soap is used at the rate of i lb. to each gallon of water; on ferns however, fir-tree oil or lemon oil (1-15 or 20 water) is used as these plants are readily injured by whale-oil soap. Soap Solution. — This solution is made by dissolving i lb. of hard soap in 5 gal. of water. It is effective in controlling plant- lice and other sucking insects on house and garden plants. The addition of soap solution, 3-5 lb. in 80 gal. of tobacco ex- tract solution, is recommended for plant-lice. THE CONTROL OF INJURIOUS INSECTS 39 1 Sulphur-soap Mixture (for Red Spider). — Prepared by dissolving I lb. laundry soap in 8 gal. water and adding 3^^ lb. flowers of sulphur. The under side of the leaves should be sprayed. {c) Kerosene Emulsion. — A soap emulsion of kerosene has for many years been used against aphids and other sucking insects. It is prepared by dissolving J^ lb. of soap in i gal. of warm water, and adding 2 gal. of kerosene to the hot soap solution. The whole is then agitated until a creamy emulsion is formed. This stock solution when properly made keeps indefinitely. When required for use the stock solution is diluted with 10 times its volume of water. {d) Tobacco Decoction. — A strong decoction of tobacco stems or leaves is an excellent remedy against aphids, either in the field or in the greenhouse. The decoction is an extract and is made by steeping refuse tobacco in warm water for several hours until a deep brown liquid is obtained. Two pounds of tobacco are treated in 2 gal. of water and afterward made up to 5 gal. It is a safe remedy. Several tobacco preparations are now on the market, the most valuable for orchard spraying being "Black Leaf 40." This concen- trated extract contains 40 per cent, nicotine sulphate and is usually diluted with water, i part to 1000, when used against plant-lice and other sucking insects. It can be safely used with lime-sulphur, ar- senate of lead or soap solutions. "Nico-fume" contains 40 per cent, nicotine sulphate and is much used in greenhouses by vaporizing it at the rate of 3^^ oz. to 2000 cu. ft. Tobacco papers are also used in greenhouses. Dense fumes are given off when they are ignited. (e) Miscible Oils. — Certain proprietary mixtures containing mineral oils in combination with a small quantity of vegetable oil and some alkali to make them miscible with water are valuable in the control of scale insects. Reliable market preparations are more satisfactory than those made at home and less likely to be injurious to the trees. There is always a certain amount of risk in using these oils, but the danger is lessened if they are used on dormant trees in fine weather. The more reliable brands are "Scalecide," '^ Target Brand," " Orchard Brand" and "Kil-0-Scale." (/■) Pyrethrum. — Pyrethrum, known also as Buhach, Persian and Dalmatian insect powders, and by other trade narnes, is used fre- 392 ECONOMIC ENTOMOLOGY quently on aphids, slugs, and some household pests, where operations are confined to a small area. It may be used either as a spray or in the dry form. As a spray it should first of all be made into a paste in a small quantity of water and afterward diluted to the proper strength, viz. : i oz. to 3 gal. of water. When used dry, i part of powder is thoroughly mixed with 4 parts of flour, and kept in a tight can for a day. The mixture is dusted on either by a bellows or through a coarse bag, on account of the fact that the essential ingredient is a volatile oil. Pyre thrum loses its strength on exposure to the air; the can must, therefore, be kept tightly closed. (g) Lime. — Air-slaked lime is effective against slugs and other soft-bodied larvae. It should be applied as a very fine dust. Some investigators report beneficial effects from the application of thick lime-wash about onion plants as soon as they are up as a protection against the onion maggot. Professor Parrott of the Geneva Agricultural Experiment Station finds that lime with nicotine is much more effective against aphis, leaf-hopper and pear psylla than nicotine alone, or soap, or oil emulsion. Qi) Commercial Sodium Fluoride. — This substance, both a poison and a contact insecticide, is effective against cockroaches, chicken lice and other insects when applied, pure or mixed with flour or plaster, as a fine dust by means of a dust blower. (i) Carbolic Acid Emulsion. — For the control of root-feeding larvae such as onion maggots and radish maggots, an emulsion of carbolic acid has given good results. It is prepared by dissolving I lb. of hard soap in i gal. of hot water and adding i pt. of crude carbolic acid. The mixture is agitated until a thick, emulsion is produced. This is the stock solution, and is diluted with 20-30 parts of water for use. A tablespoonful is poured about the base of the plant to prevent egg-laying, and at the same time to kill the newly hatched larvae. (/') Scale insects on ferns are treated effectively by the use of i part fir-tree or lemon oil to 15 or 20 parts of water. (k) Cattle Dips. — The most widely used methods of controlling cattle-scab diseases are: I. Dipping the animals in lime-sulphur or nicotine solutions twice, 10 to 14 days apart. Dipping plants are arranged so THE CONTROL OF INJURIOUS INSECTS 393 that the cattle enter one end of a vat filled with warm dip through which they swim, and leave the vat at the opposite end. The lime- sulphur dip is made by mixing 12 lb. unslaked lime and 24 lb. flowers of sulphur in 100 gal. of water. Nicotine dips should con- tain about ^ioo ^^ I P^i" cent, of nicotine, and should be used warm, not above ioo°F. 2. Spraying the animals. This method is neither so economical nor so effective as dipping, but is recommended where but a few animals are to be treated. Cattle lice can be controlled by the following means: 1. Hand applications with a brush or cloth at intervals of about 3 weeks, of (a) cottonseed oil and kerosene (equal parts); (b) kero- sene and lard (3-^ pt. to i lb.); (c) crude petroleum; (d) any of the dip solutions. 2. Spraying with any of the dip solutions. 3. Dipping in (a), an arsenical solution, prepared as follows: 4 lb. caustic soda (85 per cent. pure). 8 lb. white arsenic (99 per cent, pure) in fine powder. 8 lb. sal soda crystals. I gal. pine tar. 500 gal. water (temp. 65°-9o°F.). (b) Coal-tar creosote, sold under many trade names and to be used according to instructions. (c) Nicotine solution, sold under many trade names and to be used according to instructions. (Consult Farmers' Bull. 909 and 1017, U. S. Dep. Agric.) 3. The Use of Poisonous Gases The more important poisonous gases used to control insects are: (a) carbon bisulphide; (b) hydrocyanic acid gas; (c) sulphur dioxide; (d) tobacco; (e^) formalin; (/") carbon tetrachloride. (a) Carbon Bisulphide. — This is an ill-smelling liquid which is readily volatile. The gas is much heavier than air, and if placed in shallow pans above or on top of grain or other vegetable foods the fumes sink, and being poisonous will kill the insects. It is specially valuable for the fumigation of peas infested with weevils, or grain 394 ECONOMIC ENTOMOLOGY infested with weevils and other insects. It is also used for the de- struction of household pests such as clothes moths, etc. Two pounds of the liquid is sufficient for loo bu. of peas or grain, or looo cu. ft. of space. It is inflammable. (b) Hydrocyanic Acid Gas. — This gas is liberated when diluted sulphuric acid is added to potassium or sodium cyanide. It is a deadly poisonous gas, and great care should be taken in its use as an insecticide. It came into use in California for the fumigation of citrus and olive trees. Later it was introduced into eastern nurseries for the treatment of San Jose scale on dormant nursery stock, and for the control of flour mill pests, and, in some cases, greenhouse and household pests. The formula for nursery stock and household fumigation is: Cya- nide of potash or soda, i oz.; sulphuric acid (sp. gr., 1.83), i fl. oz.; water, 3 fl. oz. per 100 cu. ft. space. For greenhouse fumigation at night the formula is: Cyanide of potash or soda, J^ oz.; sulphuric acid, I fl. oz.; water, 3 fl. oz. per 1000 cu. ft. space. This gas is lighter than air and diffuses very rapidly. (c) Sulphur Fumes. — The destructive action of sulphur is largely due to the readiness with which it oxidizes to sulphur dioxide, a gas fatal to many forms of insect life. Mites are controlled in green- houses by the dusting of fine sulphur on the surfaces of the leaves. When sulphur is burned on a hot plate over a low flame sulphur dioxide is rapidly formed, recognized by its suffocating odor. This is, perhaps, the simplest method of dealing with ordinary household pests such as bed bugs, fleas, and other forms. Combined with a soap, sulphur is used as a wash for mange which is caused by a mite. (d) Tobacco. — Tobacco fumes are destructive to aphids on green- house and household plants. They are liberated by the application of heat to certain Nicotine Extracts, Nicotine Paper, or finely divided tobacco powders. These "fumigating" powders and extracts may now be had in the market and are convenient methods of dealing with house plants. (e) Formalin. — As a rule, formalin (40 per cent, formaldehyde) is not effective as an insecticide, although an excellent germicide. As a fly-poison, however, it is strongly recommended when used as follows: Mix I tablespoonful formalin with J^ cup sweet milk or J^ cup water, and expose in a shallow plate with a slice of bread in it. THE CONTROL OF INJURIOUS INSECTS 395 (/) Carbon Tetrachloride. — This liquid although not so active as carbon bisulphide is not explosive. It may be used for fumigating bins infested with insects, when applied at the rate of 2 lb. for every 100 cu. ft. of space or 100 bu. of grain. 4. The Application of Repellent Substances Several substances are known to act as '^repellents" to insects and may sometimes be used to advantage in preventing insect attack Among such substances are: {a) Bordeaux mixture; {h) tobacco dust {c) carbolic acid emulsion; {d) kerosene; {e) turpentine; {f), coal tar (g) naphthaline; Qi) zenoleum and creolin compounds; {i) tanglefoot (7) carbolineum emulsion; {k) soap-carbolic-Paris green wash. {a) Bordeaux Mixture. — This fungicidal mixture keeps away flea- beetles from potato leaves and striped cucumber beetles from pumpkins and squashes when applied as a fine spray. It is prepared as follows : Copper sulphate (blues tone), 4 lb.; quickhme, 4 lb.; water, 40 gal. CUSO4, 5H2O + Ca(0H)2 = Cu(0H)2 + CaS04 + 5H2O. 2[Cu(OH)2, CuSOJ + CO2 = 2CUSO4 + Cu(0H)2 + CuCOs + H2O. In mixing solutions of these two substances care must be taken that they come together in a large quantity of water, and that enough lime is present to act on all the bluestone. {h) Tobacco Dust. — In the case of certain garden crops fine sprin- kling of the ground when moist with refuse tobacco dust not only fertilizes the soil but also repels the striped cucumber beetle and the melon aphis. {c) Carbolic Acid Emulsion. — Carbolic acid is a repellent, as well as an irritant and stomach poison, and in various forms is used for the control of insects. Reference has already been made to its use as a contact insecticide. As a repellent it is added to a solution of wash- ing soda or lye as a protective wash against borers in orchards and shade trees; as an emulsion with soap against root-maggots of cab- bage and onion; and often also used in poultry house against biting lice and mites. {d) Kerosene, (e) Turpentine and (/") Coal tar are sometimes mixed with saw-dust, sand, or other materials; when placed around plants or seeds they are said to have a repellent action toward insects. 396 ECONOMIC ENTOMOLOGY (g) Naphthaline.— This substance is the basis of camphor balls, and is commonly used as a preservative of household goods and wearing apparel against the attacks of clothes moths and other insects. (h) Zenoleum and Creolin Compounds. — Some excellent com- pounds of creolin and related substances are prepared as repellents against flies that bother cattle, and against biting lice and mites of poultry. The cow horn-fly may be controlled by the use of such substances. {i) Tanglefoot. — A sticky substance; is used as fly-paper and as sticky bands for trees to prevent caterpillars such as those of Gypsy moth and Tussock moth from ascending. ij) Carholineum Emulsion. — Used against bark beetles, shot-hole borers and poplar borers. Four pounds naphtha soap are dissolved in 4 gal. of hot water, the carbolineum added, and the whole agitated to form an emulsion. For use 3 gal. of hot water are added and emulsion is sprayed on the trees while warm. {k) Wash for Tree Trunks. — To protect trees against borers the following wash is of value: Dissolve i lb. of hard soap or 2 qt. of soft soap in a pail of water, then add J2 pt. of crude carbolic acid, and 2 oz. of Paris green; thicken with lime. 5. The Use of Protectors Various forms of protectors are used to ward off insect attacks. The application is confined mainly to the street, orchard and garden. The following methods are those most commonly in use: (a) metal or sticky bands; {b) cheese-cloth or muslin screens; {c) wire-netting; {d) tarred felt paper. (a) Metal or Sticky Bands. — To protect trees from the attacks of climbing caterpillars such as the tussock and canker worms, special bands are placed about the trunk a few feet above the ground. The caterpillars are prevented from passing up, and they often collect in large numbers under the flaps or rim of the hand where they are readily destroyed. The gypsy, the tent-caterpillars, climbing cutworms and walnut caterpillars are also kept in check by this method. {b) Cheese-cloth or Muslin Screens. — Such devices are often effect- ive against cucumber beetles, flea-beetles and the radish root-maggot. As these insects are most injurious while the plants are just coming THE CONTROL OF INJURIOUS INSECTS 397 above the ground, the frames holding the screens should be placed in position soon after the plants are set out or the seeds planted. They can be readily removed for a short time whenever weeding, cultivation and watering are necessary. (c) Wire-netting. — Wire-netting is often placed about trees to protect them from the Peach-borer, and the Round-headed apple tree Borer. Fig. 251. — Tool and device for cutting disks. (After Britton.) (d) Single-ply Tar Felt Paper Disks. — Used to protect cabbage and cauHflower plants against the cabbage-root maggot (Figs. 251-253). 6. The Use of Traps, Trap Crops, Etc. The following forms of traps are sometimes used to advantage: (a) boards or chips; {b) special crops; {c) poison baits. (a) Boards or Chips. — Squash bugs, cutworms and other insects may be readily trapped in large numbers by placing small bits of board or chips or bunches of grass among the rows of plants where these insects hide. 398 ECONOMIC ENTOMOLOGY (b) Special Crops. — Such crops have been found advantageous in the control of Hessian fly, army worms, squash bugs, cucumber beetles, and asparagus beetles. In the case of the Hessian fly narrow strips are planted early so that the flies may deposit their eggs on the wheat before the regular planting of the field. These trap strips are then destroyed. With the army worm, a similar narrow strip on the border of the field may be poisoned with an arsenical spray. With cucumber beetles and asparagus beetles, a few plants may be set apart to trap the early beetles nd then destroyed. (c) Poison Baits. — Such are very effective against grasshoppers, cutworms and other insects. The Criddle Mixture, made by mixing thoroughly i lb. of Paris green or white arsenic, i lb. of salt (dis- solved in water), and 15 gal., by measure, of fresh horse droppings, with sufficient water to make the Fig. 252. — Wood form for cutting hexagonal disks for the cabbage-root maggot. (After Britton.) Fig. 253. — Tool for cutting cards of tarred building paper. {After Slingerland.) whole mass moist but not soggy, is used in the West against grass- hoppers. When the mixture is scattered about grass lands and the edges of grain fields in hot, sunny weather the grasshoppers are readily poisoned. Another bait, first used in Kansas against grasshoppers, is now usually employed against cutworms, army worms and grasshoppers. The formula is: i lb. Paris green, 20 lb. wheat bran, 2 qt. of cheap molasses, the juice and pulp of 3 oranges or lemons, and 2 to 2)^ gal. water. The bait, sown broadcast in early morning, will show results in a few days. THE CONTROL OF INJURIOUS INSECTS 399 Professor Sanders of Pennsylvania recommends the following poison bait spray against the adults of the onion maggot: 5 grams of sodium arsenite dissolved in a gallon of boiling water into which is thoroughly mixed a pint of molasses. This bait is applied as a coarse spray of large drops once a week across the onion field throughout the summer. For cockroaches and ants in kitchens and pantries powdered borax mixed with sweetened chocolate, scattered in the evening about the haunts of the insects, and powdered sodium fluoride, pure or mixed with flour or plaster, applied by means of a dust blower are effective. Sponges filled with sugared water attract ants that infest houses, and large numbers can be readily destroyed. 7. Ditches, Furrows and Trenches When fields are threatened with the army worm or grasshoppers, a ditch or deep furrow made in front of the advancing army has had excellent results. The insects falling into the ditch may be destroyed in large numbers. 8. The Use of Hopperdozers, Etc. In the grasshopper-infested regions of the West hopperdozers or hopper-catchers are used to great advantage. Various devices are in use, but they all agree in principle. They are essentially machines for gathering up the grasshoppers as they are drawn across an in- fested field. Attached to each machine is a contrivance for destroying the insects when collected by means of coal-oil, or tanglefoot, or pitch tar. Best results are secured by using the dozers when the hoppers are small. If infested fields are gone over frequently the damage will be reduced to a minimum. 9. Collecting, Digging-out, Jarring, Etc. Under this head are collected a number of mechanical methods which the careful farmer and fruit grower employ to good advantage. Sometimes much damage can be averted by the timely picking of the 400 ECONOMIC ENTOMOLOGY eggs, larvae, or adults of insects such as the tobacco and tomato worms (Sphingidce), corn ear worm, potato beetle, celery caterpillar, white grubs, cabbage butterflies, asparagus beetles, etc. Again, it is often wise to cut out, burn, or otherwise destroy certain insects whenever they appear. For example, web-worms, tent-cater- pillars, stalk-borers, etc., may be effectively dealt with at certain stages in this way. Sometimes, too, under certain conditions, insects can be controlled by jarring and beating the infested plants. When poisons are objec- tionable, this method of dealing with potato beetles, currant worms, plum curculio, etc., is recommended. lo. High and Low Temperatures In flour or meal mills it has been practicable to raise the temperature to 120° or 125° for 6 to 8 hours, when it is found that all the insects — eggs, larvae and adults — are killed. On the other hand insects are not able to develop at cold-storage temperatures, hence products kept in cold storage are kept free from injury. THE ACTION OF INSECTICIDES (Consult Tech. Bulls. 11 and 21, Mich. Agric. Coll.) Until recently the mode of action of insecticides was not well under- stood. It was commonly stated that contact substances kill insects by stopping the breathing pores or plugging the tracheae, producing death by suffocation. Recent investigations, however, go to show that insects are not readily suffocated. The death-producing action of chemicals is mainly due to their absorption into their tissues. The volatile portions of kerosene, carbon bisulphide, gasoline, creolin, pyr- ethrum, etc., are effective long before the liquids have time to pene- trate the chitin or the spiracles into the tissues. With the penetration of the volatile substances the nervous system is seriously affected, and results resembling narcosis are produced, where there is a disturbance of the respiratory activity. Insect tissues soon become saturated when exposed to the vapors of the substances mentioned, and death ensues through the inability of the tissues to absorb oxygen in the presence of these vapors. THE CONTROL OF INJURIOUS INSECTS 401 In the case of lime-sulphur, its effectiveness is due to its reducing power, and with scale insects to its softening action on the wax about the margin of the scales and to its effect on the waxen covering making it less permeable to oxygen. Alkaline washes, corrosive subhmate solution and other Kquids, which are able to dissolve or precipitate certain constituents of the tissues, pass through the chitin slowly. Moreover, gasoline, carbon bisulphide, hydrocyanic acid gas, sodium fluoride, etc. act strongly on the oxidases and other enzymes in the tissues of insects causing serious disturbances. Fat or fat-like membranes absorb the vapors of gasoHne and chloroform, but in doing so become less permeable to oxygen; and waxen membranes when wet with lime-sulphur also become less permeable to oxygen. Non-volatile finely powdered solids, such as borax, hellebore, sodium fluoride, etc., in addition to being stomach poisons, are effective also as contact insecticides because they adhere to exudations on the body wall, and later become dissolved and absorbed through the integument into the tissues. The Utilization or Parasitic Insects The economic use of parasitic insects shows three phases: (i) the utilization of the native parasites of the district; (2) the transportation of the parasites from one district to another; and (3) the importation of parasites from one country to another. 1. In the great majority of cases of insect outbreak the native para- sites are able to control it in time. In fact injurious forms are mainly held in check by their parasites. Occasionally, however, through the operation of some obscure factor, the multipHcation of parasites is prevented; then the injurious forms are permitted to reproduce with much less check and much loss occurs before parasites are able to "catch-up" again. 2. Some successes have been reported where parasites were trans- ported from one locality to another. LeBaron of Illinois in 1872 introduced Aphelinus malt, a parasite of the Oyster Shell Scale. Webster in 1907 transported Polygnotus hiemalis from Marion, Pa., to a field of wheat infested with Hessian fly at Sharpsburg, Md., and 26 402 ECONOMIC ENTOMOLOGY observed that later in the season nearly every "flaxseed" was para- sitized. W. D. Hunter introduced parasites of the Cotton Boll-weevil from Waco to Dallas and from Texas to Louisiana with considerable success (Fig. 254). 3. Several conspicuous successes have attended the importation of parasites from foreign countries. Perhaps the introduction of the lady-bird, Novius cardinalis, from Australia to California in 1888 for the purpose of controlling the Cottony Cushion or Fluted Scale of the Orange (Icerya purchasi) is one of the most interesting cases. This scale was brought to California about 1868, probably on Acacia Fig. 254. — Polygnotus hiemalis, a parasite of the Hessian fly: adult. Greatly- enlarged. {From Webster, U. S. Bur. Ent.) latifolia. It began to multiply rapidly in the orange and lemon groves in spite of every measure that was tried against it. Dr. Riley, U. S. entomologist, and his staff made the scale a subject of special study for 4 or 5 years and he became convinced that it was a native of Australia. Accordingly, two entomologists, Koebele and Webster, were sent to that country to collect possible parasites, and to send them to California. Novius cardinalis was found at Adelaide and small shipments of it were sent. The lady-birds began to feed on the Icerya scale insect as soon as they were liberated, and to breed rapidly — the result being that within a year the orange growers confessed that their groves had been saved. Later, Novius cardinalis was sent THE CONTROL OF INJURIOUS INSECTS 403 to New Zealand, Portugal, Cape Colony, Florida, Hawaiian Islands, Italy, Syria and Egypt, and equally good results were secured. Dr. Howard gives the following reasons for this success: (i) Novius pro- duces in one year double the number of generations that Icerya does; (2) Novius feeds preferably on eggs of Icerya; (3) the absence of para- sites of Novius; and (4) Novius is an active insect, while Icerya is fixed to the plant. Another interesting example of successful parasitism through importation in 1901 is that of Scutellista cyanea, a chalcid insect from South Africa to control the Black Scale of the Olive {Lecanium olece) of California. The West Indian Peach Scale (Diaspis pentagona) occurs in the Southern States but is not very injurious on account of the presence of a parasite, Prospaltella berlesei. Specimens of the parasite were sent to Italy where mulberry plantations were seriously injured, with the result that it is now well established and holding the scale in check. The recent attempt to control the Gypsy and Brown-tail Moths in New England has been of great value to entomologists in demon- strating the many complicated factors that exist when foreign parasites are introduced. From 1905 to 191 3 more than thirty species of para- sites were imported from Europe and Japan and a number of the most important ones have been accHmatized and are rapidly spreading. The present improvement in Massachusetts "is due to at least four main causes: (i) The perfection and standardization of the methods for artificial repression; (2) the death of a large proportion of the more susceptible trees or their removal from the infested woodlands; (3) the importation of parasitic and predatory insect enemies; (4) the development of the 'wilt' disease" (Fiske). The problem of the control of insects such as the Gypsy Moth and the Brown-tail Moth by parasites is a more difficult one than appears on the surface. From extensive studies of the life-history of the Gypsy Moth it has been determined that the probable potential rate of in- crease is 250-fold annually. On account, however, of the heavy death- rate from various causes the actual rate of increase is only 6- to lo-fold. The problem was then to secure sufficient parasites to keep the insect in control. In other words, if the increase annually be 6-fold, five out of every six insects, either egg, caterpillar, or pupa, or Ss-S P^r cent, would require to be parasitized. If the increase be lo-fold, nine out of 404 ECONOMIC ENTOMOLOGY every ten, or 90 per cent, must be parasitized. To rely entirely upon egg parasites, such as Anastatus or Schedius, to destroy such a large percentage of the eggs was out of the question, for these parasitized only the upper layer of eggs in each mass. It became necessary, therefore, to call in the aid of the parasites affecting the caterpillar and the pupa. Consequently efforts have been made to secure a sequence of parasites from foreign countries so that every stage of the moth is subjected to attack, and which would bring up the death-rate to 85 or 90 per cent. (See Bull. 91, U. S. Bureau of Ent.) ,vC>'r.l-^ Fig. 255. — Apanteles lacteicolor: adult female and cocoon. Much enlarged. (After Howard and Fiske.) The task of importing the foreign parasites of the Gypsy and the Brown-tail Moths to the United States has been a most arduous and difficult one. In the first place it has involved much labor in getting competent collectors in Europe to gather sufficient parasitized material, for the plan of the utilization of foreign parasites on a large scale in the control of injurious forms is recent in conception, and was put into operation for the first time by the U. S. Bureau of Entomology in the fight against the Gypsy and the Brown- tail Moths. In the second place, many difficulties in transportation have had to be overcome. In the third place, the work of sorting out the various parasites and herding them in sufficiently large numbers in the laboratories for THE CONTROL OF INJURIOUS INSECTS 405 Fig. 256. — Pteromalus egregius: adult female. Greatly enlarged. {After Howard and Fiske.) Fig, 257. — Monodontomerus cereus: adult female. Greatly enlarged. (After Howard and Fiske.) 4o6 ECONOMIC ENTOMOLOGY colonization purposes in the field has been much greater than was anticipated at the outset. In the fourth place, the habits of many of the parasites were not well known and had to be determined for American conditions. As a result, many of the parasites reported favorably in Europe were found to be secondary parasites, or unsuited for the task in hand (Figs. 255-257). The parasites of the Gypsy and Brown-tail Moths may be grouped as follows: (I = Imported, N = Native, C = Chalcid, T = Tachinid, Ic = Ich- neumon, Ca = Carabid.) Host Egg parasites Larval parasites Pupal parasites Gypsy Anastatus bifasciatus Compsilura concinnata Monodontomerus Moth. (C.I.) (T.I.) Schedius kuvanae i Blepharipa scutellata aereus (C.I.) (C.I.) (T.I.) Calosoma sycophanta (Ca.I.) Brown-tail Trichogramma pretiosa Pteromalus egregius Monodontomerus Moth. (C.N.) (C.L) aereus (C.I.) • Apanteles lacteicolor Pimpla conquisitor (B.I.) (Ic.N.) Meteorus versicolor Chalcis compsilurae (B.I.) (C.N.) Zygobothria nidicola (T.I.) Pales favida (T.I.) Dexodes nigripes (T.I.) Calosoma sycophanta (Ca.I.) From Melrose Highlands, Mass., where the parasite laboratory is located, not only have the parasites and the predaceous Calosoma sycophanta been distributed throughout the infested areas of New Eng- land but also into New Brunswick and other eastern provinces lying in the probable zone of infestation. Hewitt introduced into Canada in 191 o the European ichneumonid, Mesoleius tenthredinidis Morley, to combat the larch saw-fly. The THE CONTROL OF INJURIOUS INSECTS 407 results have been fairly satisfactory. In 1908 the egg parasite, Tetra- stichus xanfhomelcencB, of the elm leaf beetle was introduced into New England from France. The results are not conclusive although the parasite has multiplied and spread slightly. Other examples of the introduction of parasites to combat injurious insects might be cited of which many have been unsuccessful. The valuable experience gained in the Gypsy and Brown-tail experiments will no doubt be utilized in future work of this nature and more successes will probably be recorded. BIBLIOGRAPHY General Berlese, a.: Gli Insetti. 1909. Societa Editrice Libraria-Milan. CoMSTOCK, J. H. : A Manual for the Study of Insects. 1895. Comstock Publishing Co., Ithaca, N. Y. Comstock, J. H.: The Wings of Insects. 1918. Comstock Pub. Co. Comstock, J. H., and A. B.: Insect Life. 1901. Appleton and Co., N. Y. EscHERiCH, K. : Forst Insekten Mitteleuropas. 1914. Paul Parey, Berlin. FoLSOM, J. W. : Entomology with Special Reference to its Biological and Economic Aspects. 3d Ed. 191 7. Blakiston's Son and Co., Philadelphia. Henneguy, L. F, : Les Insectes. 1904. Masson and Co., Paris. Howard, L. O. : The Insect Book. 1904. Doubleday Page and Co., N. Y. Kellogg, V. L. : American Insects. 1904. Henry Holt and Co., N. Y. Packard, A. D.: A Text-book of Entomology. 1898. MacMillan and Co. Sanderson and Jackson: Elementary Entomology. 191 2. Ginn and Co. Sharp, D.: Insects. 2 vols. 1895-99. Cambridge Nat. Hist., MacMillan Co., London. Smith, J. B.: Glossary of Entomology. 1906. Brooklyn Ent. Soc. Economic Banks, Nathan: Index of American Economic Entomology. 1905-14. Am. Assoc. Ec. Entom. Chittenden, F. H. : Insects Injurious to Vegetables. 1907. Orange Judd Co., N. Y. EssiG, E. O. : Injurious and Beneficial Insects of California. 1915. Felt, E. P. : Insects Affecting Park and Woodland Trees. 2 vols. 1905-06. N. Y. State Museum, Albany, N. Y. Herms, W. B. : Medical and Veterinary Entomology. 191 5. MacMillan Co., N. Y. Herrick, G. W. : Insects Injurious to the Household. 1914- MacMillan Co., N. Y. Herrick, G. W.: Insects of Economic Importance. 1915. Carpenter and Co., Ithaca, N. Y. Hewitt, C. G.: The House-fly. 1914. Cambridge Univ. Press, 4o8 ECONOMIC ENTOMOLOGY Hewitt, C. G. : House-flies and How They Spread Disease. 191 2. Camb. Science Manuals. Howard, L. O. : The House-fly: Disease Carrier. 191 1. Stokes, N. Y. O'Kane, W. C. : Injurious Insects. 191 2. MacMillan Co., N. Y. Ormerod, Eleanor: Text-book of Agricultural Entomology. 1892. Simpkin, Marshall and Co., London. OsBORN, H. : Agricultural Entomology. 1916. Lea and Febiger, Philadelphia. Riley and Johannsen: Handbook of Medical Entomology. 191 5. Comstock Pub. Co. Sanderson, E. D.: Insect Pests of Farm, Garden and Orchard. 191 2. Wiley and Sons, N. Y. Saunders, W. : Insects Injurious to Fruits. 1883. Lippincott. Slingerland and Crosby: Manual of Fruit Insects. 1914. MacMillan Co., N. Y. Smith, J. B. : Economic Entomology. 1896. Lippincott Co. Smith, J. B.: Our Insect Friends and Foes. 1909. Lippincott Co. Washburn, F. L. : Injurious Insects and Useful Birds. 1918. Lippincott Co. Special Systematic Aldrich, J. M.: Catalogue of N. A. Diptera. 1905. Smithson Inst. Aldrich, J. M. : Sarcophaga and Allies. Thomas Say Foundation. Barnes and McDonnough: Check List of Lepidoptera of Boreal America. Blatchley, W. S. : Coleoptera of Indiana. Nature Publ. Co., Indianapolis, Blatchley, W. S. : Orthoptera of Indiana. Nature Publ. Co., Indianapolis. Blatchley andLENC: The Rhyncophora or Weevils of N. E. America. Brues and Melander. : Key to the Families of North American Insects. 1915. Cresson, E. T. : Families and Genera of the Hymenoptera. Philadelphia. Holland, W. J.: The Moth Book. 1903. Doubleday Page Co., N. Y. Holland, W. J. : The Butterfly Book. 1905. Doubleday Page Co., N. Y. Leconte and Horn: Families and Genera of the Coleoptera. Lutz, F. E: Field Book of Insects. 191 8. Putnam's Sons, N. Y, Sladen, F. W. L. : The Humble Bee. 1912. MacMillan Co., London. Van Duzee, E. P.: Check List of the Hemiptera. 1916. N. Y. Ent. Soc. ViERECK et al.: Hymenoptera of Connecticut. 191 7. Conn. Geol. Survey. Ward and Whipple: Fresh Water Biology. 191 8. Wiley and Son. Wheeler, W. M. : Ants. 1910. Columbia Univ. Press., N. Y. WiLLiSTON, S. W. : North American Diptera. 1908. Hathaway, N. Y. Publications Annals of the Entomological Psyche. Society of America. Reports and Bulletins of Federal, Canadian Entomologist. State and Provincial Departments Entomological News. of Agriculture. Journal of Economic Entomology. Review of Applied Entomology. THE CONTROL OF INJURIOUS INSECTS 409 Acalyptrata. Acalypterae. Accessory Glands. Androconia. Aculeata. Agamic. Alate. Alternation of Generations. Alulae. Alulet. Amnion. Anal Angle. Anal Area. Anal Plate. Apterous. Arista. Arthropoda. Brachycerous. Caecimi. Calypter. C cecum. Capitate. Carabidoid. Cauda. GLOSSARY (After Smith) Those muscoid ilies in which alulae are absent or elementary. Any glands opening into the ducts of the reproductive system (Fig. 32). Specialized, usually small scales of peculiar form, found localized on some male butterflies. Hymenoptera; the stingers, including bees and wasps. Reproducing without union with a male. Winged. Periodic productions of parthenogenetic females in a species that occurs in both sexes. These females produce both sexes. Examples occur in Cynipidae and in some Homoptera. A pair of membranous scales above the halteres, behind the root of the wing, one above or before the other; the anterior attached to the wing and moving with it, the posterior fastened to the thorax and stationary. Occurs in Diptera. Synonyms calyptra; squama; squamula; lobulus; axillary lobe; aileron; scale; tegulae. In Coleoptera a membranous appendage of the elytra which prevents dislocation. The lobe at basal portion of wing in Diptera (posterior lobe). Sometimes used for alula. The inner of the two membranes enclosing the embryo (Fig. 36). That angle on the secondaries nearest the end of the abdomen when the wings are expanded. The angle between the inner and outer margin of any wing. In Orthoptera and Neuroptera the hinder or anal portion of a wing within the anal vein. In caterpillars the shield-like covering of the dorsum of the last segment (Fig. 18). Without wings. A specialized bristle or process on the antennae of certain Diptera (Fig. 180). Jointed animals having jointed appendages. Having short three-jointed antennae, Diptera (Fig. 144). A blind sac or tube supplied to appendages, opening into the alimentary canal at the junction of the mid and hind gut (Fig. 29). In Diptera, the alula when it covers the haltere. See Caecum. Terminating in a little head or knob (Fig. 88). Resembling a Carabid (Fig. 40). The tail; any process resembling a tail (Fig. 87). 4IO ECONOMIC ENTOMOLOGY Caudal Setae. Chaetotaxy. Chitin. Chrysalis — id. Cilia. Clavate. Clavus. Clypeus. Coarctate. Corium. Cornicles. Costa. Coxa. Coxal Cavity. Crenate. Cuneus. Dorsum. Ecdysis. Ecology. Elytra. Embolium. Empodium. Entomophagous. Thread-like processes at the end of the abdomen. The science dealing with the arrangement and nomenclature of the bristles on the body of insects. The material of which the hard parts of the insect body are formed. The intermediate stage between larvae and adult in the butterflies (Fig. 39). Fringes. Club-shaped; thickening gradually toward end (Fig. 87). The club of an antenna; clava and clavola; in Heteroptera the oblong sclerite at the base of the inferior margin of the hemelytra; the knob at the end of the stigmal or radial veins in certain Hymenoptera. The anterior median portion of the head to which the labrum is usually attached (Fig. 4). Contracted; compact. Applied to a pupa in which all the appendages are concealed in a hardened covering which is usually the last larval skin (Fig. 39). The elongate middle section of the hemelytra which extends from base to membrane below the embolium (Fig. loi). Glandular tubes on the abdomen of plant-lice which secrete a yellowish waxy liquid (Fig. 88). An elevated ridge that is rounded at its crest; the thickened anterior margin of a wing. The basal segment of the leg (Fig. 19). The opening or space in which the coxa articulates. In the Coleoptera the coxal cavity is said to be closed when the epimeron extends behind the coxa to the sternum. It is described as open when the epimeron does not reach the sternum (Fig. 185). Scalloped. Heteroptera; the small triangular area at the end of the embolium of hemelytra; Odonata, the small triangle of the vertex between the compound eyes (Fig. loi). The upper surface. Moulting or casting of the skin. The science of the relation of organisms to each other and to their surroundings. The anterior leathery or chitinous wings of beetles (Fig. 181). The narrow sclerite extending along the anterior margin of the hemelytra, from base to cuneus or membrane, in Heter- optera (Fig. loi). The small process between the pulvilli in Diptera. The bi- fid pseudotarsi between the claws in Coleoptera (p. 14). Insect-feeding. THE CONTROL OF INJURIOUS INSECTS 411 Epistemum. Eruciform. Evaginate. Exserted. Foveola — ae. Frenulum. Front. Frontal Lunule, Gena. Genitalia. Halteres. Hermaphrodite. Heterogamy. Hibemaculum. Histogenesis. Histolysis. Hyper- metamorphosis. Hyperparasite. Imago. Instar. Integument. Labium. Labrum. Lacinia. Lamellate. Larva. Macrochaetae. Maggot. Mandibulate. Maxilla — ae. The anterior and larger lateral thoracic sclerite between the sternum and no turn (Fig. 18). Caterpillar-like in appearance (Fig. 38). Extruded by e version; turned inside out when extruded. Protruded. A pit-like shallow depression. The spine, simple in males, compound in females, arising from the base of secondaries in many Lepidoptera, whose function it is to unite the wings in flight (Fig. 120). Anterior portion of the head between the base of antennae and below the ocelli (Fig. 2). Diptera; an oval or crescentic space above the base of antennae in Cydorrhapha, bounded by the frontal suture. Cheek; that portion of the head below the eyes on each side extending to the gular suture (Fig. 2). External organs of reproduction and their appendages (p. 23)- The poisers or balancers; capitate movable filaments in Diptera, situated one on each side of the thorax and repre- senting rudimentary hind wings (p. 15). A bisexual individual. Alternation of generations, two sexual or a sexual and a parthenogenetic. A tent or sheath in which a lan^a hibernates. The formation and development of tissue. The degeneration and dissolution of organic tissue. The case in which an insect passes through more than the normal stages of development (Fig. 40). A parasite that is parasitic upon another parasite. The adult or sexually mature insect. The period or stage between moults in a larva (Fig. 38). The outer covering to the insect body. The lower lip (Fig. 7). The upper lip (Fig. 4). The inner lobe of the first maxilla, articulated to the stipes, bearing brushes of hairs or spines (Fig. 6). Divided laterally into distinct leaf-like plates (Fig. 183). The second stage in the development of the insect, follows immediately after the egg stage. The long bristles occurring singly on the body of Diptera. The footless larva of Diptera (Fig. 38). With jaws or mandibles. Jaws; one on each side of the mouth immediately beneath the mandibles (Fig. 6). 412 ECONOMIC ENTOMOLOGY Mentum. Mesenteron. Mesonotum. Metabolism. Metanotum. Metathorax. Microchaetse. Moniliform. Nectaries. Nymph. Obtect. Ocellus. Oogenesis. Ova. Ovipositor. Paedogenesis. Parthenogenesis. Pleura. Polyembryony. Pulvillus — i. Pupa. Puparium. Pygidiimi. Reticulate, Rostrum. Sclerite. Scrobes. A labial sclerite bearing the movable parts (Fig. 7). The middle portion of the primitive intestinal canal; the mid-gut (Figs, i, 36). The primitively upper surface of the middle thoracic ring (Fig. 18). Transformation, changes of food into tissue and of tissue into waste products. The primitively upper surface of the third or posterior thoracic ring (Fig. 18). The third thoracic ring or segment (Fig. 18). Small bristles, as opposed to macrochaetae, in Diptera. Beaded like a necklace (Fig. 183). A term which was applied to the cornicles of the Aphids under the mistaken notion that these structures secreted the honey dew (Fig. 88). The larval stage of insects with incomplete metamorphosis (Fig. 88). Wrapped in a hard covering (Fig. 39). A simple eye. The process of egg-formation. Eggs. The structure by means of which the eggs are placed (Fig, 23). Reproduction in the larval or the pupal stage. Reproduction by direct growth of germs from egg-cells without fertilization by the male. Plural of pleuron or pleurum; the lateral sclerites between the dorsal and sternal portion of the thorax; in general, the sides of the body between the dorsum and sternum. Production of more than one embryo from one egg. Soft, pad-like structures between tarsal claws; the cushions of short stiff hair or other clothing on the under side of tarsal joints; rarely fleshy lobes (p. 14). The intermediate stage between larva and adult (Fig. 39). The thickened larval skin within which the pupa is sometimes formed (Fig. 39). The last dorsal segment left exposed by the elytra. In DiaspifKB (Coccidae) the compound terminal segment (Fig. 127). Like net-work. A snout-like prolongation of the head. Any piece of the body- wall bounded by sutures (p. 2). Grooves formed for the reception or concealment of the appendages. In Rhyncophora grooves at the sides of the rostrum to receive the scape of antennae. THE CONTROL OF INJURIOUS INSECTS 413 Sensoria. Spermatogenesis. Spinneret. Spiracle. Stemite. Suctorial. Sulcus. Suture. Tergal. Thorax. Trachea — ae. Transition Zone. Truncate. Venation. ' Viscera. Vittate. Viviparous. The circular openings covered by membrane on the antennae or legs of plant-lice. Development of the spermatozoa. Any organ consisting of an internal tube, terminating in a pore, spine or process, producing a silky or waxy fibre. A breathing pore opening to the trachea (Fig. 28). The ventral piece in a ring or segment (Fig. 17). Adapted for sucking. A furrow or groove; a groove-like excavation. A seam or compressed line indicating the division of distinct parts of body-wall; the line of junction of elytra in Coleop- tera. Belonging to the primitively upper surface. The second or middle portion of the insect body, bearing the true legs and wings; made up of three sections, the pro-meso- and meta-thorax (p. 14). The breathing tubes of insects (p. 23). The transcontinental belt in which the austral and boreal elements overlap; it is divided into a humid or Alleghanian area, a western arid area, and a Pacific coast humid area. Cut oflE squarely at tip. The system of chitinous framework supporting the wings. The internal organs of the body. Striped. , Bearing living young. INDEX Abbott's sphinx, 178 Abdomen, 17 Acalyptrata, 241 Acanthiidae, 159, 167 Acarina, 364 Accessory glands, 29 Achemon sphinx, 178 Achorutes, 96 Acrididae, 107 Acronycta, 87, 198 Adalia bipunctata, 287 Adult stage, 38 Aedes, 243, 245 ^geriidae, 174, 216 Agaristidae, 183 Aglais antiopa, 176 Agrilus anxius, 89, 301 bilineatus, 301 ruficollis, 84, 301 Agriotes mancus, 293, 295 Agromyza simplex, 263 Agromyzidae, 242, 262 Agrotis c-nigrum, 185 fennica, 192 unicolor, 185 ypsilon, 186 Alaus oculatus, 78 Alder blight, 149 Aleyrodes citri, 152 vaporariorum, 90, 151 Aleyrodidae, 122, 151 Alfalfa caterpillar, 176 insects, 73 leaf weevil, 332 looper, 194 Alimentary canal, 24 Allorhina, 304 Alsophila pometaria, 78, 81, 87, 205 Alypia octomaculata, 183 Ambush bugs, 43, 159 American cockroach, 104 frit fly, 71, 261 dagger moth, 87 grass stem maggot, 261 Ametastegia glabrata, 80, 347 Ampelceca myron, 86, 178 Amphibolips, 351 Amphicerus bicaudatus, 82, 328 Amphidasis cognataria, 206 Anametis granulatus, 337 Anaphothrips striatus, 72 Anarsia li»eatella, 83, 86, 215 Anasa tristis, 8, 46, 77, 160 Anastatus bifasciatus, 200, 404, 406 Anatis 15-punctata, 291 Anatomy of insects, 2-30 Ancylis comptana, 86, 232 nubeculana, 79, 218, 230 Andrena, 357 Andrenidas, 356 Androconia, 17 Angoumois grain moth, 74, 214 Anisandrus pyri, 341 Anisota, 179 Anobium tesselatum, 328 Anomalon exile, 204 Anopedius, 352 Anopheles and malaria, 50 maculipennis, 92, 243, 244 Antennae, 10, 11 Anthomyidae, 242, 273 Anthonomus grandis, 333 quadrigibbus, 80, 335 signatus, 84, 87, 332 415 4i6 INDEX Anthrax, 53 Anthrenus scrophulariie, 92, 291 Antique tussock moth, 203 Ant lions, 43, 99, 100 Ants, 92, 359 Apanteles glomeratus, 175, 353 lacteicolor, 202, 404, 406 militaris, 190 Aphelinus mali, 354, 401 diaspidis, 129, 354 Aphididae, 122, 136 Aphidius, 352 fletcheri, 149 rapse, 148 Aphids, 68, 136 Aphis, 138 abietina, 149 a venae, 59, 71 bakeri, 142 brassicae, 77, 148 forbesi, 148 gossypii, 47, 77, 148 maidis, 72, 142 • maidi-radicis, 72, 142 mali, 78, 143 malifoliae, 144 persicae-niger, 147 pomi, 78, 143 pseudobrassicae, 148 rumicis, 74, 148 sanborni, 85, 147 sorbi, 78, 144 varians, 147 Aphis-lion, 43, 100 Aphycus, 354 Apidae, 356, 357 Apis mellifera, 10, 12, 19, 40, 357, 358 Apoidea, 345, 356 Apple aphids, 78, 80 bud aphis, 78, 80, 142 curculio, 80, 331 ermine moth, 233 , fruit miner, 233 insects, 77-80 leaf bucculatrix, 80, 236 leaf crumpler, 79, 213 Apple leaf hopper, 155 leaf miner, 79, 235 leaf rollers, 78, 79, 229 leaf sewer, 79, 218, 230 leaf skeletonizer, 79, 213 maggot, 80, 266 red bugs, 165 seed chalcid, 80, 355 sphinx, 79, 178 tent caterpillar, 79, 87, 203 worm, 219 Apple-tree borer, flat-headed, 78, 300 round-headed, 78, 320 Application of poisons, 377, 386 Aptera, 94 Arachnida, i, 364 Arctiidae, 173, 181 Argasidae, 364, 365 Argentine ant, 360 Argyresthia conjugella, 233 thuiella, 233 Argyroploce consanguinana, 226 Armadillidium vulgare, 363 Army beetles, 325 cutworms, 187, 192 worms, 71, 190 Arsenate of lead, 384 lime, 385 Arsenic, white, 384, 393 Arsenite of lime, 384' Arthropoda, i Artificial methods of control, 374, 377 Asaphes decoloratus, 293, 297 Ash gray pinion, 197 Asilidae, 240 Asparagus beetles, 36, 61, 63, 312 miner, 263 Aspen tortrix, 230 Aspidiotus, 123 ancylus, 126 forbesi, 127, 128 hederae, 134 ostreaeformis, 128 perniciosus, 78, 80, 126, 127 Aspidisca splendoriferella, 79, 232 Aspidistra scale, 90, 135 INDEX 417 Assassin bugs, 43 Asterolecanium variolosum, 130 Atropos divinatoria, 103 Attagenus piceus, 292 Auchenorhynchi, 122 Aulacaspis rosas, 123, 128 Austral zones, 61 Australian cockroach, 104 Autographa brassicae, 193 californica, 194 simplex, 194 Automeris io, 180 B Babesia bovis, 56 Bachmetjew, Dr., 59 Bacillus amylovorus, 46 pestis, 55 Bagworm moths, 174, 207 Baits, poison, 398 Baker, A. C, 141 Banded flea beetle, 316 Bands, metal, 396 Bark beetles, 339 Bassus earinoides, 226, 353 Bean aphis, 74, 148 insects, 74 leaf beetle, 313 weevil, 74, 319 Bed bugs, 92 Bee flies, 240 moths, 212 Beech tree blight, 149 Bees, 345, 356 Beet leaf hopper, 155 leaf miner, 277 Beetles, 280 Bembecia marginata, 84, 218 Beneficial insects, 39-44 Berlese, Prof., 40 Bethune, Dr. C. J. S., xiii Bethune's green fruit worm, 197 Bibliography, 407 Bill bugs, 338 Biosteres rhagoletis, 267 27 Birch leaf skeletonizer, 88, 236 saw fly, 346 Birds, 44 Biting lice, 106 Black ants, 92 apple leaf hopper, 155 army worm, 192 bodied cherry fruit fly, 266 carpet beetle, 292 chrysanthemum aphis, 149 flies, 53, 251 horned tree cricket, 116 leaf, 40, 391 peach aphis, 144 snouted rose beetle, 335 swallow tail, 174 vine weevil, 336 Blackberry crown borer, 218 insects, 84 Blastoderm, 30 Blastula, 31 Blatta, 103, 104 Blattidae, 103 Blattoidea, 102, 103 Blepharipa scutellata, 200, 406 Blissus leucopterus, 71, 161 Blister beetles, 77, 325 mites, 368 Blood gills, 23 Blow fly, 53, 92, 273 Bluebottle fly, 273 Body louse of man, 56, 168 Bombus, 357 Bombycidse, 179 Bombyliidae, 240 Bombyx mori, 40, 179 Book lice, 103 Borax, 399 Bordeaux mixture, 395 nozzle, 380 Borers, 78, 88, 89 Bot flies, 60, 254 Box-elder plant bug, 159 Brachycera, 239 Brachycolus tritici, 141 Braconid flies, 42 4i8 INDEX Braconidae, 42, 344, 352 Brain, 28 Bramble flea-louse, 84, 152 crown-borer, 84, 218 Breeding cages, 67-69 Bronze apple-tree weevil, 335 birch borer, 89, 301 cutworm, 188 Brown tail moth, 60, 64, 88, 200, 403 Bruce's measuring worm, 207 Bruchidae, 283, 319 Bruchophagus funebris, 73, 355 Bruchus obtectus, 74, 319 pisorum, 74, 319 Bryobia pratensis, 80, 367 Bucculatrix canadensisella, 88, 236 pomifoliella, 80, 236 Bud moth, 23, 26, 36, 78, 79, 225 Buffalo carpet beetle, 92, 291 tree-hopper, 78, 157 Bumble flower beetle, 80, 305 Buprestidae, 283, 300 Butterflies, 94 Butterfly, mouth parts of, 9, 10 Byturus unicolor, 84, 292 Cabbage aphis, 77, 148 butterfly, 63, 175 looper, 193 plant louse, 77, 148 root maggot, 36, 76, 273 worm, 76, 77, 17s Cacoecia argyrospila, 229 cerasivorana, 230 conflictana, 230 obsoletana, 232 rosaceana, 230 Cadelle, 76, 327 Caddice flies, 99 Caesar, Prof. L., 60, 229 Calandra granaria, 75, 2>M oryzae, 75, 337 Calandridae, 284, 337 Caliroa cerasi, 348 Calliphora, 270 erythrocephala, 273 vomitoria, 92, 273 Callipterus, 137 Callosamia promethea, 82, 180 Calosoma calidum, 287 scrutator, 287 sycophanta, 200, 202, 287, 406 Calyptrata, 242 Camnula pellucida, 113 Campodeidae, 95 Camponotinae, 360 Camponotus, 360 Canker worm, fall, 78, 205 spring, 78, 205 Cantharis nuttalli, 325 Capsidae, 159, 163 Carabidae, 41, 282, 285 Carbolic acid emulsion, 392, 395 Carbolineum emulsion, 396 Carbon bisulphide, 393 tetrachloride, 395 Carnivora, 280, 282 Carolina locust, 113 Carpenter bee, 357 moth, 88, 237, 238 Carpocapsa pomonella, 80, 219 Carrion beetles, 293 Case bearers, 234 making clothes moth, 236 Cat and dog flea, 92, 280 Caterpillar, 34 Catocala, 198 Cattle dips, 392 insects, 91 louse, 91, 169 tick, 366 Cecidomyiidae, 239, 245 Cecropia moth, 79, 180 Celerio lineata, 178 Celery looper, 194 Centipedes, i Cephus occidentalis, 71, 349 Cerambycidae, 283, 320 Ceramica picta, 76, 188 Ceratina, 357 INDEX 419 Ceratitis capitata, 264 Ceratopogon, 252 Cerci, 17 Cercopodse, 122, 153 Cereal insects, 71, 72 Ceresa bubalus, 77, 83, 157 Cerodonta dorsalis, 263 Ceuthophilus, 114 Chaetopsis oenea, 277 Chaitophorus, 136 negundinis, 149 Chalcid flies, 42 Chalcididae, 42, 344, 353 Charts of life cycles, 221, 225, 247 Checkered beetles, 283 tiger moth, 183 Cheese-cloth screens, 396 Chermes, 139 abietis, 89, 149 cooleyi, 148 funitectis, 148 pinicorticis, 90, 150 similis, 89, 150 Cherry aphis, 139 ermine moth, 233 fruit fly, black-bodied, 83, 265 fruit fly, white-banded, 83 insects, 82 leaf beetle, 82, 311 leaf miner, 348 saw fly, 348 tree tortrix, 82, 230 Chicken lice, 91, loi mite, 91, 364 Chilocorus bivulnerus, 288, 289 Chilopoda, i Chin flies, 259 Chinch bug, 61, 71, 72, 161 Chionaspis euonymi, 128 furfurus, 78, 81, 125 Chironomidae, 240, 252 Chorizagrotis auxiliaris, 187 Chrysanthemum black aphis, 149 Chrysididae, 345 Chrysobothris femorata, 78, 89, 300 Chrysomelidae, 283, 306 Chrysomphalus, 123 aonidum, 134 Chrysomyia, 268, 273 Cicada, 156 septendecem, 156 tibicen, 82, 157 Cicadellidae, 122, 154 Cicadidae, 122, 156 Cicadula 6-notata, 72, 154 Cicindela, 284 Cicindelidae, 41, 282, 284 Cigar case-bearer, 78, 234 Cigarette beetle, 328 Cimbex americana, 88, 347 Cimex lectularius, 92, 167 Circular scale, 134 Circulatory system, 23, 24, 71, 190 Cirphis unipuncta, 23, 24, 71, 190 Citheroniidae, 179 Citrus mealy bug, 133 white fly, 152 Cladius pecticornis, 349 Classification of insects, 93 Clavicornia, 280, 282 Clear winged locust, 113 moths, 174, 216 Cleridae, 283 Click beetles, 293 Climatic factors, 61, 373 Climbing cutworms, 81, 192 Clothes moths, 92, 236 Clouded apple capsid, 165 Clover aphis, 142 cutworm, 189 hay worm, 73, 208 insects, 73 leaf midge, 73, 248 leaf weevil, 63, 73, 332 mealy bug, 73 mite, 80, 367 root borer, 63, 73, 341 root mealy bug, 133 seed caterpillar, 73, 228 seed chalcid, 73, 355 seed midge, 73, 246 Club-horn beetles, 280 420 INDEX Cluster fly, 53, 273 Coal tar, 395 Coccidae, 122 Coccinae, 123, 129 Coccinella, 5-notata, 290 9-notata, 290 Coccinellidse, 281, 287 Coccobacillus acridiorum, 46 Coccophagus, 354 Coccus, 123 hesperidum, 134 Cockroaches, 92 Codling moth, 59, 80, 219 records, 221 Coecal tubes, 26 Coelopistha nematicida, 354 Coleoptera, 94, 280 Collembola, 93, 95 Colopha, 138 Colorado potato beetle, 77, 308 Common striped cutworm, 187 Compsilura concinnata, 200, 202, 406 Comstock, Prof. J. H., 16, 298 Conchylidae, 174 Confused flour beetle, 75, 329 Conopidas, 241 Conotrachelus nenuphar, 81, 83, 330 Contact insecticides, 386 Contarinia johnsoni, 249 Control of insects, 373 Convergent ladybird, 288 Co-operative measures, 375 Coptodisca splendoriferella, 232 Cordyceps, 46, 304 Coreidae, 159 Corimelaenidae, 159, 167 Corn ant, 362 bill bugs, 72, 338 ear worm, 73, 195 feeding syrphid fly, 251 insects, 72 leaf aphis, 72, 73, 142 leaf miner, 263 root aphis, 72, 140, 141, 142 seed maggot, 72, 277 stalk borer, 211 Corn wire worm, 72, 211 Cornicles, 137 Corymbites, 78, 297 Cosmopepla carnifex, 167 Cossidae, 174, 237 Cost of spraying, 381 Cotalpa, 302, 304 Cotton boll weevil, 59, 333 worm, 196 -wood leaf beetles, 310 Cottony grass scale, 130 maple scale, 89, 130 Crab-louse of man, 168 Crambidae, 210 Crambus hortuellus, 211 Cranberry girdler, 211 Crane flies, 242 Craponius inaequalis, 336 Cremastogaster, 360 Creolin, 396 Crepidodera helxines, 311 rufipes, 316 Cricket-like grasshoppers, 114 Crickets, 107 Crioceris asparagi, 64, 312 i2-punctata, 313 Crop rotation, 374 Croton bug, 105 Crustacea, i, 363 Cryptohypnus, 297 Cryptorhynchus lapathi, 329 Ctenocephalis canis, 280 Cucumber beetles, 77, 307, 308 Cucujidae, 327 Culex, 52, 243 pipiens, 92, 243 Culicidae, 239, 243 Culicoides, 252 Cultivation of the soil, 375 Cultural control methods, 374 Curculio, apple, 80, 332 plum, 330 Curculionidae, 284, 329 Currant borer, 84, 217 fruit fly, 85, 265 . fruit miner, 85, 265 INDEX 421 Currant insects, 84, 85 lecanium, 84 moth, 206 plant louse, 85, 145 spanworm, 85, 206 stem girdler, 84, 345 worm, 85, 346 Curtis scale, 128 Cutworms, 72, 74, 76, 77, 185 climbing, 81 control of, 185 Cyclamen borer, 90, 336 mite, 369 Cyclocephala, 302, 304 Cyclorrhapha, 239 Cyllene robinise, 89, 322 Cymatophora ribearia, 85, 206 Cynipidae, 344, 351 Cynomyia cadaverina, 273 D Dactylopinae, 123, 131 Dagger moths, 197 Damsel flies, 99 Danaidae, 177 Danais archippus, 177 Dark meal worm, 76, 329 Darkling beetles, 328 Dark-sided cutworm, 186 Dasyneura leguminicola, 73, 246 rhodophaga, 90, 248 trifolii, 73, 248 Datana integerrima, 88, 199 ministra, 79, 198 Davis, J. J., 66-68, 141 Death watch beetles, 328 Dendroctonus, 342 Depressaria heracliana, 215 Dermacentor variabilis, 367 venustus, 56, 366 Dermanyssidae, 364 Dermanyssus gallinae, 364 Dermaptera, 102, 106 Dermestes lardarius, 92, 291 Dermestidae, 282, 291 Desmia funeralis, 209 Development of insects, 30 Dexiidae, 242 Diabrotica longicornis, 64, 308 i2-punctata, 64, 308 vittata, 77, 307 Diacrisia virginica, 181 Dialeurodes citri, 152 Diamond back moth, 76, 232 Diapheromera femorata, 106 Diaspinae, 123 Diaspis, 123, 403 Diastrophus turgidus, 351 Diatraea saccharalis, 211 Dibrachys, 354 Dicerca, 82 Dichomeris ligulella, 79, 215 Differential locust, 112 Digestive system, 24-28 Digger wasps, 356 Dingy cutworm, 193 Diplopoda, i, 369 Diplosis tritici, 72, 249 Diptera, 93, 239 Diseases by insects, 46, 49-57 of insects, 45 Disk nozzle, 380 Disonycha xanthomelaena, 317 Dissosteira Carolina, 109, 113 Distribution of insects, 60-64 Ditches, 399 Diving beetles, 282 Doane, Prof. R. W., 55 Dobson flies, 99 Dock false-worm, 80, 347 Docophorus icterodes, loi Dog day harvest fly, 157 flea, 280 louse, 169 Double host aphids, 150 Dragon flies, 99 Drasterius elegans, 293, 295, 296 Drosophila ampelophila, 260 Drosophilidae, 242, 260 Drug store beetles, 328 Dryocoetes confusus, 342 422 INDEX Duck lice, loi Dung-eating beetles, 301 Dust spraying, 382 Dytiscidae, 282 E Earwigs, 102, 106 Earworm, corn, 195 Eccoptogaster rugulosus, 78, 339 Ecdysis, 34 Ecological sciences, 65 Ectobia germanica, 92, 103, 105 Eel worms, 371 Eight-spotted forester, 183 Elaphidion villosum, 89, 324 Elateridae, 283, 293 Elm bark louse, 89, 130 borer, 89 leaf beetle, 63, 88, 309 saw fly, 88, 347 Embryology, 30-33 Emphytus, 87, 349 Empoa rosae, 156 Empoasca mali, 155 Empusa, 46 ' Endelomyia rosae, 348 aethiops, 349 English grain aphis, 71 Ennomidae, 206 Ennomos, 88 Entomobryidae, 96 Entomophagous, 40 Entomophthora, 46 Entomoscelis adonidis, 76, 309 Ephemerida, 97, 98 Ephestia kuehniella, 74, 213 Epicauta cinerea, 37, 38, 77, 325 marginata, 326 pennsylvanica, 77, 326 vittata, 37, 326 Epicerus imbricatus, 78, 82 Epilachna borealis, 290, 291 Epitrimerus pyri, 368 Epitrix cucumeris, 77, 313 subscrinata, 314 Epochra, 264 canadensis, 85, 265 Erannis defoliaria, 207 tiliaria, 88, 206 Eriocampoides limacina, 82, 348 Eriococcus, 124 Eriopeltis festucas, 130 Eriophyes pyri, 368 Eriophyidas, 364, 368 Eriosoma, 138 Eristalis, 251 Eruciform larva, :^:^ Erythroneura vitis, 155 Escherich, Dr., 34, 35 Estigmene acraea, 181 Eucosmidas, 218 Euonymus scale, 128 Eupelmus, 354 Euphoria, 302 inda, 80, 305 Euproctis chrysorrhoea, 88, 200 European corn borer, 72, 212 earwig, 106 fruit lecanium, 129 grain aphis, 71, 141 Eurymus eurytheme, 176 Eutettix tenella, 46, 155 Euthrips tritici, 122 Euxoa auxiliaris, 58 excellens, 188 messoria, 186 ochrogaster, 187 tesselata, 187 Evergestis rimosalis, 209 Evergreen bagworm, 207 External anatomy, 2-19 Eyed elater, 78 Eyes, II Factors of insect control, 373 Fall army worm, 192 canker worm, 205 webworm, 79, 87, 181 False tarnished plant bug, 164 INDEX 423 Fannia canicularis, 53 scalaris, 53 Fat bodies, 24 Feather lice, 100 Felt tar paper, 397 Feltia ducens, 193 Fernald, Prof. H. T., 63 Fevers, 49-52 Fidia viticida, 85, 311 Field stations, xii, 64 Fiery hunter, 287 Fifteen-spotted ladybird, 291 Filariasis, 52 Fir saw fly, 346 Fire flies, 283 Fish moths, 95 Fiske, W. F., 403 Fitch, Asa, xi, xiii Five-spotted ladybird, 290 Flat-headed apple tree borer, 78, 300 Flea beetles, 313 alder, 318 banded, 316 cucumber, 77 grape vine, 316 horse radish, 315 mangel, 318 pale striped, 316 potato, 77, 314 red-headed, 316 red-legged, 317 smartweed, 316 spinach, 317 strawberry, 86, 317 turnip, 76, 315 western potato, 315 willow, 317 Fleas, 55, 279 Flesh flies, 242 Fletcher, Dr. Jas., xiii Flies, 53 Flour beetles, 75 Flower flies, 43, 240, 250 Forbes, Dr. S. A., 40, 48, 60, 141, 298 Forbes scale, 128 Forest bark beetles, 342 Forest tent-caterpillar, 87, 204 Forficula auricularia, 106 Formalin, 394 Formicidae, 359 Formicoidea, 345, 359 Four-lined leaf bug, 85, 163 Fruit aphids, 143 bark beetles, 78, 81, 339 flies, 264 leaf syneta, 311 lecanium, 81 tree leaf roller, 78, 229 worms, green, 80, 197 Froghoppers, 72, 153 Fulgoridae, 122 Fumigation, 394 Gad flies, 53, 252 Galerita janus, 281 Galerucella clavicollis, 82, 311 decora, 310 luteola, 88, 309 Gall flies, 45, 351 gnats, 45 lice, 45 midges, 45, 245 Galleria mellonella, 212 Galleriidae, 212 Gamasidae, 364 Ganglia, 28 Garden aphids, 148 slugs, 370 stalk borer, 196 vegetable insects, 77 Gastric coeca, 26 Gastrophilus haemorrhoidalis, 91, 254, 259 intestinalis, 91, 254, 258 nasalis, 91, 254, 250 Gastropoda, 370 Geese lice, 10 1 Gelechiidae, 214 Genitalia, 17, 18 Geometridse, 204 424 INDEX Geometrids, 170 Geometrina, 170, 204 Germ band, 31,32 German cockroach, 92 Giant root borer, 83, 322 Gizzard, 24 Glassy cutworm, 188 Glossary, 409 Glossina, 54 Goat moth, 238 Golden oak scale, 130 Gonapophysies, 17 Goniocotes abdominalis, 101 burnetti, loi hologaster, loi Goniodes dissimilis, loi stylifer, 102 Gooseberry insects, 84, 85 Gortyna, 196 Gossyparia, 124 spuria, 89, 130 Grain aphis, 141 weevils, 337 Granary weevil, 75, ^;^-;i Grape berry moth, 86, 228 blossom midge, 249 curculio, 336 insects, 85, 86 leaf folder, 209 leaf hopper, 86, 155 phylloxera, 85, 86, 148 root worm, 85, 311 sphinx, 86, 178 vine fidia, 85, 311 vine flea beetle, 86, 315 Grapholithida?, 86, 178 Graptolitha, 80, 197 Grass feeding froghopper, 153 stem maggots, 260 thrips, 72 Greasy cutworm, 186 Green apple aphis, 78, 141, 143 bottle flies, 273 bug, 142 clover worm, 195 fruit worm, 80, 197 Green gooseberry aphis, 147 peach aphis, 83, 144 rose aphis, 149 soldier bug, 166 thrips, 119 Greenhouse insects, 90 leaf tyer, 210 orthezia, 135 scales, 90, 133-135 Ground beetles, 40, 41, 282, 285 Grub, 34 Gryllidae, 107, 114 Gryllotalpa, 114 Gryllus pennsylvanicus, 115 Gypsy moth, 64, 87, 200, 403 Gyrinida?, 282 Gyropidae, 100 H Hadwen, Dr. S., 256 Haematobia, 268 serrata, 91, 272 Haematopinus, 168 asini, 169 curysternus, 91, 169 piliferus, 169 urius, 91, 169 vituli, 91, 169 Halictus, 357 Halisidota, caryae, 64, 183 maculata, 183 tessellaris, 87, 183 Haltica chalybea, 86, 315 ignita, 316 Hamamelistes, 138 Handmaid moths, 198 Haploptilia fletcherella, 234 malivorella, 235 Haploptilidae, 234 Hard scales, 124 Harlequin cabbage bug, 63, 166 Harmologa fumiferana, 231 Harpalus caliginosus, 287 pennsylvanicus, 287 Harpiphorus maculatus, 347 INDEX 4'^5 Hawk moths, 169 Hay worm, clover, 73 Head, 2 Head-louse of man, 168 Hearing, organs of, 11 Hedgehog caterpillar, 181 Heliothis obsoleta, 73, 195 Heliothrips ha^morrhoidalis, 119 Heliozelidae, 232 Hellebore, 385 Hemerocampa leucostigma, 79, 87, 202 Hemichionaspis aspidistras, 90, 135 Hemiptera, 43, 94, 158 Hemispherical scale, 132, 134 Hesperidae, 169 Hessian fly, 39, 59, 60, 71, 245 Heterocordylus malinus, 165 Heterodera radicicola, 371 Heteromera, 281, 283 Heterometabolic, 33 Heteroptera, 158 Hewitt, Dr. C. G., 58, 406 Hickory tiger moth, 183 Hippoboscidae, 279 Hippodamia convergens, 288, 289 13-punctata, 290 Histogenesis, 37 Histolysis, 37 Hog louse, 9I; 169 pests, 91 Holcaspis, 351 Holometabolic, S3 Homalomyia brevis, 278 canicularis, 53, 278 scalaris, 53, 278 Homoptera, 94, 122 Honey bee, 10, 12, 19, 40, 357, 358 Hookworm disease, 56 Hop merchant, 176 plant louse, 145 red bug, 165 vine looper, 195 Hopperdozer, 399 Hormaphis, 138 Horn fly, 38, 53 63, 272 tails, 350 Hornet, white faced, 356 yellow jacket, 356 Horse bot fly, 91, 258^259 flies, 8, 240, 252 insects, 91 louse, 169 House ant, 92, 361 flea, 279, 280 fly; 7, 18, 53, 92, 270 hold pests, 92 Howard, Dr. L. O., vii, 403 Human flea, 279 Hunter, Prof. W. D., 402 Hyadaphis, 138 Hyalopterus, 138 arundinis, 147 Hydrocyanic acid gas, 394 Hydrcecia, 196 Hydrophilidae, 282 Hylastinus obscurus, 64, 73, 341 Hylemyia antiqua, 276 Hylotoma pectoralis, 346 Hymenoptera, 94, 343 Hypena humuli, 195 Hyperaspis signata, 288 ' . Hypermetamorphosis, 'S^ Hyperparasitism, 43 Hyphantria, textor, 79, 87 Hypoderma bo vis, 91 y 257 lineatum, 91, 255 Hypsopygia, costalis, 73, 280 Icerya purchasi, 402 Ichneumon flies, 41 Ichneumonidae, 41, 344, 352 Idiocerus fitchi, 155 Imaginal buds, 37 Imago stage, 38 Imbricated snout beetle, 78 Imported cabbage worm, 63, 64, 77, 175 currant borer, 84, 217 worm, 346 Incomplete metamorphosis, s^ Indian euphoria, 80, 305 426 INDEX Indian meal moth, 74, 214 Insect behavior toward stimuh', 57, 58 Insects and birds, 44 as carriers of plant diseases, 46-47 and disease, 49-57 distribution of, 60-64 and plants, 45 in relation to temperature, 59-60 Insectary, 66-68 Insecticides, 377 action of, 400 Insectivorous plants, 45 Internal anatomy, 19-30 changes, 2,7 Inter-relations in nature, 45 Intromittent organ, 28 lo moth, 82, 180 Ipidai, 284, 339 Isaria, 46 Ischnoptera, 103 Isia Isabella, 181 Isomera, 280 Isoptera, 102 Isosoma grande, 354 hordci, 355 secale, 355 . tritici, 71, 354 Itamera ribearia, 206 Itch mite of man, 365 poultry, 91, 365 Ivy scale, 134 Ixodida;, 364, 366 Janus integer, 84, 345 Jarring, 399 Jassoidea, 122 Joint worm, 71, 354 Julidx, 369 Julus canadensis, 369 coeruleocinctus, 370 virgatus, 370 Jumping plant lice, 122 June beetles, 302, 303 K Katydids, 114 Kellogg, Prof. V. L., 50 Kermes, 124, 131 Kerosene, 395 emulsion, xi, 391 Labia minor, 106 Lace wings, 43, 99, 100 Lachnosterna, 80, 81, 302, 303 Lachnus, 136 Ladybirds, 40, 41 Lamellicornia, 281, 283 Lampyridae, 283 Languria mozardi, 173 Laphygma frugiperda, 192 Larch saw fly, 88, 346 Larder beetle, 92, 282, 291 Large blue bottle fly, 273 Larger corn stalk borer, 211 Larvae, classification of, 34-35 Larval stage, 32-35 Lasiocampidae, 174, 203 Lasioderma serricorne, 328 Lasius niger, 48, 140, 360, 362 Laspeyresia interstinctana, 73, 228 » nigricana, 74, 226 prunivora, 80, 227 Latrine fly, 53, 278 Lead arsenate, 384 Leaf beetles, 80, 283, 306 bugs, 159, 163 chafers, 283, 302 crumpler, 78, 83, 213 hoppers, 122, 154 horn beetles, 281 miner flies, 262 miners, 79, 235 rollers, 78, 229 sewer, 79, 218, 230 skeletonizer, 79, 236 Leather jackets, 71, 242 Lebia grandis, 286 INDEX 427 Lecanium corni, 81, 129 nigrofasciatum, 83, 90, 129 oleoe, 403 ribis, 84 Legs, 14 Leopard moth, 88, 237 Lepidoptera, 94, 169 Lepidosaphes ulmi, 78, 81, 124 Lepisma domestica, 95 saccharina, 94 Lepismidae, 94 Leprosy, 56 Leptinotarsa lo-lineata, 77, 308 Leptocoris trivittatiis, 159 Lesser apple worm, 80, 227 bud moth, 215 clover leaf weevil, 332 house fly, 278 leaf roller, 231 migratory locust, 1 1 1 peach borer, 217 Leucotermes flavipes, 103 Lice, biting, 100 sucking, 56 Life cycle charts, 221, 225, 247 zones, 61, 62 Ligyrus, 304 Limax, 370 Lime, 389 sulphur, 386 tree winter moth, 88, 206 Lina interrupta, 310 scripta, 310 tremulae, 310 Liotheidae, 100 Liparida;, 170 Lipeurus poly trapezius, 102 squalidus, 102 tadornae, loi variabilis, loi Little house fly, 278 Locust borer, 89, 322 Locustidse, 107 Locusts, 107 Long horned beetles, 320 grasshoppers, 114 Long tailed mealy bug, 133 Longistigma, 136 Loopers, 193, 204 Lophyrus abbotti, 346 abietis, 346 Losses due to insects, 38-39 Loxostege sticticalis, 210 Lucanidae, 283, 318 Lucanus dama, 82 Lucilia, 270 caesar, 273 Luna moth, 180 Lycaenidae, 169 Lycophotia margaritosa, 186 scandens, 192 Lyctidae, 328 Lyctus, 328 Lygaeidae, 159 Lygaeonematus erichsonii, 88, 346 Lygidia mendax, 165 Lygus communis, 164 invitus, 164 pratensis, 84, 163 Lymantriidae, 170, 200 Lyonetiidae, 236 Lyperosia, 268 Lysiphlebus tritici, 352 M Macrobasis unicolor, 326 Macrodactylus subspinosus, 82, 83, 305 Macrolepidoptera, 169 Macrosiphum, 138 granariura, 71, 141 pisi, 73, 149 rosae, 149 sanborni, 90, 149 solanifolii, 77, 149 Magdalis oenescens, 335 Maggot, 34 apple, 266 onion, 276 seed corn, 72, 277 wheat stem, 71, 72, 260 Malacosoma americana, 79, 87, 203 disstria, 87, 204 428 INDEX Malarial mosquito, 50, 243, 244 Mallophaga, 94, 100 Mandibulate mouth parts, 5 suctorial mouth parts, 10 Mangel flea beetle, 317 Manson and Ross, 50 Mantids, praying, 105 Mantis religiosa, 106 Mantoidea, 102, 105 Maple sesian, 217 worm, 179 Margaropus annulatus, 56, 366 Marguerite fly, 262 Mash, poison, 185, 398 Mason bees, 357 May beetles, 80, 81 flies, 97, 98 Mayetiola destructor, 71, 245 Meadow froghopper, 153 grasshopper, 114 maggots, 71, 242 Meal snout moth, 75, 208 worms, 76, 327 Mealy bugs, 131 plum louse, 147 Measuring worms, 207 Meat fly, 92, 273 Mecoptera, 97, 100 Mediterranean flour moth, 74, 213 fruit fly, 264 Megachile, 357 Megilla fuscilabris, 288 maculata, 288 Megorismus fletcheri, 149 Melanoplus atlanis, 108, iii bivittatus, 108, 112 differentialis, 108, 112 femur-rubrum, 71, 108, 109 spretus, 108, 109 Melanotus communis, 294, 296 cribulosus, 294 Melittia satyriniformis, 217 Meloidae, 38, 283, 325 Melon insects, 77 plant louse, 77, 148 Melophagus ovinus, 91, 279 Membracidas, 122 Menopon pallidum, 91, 100 Merodon equestris, 251 Meromyza americana, 71, 260 Merriam's life zones, 61 Mesochorus, 197 Mesogramma politus, 72, 251 Mesoleius tenthredinidis, 406 Metallic ground beetles, 287 wood borers, 89, 300 Metamorphosis, 33-38 Meteorus, 197, 353, 406 Methods of studying insects, 64-69 Microcentrum, 114 Microgaster, 42, 353 Microlepidoptera, 174 Midaidae, 240 Midas flies, 240 Midges, 252 Millipeds, i, 76, 369 Mineola indigenella, 78, 213 Miscible oils, 391 Mites, 364 Mollusca, 370 Monellia, 136 Monocteniidae, 205 Monodontomerus aereus, 200, 202, 354, 405, 406 Monohammus, 58, 325 Monomorium minutum, 92, 360 pharaonis, 92, 360 Monophadnus rubi, 84, 347 Mosquitoes, 243 house, 8, 92 malarial, 50, 92 Mossy rose gall, 351 Moths, 94, 169 Mottled umber moth, 207 Moulting, 34 Mourning cloak, 177 Mouth parts, 2-10 Mud wasps, 356 Murgantia histrionica, 63, 166 Murky ground beetles, 286 Musca domestica, 8, 53, 269, 270 Muscidae, 242, 268 INDEX 429 Muscina, 268, 273 Muscoidea, 241 Muscular system, 19 Myrmicinae, 360 Myzocallis, 137 Myzus, 138 cerasi, 144 persicae, 83, 90, 144 ribis, 85, 143 N Nabidae, 159 Nagana, 49, 54 Naphthaline, 396 Narcissus fly, 251 Natural enemies of insects, 376 Negro bug, 167 Negundo plant louse, 149 Nematocera, 239 Nematodes, 371 Nemobius, 115 Nephelodes emmedonia, 188 Nepticula pomivorella, 238 Nepticulidae, 238 Nerve winged insects, 94, 96 Nervous system, 28 Neuria procincta, 188 Neurocolpus nubilis, 165 Neuroptera, 96, 99 Neuropteroida, 94, 96 Neurotoma inconspicua, 348 Nezara hilaris, 166 pennsylvanica, 167 Nine-spotted ladybird, 290 Noctuidae, 173, 184 Nose flies, 91, 259 Notodontidae, 170 Notolophus antiqua, 203 Novius cardinalis, 40, 402 Nozzles, 380 Nymphalidae, 169, 176 O Oak twig pruner, 324 Oat aphis, 72, 78, 80, 141, 142 Oberea bimaculata, 84, 322 Oblique-banded leaf-roller, 78, 83, 230 Odonata, 97, 99 (Ecanthus, 47, 83, 84, 115 nigricornis, 115, 116 niveus, 115, 116 (Edopodinae, 109 OEstridae, 241, 254 (Estrus, 254, 256 ovis, 90, 260 O'kane, Prof. W. C, 268 Oleander scale, 134 Onion maggot, 77, 276 thrips, 121 Oniscus asellus, 363 Opheltes, 347 Ophion, 352 Orchard tent caterpillar, 79, 87, 203 Oriental cockroach, 104 Ornithodoros megnini, 365 Orthezia insignis, 135 Orthoptera, 102, 107 Orthopteroida, 94, 102 Orthorrhapha, 239 Orthosia hibisci, 197 Oscinidae, 241, 260 Oscinis carbonaria, 71, 261 Osmia, 357 Osmoderma scabra, 82, 305 Ostomatidae, 327 Otiorhynchidae, 284, 336 Otiorhynchus ovatus, 86, 336 sulcatus, 90, 336 Ovaries, 28 Oviduct, 29 Ovipositor, 18, 19 Oxidus gracilis, 370 Ox warble fly, 91, 257 Oyster shell scale, 78, 124 Paedogenesis, 30 Paleacrita vernata, 205 Pales favida, 202 Pale striped flea beetle, 316 Palmer worm, 79, 215 Pamphilius fletcheri, 346 430 INDEX I';ip;ii|>ili(>ni(la', j6f;, / 74 I';ir;iIu(:oris huwl(;yi, J65 I'arasif.cH, 4^ I'arasilic insects, iilili/,;ilif>/i of, 40; l';i.ris K'"'"*'", ^', .'i^.i I';i.rr(*t, l'rf»f., -^9-^ I'-'irsnip wc)> worm, 21/5 l';irlli(;iioj.MTicsis, y.() I'avcnicnl ;ui(, ',0( f'c.'i inscc Is, 74 rriol li, 74, y.y.(> |)l;iiil loii;,c, 74, i4f; weevil, :^i), 74, v,,^ I'e.'K.li uj)his, M.5 inscctH, 8;^ le.'if weevil, ^','/ tree hark Ijectth;, ,5.50, ^40 l>or(rr, So, «3, 'Ai<> I wi^ borer, H^, 215 Tear leaf hiisf.er mile, ^(iH I)Hylla, 152 sluK, 82, .i4« Jlirips, I K) l'ef|i( iilijs capitis, 5O, j08 pubis, 168 vesti(nef)li, 56, 1 08 I'egoiiiyia vicina, 277 I'clec inida;, 345, .^52 I'elec ifius obturator, .352 Pelidnola puiu faf;i,, 86, .502 l'«llaj',ra, .'/> l'(t I'entiiia misc-lla, 288, 289 l'epp;iea niinuta, 2,^1 Persian insect powder, >/)i f'liarynx, 24 I'liasfnid.e, jo6 I'haHrrifjidea, 102, 106 F'lienaf ocf us, ajcricoia, 124, i.^^ I'liilajnus lincatus, 72, 15.3 Hjiumarius, 15.3 I'liilopferida-, 100 ridy( ta-nia ferruj^.'dis, 90, 210 Pliolus, I y<) I'liorbia brassif .'f, '/(>, 273 (cparum, 77, 274, 276 fuscircps, 72, 277 rubivora, 84, 277 I'lior/rii.'i, 270, 273 I'liorodon, i /// liiiiniili, 145 riiolo(riy/,a chrysanllietrii, 2O2 riiololaxis, t;7 ^9 I'lillioropliloiis liiiiinaris, ,',40 f'liy< it i rapa-, 64, y/, 175 Pi^-^eon trcmex, 350 Pill bu^s, 363 Pinipla con(|uisitor, 204, 22O, 231, 352, 406 in(|ui8itor, 203, 204, 231, 352 INDKX 4.U IMiic l)ark aphid, i 50 saw lly, ,u() Wood borers, ^^2^ IMstoI case lu'arcr, 78, 235 rilliy hiackbrrry KivH. 35 1 I'ilifid ladybird, 2^H IMtyoktcincs sparsus, 34.; IMaKionotus sptxiosus, .S(^, 3^4 I'lant cahMS, .'Si Hco, 1 22, 130 lMatiiyi)cna scabra, 105 PlutyK.istcr, 3S IMcioptcra, oS I'lodia in(iM|)iiiu Iclla, /.], • 1 4 IMuni a[)his, So curcuHo, So, 330 i user Is, So scale, Si , I .'(> sphinx, Si , 1 yS web s|)iniiiiiK saw lly, 34S I'hihila MKK iilipciinis, 7O, 232 Podisiis spiiiosiis, i()7 Podiirida*, (jO INcc iloca|)SUS lineatiis, S5, i()3 Poison baits, 308 F*ois()nous jj;asrs, ^](),\ Poisons, ^Hj^ l*oHsU'8, 356 Pollcnia, 26H, 273 I'oiychrosis vilcana, S(>, 22H Polydc'snuis canadensis, 370 Polyf^noliis hicniabs, 35.*, 401 PoIy^ra|)hiis inlipcnnis, 342 IN)ly[)h<'iniis molh, •/(), iSo Polyphylla, 302, 304 Poma(c MifS, 2C)0 l'<»|)lar borer, S() leaf ^all lons<', 1 4(^ I'orccllio hevis, :i()_^ Porosa^rolis, iSS, 193 Porlhetria dispar, 87, 200 Potato beetle, 77, 308 Ilea beetle, 77, 313 insects, 76, 77 plaiil louse, 77, I4(; Potato stalk borer, 77, m)(), j,\<; Poullry ilch mile, 3(>5 miles, 3()4 pests, ()i l\>W(l(>r post beetle, 3,'S Piiiyin^ manlids, 105 Predaceous beetles, 40, 41 insects, 40, 4 i Pre\("iiti\'e met hods, 374 Prioinis lati(<)Ilis, X^, 322 Prionoxyslus lobini.r, SS, 238 Proctotrypida-, 4.;, 344, 351 Profenusa collaris, 348 Promethea moth,S.', 1 So I'rosopis, 357 ]*rospaltella, 40, 354, 403 I'rolectors, 3()(> Protoparce, i 77 Proveiilriculus, 2.\ Provisional larval or^'ans, 35 Pseudococcns, 1 .'4 (itri, 133 lonf^ispiiuis, ()o, 133 trifolii, 73, 133 Psila rosa*, 7(), 2(12 I'silida*, 242, 262 l*sithyrns, 357 Ps»)( i(he, 103 Psorosina, 70, ^13 Psoro|)les communis, 300 Psylla pyri( ola, 1 52 Psylli(h-e, I,'.- Psylliodcs pniK I iiiala, 3 1 •/ Plenxomma, 13O Pterom.'ilns pnpariim, 175, 354 cKreniiis, 202, 405 Pteroniis ribesii, 85, 34O l'terosli( hus lucublandus, ^S(» Ptinidu;, 283, 328 Piilex irritans, 2 7() serraticeps, 0^, 2S0 Puliciche, 270 Pulvinaria, 1 ,'4 vitis, 85, 8(;, 130 I'nnkies, ,?5- Pnpal stage, 3O, 37 432 INDEX Pupipara, 242 Purple-backed cabbage worm, 209 Putnam scale, 127 Pygidia, 127 Pyralididae, 208 Pyralids, 174, 207 Pyralis farinalis, 75, 208 Pyrausta nubilalis, 72, 73, 212 Pyraustidae, 208, 212 Pyrethrum, 391 Pyrrhocoridffi, 159 R Rachela bruceata, 207 Railroad worm, 266 Raspberry byturus, 84, 292 cane borer, 84, 322 maggot, 84, 277 insects, 83-84 saw fly, 84, 347 webworm, 346 Recurvaria nanella, 215 Red bugs, 159 apple, 165 backed cutworm, 187 humped apple caterpillar, 79, 199 legged flea beetle, 316 locust, 71, 108, 109 necked blackberry borer, 84, 301 spider, 76, 367 tailed bot fly, 91, 259 turnip beetle, 309 Reed, Major Walter, 52 Relatives of insects, near, i, 363 Remedial methods of control, 374 Repellents, 395 Reproductive system, 28-29 Respiratory system, 22-23 Resplendent shield bearer, 79, 232 Restriction and exclusion of insects, 376 Rhagoletis, 264 cingulata, 83, 265 fuasta, 83, 266 pomonella, 266 Rhodites rosae, 351 Rhopalosiphum, 138 Rhynchites bicolor, 334 Rhyncophora, 281, 328 Rice weevil, 75, 337 Riley, Dr. C. V., xi, xiii Dr. W. A., 252 Rise of economic entomology, x Roaches, 104 Robber flies, 240 Rocky mountain locust, xi, 61, 108, 109 spotted fever tick, 56, 366 Root aphids, 144, 147, 148 borers, 83, 321 crop insects, 76 maggots, 72, 76, 77, 273 web worms, 210 Rose beetle, 82, 334 chafer, 82, 305 leaf hopper, 156 midge, 248 sawfly, 348 scale, 128 slugs, 348, 349 Rosy apple aphis, 78, 80, 144 Rotation of crops, 374 Rough osmoderma, 82, 305 Round headed apple tree borer, 78, 320 Rove beetles, 282 Rust flies, 262 fly, carrot, 76, 262 Saissetia, 123, 134 hemispherica, 134 Salivary glands, 24 Salt marsh caterpillar, 181 Samia cecropia, 79, 180 San Jose scale, xi, 2, 38, 48, 60, 63, 64, 78, 80, 126, 127 Saperda Candida, 78, 320 Sarcophagidae, 242 Sarcoptes mutans, 91, 365 scabiei, 365 INDEX 433 Sarcoptidae, 364, 365 Saturniidae, 180 Saturniina, 174, 179 Saunders, Dr. W., xiii Sawflies, 345 Sawhorn beetles, 280 Saw- toothed grain beetle, 75, 327 Scale insects, 122 Scarabaeidae, 283, 302 Scatophagidae, 241 Scavenger beetles, 40, 301 Schedius, 404, 406 Schizoneura lanigera, 77, 145 Schizura concinna, 79, 199 Sclerites, 2 Scolytidae, 339 Scorpion flies, 100 Scotogramma trifolii, 189 Screens, muslin, 396 Screw worm, fly, 273 Scudderia furcata, 44 Scurfy scale, 78, 125 Scutelleridae, 159 Scutellista cyanea, 354, 403 Searcher, 287 Seed corn maggot, 72, 277 Seidemia devastator, 188 Sensoria, 134 Septis arctica, 188 Serpentine leaf miner, 238 Serphoidea, 352 Serricornia, 280, 283 Sesiidae, 216 Seventeen-year locust, 156 Shade tree insects, 87-89 Sheep bot fly, 90, 260 insects, 90 scab mite, 90, 366 tick, 91, 279 Shot hole borer, 341 Silk worm moths, 174, 179 Silpha bituberosa, 293 opaca, 293 Silphidae, 282, 293 Silvanus surinamensis, 75, 327 Silver fish, 92 28 Simuliidae, 240, 251 Simulium, 53, 251 Sipha, 136 Siphocoryne avenae, 138 Siphonaptera,,94, 279 Siphunculata, 94, 167 Siricidae, 344, 350 Sitka spruce gall louse, 149 Sitodrepa panicea, 328 Sitotroga cerealella, 74, 214 Six-spotted leaf hopper, 72, 154 Skippers, 169 Sladen, F. W. L., 48 Sleeping sickness, 54 Slugs, 348, 349, 370 Smell, organs of, 11 Snout beetles, 281, 328 moths, 207 Snowy tree cricket, 116 Soap, 390 Sodium fluoride, 385, 392 Soft scales, 129 Soldier flies, 240 Solenopsis, 360 Soluble sulphur, 389, 390 Span worms, 204 Sphaerostilbe coccophila, 46 Sphecius, 356 Sphecoidea, 345, 356 Sphenophorus, 72, 338 Sphinx, 79 abbott's, 178 achemon, 178 drupiferarum, 81, 178 grape vine, 178 pandorus, 179 plum, 81, 178 tomato, 177 twin spotted, 179 white lined, 178 Spinach carrion beetle, 293 flea beetle, 316 Spinose ear tick, 365 Spirobolus, 370 Spittle insects, 122, 153 Sporotrichum globuliferum, 46 434 INDEX Spotted cutworm, 185 fever, 56 halisidota, 183 legged cutworm, 193 megilla, 288 paria, 86 pelidnota, 86 Smartweed flea beetle, 315 Spray gun nozzle, 381 Spraying, 377, 381 equipment, 378 Spring canker worm, 205 grain aphis, 142 Spruce bud worm, 231 gall aphids, 89, 149, 150 Squash bug, 77, 160 insects, 77 ladybird, 290 vine borer, 217 Stable fly, 8, 10, 53, 92, 271 Stag beetles, 82, 318 Stagmomantis Carolina, 105 Stalk borers, 87, 196 Staphylinidae, 282 Stegomyia fasciata, 52 Stem girdler, currant, 84, 345 Sternorhynchi, 122 Sternum, 14, 17 Stigmus, 356 Stimuli, 57 Stink bugs, 166 Stomach, 24 Stomoxys calcitrans, 8, 10, 53, 92, 268, 271 Stone flies, 98 Stratiomyiidje, 240 Strawberry crown borer, 86, 335 flea beetle, 86, 307 insects, 86 leaf roller, 86, 232 root borer, 86, 313 louse, 148 weevil, 87, 332 saw fly, 347 thrips, 87, 122 Striped cucumber beetle, 76, 307 Structure of insects, 2-30 Sucking lice, 167 Suctorial mouth parts, 6-10 Sugar beet web worm, 210 maple borer, 89, 324 Sulphur, 394 soap, 391 and lime, 389 Swallow tails, 174 Sweet cherry aphis, 144 Sympathetic nerve system, 28 Synanthedon acerni, 217 exitiosa, 80, 216 pictipes, 217 ' tipuliformis, 84, 217 Synchlora ajrata, 84 Syriphidae, 240, 250 Syrphids, ^50 Systena blanda, 315 frontalis, 86, 315 hudsonias, 315 taeniata, 315 Tabanids, 252 Tabanus, 8 atratus, 91, 252 Tachina flies, 42, 278 mella, 203, 204 Tachinidae, 42, 242, 278 Tajniothrips inconsequens, 119 Taeniopteryx, 97 Tanglefoot, 396 Tapestry moth, 92, 237 Tar-felt paper disks, 397 Tarnished plant bug, 84, 163 false, 164 Tarsonemidae, 364, 369 Tarsonemus, 369 Taste, organs of, 1 1 Telea polyphemus, 79, 180 Telenomus bifidus, 352 Temperatures, high and low, 400 Tenebrio molitor, 76, 328 obscurus, 329 INDEX 435 Tenebrionidae, 283, 328 Tenebroides mauritanicus, 76, 327 Tent caterpillar moths, 79, 174, 203 Tenthredinidae, 344, 345 Tergum, 14, 17 Termitidae, 102 Terrapin scale, 90, 1 29 Testes, 28 Tetramorium, 360 Tetraneura, 138 Tetranychidae, 364, 367 Tetranychus bimaculatus, 367 Tetrastichus, 354, 407 Thalessa, 352 Thick-headed flies, 241 Thirteen-spotted ladybird, 290 Thomas, C, xiii Thorax, 14 Thrips, 72, 118 tabaci, 14, 121 Thyridopteryx ephemeraeformis, 207 Thysanura, 95 Thysanoptera, 94, 118 Thysanuriform larva, 33 Thysbe, clear-wing, 179 Ticks, 56, 366 Tiger moths, 87 beetles, 41, 284 Tinea pellionella, 92, 236 Tineids, 174, 236 Tineina, 174, 236 Tineola biselliella, 92, 237 Tiphia, 356 Tipulidae, 239, 242 Tischeria malifoliella, 79, 235 Tischeriidae, 235 Tmetocera ocellana, 23, 26, 78, 225 Tobacco, 391, 394, 3Q5 extracts, 391 sphinx, 177 Tomato sphinx, 177 Tortricidae, 229 Tortricina, 174, 218 Toxoptera graminum, 138, 142 Tracheal gills, 2^ Transition zone, 61 Traps and trap crops, 397 Tree crickets, 116 hoppers, 122 Tremex columba, 350 Tribolium confusum, 75, 329 Trichobaris trinotata, 77, 335 Trichodectes scalaris, 91 Trichodectidae, 100 Trichogramma, 354, 406 Trichophaga, 92 tapetzella, 237 Trichoptera, 99 Trimera, 281 Trinotum lituratum, 102 luridum, 102 Trioza tripunctata, 84, 152 Trogositidae, 327 Trogus, 352 Trombidiidae, 364 Tropisms, 57, 59 Tropoea luna, 180 Trypanosomiasis, 54 Trypeta pomonella, 80, 266 Trypetidae, 242, 264 Try poxy Ion, 356 Tsetse flies, 54 Turkey lice, 102 Turnip beetle, red, 309 Turnip flea beetle, 76, 314 Turpentine, 395 Tussock moth, 79, 87, 170, 202 Twelve-spotted cucumber beetle, 308 asparagus beetle, 313 Twice-stabbed chilocorus, 288 Twig-borer, apple, 328 Two-lined chestnut borer, 308 Two-spotted adalia, 287 hyperaspis, 288 Two-striped locust, 112 Twin-spotted sphinx, 179 Tychius picirostris, 335 Tyloderma fragariae, 86, 335 Typhoid fly, 53 Typhus fever, 56 Typophorus canellus, 313 Tyroglyphidas, 364 436 INDEX U Umber moth, mottled, 207 Underwing moths, 198 Upper Austral zone, 61 Utilization of parasitic insects, 401 Variable currant aphis, 147 Variegated cutworm, 186 Venation of wings, 15, 139, 158, 170-173, 240-241, 344 Vespa, 356 Vespidae, 356 Vespoidea, 345, 356 Violet gall fly, 90 Vermorel nozzle, 380 W Wheat thrips, 122 wineworm, 295 Wheeler, Dr. W. M., 59 Whirligig beetles, 282 White ants, 102 banded cherry fruit fly, 265 cedar twig borer, 233 cutworm, 192 fly, 90, 122, 151 grubs, 56, 71, 72, 77, 302 lined sphinx, 178 marked tussock moth, 202 Willow flea beetle, 311 Wings, 15, 16 Winthemia 4-pustulata, 184, 190 Wire-netting, 397 Wireworms, 71, 72, 77, 293 Wood lice, 363 Woolly aphis of apple and elm, 77, 89, 14s maple leaf scale, 133 W-marked cutworm, 185 Wash for tree trunks, 396 Walking sticks, 106 Walnut caterpillar, 88, 199 Walsh, B. D., xiii Warble flies, 91, 255-258 Wasps, 356 Water scavengers, 282 Webbing clothes moths, 82, 237 Webster, F. M., xi, 63, 401 Web worms, 210 Weevils, 329 Western corn root worm, 308 hemlock woolly aphis, 149 wheat stem sawfly, 71, 349 willow leaf beetle, 310 Whaleoil soap, 390 Wheat insects, 71 jointworm, 354 midge, 72, 249 plant louse, 71, 142 stem maggot, 71, 72, 260 sawfly, 349 straw worm, 354 X Xiphidium, 114 Xylocopa, 357 Yellow bear caterpillar, 181 fever, 83 headed cutworm, 188 mealworm, 76, 328 necked caterpillar, 79, 198 Yponomeuta malina, 233 padella, 233 Yponomeutidae, 233 Zebra caterpillar, 76, 188 Zenoleum, 396 Zeuzera pyrina, 88, 237 Zophodia grossulariae, 85