Historic, archived document Do not assume content reflects current scientific knowledge, policies, or practices. "4 sae - - >t i. a ¥ os os a a5 3 aft PE TS ee es q , - ey yn Cae Wo. 52 B—New SERIES.” : U, Ve DEPARTMENT OF AGRICULTURE. _DIVISION OF ENTOMOLOGY, f “INSECTS AFFECTING DOMESTIC ANIMALS: AN ACCOUNT OF THE SPECIES OF IMPORTANCE IN NORTH AMERICA, WITH MENTION OF RELATED FORMS OCCURRING ON OTHER AN'MALS. PREPARED UNDER Ti‘) DIRECTION OF THE ENTOMOLOGIST, by HERBERT OSBORN, Professor of Zoology and Entomology, Lowa Agricultural Colleye, Ames, lowa. . mS WASHINGTON : GOVERNMENT PRINTING OFFICE, - 1596, Yh DIVISION OF ENTOMOLOGY. ae, ; + y ee ~ Entomologist : L. 0. Howard. . ott rack, Assistant Entomologists : 07 roe Marlatt, Th. Persunie, Pe He Phishemaent se a if eidaegators Ey A. Schwarz, H. G. Hubbard, W. H. Ashmead, D, Ww. Coquillet, Assistants: Frank Benton, R. S. Clifton, F. C, Tr atte » Anti: ‘Miss it Sullivan, . BULLETIN No. 5.—New SERIES. U. S. DEPARTMENT OF AGRICULTURE. DIVISION OF ENTOMOLOGY. INSECTS AFFECTING DOMESTIC ANIMALS: AN ACCOUNT OF THE SPECIES OF IMPORTANCE IN NORTH AMERICA, WITIL MENTION OF RELATED FORMS OCCURRING ON OTHER ANIMALS. PREPARED UNDER THE DIRECTION OF THE ENTOMOLOGIST, By HERBERT OSBORN, Professor of Zoology and Entomology, Iowa Agricultural College, Ames, Lowa, Sl A Nal ee a a de ek hr WASHINGTON : GOVERNMENT PRINTING OFFICE. 1896. LETTER OF TRANSMITTAL. U. S. DEPARTMENT OF AGRICULTURE, DIVISION OF ENTOMOLOGY, Washington, D. C., July 8, 1896. Str: I transmit herewith the manuscript of a report upon insects affecting domestic animals in the United States. This report has been prepared by Prof. Herbert Osborn, of the Zoological Department of the State Agricultural College at Ames, Iowa. Professor Osborn was a field agent of this Division for some years prior to 1893, and was engaged, during part of the time of his employment by the Depart- ment, in the preparation of this report. As explained in the prefatory statement, it was the intention of Professor Riley to collaborate with Professor Osborn in this work, but other duties interfered. The report, in its present condition, is largely the result of work done by Professor Osborn, under a special commission from the Department during the past winter. The chapter on remedies has been carefully read and revised by Dr. D. E. Salmon, chief of the Bureau of Animal Industry. The report will form an excellent text-book of the subject, and is a work which, in the opinion of the writer, should be in the hands of all stock raisers. J recommend its publication as Bulletin No. 5, new series, of this Division. Respectfully, L. O. HOWARD, Entomologist. Hon. J. STERLING MORTON, Secretary of Agriculture. PREFATORY NOTE. The report herewith submitted was originally planned in 1885 as a conjoint work with Dr. C. V. Riley, the intention being that the writer should make a first draft of the matter, presenting the results of his own studies, and that the material should then be reviewed by Dr. Riley to make such corrections and additions as the material in his hands might permit. On this basis, manuscript was prepared and transmitted to Washington at intervals up to 1890, but the numerous duties of Dr. Riley, especially his work for the Paris Exposition in 1889, prevented his giving any attention to this matter, and in 1890, at his suggestion, the chapter on “ Pediculi and Mallophaga,” which had been my special study, was put in shape for the press and issued shortly after as Bulletin 7 of the series of Division Bulletins. The other matter was held in reserve, though receiving attention at times when other work permitted. After Dr. Riley’s death his successor, Dr. Howard, found the writer’s incompleted manuscripts and proposed that they should be revised, completed, brought up to date, and published—a proposition which I was very glad to accept, as it seemed after so much of my time had been given to this work while in the employ of the Division of Ento- mology it was but right that there should be some published results. In completing the work the original plan and scope has been followed in most respects, but it has been found necessary, on account of the mass of material collected, to restrict the treatment of the species, giving special prominence only to those forms of interest to the Amer- ican stock breeder and poulterer, and especially in the bibliography to limit the titles. While a large number of the figures have been prepared expressly for this work, a number have been secured from other sources, and will be found duly credited in each instance. Of the original figures, 34, 36, 50, 51, and 52 were prepared in the Division of Entomology; the others have been drawn by Miss Charlotte M. King, under my personal Supervision. ji I take this opportunity to acknowledge my indebtedness to Professor Riley for his interest and assistance in the inception and preparation of the report, and to Dr. M. Francis, Prof. 8. A. Forbes, Dr. A.S. Packard, Prof. Lawrence Bruner, Dr. A. Hassall, Prof. J. H. Comstock, Mr. C. F. Baker, Mr. 8. E. Cassino, and others who have kindly aided me with the use of cuts or with specimens for study. To Dr. L. O. Howard I am under especial obligations for most valuable aid in the final revision and completion. He has taken great pains to furnish me references not otherwise at command and to provide illustrations. HERBERT OSBORN. Iowa Agricultural College, Ames, Iowa. 4 CONTENTS. ennai EOP UCT IOWN bois 2 rw hace Sale ow Been nose sien ep Soaps em oon Definitions and arrangement (p. 9)—Grouping of parasitic insects (p. 11)—Life histories of parasites in general (p. 14)—Origin of the parasitic habit (p. 16)—Results of parasitism (p.16)—Distribution of parasites (p. 17)—Effects of parasites on the host (p. 18)—Losses due to parasites (p. 20)—Popular notions about parasites (p. 21). CHAPTER II.—DIPTERA (mosquitoes, gnats, flies, and ticks)-.....----..----.-- DRamily: Cplicig 2. (mosguiees, onats, 6bC.).-.2..-2-2-5-2---5-b-- 2 -s4-2-- Pee MeMA ANS TOMUNEN, 325.06 Fo eo ae LS eee nes Peet ERONOMID.2: (minees) oss 6- ws Sais os ee as eee nae ne se- =o The blood-sucking gnat ( Tersesthes torrens)....--.-------------------- Family SIMULIID (black flies, buffalo-gnats)-.--.-..--.-...-.---------- Losses from buffalo gnats (p. 32)—Life history and habits (p. 33)— Preventives (p.36)—Remedies for the bites (p.37)—Natural enemies of buffalo gnats (p.38)— Descriptions of species, with notes on their habits (p. 38)—The columbacz midge (p. 38)—Simulium ornatum (p.39)—The black fly (p.40)—The Southern buffalo gnat (p.41)— The turkey gnat(p.52)—The Western buffalo gnat(p.55)—Simulium piscicidium (p.56)—Simulium canescens (p.57)—Simulium rivulara » (p. 57) —Simulium sp. (in Brazil) (p. 57)—Simulium venustum (p.57)—Simulium sp. (near Washington) (p.58)—Simulium pictipes (p. 58). Family TABANID& (horse flies, gad flies, etc.) .-...........-----.-.-.------ The black gad fly or breeze fly (p. 60)—The green-head horse fly (p. 63)—Tabanus stygius (p. 66)—Tabanus molestus (p. 68)—European gad fly (p.68)—The banded breeze fly (p.69)—The ear fly (p. 69)— Chrysops niger (p. 70)—Chrysops quadrivittatus (p. 70)—Chrysops costatus (p. 70)—Chrysops fugax (p. 70)—The hippoboscid-like tabanid (p.71). RT NESTOR) iia 2 i nL Family GisTRID& (hot-flies, breeze flies) ........-..----..-. 2-52. -e-5-- The horse bot-fly (p.76)—The hemorrhoidal bot-fly............------ Horse bot-fly or ‘chin fly” (p. 85)—Gastrophilus pecorum........---- The bot-flies of cattle (p.87)—Warble flies: Extent and manner of injury (p.88)—Loss on hides (p.88)—Loss in milk and beef from attack of bot-flies (p.89)—Occurrence of warbles in man (p.91)— * Life history and habits (p. 91)—Remedial measures (p. 93)—Ox bot- - fly or warble fly (p. 95)—Ox bot-fly or heel fly (p. 97). Zee sneep Dot-ly OF head maggot.*.. - 2... 2... 2 - nn an eneee- Be -, The reindeer bot or deer bot (p. 105)—The emasculating bot-tly (p. 105)—The rabbit bot-fly (p. 108)—The cotton-tail bot (p. 110)—Other species (p. 110)—Bot-fly of man, monkeys, dogs, ete. (p. 110). 6 CONTENTS. CHAPTER II.—DIPTERA (mosquitoes, gnats, flies, and ticks)—Continued. Family Muscina: (house dies, and allies) => .2 aces ae ee eee The horn fly (p. 114)—The flesh fly (p. 121)—The stable fly (p. 122)—The meat fly or blow fly (p. 123)—Blue-bottle fly (p. 123)—The screw-worm fly (p. 123)—The tsetse fly (p. 183)—The Hippelates flies (134). Family, HterPoBoscipa: (forestiilies, ticks) se 4-5 sos se eee ae eee eee The bird ticks (Olfersia and Ornithomyia) (p. 137)—The deer tick (p. 137)—The forest fly or horse tick (p. 137)—The sheep tick (p. 188). Family NY CreRiBitpa: (bat: flies) 22 sc oes ee ee ee CHAPTER [TT-=SIPHONAPTERA (leas). 2252. Sace so See eso eee The jigger flea, or chigoe (p. 142)—The hen flea (p. 144)—The opossum flea (p. 146)—The house flea (p. 147)—The bird flea (p. 147)—The rat and mouse flea (p. 148)—Squirrel fleas (p. 148)—The spermophile flea (p. 149)—The dog and cat flea (p.150)—Rabbit fleas (p. 152)—The mole flea (p. 153)—The pocket gopher flea (p. 154). CHAPTER [V:—HEMIPTERA (bugs and lee)... eo eee ee eee ee eee Suborder HETEROPTERA: Family ACANTHIIDZ (bed bug and allied forms). The common bed bug (p. 157)—The ‘‘coruco,” or Mexican chicken bug (p. 160)—The barn-swallow bug (p. 161). amily REDU VIED AL. o6 soos 4 oe 2 as oo gos te sa ae © Se The blood-sucking cone-nose (p. 163). Suborder PARASITA: Family PEDICULID£—The suctorial lice. ie The crab louse (p. 165)—The head louse (p. 166)—The body? lous! ee. 167)— Louse of the ape (p. 168)—Lice infesting the monkey (p. 168)— The sucking dog louse (p. 169)—The louse of the camel (p. 170)—Lice infesting the giraffe, deer, and antelope (p. 170)—The sucking louse of the goat (p. 170)—The sheep foot louse (p. 170)—The short-nosed ox louse (p. 172)—The long-nosed ox lonse (p. 176)—The buftalo louse (p. 177)—The hog louse (p.178)—The sucking horse louse (p. 180)— Sucking lice of rodents (p. 181)—Louse of the rat (p. 181)—Louse of the field mouse (p.181)—Louse of the rabbit and hare (p. 182)— Louse of the flying squirrel (p. 182)—Louse of the fox squirrel (p. 183)—Louse of the gray squirrel (p. 184)—Louse of the white-footed mouse (p. 184)—Louse of the ground squirrels and chipmunk (p. 185)—Hematopinus erraticus (p. 186)—Euhematopinus: Mole louse (p. 186)— Euhiematopinus abnormis (p. 187) -—- Hematopinoides: Sucking louse of the pocket gopher (p. 187)—The elephant louse (p. 188)—The louse of the harbor seal (p. 188). CHAPTER V.—Suborder MaLLOPHAGA (birddice)222 2. =. S225 -e-5e- eee eee Family PHILOPTERID A .2.52 isin e oe ane oases eee eee ee ee Louse of ducks and geese (p. 192)—The little red swan louse (p. 192)— Lesser chicken louse (p. 192)—Large chicken louse (p. 193)—Pigeox 134 140 141 157 157 163 164 189 191 louse (p. 193)—The peacock goniocotes (p. 194)—Goniocotes of the . pheasant (p. 194)—Burnett’s goniocotes (p. 194)—The chicken gon- iodes (p. 195)—Guinea fowl goniodes (p. 195)—The pigeon goniodes (p.195)—The little pigeon goniodes (p. 196)—Louse of the turkey (p. 196)—The peacock goniodes (p. 197)—The pheasant goniodes (p. 197)—Goniodes gigas (p. 197)—Lipeurus of the chicken and pheasant (p. 197)—Guinea fowl lipeurus (p. 198)— Louse of the shel- drake (p. 198)—The pigeon lipeurus (p. 199)—The squalid duck louse (p. 200)—Lipeurus anseris (p.200)—The lipeurus of the goose (p. 200)—The turkey louse (p. 201)—The variable chicken louse (p. 202)—The white swan louse (p. 202)—The louse of the cat (p.203)— The biting louse of the dog (p. 203)—The louse of the bear (p. 204)— The louse of the llama (p. 204)—The louse of the goat (p.204)—The louse of the sheep (p.206)—The biting lice of horses, mules, asses, etc. (p. 207)—Trichodectes pilosus (p. 208)—Trichodectes parum- pilosus (p. 208)—Biting lice of cattle (p. 209). CONTENTS. PAM EP SO Falees oboe ae aes oboe s aac e ee rte cee wo dies odecde be ceee Louse of the dove (p.210)—The common hen louse (p. 210)—Menopon biseriatum (p.212)—The pheasant menopon (p. 212)—The peacock louse (p.212)—Louse of the Guinea hen (p.213)—Louse of ducks (p. 213)—Louse of the goose and swan (p. 213)—Louse of the goose (p. 214)—The pigeon louse (p. 214)—The swan louse (p. 215) —Louse of the Guinea pig (p. 215)—Gyropus ovalis (p. 216). Peers ON aT SSE Set ee ees eee eee - ot teelieeae ne List of species of Mallophaga in United States, with descriptions of new species (p. 216)—Philopterid (p. 216)—Liotheide (p. 243). ee A CEO A So ot roto nn edn 2 ot adiawed enon skew nseae cs oueees teem ae reer sears > Harvest mites; chigpers:— ...0 2. -- 22 25...2006 oleews soem ep AMMEN AT eo) Se She ee eects DIPTERA. eS ‘In the year 1830 there appeared in.the end of April and beginning of May, after a previous overflowing in the month of March, the same notorious Simulium columbatezense as I was convinced by a close com- parison on the shores of the marsh from its junction with the Danube as far as Hanna, in Austria-Hungary and Moravia, and most plentifully in the countries lying on the banks exposed to the inundations. It attacked cattle in the meadows as in the Banat, and the villages im that neighborhood lost some hundreds of cattle, such as horses, cows, and swine.” Fig. 7.—Simulium ornatum: a, larva, side view; b, same, back view; ¢, pupa, beneath; d, same, from above; e, cocoon—much enlarged (after Verdat). Simulium reptans Linn. is considered by many authorities as equiva- lent to the columbatczense. It was described from Lapland previous to the description of columbatczense, and, if identical, should of course include the form referred to that species. Simulium ornatum Meig. This is the species upon which Verdat and Fries made the extended studies which have been mentioned in the fore part of this chapter 40 INSECTS AFFECTING DOMESTIC ANIMALS. under the name of Simulium sericeum. Baron Osten Sacken, however, states that he inclines to the opinion that it is in reality the ornatum, and in deference to this opinion we include mention of it under that name. It may be remarked that sericewm is considered the same as columbatczense, mention of which has already been made. Fia. 8.—Simulium ornatum: a, head of larva, beneath: b, mandible; c, maxilla; e, under lip; f, upper lip—all enlarged; d, larva attached to plant; g, pupa in cocoon—natural size (after Verdat). This species has not the record of having proven a source of any ereat annoyance in the region to which it is common, nor is its geo- graphical limit given with precision in any work at hand. The studies of its larval and pupal stages, however, gave a foundation for later researches upon the subject, and as furnishing interesting subjects for comparison, we reproduce the figures published by Verdat. TEE BEACK VEnY. (Simulium molestum Harris, MSS. ) The celebrated black fly of the Northern States has long been known in the adult form as a torment to travelers and to domestic animals. The following account by Dr. A. 8S. Packard (Amer. Nat., Vol. I, pp. 589-590) is sufficiently characteristic: The black fly is even a more formidable pest than the mosquito. In the northern, subarctic regions it opposes a barrier against travel. The Labrador fisherman spends his summer on the seashore, scarcely daring to penetrate the interior on account of the swarms of these flies. During asummer residence on this coast we sailed up the Esquimaux River for 6 or 8 miles, spending a few hours at a house situated on the bank. The day was warm and but little wind blowing and the swarms of black flies were absolutely terrific. In vain we frantically waved our net among them, allured by some rare moth. After making a few desperate charges in the face of the throng- ing pests, we had to retire to the house where the windows actually swarmed with ‘them; but here they would fly in our face, crawl under our clothes, where they would even remain and bite in the night. The children of the house were sickly and worn by their unceasing torments; and the shaggy Newfoundland dogs, whose thick coats would seem to be proof against their bites, ran from their shelter beneath the bench and dashed into the river, their only retreat. In cloudy weather, unlike the mos- quito, the black fly disappears, only flying when the sun shines. The bite of the black fly is often severe, the creature leaving a large clot of blood to mark the scene of its surgical triumphs. The distribution of this species is not accurately defined, but south- ward it occupies the mountainous regions of northern New England, DIPTERA. ~ 41 and it probably occurs in localities throughout much of the British provinces, its local distribution depending upon the occurrence of swiftly running streams, which are essential to the life of the larve. The larval form has not been positively identified, but Dr. Packard figures a specimen which he collected in Labrador and which he sup- poses to be the larva of molestum or a closely related species. THE SOUTHERN BUFFALO GNAT. (Simulium pecuarum Riley.) EARLY HISTORY. In the American Journal of Science (Vol. I, 1818) there occurs on page 328, under the heading, “A destructive insect,” the following interesting account, which must certainly refer to the buffalo-gnat, and which is, so far as I know, the earliest authentic account of its operations: But I will not enlarge upon a fact already familiar. Iwill ask your further indul- gence only while I communicate an authentic and curious fact for the information of the zoologist. In the Choctaw country, 130 miles northeast of Natchez, a part of the public road is rendered famous on account of the periodical return of a poisonous and destruc- tive fly. Contrary to the custom of other insects, it always appears when the cold weather commences in December, and as invariably disappears on the approach of warm weather, which is about the Ist of April. It is said to have been remarked first in the winter of 1807, during a snowstorm, when its effects upon the horses and cattle were observed to be similar to those of the gnat and mosquito in summer, except that they were more severe. It continued to return at the same season of the year, without producing extensive mischief, until the winter of 1816, when it began to be generally fatal to the horses of travelers. So far as I recollect, it was stated that from thirty to forty traveling horses were destroyed during this winter. The consequences were alarming. In the wilderness where the man’s horse is his chief dependence, the traveler was surprised and distressed to see the beast sicken and die in convulsions, sometimes within three hours after encountering this little insect. Or, if the animal were fortunate enough to live, a sickness followed, commonly attended with the sudden and entire shedding of the hair, which rendered the brute unfit for use. Unwilling to believe that eftects so dreadful could be produced by a cause apparently so trifling, travelers began to suspect that the Indians or others, of whom they obtained food for their horses, had, for some base and selfish end, mingled poison with it. The greatest precaution was observed. They refused to stop at any house on the way and carried, for the distance of 40 or 50 miles their own provisions, but after all suffered the same calamities. This excited serious inquiry into the true cause of their distress. The fly which has been mentioned was known to be a most singular insect, and peculiarly troublesome to horses. At length it was admitted by all that the cause of the evils complained of could be no other than this insect. Other precautions have since been observed, particularly that of riding over the road infested with it in the night; and it now happens that compar- atively few horses are destroyed. Iam unable to describe it from my own observa- tion. I passed over the same road in April last, only two weeks after it disappeared, and was obliged to take the description from others. Its color is a dark brown. It has an elongated head, with a small and sharp proboscis, and in size between the gnat and mosquito. When it alights upon a horse it darts through the air, much like a gnat, and never quits its hold until removed by foree. When a horse stops to drink swarms fly about the head and crowd into the mouth, nostrils, and ears; 42 INSECTS AFFECTING DOMESTIC ANIMALS. hence it is supposed the poison is communicated inwardly. Whether this be true or not, the most fatal consequences result. It is singular that from the time of its first appearance it has never extended for a greater distance than 40 miles in one direc- tion, and usually it is confined to 15 miles. In no other part of the country has it ever been seen. From this fact it would seem probable that the cause of its exist- ence is local. But whatitis none can tell. After the warm weather commences it disappears as effectually from human observation as if it were annihilated. Toward the close of December it springs up all at once into being again, and resumes the work of destruction. A fact so singular I could not have ventured to state without the best evidence of its reality. All the circumstances here related are familiar to hundreds, and were in almost every man’s mouth when I passed through the country. In addition to this they were confirmed by the account which I received from Col. John McKee, a gentleman of much intelligence and respectability, who is the present agent of the General Government for the Choctaw Nation. He has consented to obtain specimens of the insect for your examination when it returns again; and will, I hope, accompany the transmission with a more perfect description than it has been possible for me to communicate.—REv. ELIAS CORNELIUS. In the report of the United States Department of Agriculture for 1886, the following summary of early occurrences is given: It seems that no authentic record exists in Louisiana about the occurrence of the Southern buffalo-gnat prior to the year 1850. It has been reported, however, that they had previously appeared in 1846. In 1861 and 1862 they were very troublesome in portions of Mississippi and Louisiana; in 1863 and 1864 they abounded about Shreveport, La., and in Chicot County, Ark. None are reported to occur in 1865, but in 1866 they invaded the alluvial country between the Arkansas and Red rivers east of the Washita. In 1873 and 1874 serious injury was occasioned by them in several regions in Louisiana. But in 1882 and 1884 they were more destructive than ever before, doing immense damage to live stock of all kinds. Although not gener- ally very numerous in 1885, they appeared in sufficient numbers in several counties of Louisiana to kill quite a number of mules. In 1886 they appeared generally throughout the whole extent of the region infested by them, and they appeared rather unexpectedly, because it was so unprecedentedly late in the season. In Indiana this insect was well known as far back as 1843, when the settlers used to watch for it every year, as swarms would appear in certain regions with more or less regularity, often occasioning considerable damage. It was ascertained from a number of gentlemen in Tennessee and Mississippi that the buffalo-gnats were well known to their ancestors who first settled in that region at a time when Indians were their neighbors. But everyone questioned in the States of Louisiana, Mississippi, Tennessee, and Arkansas would voice this universal opinion, viz., that buffalo-gnats come only with high water and are contemporary with an overflow. The connection between an overflow and the appearance of the buffalo-gnats will be considered farther on. AREA INFESTED. The investigations of 1885-86-87, which have been reported very fully in the Department publications and from which the statements here made are mostly compiled, have shown that the extent of territory invaded by these insects is much greater than formerly supposed. It . may be stated to comprise, in the worst years, the whole of the Missis- sippi Valley from the mouth of the Red River, in Louisiana, to St. Louis, Mo. All the land adjacent to the many rivers and creeks that empty from the east and the west into the Mississippi River is invaded DIPTERA. AS by swarms. They are driven about by the wind and reach points far away from their breeding places. In Louisiana all the land inclosed by the Mississippi and Red rivers, with perhaps the exception of the extreme western counties, is usually invaded by the buffalo- gnats during a gnat year. South of the Red River they become scarce, less aggres- sive, and appear only at very irregular intervals. In Mississippi all the counties bordering on the river that gives the name to the State are more or less invaded during gnat years. All Arkansas, excepting perhaps the western counties, shares the same fate. In the numerous creeks and rivers of this State and of Louisiana the buffalo-gnat breeds most abundantly. In Tennessee the same conditions prevail as in Mississippi, but the swarms do not reach so far east as in the latter State. In Missouri the buffalo-gnats infest only the southeastern counties. Kentucky does not fare as well as Missouri, since swarms of them frequently ascend the Ohio River for some distance. Illinois and Indiana are also more or less invaded; in the former, it is the region bordering upon the Mississippi and Wabash rivers; in the latter, that on the Ohio and Wabash rivers. In 1886 buffalo-gnats appeared in large swarms at De Soto, in Jackson County, Il., and along the White River, in Daviess County, Ind. In eastern Kansas swarms have repeatedly done great damage. LOSSES OCCASIONED. The extent of the losses due to this species have already been stated, though it is of course impossible to separate the losses due to this species from those caused by the turkey-gnat. In a general way the latter may be said to be more destructive to poultry, while the attacks of this species are more particularly directed against the larger domestic animals. Domestic animals are attacked in the following order, varying somewhat in dif- ferent localities, viz, mules, horses, cattle, sheep, setting turkeys and hens, hogs, dogs, and cats. The death rate of mules is highest, both because they seem to be more susceptible to the bite, and because they are almost exclusively used in the Southern States for farm work. Horses alsosuffer greatly. Cattle, when weakened by winter exposure and by scarcity of food, succumb easily to the continued attacks of their winged foes. Hogs show at first the effects of the bite but very little; yet large numbers die soon after the attack, while others die about six weeks after the disappearance of the buffalo-gnats; they usually perish from large ulcerating sores, which cause blood poisoning. Many persons claim that the so-called charbon is produced by the bites of these gnats, a statement which is, of course, not borne out by facts. Sheep, although well protected by their wool, suffer greatly by bites upon the unprotected portions of their skins, and injure themselves still more by crowding too close to fires, which are built to produce protecting smoke. Many sheep crowd so close to the fire as to be burned to death. Setting turkeys and hens are frequently forced by the gnats to leave their nests. Young fowls are killed out- right. The gnats, in attacking fowls of all kinds, force their way under the wings of their victims, where they can not be dislodged. Dogs and cats are also greatly tormented, and will not remain outdoors during a buffalo-gnat invasion if they can help it. Deer, forgetful of any other threatening danger, are tormented to such a degree as to lose all fear, and approach the smoldering fires; in their agony they sometimes allow people to rub the gnats from their bodies, and will, in their frantic endeavors for relief, even lie down in the glowing embers or hot ashes. 44 INSECTS AFFECTING DOMESTIC ANIMALS. EFFECT OF THE BITES. Animals bitten by many buffalo-gnats show all the symptoms of colic, and many people believe that these bites bring on that disease. Mules especially are thus aftected, yet large numbers of post-mortem examinations made by Dr. Warren King, of Vicksburg, and others, failed to show any relationship between this disease and the bites, nor were any facts obtained which would justify the correctness of such a popular conclusion. Dr. King opines that the effects of these bites on animals are much the same as that of the rattlesnake on the human system. This seems to be the generally accepted opinion among the more intelligent planters. The animal attacked becomes at first frantic, but within a very short time it ceases to show symptoms of pain, submits passively to the infliction, rolls over, and dies; sometimes all within the space of three or four hours. Even if bitten by a very great number of gnats death does not necessarily follow, and then it is not always suddenly fatal. Mules which at night do not appear to be seriously injured will often be found dead next morning. Animals of various kinds become gradually accustomed to these bites, and during a long-continued invasion but few are killed toward the end of it. Itisa prevailing notion that the bite of the gnats appearing first is the most poison- ous. It would seem to be more probable, however, that the poison introduced into the systems of animals—unless sufficient to prove fatal—may to some extent serve as an antidote against that intro- duced later, and if this poison should remain in the system with any stability, such a fact would also account for native or acclimated stock being less susceptible to the poison from bites than that re- cently imported. There is no doubt that stock freshly imported from Kentucky to Tennessee and Mississippiis more apt to be killed than that raised in the infested portions of these States, and that, having withstood one invasion, a second one proves fatal but seldom. One reason why buffalo-gnats appearing very early in the season are more dangerous may be found in the fact that the stock, weakened by exposure during the winter, have had as yet no chance to gain in strength by feeding upon the early vegetation, which it obtains pre- vious to and during a later invasion. Consequently, the resisting power of animals is greater later in the season. Experience has also taught owners of stock how to protect the same, and in comparison with former gnat seasons fewer animals are killed of late. Prof. J. Fie. 9.—Simulium A Schénbauer, who wrote nearly one hundred years ago about the pecuarum: larva Kojumbacz gnats of Hungary, witnessed the post-mortem examina- ey hen tion of a horse killed by these gnats. Upon dissection it was found Department ag that not only was the anus entirely filled with the flies, but also the riculture, 1886). genital orifices, the nasal passages, and the bronchial tube and its ramifications. A case of this kind must be very exceptional. No doubt gnats will sometimes enter these passages, but as a rule death is not occasioned in this manner. The loss of blood and the terrible irritation of the skin by so many poisonous bites are reasons sufficient to account for the reflex irritation of the nerves and blood poisoning. LIFE HISTORY AND HABITS. The larva is not different in general appearance from that of other species and the general characters have already been stated. The annexed cut (fig. 9) shows it considerably enlarged and will make a detailed description unnecessary. It is translucent when living; the | | DIPTERA. 45 body in some individuals is without markings, while in most it is dis- tinctly marked with dark cross bands on the back in the middle of the joints, while at each side is a white space; the under side is more or less irregularly spotted with brown. The head is yellowish brown, nearly square, horny, and marked as in the figure (fig. 10). Qdaneboee Fic. 10.—Simulium pecuarum: head of larva—a, beneath; b, side; c, above—greatly enlarged (from Annual Report Department Agriculture, 1886). The tip of the abdomen is crowned with rows of hooks (see fig. 11) and on the upper side of the abdomen is the set of breathing organs, which have been mentioned heretofore. The larve are found more particularly attached to submerged logs, wholly or partly submerged stumps, brush, bushes, and other like objects in the larger creeks and bayous of the region to which they are common. They cluster together, and, fastened by the posterior protuberance to the leaf, they assume an erect position, or make their way upward and downward with a looping gait. Frequently attached by a minute thread, they sway with the ripples at or near the surface of the water, often as many as half a dozen being attached toa single thread. * * * They make their way up and down these objects with perfect freedom, but do not venture above the water. Food of the larvea.—The larvez of the Southern buffalo-gnat are carnivorous in their habits, although they do not, perhaps, reject floating particles of a vegetable origin. Their mouth is not adapted for biting off any pieces from a large or solid substance, but 1s constructed to catch and ingulf small objects. To obtain these the fan-like organs peculiar to these larve create currents of water directed toward the month. Anysmall and floating matter drifted by the current of water into the vicinity of these fans is attracted by the ciliary motions of the component rays of the same, and thus yh ; Fig. 11.—Simulium pecuarum: Tip reaches the space embraced by them, and they, bend- of abdomen—enlarged (frean Am ing over the mouth, direct the further motions of the nual Report Department Agri- particles. If of the proper kind they are eaten, other- culture, 1886). wise they are expelled by a sudden opening or parting of the fans. They do not feed, as has been claimed, upon plants which they are unable to bite off or chew, and which do not exist in the water at the time when the larvee grow most rapidly. A searching investigation of the water in their breeding places revealed the fact that it was swarming with animal life, and was filled with the larval forms of small crustaceans belonging to various families, but chiefly to those of Copepods and Isopods. An abundant supply of food must also be found in 46 INSECTS AFFECTING DOMESTIC ANIMALS. the presence of immense numbers of fresh-water sponges, polyps, and animaleula. Larvez of the Southern buffalo-gnat kept in glass vessels were observed to swallow these minute crustaceans, and none of this food was seen to be expelled again. A number of square diatoms, jointed together in a chain, have also been observed in Fig. 12.— Simulium pecuarum pupa—en- larged (from Riley). the intestines of these larvie by the aid of the microscope. The presence of such quantities of animal food will also account for the observed fact that the larvze grow so very rapidly dur- ing the early spring, since this is the time of the year in which most of the small fresh-water crustaceans spawn and produce living young, and food is, therefore, much more abundant at this season than at any other. When fully grown the larve descend to near the bottonr of the stream, sometimes 8 or 10 feet, to make their cocoons. The cocoon upon these leaves is conical, grayish or brownish, semitransparent, and has its upper half cut square off, more or less ragged, as if left unfin- ished. Its shape is irregular, the threads composing it very coarse, and the meshes rather open and ordi- narily filled with mud. They are not always fastened separately, but frequently crowded together, not forming, however, such coral-like aggregations as in some of the Northern species. The larva in spinning does not leave its foothold, but running in the center of its work uses its mouth to spin this snug little house. In it, it changes to a pupa, which has its anterior end protruding above the rim. The pupa (fig. 12) is, when fresh, of a honey-yellow color, the filaments of the front part of the body brown and the abdomen above tinged with brown. The filaments consist of Six main rays issuing from the basal prominence and subdivided two or three times, so that in most cases aS many as forty-eight terminal filaments can be counted. The color of the pupa changes with age, becoming pinkish, and, just be- fore emergence of the fly, black. ‘During the first of these colora- tional epochs they are attached to the vegetable substance upon which the Fig. 13.—Simulium pecuarum: female, side view—enlarged (from Annual Report De- partment of Agriculture, 1886). pouch has been fastened by the thoracic filaments, by threads about the body, and by the anal extremity; but during the last two the pup hang by the short anal attachment alone to the threads at the bottom of the pouch and rise more and more out of it, until they swing freely in the current, attached only by the drawn-out threads,” eee Se eee DIPTERA. et They remain in the pupa state but a short time. Both larval and pupal skins remain in the pouch for some time. The adult fly on emergence from the pupa rises quickly to the sur- face, runs a few inches over the water, and the wings expanding almost instantly it darts away. The fly (fig. 13 side view, fig. 14 dorsal view of female) is nearly a quarter of an | 2 inch in length, the female being somewhat larger than the male and differing in many respects. The color is black, but the body is covered with grayish brown, short, and silken hairs, which are arranged upon the thorax in such a manner as to show three parallel longitudinal black to stripes. The abdomen is more densely covered with simi- ie lar hairs and shows, furthermore, a broad dorsal whitish i stripe, which widens toward the posterior end. \f The male differs in the structure of the head (fig. 15; | head of male at the right; of female at the left), the eyes ef being larger, joining each other in the middle line, and = Fis. 14.—Simu- the individual facets being much larger on the upper part ets Saas of the eye, while those of the lower part (not correctly — from above— shown in the figure) are minute, the line of separation es ay between the two sizes being well marked. port Depart- The time of appearance of the swarms is regulated by = ment of Agri. the earliness or lateness of the spring, and consequently sgt ac it is much earlier in the southern parts of the Mississippi Valley. As a rule, they can be expected soon after the first continuous warm een | | = 3 J le | .. he ; Fig. 15.—Simulium pecuarum: head of male, at right; head of female, at left—greatly enlarged (from Annual Report Department of Agriculture, 1886). weather in early spring. In 1885 the first swarms were observed in Louisiana March 11, in Mississippi and Tennessee May 1, and in Indiana and Illinois May 12. The accoants of its occurrence in December or other winter months do not seem to agree with the observations of recent years, but are i perhaps explicable on the ground of unusual seasons at the time of Such appearance, Small or local swarms may appear somewhat earlier 48 INSECTS AFFECTING DOMESTIC ANIMALS. or later in the neighborhood of their breeding places. The number of individuals in a swarm can not be computed, as it varies greatly. The swarms lead a roving life, being drifted about by the wind and are frequently carried long distances from their usual haunts. At first the members composing a swarm are very active and bloodthirsty; but they soon die, and the swarm decreases gradually and soon disappears entirely. New swarms appear continually and replace the former ones. The duration of an invasion throughout the regions infested varies from a few days to five or six weeks. If cold weather follow their appearance, the gnats become semi-dormant; they are not killed by it nor by rain, but revive and become aggressive again with the first warm rays of the sun. Hot weather, however, soon kills them and puts an end to any further injury. The duration of life of a single individual is short; at least specimens confined even in large and well-lit boxes soon die. Buffalo-gnats that have once imbibed blood of any animal alsosoon die, as seen by the large num- bers found dried up in stables in which they have been carried attached to mules or horses. In the fields gnats filled to repletion with blood drop to the ground and crawl away, soon to die. They suffer, therefore, from their bloodthirsty habits, and this seems to be quite a general rule with all those blood-sucking species which are known to annoy man and other warm-blocded animals; for the love of blood gener- ally proves ruinous to those individuals which are anxious to indulge in it, as we have shown to be the case with the harvest mite or jigger. ' CHARACTER OF A SWARM. The number of individuals comprising a swarm can not be computed, as swarms vary greatly insize. Their presence is at once indicated by the actions of the various animals in the field. Horses and mules snort, switch their tails, stamp the ground, and show great restlessness and symptoms of fear. If not harnessed to plow and wagon they will try to escape byrunning away. Cattle rush wildly about in search of relief. Formerly, when deer were still numerous, they would be so tormented by these insects as to leave their hiding places and run away, seeking protection even in the presence of their greatest enemy, man. Approaching animals in the field, we notice at once small black bodies, exceedingly swift in their flight, darting about their victims in search of a suitable spot to draw blood. But even during a very general invasion by these gnats these insects are not uniformly distributed through- out the region infested, but they select certain places. Only low and moist ground is frequented by them; exposed or sunny spots are never visited. There may be no indications of gnats ina whole neighborhood, and the unprepared farmer, dreaming of no danger to his mules or horses in passing dense thickets of bushes, etc., near the roadside, is suddenly attacked by a swarm of these pests, and is frequently unable to reach a place of safety in time to save his cattle. As suddenly as such swarms appear, just as suddenly do they disappear. During a gnat season cautious farmers never travel with their horses or mules without providing themselves with some kind of protective grease. | When buffalo-gnats are very numerous the whole air in the vicinity of our domes- tic animals is filled with them at times, and looking toward the suffering brute, one sees it surrounded by a kind of haze formed by these flying insects. Sweeping rap- idly with the hand through the air one can collect hundreds of gnats by a single stroke. They crawl into everything, and the plowmanhas constantly to brush them away from his face, which does not always prevent them from entering and filling his mouth, nose, and ears; he is so tormented by them, and frequently by their bite as well, that he has to cease working for the time being. Thousands try to enter — 'See American Naturalist, Vol. VII, 1873, p. 19. = DIPTERA. ‘49 the houses in villages and cities, and the windows are frequently completely cov- ered with them. MODE OF ATTACK. The flight of all species of Simulium is very swift and powerful. They possess, in comparison with most other flies, an enormously large thorax, consisting of a very tough, chitinous integument, that furnishes ample attachment for the strong muscles which propel them during their long and continuous flights. The Southern buffalo-gnat is exceedingly active in all its motions, and is at its bloody work as soon as it has gained a foothold upon an animal> The individual flight is inconspicuous and rarely more than a few feet from the ground. It is also usually noiseless, but when one passes rapidly close to the ear of a person the sound produced is faintly like that of a passing bullet, and no one who has listened to it will ever forget it, but will always connect it with their presence. If the insects are not very hungry, orif influenced by too warm or too dry an atmosphere, they circle round a mule or a horse very much like so many small bees; if hungry, however, they lose no time whatever, but with a few nervous jerks settle upon the selected spots and immediately go to work. They are never quiet, but are most active during early morning and toward evening. They also fly during moon- light nights. During the hottest portions of the day, from 11 a. m. to 4 p. m., they are more or less inactive. Their favorite time of attack is a cloudy, dark day, or when rain is threatening. If the gnats try to enter houses or stables by means of the windows, they constantly butt their heads against the panes of glass, until they become so exhausted that they drop to the ground and die. Specimens kept in con- finement in large vessels, with the bottoms covered with moss and soil and contain- ing a wet sponge and a saucer filled with water, die within forty hours. During all this time they never cease trying to escape. The sense of smell (and sight) of these insects must be well developed, because they unerringly find animals a long distance away from their breeding places. If very numerous they cover the whole animal, without making any selection of position. The smaller turkey-gnats are nof so bloodthirsty, nor do they form such large swarms. The snorting, biting, switching of tails, and the general restlessness of the stock in the fields soon reveal the presence of their foes. The gnats will, upon arrival, rapidly circle around the animal, select a point of attack, fasten themselves upon the chosen spot, and immediately commence to bite. The genital and anal regions, the ears and portions of body between the forelegs—in short, those parts where the skin is most easily punctured—are selected by these insects. The attack is so rapid that in course of one minute the body of the tormentor is seen to expand with blood, which shows plainly through the epidermis of the abdomen. The bitten part of the animal shows a nipple-like projection, and if the insect is removed by force a drop of blood as large as a good-sized pin’s head will ooze out. Other gnats will almost at once pounce upon the same spot and continue the biting. All those veins which project under the skin of the animal are also favorable points of attack, and their course is made visible by the hordes of gnats fastened upon them. REMEDIES TRIED AND PROPOSED AGAINST THE LARV. The results of a number of different experiments with insecticides upon the larve of the buffalo-gnats made by Mr. Lugger during the early spring indicate that it is nearly if not quite impossible to reduce their numbers by killing them in the streams, To attempt to do so when all these streams are swollen, and frequently from 10 to 20 yards wide and half as deep, would be sheer waste of time. When the water is very low and much more sluggish in its motion, thus bringing the chemicals in contact with the larve, an application of them might be more effective. Great caution must be used in any efforts in this direction, however, as both man and beast are in» 4653—No. 5—4 | | i 5O INSECTS AFFECTING DOMESTIC ANIMALS. many localities entirely dependent upon these streams for their water supply, and the introduction of poisonous substances might cause much trouble. Some of the experiments were made by confining the larve in glass tubes and submitting them to a current of water to which the following decoctions and solu- tions had been added, viz: China berries, salt, lime, sulphur, tar water, kerosene emulsion, and carbon-bisulphide. Strong tar water killed them; diluted, it proved harmless. Kerosene emulsion diluted to contain 5 per cent kerosene was effective; 3 ounces of carbon-bisulphide in 7 quarts of water proved fatal within ten minutes; the other insecticides were ineffective. It would be very costly to put enough of these materials in the water to produce the desired effect. If the general opinion that broken levees are to blame for the destructive swarms of buffalo-gnats prove to be the correct one, the restoration of such levees would, within a few years at most, restore the former immunity from these insects. This time would be materially hastened by the removal of obstructions in all such parts of the bayous where they would come 1n contact with the swiftest current. OVERFLOWS AND BUFFALO GNATS. It is very generally claimed by the inhabitants of the infested region that as long as the States bordering upon the Mississippi River had a perfect levee system, which prevented the water from escaping into the inland bayous, no damage was occa- sioned by buffalo-gnats, not even in districts now badly infested. It is further claimed that the buffalo-gnats appear with every overflow, and only with an over- flow if such overflow occur at the proper season and with the proper temperature, viz., during the first continuous warm days of March, April, or May. The chronological data already given seem to prove such assertions correct. Too much weight should not, however, be attached to these data. The region is as yet rather thinly settled, and no systematic records of the appearance of buffalo-gnats in injurious numbers have ever been kept. A general and widespread appearance of these insects seems to take place, however, only during an inundation, and, granting the connection between the two phenomena, the causes for it are yet obscure. It was by the elucidation of this problem that we hoped to discover some means of preventing the injury of the flies by preventing the multiplication of the larvx. Inundations in the lower Mississippi Valley are not occasioned by local rains, but by the immense volume of water brought down by the river and its more northern. tributaries, and such overflows first take place in the northern regions infested by the buffalo-gnats, and not in the southern. The earlier appearance of these insects in the South would seem to invalidate the prevailing belief that an overflow brings them. Similar conditions prevail in Hungary, where a closely allied insect does so much injury to all kinds of live stock. There the gnats appear every spring in varying numbers, forming local swarms which move about with the wind; but no general invasion takes place until the River Danube inundates the region infested. Is it not probable that swarms of these gnats are forced by the conditions conse- quent upon an inundation to extend their flight beyond their usual haunts to the more elevated and drier regions, and that in this fact we have at least one of the causes of the connection? Small swarms, otherwise local and unobserved, would thus, during a period of high water, be forced to band together in such immense armies. There must be other reasons, not yet clearly demonstrated, why these insects appear in such vast swarms with an overflow, and this problem can only be solved by a critical study of many breeding places during several seasons over the whole region involved. Some peculiarities of the swarms of buftalo-gnats have been observed, and these may, by closer study in future, throw some light upon the problem. It is to be noted that all the specimens composing these swarms are females, and that not one male has been found among them either here or in Europe. There is every reason to believe that none of the females composing the blood-thirsty swarms return to —— Be er a pe oe ee DIPTERA. . os | the localities where they were born and developed. Experience indicates that once gorged with blood they die. The swarms dwindle in proportion as they are carried away or move from their breeding places. if Close investigation with the microscope has failed to reveal any eggs in the ovaries of the females composing these swarms, and if they deposit eggs at all it is before congregating to attack animals. a These singular facts invite speculation and theory, but it were unwise to indulge in these before we have learned more about the eggs, when and where deposited, and whether the females depositing them are in any way different from those comprising the swarms. Dr. Fritz Miiller has published in the Archivos do Museu Nacional do Rio de Janeiro, Vol. IV, page 47, Pls. I[V-VII,' some very interesting observations on another fly (Paltostoma torrentium), the larva of which is only found in the torrents y and cascades of certain streams descending the mountains of Brazil. There the pupz fasten by the flat venter to the rocks under water, and change into the per- fect flies. He found by opening the mature pupz that there are always two forms E of females associated with one form of male. The one form of female possesses a i rudimentary mouth, only fit to sip honey, while the other has a mouth well adapted to penetrate the skin of warm-blooded animals and to suck blood. The male Simulium, so far as known, is only found near where it developed. The structure of its mouth prevents it from biting, and it shows no inclination to join the roving swarms of females. Hence pairing of the sexes must take place in the vicinity of birth, and the eggs are probably deposited soon afterwards. It is also possible, as in the case of other Diptera, that the eggs are already well developed in the pupa. The condition of the inundated region forbids an indiscriminate selection of places to deposit in, since the young larve must in time find suitable swift currents of water after the subsidence to the normal level. Such breeding places we hope to be able to map out in future. It has also been claimed that a number of successive broods of the buffalo-gnat appear in early spring. If such were the case the relationship between the presence of the gnats and an overflow could be very readily imagined; but we have already shown that there is absolutely no proof thus far of more than one annual brood. Mr. Webster, while studying in the neighborhood of Vicksburg last spring, was impressed with the idea that the connection between the Simulinum increase and overflows was dependent upon the condition of the levees, in that the river water ; in swelling the waters of the bayous not only creates a stronger current in the main bayou, but brings the current in contact with many trees and shrubs, as well as stumps and vines, along the bayous, thereby offering much greater chance for the larv to attach themselves. While we were at first inclined to give some weight to this view, and it seemed to afford an additional important argument in favor of keeping the levees in good con- dition, a survey of the whole field leads us to abandon this as the most important cause in the increase of the gnats during the period of the overflow, and to adopt the theory already advanced, viz., that the connection is at least partly due to the gnats being driven by the advancing waters from the lower to the higher lands. Another theory, not supplanting this last, but supplementing it, we would advance here: There is no doubt but that the advance of the waters from the main river and d their commingling with the clearer streams and tributaries carry asuddenly increased food supply, in the way of minute crustacea and other aqnatic creatures, to the Simulium larve just at the season when these are about to transform. It is quite probable that development in these larvze remains more or less latent or stationary during the cold winter months or when the water in which they occur is depleted of as me is 5 = s ' Reviews of his paper appeared in Kosmos, Vol. VIII, pp. 37-42; Nakire, July 7, J 1881, p. 214; Entomologist’s oe Magazine, February, 1881, p. 206 and pp. 130-132, and March, 1881, pp. 225, 226. 52 INSECTS AFFECTING DOMESTIC ANIMALS. minute animal life, and that a sudden access of food would accelerate the final transformations. A possible third connection between the overflow and this increase may arise from the fact that the larve, when the water rises, leave their attachments, or that the débris upon which they are fastene 2 becomes itself started by the flood current, and that in consequence the Jarve from hundreds of smaller streams and tributaries are carried away by the rising water and impelled into the current of the large streams, by which they may be carried for many miles, spreading out at last in the overflowed region at just the time when they are ready for their final transformations. On this theory the larve from regions far distant become massed in the overflowed region and vastly augment the numbers which have naturally bred there. THE TURKEY GNAT. (Simulium meridionale Riley.) The early history of the turkey-gnat is so intimately connected with that of the preceding species, and the losses due to the two species have been so generally confused, that what has been already stated upon these topics covers about all that can be said. It is unnecessary, therefore, even if it were possible, to give separate account in detail. In the insect itself, however, and in many details of its life history and habits, there is so much difference that it becomes necessary to give some attention to them. LIFE HISTORY. While the area occupied by the adults corresponds in general with that of the S. pecuarum, the breeding places appear to be quite different. In this species the breeding grounds are limited to the smaller streams and branches, and the larve are found attached to submerged dead leaves. Often these leaves are held by sticks, rails, and other obstructions, which serve to fasten them in the mud and at the same time create currents which are favorable to the existence of the larvee. The larva has the peculiar shape and appearance of the Simuliide larve in general (see fig. 16 for the larva, the hair line giving natural length). The markings of the head and body are much more irregular than in 8. pecuarum. They usually possess one or two lateral spots on the enlarged hind part of the body; the head lacks the regular arrangement of spots and lines; the breathing organs are quite different, and three main Fie. 16.—Simulium trynks branch each six times and the branches enter meridionale: lar- ; 3 3 va, side view the trunk from the sides. enlarged (from Ann. Rept. Dept. : a ‘ ; f Agr. 1886). they crowd together upon one leaf in numbers varying from ten to thirty, and, judging from their uniform size, they must be the off- spring of the same parent. As the current away from obstructions caused by twigs and leaves decreases in swiftness, so do the larve decrease in numbers, until only a few feet away but one or two can be found. These larve are evidently somewhat social in their habits, as | DIPTERA. | chs When first found, in early March, they are quite small, but they grow rapidly dur- ing the latter part of March and early April. They are quite stationary when not disturbed. Besides being fastened to the leaf by the last posterior segment, they are also securely anchored by a very fine silken thread. When disturbed they loosen their hold at once and float down stream, suspended and retarded by this thread, which very rapidly increases in length while the larve are drifting with the current. While thus drifting they jerk about in a lively manner, searching for a new resting place, and sink to the bottom quite gradually. Owing to their small size and to the fact already stated, that their color is in harmony with their surroundings, or with the leaf upon which they are fastened, these larve are difficult to detect in a depth of 3 to 4 inches. When removed and put ina glass vessel they soon settle against the sides of their prison and can then be studied with a lens. - The larva can move about very rapidly in the manner of a span-worm, but with this difference, that it always remains anchored by means of a thread, which length- ens as the animal proceeds. Being very restless and active in such confinement, it will keep on looping for hours, at a rate of twenty to twenty- five loops per minute. It can move both forward and backward, the forward motion being pro- duced by fastening the single thoracic leg to the side or bottom of the vessel, loosening the anal proleg, bringing it close to the former, and let- ting the latter go at almost the same moment, the backward motion being simply a reversal. In the course of six to eight hours the larva becomes weak and sickly. It will drop to the bottom of the vessel if disturbed, but will no longer try to escape. All the larve thus imprisoned, in re- peated trials, died in the course of twenty-four hours. A colony of nearly full-grown larve, in a small creek, shared the same fate when the over- flow of the Mississippi River created a back flow Fig. 17.—Simulium meridionale: a, co- and made the water in this creek stationary for coon; b, pupa—enlarged (from Riley). some time. All the creeks and branches in which such larve were found by Mr. Lugger descend in beds composed of clay. The Rocky Bottom Branch, a tributary to the Horn Lake Creek, Mississippi, has worn out a bed in a solid deposit of stratified ferruginous sandstone, intermixed with conglomerations of the same substance. The water, 6 to 8 inches deep in normal seasons, even during the summer months, runs over this stony bed in very rapid currents, forming everywhere little cascades, and no better breeding places for the larvie of any Simulium could be imagined. Yet none could be found, plainly indicating that the species under consideration must be able to fasten to submerged material to find a suitable home. The larve form their cocoons just above the bottom of the smaller perennial streams and are hence not endangered by the variations in the depth of the water, for while it may rise suddenly with every heavy rain and fall as suddenly afterwards the depth is quite uniform at other times. The cocoon (fig. 17, a) is much neater than that of S. pecuarum, being formed of fine threads, lined with gelatinous ones. The web is quite dense, uniform, with well-defined, sometimes thickened rims. The cocoon is always securely fastened singly to a leaf or stick, and even if many are fastened upon the same leaf they do not crowd each other. 54 INSECTS AFFECTING DOMESTIC ANIMALS. It fits snugly about the pupa, which is so securely anchored inside as to be with difficulty extricated. The pupa (fig. 17, b) has the general shape and color- ation of that of S. pecuarum, but the thoracic filaments consist only of the original six rays, which do not branch. The length of the pupa stage for this species averages five days. The adult insect (fig. 18, female; fig. 19, male) has the general apearance of pecuarum, but is smaller and lighter in color. The females are 2.5 to 3 mm. in length, the males from me mum 1.5 to 2mm. The females are of a general slate-blue male—enlargea COlor and have darker markings on the thorax and (from Ann. Rept. gbdomen, as shown in the figure. There is also a sil- Dept. Agr., 1886). < very pubescence over most portions of the body, and the colors of Some parts change in certain lights, giving greenish, coppery, and dark blue. The male has confluent eyes composed of two very different sets of facets, which are clearly shown in the figure. The body throughout is darker, mostly black with bluish luster, and rather sparse white pubes- cence. . The flight, method of attack, and other habits of this species need not be given separate de- scription, neither is there any- thing to add regarding remedies that may be available for the de- struction of the adults or preven- tion of their injuries. The breeding places of the larve, however, seem more open to attack than the others, and ex- periments recorded in the report of the Department for 1886 show that it is possible to affect them with solutions added to the water, but not with great success, except when used in such quantities as to kill other insects, fishes, ete., which probably prey upon the gnat larvee. If the breeding places in the creeks have to be searched out to apply the insecti- cides, it would be much more simple to remove all the logs, sticks, and leaves. All the fences across the branches should be removed, or ratber replaced by wire fences, which would neither impede the current nor catch as many sticks and leaves. Logs and larger twigs, if not embedded too deep in the mud of the creek or banks, will always be removed by the high water, a very common occurrence in the buffalo-gnat region. Old leaves made heavy by the adhering mud would also be carried away by Fig. 19.—Simuliwm meridionale: male—enlarged (from Ann. Rept. Dept. Agr., 1886). DIPTERA. . 55 any high water if the obstructions in these creeks were removed, and with the sticks and leaves many, if not most of the larve, would be carried away either into the main rivers or the lower level of the creeks or lakes where there is no current and where they would perish. THE WESTERN BUFFALO GNAT. (Simulium occidentale Townsend. ) This buffalo-gnat is first recorded by Mr. C. H. T. Townsend, in 1891 (Psyche, Vol. VI, p. 106), from southern New Mexico. While no subsequent records have appeared, there is little doubt that it has continued to appear along the river valley where it was first observed. I can do no better than to quote from Mr. Townsend with regard to its habits, ete.: In the southern part of New Mexico, along the valley of the Rio Grande, there begins to appear about the Ist of May a buffalo-gnat which is quite as troublesome, especially to man, as its more Eastern congener, S. pecuarum. It proves to be an undescribed species. The first individuals that I have noticed this year were in an orchard near Mesilla, on the 7th of May, and they were at that date swarming in considerable numbers. Mesilla is about a mile from the Rio Grande, which flows to the west of the town. Gnats were found also on the same date, but in less numbers, on the college grounds, which are situated about 4 miles from the river. The river rises in May, overflows all the low areas lying adjacent to it, and becomes a roaring, rushing body of water. Its volume is dependent upon the amount of snow in the foothills to the north, particularly in Colorado, and on the rains, which are only exceptionally a factor. The snow in the canyons exerts little influence, for its thaw is so gradual as not to be felt. I give these data for what bearing they may have on the breeding habits of this species. It is well known that Simulium breeds in running water, and our species is no doubt dependent on the rise of the Kio Grande for its appearance. Doubtless, also, it is distributed through the valley by the sys- tem of acequias or irrigation ditches in use in this country, which open from the river on a higher level to the north, and furnish the only source of water supply for the raising of crops. This is an adverse bearing of the riparian irrigation on inju- rious insects. The securing of artesian water and shutting off of the river water would no doubt lessen the dispersion of the gnats through the valley. From the first part of May the gnats increase in numbers, until by the middle or last of the month they are very abundant in all parts of the valley. It is usually between this time and the middle of June that the river is at its highest point. They are then to be found on the mesa to the east toward the Organ Mountains, and may be met with also on the elevated mesa nearer the mountains, especially to the north. On May 171 observed them on the summit of the first mountain at the east- ern end of the Dojia Ana range, which is nearer the river than the Organs, and farther north. The elevation is at least 4,500 (probably 5,000) feet above sea level, or about 1,500 (perhaps 2,000) feet above the level of the river. They are not found in the Organ Mountains, which are about 20 miles east of the river, nor on the plains to the east and south of them, though on the mesa to the west they approach to within a few miles. This was observed May 23-24, while in the valley itself at this time they were almost unbearable. These gnats are a great annoyance to man, by far greater than any other insect that we have in this locality. Many persons are so susceptible to them as to pre- serve through the height of the gnat season a chronic inflammation of the exposed 56 INSECTS AFFECTING DOMESTIC ANIMALS. parts of the face and neck, resulting from the repeated bites, which cause an intense irritation and even give rise to cutaneous sores. The inclination of the gnats to bite increases with the advance of the Season, but the pest is considera- bly abated after the fall of the water. They are also very trou- blesome to animals, and are sup- posed to cause the inflamed eyes in the horses of this region through the summer months. I append a description of the species. The female is alone described, as that is the only sex which composes the biting swarms, and I have not se- cured either the male or the early stages. Compared with other forms, Townsend says: This species is smaller than either S. pecuarum or S. meridionale. ft eae S. metallicum Bell , from Mexico, is given 'as 2 mm. long, but it is the Fig. 20.—Si ium piscicidium: a a; a - - : eS 20 imulium pis tetdium a, larva; b, pupa, dorsal male which is described, and the view; c, same, lateral view; d, same, ventral view; e, thoracic proleg; /, rows of bristles at end of body (from female would bevery much larger. American Entomologist). S. occidentale differs from S. pecuarum very markedly in the thoracic and abdominal markings. These markings are very much like those of S. meridionale; but the median thoracic line is always very faint, the abdomen is light fulvous, the lateral lines of segments 5, 6, and 7 are curved, and the abdominal mark- ings are of a different color, besides other minor differences. Simulium piscicidium Riley. The past history of this species, together with the important features of its life history, have already been stated in connection with the dis- cussion of the habits of the members of the family. It has been recorded from New York and Ohio, but further than this we are not informed as to its geographical limits. The eggs of this species have not been described, nor is it known where they are laid, or the details of the early life of the larva. The larger larve and their habits, to some extent, have been detailed and already referred to ‘The accompanying figures will serve to show the similarity to the other species, and we include them in order to bring together as much as possible the material which will be of service in the further study of the habits of the group. The adult described in the American Entomologist (Vol. II, p. 367) is for the most part velvety black, with a faint fulvous pubescence on the thorax, and the eyes and sides of the abdomen inclining to brown- ish or rufous. The length of the body in alcoholic specimens is 0.14 to 0.17 of an inch. | ] DIPTERA. _ tg So far as known the adults never exhibit the bloodthirsty propensi- ties of their Southern cousins. Simulium canescens Bremi. This species has been studied by Kolliker, according to a citation of Osten Sacken (American Entomologist, Vol. I], p. 231), Simulium rivulare Planch. Cited by Osten Sacken (American Entomologist, Vol. II, p. 231). It does not appear that it is discussed from an economic standpoint. Simulium sp. A species of Simulium is said to be a serious pest in Brazil. It was first technically discussed by Pohl and Kollar. Simulium venustum Say. In 1823 Thomas Say described in a paper entitled ‘“‘ Descriptions of dipterous insects of the United States” a number of Diptera which he says were collected chiefly during the expedition to the Rocky Moun- tains under the command of Major Long. Among the rest is the description of the present species and the followin note: ‘This very pretty species perched in considerable numbers on our boat at Ship- pingsport, Falls of the Ohio. It ran with considerable rapidity, con- stantly advancing its long anterior feet. Its bite is pungent.” While very probably one of the forms included under the general head of buffalo-gnats of the Mississippi Valley no further records of its especial attacks are known, and nothing is known as to the larval form from which it develops. Shippingsport does not appear on pres- ent maps, but the “ Falls of the Ohio”-lie between Louisville, Ky., and Jeffersonville, Ind., and since some of these species are peculiarly local in their distribution, it would be courting success to search for the larvie in the rapids of the river at that point. Say’s description of the adult form is as follows: Black; thorax, two perlaceous spots before and a larger one behind; poisers black, capitulum bright yellow, dilated. Inhabits Shippingsport. Body black; wings whitish, with yellow and iridescent reflections. Male, eyes very large, separated only by a simple line, dull reddish yellow, inferior half black; thorax velvet-black, a bright oblique, perlaceous, dilated line each side before, and a large perlaceous spot or band behind; sides beneath varied with per- laceous; feet, tibia above, and first joint of the four posterior tarsi white; abdomen with an oblique perlaceous line at base, and two approximate, lateral, perlaceous ones near the tip. Female, eyes moderate; thorax plumbeous-black, immaculate; scutel black; abdo- men whitish beneath. 58 INSECTS AFFECTING DOMESTIC ANIMALS. Simulium sp. Baron Osten Sacken, in his careful paper in the American Entomolo- gist on the habits and structure of species of Simulium, describes a larval form common in streams near Wash- ington, but does not connect it with any species described in the adult form. His fig- ures, which represent only certain parts of e 4 the anatomy, are here reproduced (fig. 21). lil Hil : Possibly the observations made by Dr. | ly My Ne Howard may refer to the same species. In e i this case the larve are found attached to the FiG. 21.—Simuliwm sp.: a, portion rocks forming the bed of the stream, and of ray of fan; b, mandible; ¢ their habits generally conform with those of maxilla; d, under lip; e, upper y lip—all enlarged (after Osten the Northern species. Sacken). Simulium pictipes Hagen. This species has already been mentioned as described by Hagen (Proc. Bost. Soc. Nat. Hist., Jan., 1880). Larve and pup occurred in the Au Sable River, Adirondack Mountains. Family TABANID 4. (Horse Flies, Gad Flies, ete:) The members of this family are large, some of them being among the largest of the order Diptera, and the females are provided with pow- erful mouth parts by means of which they inflict very painful bites upon cattle, horses, and other animals. Man does not escape, and as they are able to penetrate even thin clothing worn in summer, they sometimes become a source of annoyance to workmen in fields. The bodies are never very hairy, the head is large and composed almost entirely of the eyes, which during life are of brilliant colors and varied reflections. The antenne are prominent and the third joint is composed of from three to eight minute rings, a character which, with the large eyes, distinguishes them at once from nearly all other large flies. The strong piercing mouth parts of the female are com- posed of six lancet-like organs, while in the male there are but four and these are not adapted to piercing the skin of animals. The males, and also the females, if not finding other food, feed upon the nectar of blossoms or the juices of plants, exuding sap from trees, etc. The flight of these flies is very strong and rapid and is attended with a buzzing, tormenting noise. The males may often be seen with the wings vibrating so rapidly that they become invisible, resting motion- less in one place and then darting rapidly and resting suddenly again, generally turning the head in some other direction each time they dart, i DIPTERA. . 59 St. Fargeau has ascertained that this maneuvering is performed in order to intercept and seize the females. The power of vision is appar- ently in proportion to the size of the eyes. Dr. Williston says, ‘that they can see for a long distance seems certain. On the uninhabited plains east of the Rocky Mountains the writer has frequently seen them coming from a long distance, attracted by the sight of the horse on which he rode.” Such of the larvie as are known are either aquatic or live in moist earth and are canivorous, hence they may in some degree compensate for the bloodthirsty habits of the adult females. But notwithstanding the abundance of the insects, very little has been done toward deter- mining the early stages of the species. More than a century ago De Geer described the larva of the common European species, Tabanus bovinus, and up to 1864 this was the only larva of the kind known. In that year Mr. Walsh described « tabanid larva (Proc. Best. Soc. Nat. Hist., Vol. IX, pp. 302-306), but without obtaining the adult form. In 1869 Professor Riley bred the same kind of larva to the adult form and described the various stages (Second Rep. Mo. State Entom., pp. 128-132), the insect proving to be Tabanus atratus Fab., which is described further on. Dr. Williston says: ‘‘The spindle-shaped brown or black eggs are found in spherical or flat groups, stuck together, and attached to the leaves or stems of grass and other plants; those of the aquatic larve are fastened to rushes. The larve are carnivorous; many live in the earth, others in water. They are predaceous, often upon snails and injurious insects, thus in a measure repaying the agriculturist for the molestation they cause him. The young larvee are known to penetrate beetles or other larve and remain within them till they have completely consumed them, and their enlarged bodies have filled out the skins. Thus the larve of Hematopota have been observed feeding upon Helops and those of Tabanus upon Noctue.” (Stand. Nat. Hist., Vol. Il, p. 417.) Quite recently Mr. C. A. Hart has made a notable contribution to our knowledge of this subject,'! which will be drawn from in discussing the early stages of particular species. Authors generally agree that the after effects of the bites of these insects are less injurious than those of mosquitoes or buffalo-gnats. The painfulness of the bite and the terror inspired by their presence is, however, a source of great torment to animals that are almost help- less in protecting themselves against them. The puncture they make is large, and after the proboscis is withdrawn there is not unfrequently au exudation of blood from the wound. This would tend to remove any poisonous injection, but since there is rarely any swelling or inflammation produced by these bites, it would appear that no poison is conveyed upon their piercing organs. Dr. Packard speaks of cattle 1 Article VI, Vol. IV, Bull. Ill. State Lab Nat. Hist. 60 INSECTS AFFECTING DOMESTIC ANIMALS. and horses being “ occasionally killed by their repeated harassing bites,” and while this seems to be rather strong language, and we will refer to it again in considering Tabanus lineola, there is no question that the effects are serious enough, so that it is desirable to protect animals as far as possible from their bites. With horses in use the common practice of protecting with nets is the most effective method we know of, but for animals in pasture it would be particularly desirable to find some substance which could be rubbed over the hair, and, retaining its properties for a reasonable length of time, have sufficient repelling power to keep the flies away. The larve are not open to successful attack, and even if they were, the fact that most of them are probably beneficial should deter us from using destructive measures against them. They are widely distributed, and species occur in all parts of the world, torturing alike the elephant and lion of the tropies and the peaceful reindeer of the arctic region. It is during the hottest sum- mer months that they are the most abundant, and they frequent both our timbered and prairie regions. The species are quite numerous, over 1,300 being known, of which about 150 are credited to North America. Manifestly it would be impossible in a work like this to even mention more than a few species, and, since so little is known of the early stages, there is no necessity for treating each species in detail. We will therefore in considering the species simply refer to the more common ones, the habits of which have been observed, and more particularly those occurring in this country. Osten Sacken’s admirable ‘‘Prodrome of a Monograph of the Taba- nide of the United States” in Memoirs of the Boston Society of Natural History (Vol. I], Part IV, Nos. 1 and 4) will enable anyone to make a thorough study of our native species. THE BLACK GAD FLY OR BREEZE FLY. (Tabanus atratus Fab.) Probably this is the largest species in the family, and it is certainly | one of the most conspicuous, being quite common and of such a decided black color as to attract attention either on the wing or when perched on the back of some poor animal that tries in vain to drive it off. Fabricius described it in 1794 (Ent. Syst., Vol. IV, p. 366). Walsh described its larva in 1864 (Proc. Bost. Soc. Nat. Hist., Vol. IX, pp. 302-306), and in Riley’s Second Missouri Report (p. 128) its life history iS given except the egg and early larval stages. Its bite is one of the most severe of the tribe, but fortunately the species does not occur in such great numbers as the green-head fly. Its attacks seem more com- monly directed against cattle than horses, and it is most noticeable in sunny pastures, though occasionally seen perched on trees or the side ‘ : is ver 7 SY Pe ey, —— a DIPTERA. 61 of some building. The eggs are doubtless deposited in the vicinity of water, in moist places, but the exact details of oviposition are unknown. The larva (fig. 22, a) is a large, twelve-jointed, cylindrical affair, tapering at each end, of a trans- parent, highly polished, glassy, yellowish, or greenish appear- ance, shaded with bluish green and furnished above and below, as 1n the figure, with large, round- ish, sponge-like tubercles which are retracted or exserted at the will of the insect. Though the external integument is so trans- parent that the internal structure is readily visible, yet this integu- ment is firm and the larva most vigorous and active, burrowing with great strength either back- ; Fic. 22._Tabanus atratus: a, larva; 6, pupa; c, adult ward or forward in the earth and (after Riley). between one’s fingers when it is being held. Placed in water it will swim vigorously by suddenly curling round and lashing out its tail, but it is apparently not as much at home in this element as in the moist earth, for it is restless and remains near the surface with the tip of its tail elevated in the air. When the water is foul, it moves about actively near the surface, but when it is fresh it remains more quiet at the bottom. The specimen which I succeeded in breeding was sent to me by Mr. Adolph Engelmann, of Shiloh, St. Clair County, Ill. It was found by Mr. William Cooper, of the same county, about 10 feet from a small but permanent body of water. Mr. Cooper at first took it to be a leech, and when he attempted to capture it it immediately commenced burrowing in the ground. The larva reared by DeGeer was terrestrial. This larva is Semiaquatic, for it is quite at home either in moist earth or water. My specimen was kept for over two weeks in a large earthen jar of moist earth well supplied with earthworms. It manifested no desire to come to the surface, but burrowed in every direction below. I found several pale, dead worms in this jar, though I can not say pos- itively whether they had been killed and sucked by this larva. Mr. Walsh, in speaking of its haunts and its food, says: I have, on many different occasions, found this larva among floating rejectamenta. On one occasion [ found six or seven specimens in the interior of a floating log, so soft and rotten that ae it could be cut like cheese. Once t discovered a single specimen atratus: larva Underaflat, submerged stone, in alittle running brook. Finally, (from Hart). I once met with one alive, under a log, on a piece of dry land which had been submerged two or three weeks before, whence it appears that it can exist a long time out of water. I had on several previous occasions failed to breed this larva to maturity, and the only imago I have was 62 INSECTS AFFECTING DOMESTIC ANIMALS. obtained in 1861 from larv:e, which, suspecting them to be carnivorous from the very varied stations in which they had occurred, I had supplied with a number of fresh-water mollusks, but the habits of which, in consequence of having been away from home, I was unable to watch. On September 22, 1863, I found a nearly full- grown larva among floating rejectamenta, and between that date and December 23 he had devoured the mollusks of eleven univalves (genus Planorbis) from one-half to three-fourths of an inch in diameter; and on three separate occasions I have seen him work his way into the shell. In this operation his pseudopods were energet- ically employed, and I found, on cracking the shells after he had withdrawn, that a small portion of the tail end of the animal was left untouched—no doubt in conse- quence of his being unable to penetrate the small end of the whorl of the shell—and also the skin of the remaining part and the horny-tongued membrane. My larva transformed to pupa within the ground during the fore part of July; it remained in this state but a few days and the fly issued July 13, and soon made its presence known by its loud buzzing inside the jar. It was a perfect specimen, and the pupal integument was sufficiently firm and polished, that by carefully washing off the earth an excellent cabinet specimen was obtained, which retained almost the exact form and appearance of the living pupa. Before the escape of the fly, which was effected through a longitudinal fissure on the back of the head and thorax, remind- ing one of the mode of escape of our harvest-flies (Cicadie), this pupa by means of the horns with which it is furnished had pushed itself up to the surface of the earth. The pupa (fig. 22, b) is nearly an inch and a quarter in length and a third of an inch in diameter. It is cylindrical, slightly curved, as in the figure, rounded at the head and tapering at the extreme hind por- tion. The abdominal segments are all but the first one provided with a ring of fine yellowish bristles, pointed backward. There is a stout thorn at the anal extremity, bearing six other thorns. The pupa state lasts but a few days and before the emergence of the fly it is pushed to the surface of the ground by means of the bristles and thorns of the abdomen, with bending movements of the body. It splits along the dorsal line and the fly emerges leaving the pupa case in very perfect condition. The adult fly (fig. 22, c¢) is an inch or ea Tabinas ciratugana mole i length, black throughout, the single egg containing parasite (from back of the abdomen covered with a BEM): bluish white bloom and the wings smoky black. They are common through the summer months and it is pos- sible from the different times that full-grown larvie have been observed that there is more than a single brood in a year. It seems probable, however, that the winter is spent in the larval stage and that the full- erown larve observed by Mr. Walsh in September were simply late specimens that had lived over the previous winter and would have pupated the same fall, producing the flies a few days later, and these have laid eggs to pass the succeeding winter. Hart says the larve sccimesqenaniamss tet taetrecienti SD TERS coe tek Ribas ees, E 2 ee DIPTERA. Ga were taken every month of the season except June, at which time they had mostly reached the pupa or imago stage. The habits of the adult have already been sufficiently stated, and as we have unfortunately no certain means of repelling them from cattle so as to prevent the bites, which is the only thing we need fear from them, a discussion of remedies is unnecessary. It might be stated, however, that observations on the effect of tar and oil or other substances used to repel bot-flies would be of value in arriving at some method of preventing their attacks, pag " \ Berersacn, | k Mie ena aR Ae a Pe Bae rewers. inact “ it a te Fic. 25.—Phanurus tabanivorus Ash. (from Hart). Hart records the rearing of parasites, Phanurus tabanivorus Ashm., from the egg masses of this species. Also the apparent parasitization of a larva. GREEN-HEAD HORSE FLY. (Tabanus lineola Fab.) This is generally regarded as the most common species in North America, and its occurrence in all parts of the country in large numbers fully supports such estimate. While it must have been a familiar pest to the early inhabitants of the country, its first scientific description was given by Fabricius (Ent. Syst., Tom. LV, p. 369.) Packard, “Guide to the Study of Insects,” page 394, says: This fly is our most common species, thousands of them appearing during the hot- test part of the summer, when the sun is shining on our marshes and western prai- ries; horses and cattle are sometimes worried to death by their harassing bites. In cloudy weather they do not fly, and they perish on the cool, frosty nights of September. 64 “INSECTS AFFECTING DOMESTIC ANIMALS. And also in “* Our Common Insects,” page 74: We were told during the last summer that a horse which stood fastened to a tree in a field near the marshes at Rowley, Mass., was bitten to death by these green- heads; and it is known that horses and cattle are occasionally killed by their repeated harassing bites. , This death of animals from bites must be very rare indeed, for in many years’ residence in the Mississippi Valley, where the flies abound, the author has never known of such an incident, though the bites are certainly a great torment. : The flies are brown, with a tinge of reddish, and the abdomen has a conspicuous whitish line along the middle. The eyes are a brilliant green, from Fic. 26._Tabanus lineola. Which the name is derived. —(from Packard’s Hart has detailed the characters of the early aca stages as follows: “The larva of this species closely resembles the young of nigrescens, and was not separated from it at first.” Examples of larve are said to have been collected in April and in June, pup in May, and imagoes in May and June. ‘The tabanid pup develop much more rapidly in hot weather than in cold, and to this fact is probably due the difference in time of emergence.” Larva: Length, 20 mm.; diameter, 2.7 mm. Prothorax with lateral shining areas about as long as the dorsal area, striation about the same as that of the upper mesothoracic area; no noticeable central smooth spot; a small one on lower margin posteriorly ; remaining lateral areas a little more finely and closely striate; dorsal and ventral areas of thorax nearly smooth on disk, with basal striwe; those on abdomen with moder- ately close striz, more or less interrupted on disk; all areas more or less shining. Surface whitish, dull pubescent markings very light brown but distinct, annuli narrow, crests of false feet also dull pubescent, their sides striate; lateral stripes of thorax distinct, slender, not dilated posteriorly, lateral edges of dorsal areas of thorax diverg- ing; an opaque dark ring about the base of respiratory tube, and another encircling anal prominence, above it usually three light- brown spots. Main internal trachee rather thick and noticeable, subparallel, not strongly sinuate, at least back of the middle. Terminal stig- matal spine often protruded. Pupa: Length, 19 mm.; diameter, 3 mm. Light ferruginous brown, shining, abdomen roughly wrinkied and subopaque. Pal- pal sheaths indistinct, not distant; tubercles not dark; ocellar tubercles indistinct or wanting; thoracic spiracular tubercles (fig. 28) shghtly but nearly equally elevated, frec margin rounded at tip, rima not vertical, evenly arcuate, slightly hooked in front. Abdominal spiracular tubercles subtriangular, narrower behind, obliquely subeonical, much shorter than basal diameter, bearing a Fi¢.27.—Tabanus small subcircular or short and strongly arcuate rima (fig. 29); on —/*neola:_ pupa, anterior slope a transverse groove, usually longer than the rima; ee pei fringes formed of unequai pale spines, only one or two long spines Hart). above on seventh segment; outer terminal teeth much longer than the others, directed laterally and upward, the tips of the four upper teeth about in line (fig. 30), fringe anterior to anal prominence showing a chitinous webbing RR 7 2a DIPTERA. E 65 between the pases of the spines, so that the separated tufts of the female look like a pair of broad, low teeth with several spiny points; lateral tufts low down, near ends of ventral fringe, formed of short spines.—( Hart. ) The species may be stated to have at least one natural enemy, for in the American Entomologist (Vol. I, p. 337) there is an account, by Mr. H. J. Dunlap, of their being eaten by the Nebraska bee killer (Promachus bastardit Macq.). This account is of considerable interest,-and we quote it herewith: Champaign, Ill., August 6, 1870.—I send you an insect by mail to-day in a glass bottle that has interested me for three or four years. J] am hardly able to decide whether it is a friend or foe. My attention was first called to it by seeing several around my team during summer. Supposing them to be a new horse-fly, I watched to see one bite, but was finally rewarded by seeing 1t pounce upon a greenhead (Tabanus lineola Fabr.). It settled upon my sleeve and soon had transferred the contents of Mr. Greenhead’s body inside 1ts own by sucking the juices out by means of its stout proboscis. I saw this operation repeated many times. The present Fic. 28.—Tabanus lineola: spiracular tubercle of pupa—enlarged (from Hart). Fig. 29.—Tabanus lineola: abdominal spiracle of pupa (from Hart). Fic. 30.—Tabanus lineola: end of last segment of pupa (from Hart). summer I have seen them dozens of times, often five or six around my team, and have always noticed that in an hour or so after they appeared no more horse-flies were to be found. I have also seen them ‘‘sucking” house-flies, lady- bugs, chinch- bugs, several moths, and have also seen them eat each other. The one sent you had just captured a honeybee, for which offense I made a martyr of him (or her) for the benefit of science. THE GREENHEAD. (Tabanus costalis Wied.) This is another common species very abundant in the Prairie States, and was described many years ago. It is probably about as abundant and widely distributed as lineola, and causes a great amount of annoy- ance and suffering to domesti¢ animals. The following from Hart presents our present knowledge of the life history of the species: This seems to be normally a terrestrial larva. We have taken it two or three times in the earth of cornfields in Champaign County. The dates given are May 31 and June 4. Examples were placed in a breeding cage and an imago of costalis was secured from them. 4653—-No, 5——5 —————= 66 INSECTS AFFECTING DOMESTIC ANIMALS. The imago, known as the ‘‘greenhead,” is very generally common, and is quite a pest in some bottom land prairies. A few examples were noted along shore at Sta- tion D, August 20. The examples in our collection were taken on twenty-two occa- sions, all between July 15 and August 13, except three dates, July 8 and August 18 and 31, which would make it probable that it is smgle brooded. The localities are Carroll Lake, Cook and Ford counties at the north, and Fulton, McLean, and Champaign counties in central Illinois. The specimens were from a variety of situ- ations, usually in low herbage, often taken visiting flowers. Larva: Length, 20 mm.; diameter, 2.7 mm.; prothorax with lateral shining areas about as long as the dorsal, coarsely striate, a smooth spot near center of disk; dor- sal and ventral areas of thorax smooth, a few strizx cn those of metathorax, especially posteriorly; remaining areas moderately striate, lateral areas of abdomen a little more finely striate than the others; all more or less shining. Dark annuli pale, narrow, longitudinal stripes scarcely present; false feet with dull pubescent crests, their sides rather finely striate; a narrow dark annulus at base of respiratory tubes, another round base of last segment, inclosing anal promi- nence and giving off a pair of lateral stripes, the lower one longer; no projecting spines seen. Pupa (from defective cast skin of male): Length, 20 mm.; diameter, 3 mm.; light fuscous brown, shining; abdomen smoothly wrinkled; slightly opaque; prothoracic spiracular tubercles slightly but nearly equally elevated, free margin rounded at tip, rima not vertical, evenly arcuate, slightly hooked in front. Abdominal spiracular tubercles small, subtriangular, narrower behind, obliquely subconical, much shorter than basal diameter, bearing a very small subcircular ting; fringes formed of unequal pale spines, the longer ones sparse on seventh seg- ment above; outer terminal teeth twice as large as lower pair, directed laterally and slightly backward; upper pair smallest, directed upward; ventral fringe of last segment not noticeably webbed; lateral tufts rather high, not near ends of ventral fringe. My material of this species is not in best condition for accurate comparisons. Tabanus annulatus Say. This species was described by Say in 1822 (Jour. Acad. Phil., Vol. II, p. 31; Comp. Writ., Vol. II, p. 53), and its territory stated as Missouri. It does not seem to have received special notice since. It is probably not abundant enough to cause serious annoyance to stock or is commonly confused with some more common species and has consequently received little attention. It is smaller than Tabanus lineola, the length of the body being a little mure than two-fifths of an inch. It is of a leaden-gray color tinged with reddish; the abdomen black- ish brown with gray margins to the segments, the wings without spots and slightly dusky. (From Say’s description. ) Tabanus stygius Say. This species is almost as large as Tabanus atratus Fab., nine-tenths of an inch in length and occurs in the Mississippi Valley. Say’s description in 1822 (Jour. Acad. Nat. Sci. Phil., p. 33) locates it in Arkansas. It is violet black and with the thorax pale chestnut. The front of the head is yellowish, the thorax with five gray lines, the wings rusty with three brown spots. (From description of Say.) DIPTERA. er + | It is fairly common at Ames, Iowa, but has not been observed as especially annoying to stock. It has a wide range, however, and deserves to be studied with reference to its early stages. Hart gives the following facts concerning the species, with descrip- tions of early stages: The present species was the most abundant tabanid larva in the vicinity of Havana last spring (1895) It first appeared in our collections September 14, when a num- ber were noted swimming amidst vegetation near the margin at Station B. In the spring they were found at nearly all of the stations, but more particularly in con- nection with tipulid, muscid, and Eristalis larvie, in matted accumulations of dead stems and leaves over mud. They were especially abundant March 30 in Flag Lake, where large plump larve appeared at every turn. It was a surprise to find a few of them upon the bottom in open, shallow water, far from shore, in the middle of Quiver Lake at Station A. Young larve have been common in connection with larve of Bittacomorpha and Limnophila at Station I since March 17. At Stations B and G they have been common in moist drifts of fine rabbish washed up by waves Pupz were found in the breeding cages May 10 and 23. One emerged May 27 and another tried to emerge June 2, but died and was removed from its case. The larvie resemble those of the lineola group in their stria- tion and coloration, but differ in their short laterad prothoracic areas and larger size. They are like atratus in size, but may be readily separated from it by their coarser lateral striation, straw-yellow tint, slender lateral vitte, and usually projecting terminal stigmatal spine. Larva: Length, 45-55 mm.; diameter, 6-7 mm.; bright straw yellow, varying in some young larve to nearly clear white, marked with light fuscous brown microscopic pubescence, usually paler at each stage than atratus. Lateral prothoracic striated areas not more than half as long as the dorsal, striation not finer than that of the middle and lower lateral areas of the mesothorax, striated portion shining; a small smooth spot adjoining the impressed line below; remain- ing upper thoracic areas a little less closely striated, but not strongly different from that of the prothorax; abdominal lateral areas a little more finely striate; dorsal and ventral areas with margin striated, disks nearly smooth in adult larve, last seg- ment more strongly striate, especially beneath. Dark annuli distinct, broad, including false feet, a distinct, transverse dorsal and ventral pale spot in front of the false feet; abdominal annuli often with a small triangular backward pro- longation on median line above. Prothoracic lateral space oceu- pied by a pale brownish fuscous quadrate spot in front of the striated space. Meso- and meta-thoracic lateral stripes usually distinct, but slender, scarcely dilated posteriorly, lateral edges of dorsal areas diverging; lateral stripes above the abdomen almost wanting, except on last two segments. In these stripes the punctures of the upper and lower rows are indicated by rounded pale dots, and those of the inner rows by elongate dots. Last segment with bases of respiratory tube and anal prominence encircled with dark rings, joined by a lateral connection, its dorsum with at most a short basal line or pair of dots on each side. Coarser pubescence of false feet tipped with pale brownish. Main internal trachex thick and noticeable, especially in young larve, lustrous, subparallel, not strongly sinuate, nearly straight posteriorly; terminal stigmatal spine dark reddish brown, smooth, usually protruded (fig. 32, p. 68), Fig. 31.— Tabanus stygtus: larva (after Hart). 68 INSECTS AFFECTING DOMESTIC ANIMALS. Pupa 9: Length about 30 mm.; diameter about 6 mm.; light brownish fuscous, thorax paler, shining; abdomen roughly transversely wrinkled and subopaque. Palpal sheaths distinct, as far apart as are the sete borne by the larger tubercles at the center of the anterior surface of the head; surface between them rounded, bear- ing a small wrinkled tubercle at middle; antennze and tubercles darker than surrounding surface; ocellar tuber- cles distinct; prothoracic spiracular tubercles slightly but evenly elevated in a plane parallel with that of the sur- rounding surface; rima nearly straight in its outer half, inwardly curving strongly forward and ending in a con- spicuous hook; free margin of tubercles rounded at tip. First abdominal with two distinct sete each side above the spiracles; abdominal spiracular tubercles rounded, broad behind, low, subhemispherical, rima long, following s posterior border of tubercle, slightly curved at middle, ‘ _..; More strongly curved forward at each end; on anterior Fic. 32.—Tabanus stygius:last surface a transverse groove extending across the tubercle, eis Ge iaeseee but not as long as the rima. Fringes of unequal spines, bnlanedd (Grom Elart): often tipped with blackish, all but two of the long spines wanting in a broad space above on seventh segment. Ter- minal teeth nearly equal, tipped with blackish, their points marking the angles of a hexagon, slightly wider than high. Ventral fringe of last segment not webbed together; lateral tufts high, on a level with upper lateral line. Tabanus molestus Say. In describing this species in 1822 (Jour. Acad. Phil., Vol. III, p. 31; Comp. Writ., Vol. II, p. 53) Thomas Say states: This is one of the species that are called prairie flies. It is numerous in the prairies of the State of Missouri and is very troublesome to the cattle. I have seen cattle in the forests which margin these prairies when attacked by these insects start suddenly and plunge into the thickets that the branches may divest them of their enemies. Travelers are much incommoded by them; many cover their horses with canvas, etc., to shield them from their attacks, or rest in some shaded or secluded situation during that part of the day when they are the most abundant. No special mention is made of it in subsequent works, but we know it to be fairly common in the Mississippi Valley. Say’s account prob- ably covers territory outside of the present State of Missouri; and Wiedemann (vide O.S. Cat., p. 22) is authority for its occurrence in Kentucky. It is a rather large species, nearly four-fifths of an inch long; the thorax gray, with brown lines; the abdomen black-brown with a gray central stripe which is widened on the middle segments and consists of triangular spots on the fourth, fifth, and sixth segments. HKUROPEAN GAD-FLY. ( Tabanus bovinus Linn.) From the statements of European writers this is apparently the gad- fly of Europe, or at least the one which is particularly troublesome to cattle. According to Linnzeus (Syst. Nat., Turton Transl., Vol. III, p. 67), it inhabits Europe, and is extremely troublesome to cattle, | ts cvs vengan DIPTERA. _ 63 The eyes are greenish; back of abdomen with white triangular lon- gitudinal spots. The early stages of this species were traced by De Geer (Mem. Ins.), who found the larva to be terrestrial and carnivorous. His observa- tions on this species were the first giving information upon the early habits of the Tabanide. THE BANDED BREEZE FLY. ( Therioplectes cinctus Fab.) The banded breeze fly, or orange- belted horse-fly, is a species of some- what larger size than the greenhead. It is rather less abundant than the black breeze-fly, which it somewhat resembles, excepting the orange or reddish band on the abdomen. It is limited more to the Eastern States. It was described by Fabricius at the same time as Tabanus atratus (Ent. Syst., Vol. LV, p. 366). Hematopota pluvialis Linn. According to Kollar this is one of the most troublesome species. He says: It is not much larger than the common horse-fly, and is chiefly distinguished by its large green eyes, through each of which run four brown undulating bands, The body is gray with brownish cross stripes; the wings gray with brown spots. It frequents meadows and pastures and attacks horses and horned cattle in sultry weather before rain, nor does man escape. Although the wound it inflicts is sharp, it does not produce any lasting itching or burning. This statement regarding the injury caused does not agree entirely with the statements of other authorities, for in Kirby and Spence’s Entomology (p. 93) we find a quotation from MacLeay which reads as follows: I went down the other day to the country, and was fairly driven out of it by the Hematopota pluvialis, which attacked me with such fury that, although at last I did not venture beyond the door without a veil, my face and hands were swollen to that degree as to be scarcely yet recovered from the effects of their venom. I was obliged on my return to town to stay two days at home. Whenever this insect bites me it has this effect, and I have never been able to discover any remedy for the tor- ture it puts me to. Also, in Linnzeus under the description of the species: Like T. cwcutiens, this little insect fixes on the hands, face, and legs, exciting a painful inflammation in the part where it has drawn blood. THE EAR FLy. (Chrysops vittatus Wied.) This is a rather small species, yellow in color, with black stripes and a broad, smoky band across the middle of each wing. It was described in 1821 by Wiedemann, but without reference to its habits. 70 INSECTS AFFECTING DOMESTIC ANIMALS. . It is said to be very troublesome in the wooded regions of the Mis- sissippi Valley, directing its attacks particularly upon horses’ ears, in consequence of which it is commonly called the ‘‘ear-fly.” Chrysops univittatus Macq. This is a common species in the prairie region and is recorded from District of Columbia, Maryland, Connecticut, New Jersey, and Kentucky by Osten Sacken. It appears to be the most common species at Ames, Iowa. Chrysops niger Macq. A similar species, black in color; also very com- mon. Chrysops quadrivittatus Say. Say described this species in 1822 as inhabiting the region near the Rocky Mountains. It is of a gray color, with four iongitudinal brown lines on the thorax. The wings have a large brown spot on the front margin. It is nearly two-fifths of an inch in length. Chrysops costatus Fab. Fic. 33.—Chrysops vit : : ; tatus: larva (after Occurs in South America and the West Indies. Hart). Chrysops fugax O.S. This species, easily recognized from the figure, is widely distributed. Osten Sacken recorded it from Maine, New Hampshire, Canada, Idaho, Fic. 34.—Chrysops univittatus (original, from drawing by Miss L. Sullivan). Montana, and Yukon River. It occurs at Ames, Iowa, and doubtless throughout the northern Mississippi Valley at least. Sa lbahaes yh so Se Sr Be nee ———~-- DIPTERA. 71 THE HIpPoBOSCID-LIKE TABANID. (Goniops hippoboscoides Aldrich. ) Under the above name Mr. J. M. Aldrich has described a very pecu- liar fly, that has the structure of the tabanids, but the general appearance of a hippoboscid, although it is not known but only surmised thatit may have a parasitic or semiparasitic habit. Since nothing is known as to the . habits or the early stages of the '¢- 3—Eggmass : rhein cestuans (from species, and it would seem to be of 7 very rare occurrence, it will suffice for the purpose of this paper to Fic. 36.—Chrysops fugaz (original, from drawing by Miss L. Sullivan). simply refer to the original description and figures (Psyche, Vol. VI, pp. 236, 237). Family LEPTIDA. (Snipe Flies.) Most of the species in this family are of medium size, with rather slender bodies, and the abdomen generally somewhat tapering. They are sparsely haired; the head short; the eyes in the males set close together; the antenn short, and the third joint with a terminal bristle or slender style. The larve are carnivorous and live in the ground or else in decaying wood, in sand, moss, or water. The species generally prey upon other insects, but according to Dr, S. W. Williston ‘‘some Western species of Symphoromyia suck blood. as do the horse-flies.” As he does not particularize as to the species observed, the animals attacked, or the method of attack, we must let this brief mention suflice. Te INSECTS AFFECTING DOMESTIC ANIMALS. Family CHSTRIED Ai. (Bot-flies, Breeze Flies.) The bot-flies form a distinct family, easily recognized in larval or adult stages. The adults are heavy-bodied insects, generally rather hairy, and characterized by the small eyes standing at the sides of the head, the small antennz sunken into deep pits on the front of the head and by the rudimentary mouth parts. The larve are thick, fleshy grubs living parasitically in various por- tions of the bodies of mammals, the alimentary canal, the subcutaneous tissue, nasal passages, etc. The tracheal openings are located at the posterior extremity and protected by horny plates. Frequently the segments are provided with rows of spines which serve to assist the animal in locomotion. The pupa stage is passed in the ground, the parasite leaving its host and entering the ground for this purpose upon attaining its full larval growth. Irom the manifest economic importance of the different species and the great interest attaching to the habits of the species, which depart widely from even the most nearly related forms, they have been the subjects of investigation from the earliest periods of scientific work. The habits in general of the more common species were known more than a century ago and stated in the works of Linneus, DeGeer, Reaumur, and others, while the later studies, early in the present cen- tury, by Clark and afterwards by Joly, Brauer, and others, have cleared up most of the essential points in their life history. For the most part, these must be stated in detail for each species, since the habits are very different among the different species, aud par- ticularly so in the different genera. In all cases the eggs are deposited on the animal to be infested, either where the larve will gain access to the proper part, or in direct contact with the parts to be invaded. In one case, at least—the sheep bot-fly—the eggs may have NEE hatched and the free larve be deposited by the female. Studies of the young larva have been attended with some difficulty, though in the later stages they are well known and were accurately described at an early day. The full life of the larva has been a sub- ject of study by Joly and especially by Brauer, who presents in his ‘¢ Monographie der Oestriden” a very careful discussion of the subject. A translation of this part has been published by Mr. Bb. Pickmann Mann (Psyche, Vol. IV, pp. 305-310), and the following extracts from this translation will be of such service in gaining a full understanding of the early life of the bot-flies in general that it seems desirable to include them: The larve of the stride, although in many cases quite peculiarly shaped, are so nearly related to the larve of the rest of the Muscidie-calyptra that it has not yet been possible to discover for them a constant distinguishing character founded upon their structure. The reason of this lies in part in the estrid larvee themselves, since DIPTERA. | te they are very different among themselves, and in part also in our defective knowl- edge of the muscid larve. At present, it is true, no real muscid larve are known with large thorn-warts—as I will call the dermal formations which occur in many cestrid larve, which are con- ical, soft at the base, fleshy, and corneous at the tip—also none with the character- istic stigmatal plate of the Gastrophilus larve; on the other hand, very many are known with thorns, like those of Dermatobia, or naked, like those of the young Hypoderma, or with horny stigmatal plates, like those of Cephenomyia. The remarkable parasitic method of life in mammals can probably be looked upon as peculiar to the (stride. I leave it, therefore, to a future observer to establish a character for the estrid lary whereby they may be distinguished from all other muscid larve, and limit myself here to the description of the larve according to genera and species. The estrid larve belong to the great division of those dipterous maggots which have been called headless; since they are segmented throughout and the usual regions of the insect body are not separated. Only a cephalic and an anai end, therefore, can be distinguished on the annulate body of such larve. In general the following common characters and peculiarities of the cestrid larve can be specified. (1) The body of all cestrid larve is really composed of twelve rings. The first two are, however, not always distinctly separated, so that I take them together in the description, and designate them both by the name of cephalic ring, on which in many cases an anterior and posterior section is clearly to be distinguished. On that account I assume only eleven segments, as earlier authors havedone. Only the new- born larve of Gastrophilus make an exception to this number; they, if Joly’s state- ment is correct, possessing thirteen segments. (2) Two anterior, external breathing organs are always to be distinguished on the larv, between the first and second segments of the body, and two posterior, exter- nal breathing organs on the last ring. The former are very small and appear either as points, knobs, or fissures, or the anterior ends of the trachew are hidden entirely in a cylindrical invagination of the skin (Gastrophilus). The posterior breathing organs are either breathing tubes which are protrusile and retractile (new-born Gas- trophilus larve [p. 36] and Cephenomyia larvze), or large stigmatal plates which are constructed according to two kinds of types. One of these types is represented in Gastrophilus and Dermatobia, the other in the rest of the genera. The stigmatal plates are more or less protected by lip-like organs on the last ring or by withdrawal into the preceding ring, and are in this way cleaned from substances which adhere to them. Ihave described in detail under that genus the structure of the posterior stigmatal plates in Gastrophilus. The majority of the genera possess, however, two stigmatal plates in a real sense, consisting of corneous chitinous substance on the last ring. Each ring is usually crescent-shaped or reniform, in younger larve even quite cir- cular, and appears when magnified either as latticed with coarse meshes, finely porous or almost smooth, sometimes radially furrowed. On the inner border of each plate is in all larve in the third and in many in the second stage a thinner, mem- branous or knob-like place superposed or embedded, sometimes inclosed in the plate itself. The attachment of the trachea corresponds to this place on the inside. Since it usually has the appearance of an opening, and aiso has been taken for such, I call it the false stigmatal opening. It has not yet been ascertained without doubt that breathing goes on in such stigmatal plates, but it probably takes place through pores of the plate. It seems tome as if the plates were penetrable especially at the circumference of the attachment of the trachee. (3) The new-born larve all possess external mouth parts; in the later stages larve with oral hooks and those without them are to be distinguished. An internal pharyngeal framework of various development always occurs; this incloses the membranous gullet and by its muscular structure 1s of essential service in the suck- ing of the larva. If oral hooks are present, they are connected with this by a joint. 74 INSECTS AFFECTING DOMESTIC ANIMALS. Usually a y-shaped, bent chitinous plate is to be seen, whose open side looks up- ward; from the side it has the shape of a sitting butterfly whose large upper wing reaches far back and has the smaller, narrow under wing under it. Since the wings of the two sides are grown together firmly underneath, the whole pharyngeal frame- work appears like a flying insect, when the wings are bent apart from above, and with the base in a plane. The part lying more or less in front, which is to be found in the middle between the wings, and which really radiates out into these, or is united with them like a ligament, is what Schroeder van der Kolk calls the tongue bone. In the pharyngeal framework, therefore, there can be recognized a body (Schroeder’s tongue bone) and four wing-like processes, which often, again, consist of several parts. The body is connected with the wings posteriorly. It is always bent in a U-shape, and so that the open end looks upward, i. e., if other soft parts of its vicinity which also close this are disregarded (p.37). Bent flat, it shows a more or less distinctly H-shaped chitinous plate, with very broad side parts, which—in full-grown larve— become confluent behind into a simple, broad plate, and only Jeave an oval hole in front of them for the passage of the discharge duct of the salivary glands, but pos- teriorly bear the four wing-shaped processes (two large upper, or in the outspread plate outer ones, and two smaller slenderer inferior or inner). On the anterior end of the body, in many genera, oral hooks are jointed to the short anterior side parts. In the anterior curved excavation of this lies in the membranous expansion a small corneous chitinous plate which is pierced like a sieve and whose nature has not yet been more closely investigated. It seems to me as if this plate lay at the outlet of the salivary ducts. It is especially distinct in Cephenomyia larve. It is wanting in several others. In young larvee, the pharyngeal framework consists only of two chitinous rods, which are united in front by a chitinous band. These chitinous rods radiate out behind in little wings. A (similar) pharyngeal framework occurs in all other museid larvie, and corresponds in the perfect insect to the chitinous frame of the proboscis. I have repeatedly convinced myself that such is really the case, since I have opened the coarctate pup:e of Cephenomyia and Gastrophilus before the emergence of the flies. Since, in these genera, as we will see later, the nymph is tightly inclosed by the puparium, it can be noticed how the already freed pharyngeal framework, which remains attached to the puparium, rests in the mouth fissure of the nymph, and is drawn out of it as soon as the nymph is taken away or the lower lid is lifted off. It is also easy to form an idea that the pharyngeal framework, together with its internal parts, corresponds to the proboscis of the fly if it is observed how other muscid or syrphid larve while alive project and withdraw this exactly as the fly does its proboscis. In Hypoderma, the mouth parts undergo a retrograde metamorphosis from the second stage (after the first molt); the oral hooks disappear, and therewith all the external mouth parts, but the internal pharyngeal framework remains. (4) The estrid laryze show antenne (at least rudimentary ones) above the mouth parts; these have the appearance of corneous or usually membranous knobs, and in the latter case are provided with one or two ocelli-like points. Subulate, many- jointed antenn, such as occur in many muscid larve, are never found. (5) All possess an anus, which lies on the last ring, under the stigmata] plates, and is very small. (6) They molt twice while they are parasitic. I have observed most closely the molting in Hypoderma larvie of the second stage. In H. diana, the passage from this stage (p. 38) to the last one takes place about the beginning of February. If in a cutaneous muscle which is richly larded with such larve the capsules of those larvee whose hinder stigmatal plates have the shape of the third stage, but are still clear yellowish-brown, are carefully slit open, the skin characteristic of the preceding stage, with the many little thorns heaped in groups, will be found either still partly attached to the front end of the larva or entirely dependent from the cephalic end or folded together along the dorsal side. The process of molting DIPTERA, = UD seems to be entirely similar to that in the Melophagus larve#; at least Leuckart states that the old skin in these is shoved together toward the cephalic end of the larve, and there remains attached. The Hypoderma larva, immediately after the molt, is pure white, very soft, and appears naked, since the thorns do not become dark and distinctly separated from their surroundings until they harden. Three forms or stages are to be distinguished, corresponding to the molts, which forms in Hypoderma, Gastrophilus, and Dermatobia show great differences. In the third stage the larvze reach their full size, usually change their color, and that often very considerably, and then first leave their host animal, crawl away and pupate, after the manner of the Muscide. (7) This pupation must be considered as a third molting, in which, however, the skin is only detached around the pupa, but is not stripped off, and remains in con- nection with it by means of four trachee. The hardened larval skin, or puparium, is burst open at the cephalic end by the emerging fly by means of the frontal bladder filled with flnid, in the direction of the arcuate sutures inadouble manner. Although the pupation resembles herein that of the Muscidz in general, yet there occurs in one part of the (stride, i. e., in Hypoderma, a peculiarity which has not been observed before, namely, that the larva transforms in the puparium in a completely outstretched condition, and this, therefore, is far larger than the insect which comes forth from it. (8) So far as they have been observed, they lead a parasitic life in mammals, and feed upon the juices of these animals. In Hypoderma, a blood-red intestine often shows through, and it is likely that these sometimes suck up blood in addition to the exudation which immediately surrounds them. (9) The closely observed larvz all show at first a slow and finally a rapid devel- opment, so that there occurs a resting stage, which often lasts seven months, betweer the swarming of the imago and the first visible appearance of the larve. The larve of the (stride were formerly divided into two groups—into larve with oral hooks and those without external mouth parts. Such a separation is of service in distinguishing the full-grown larve, but scientifically unnatural and incorrect, since in the first place this peculiarity of the full-grown larve corre- sponds to no similar degree of relationship of the perfect insects, and in the second place it is ouly temporary (p. 39), since all cstrid larve possess oral hooks when they are quite young. Such a division also as Clark attempted to make into cari- cole, cuticole, and gastricola, is inadequate, for while the species of a genus do, indeed, always agree in life history so far as their occurrence as parasites in a deter- minate organ is concerned, nevertheless the larve of very different genera may also share this same manner of life with others; for instance, Hypoderma, Cuterebra, Dermatobia, among which there is far more difference between one and two than between Cuterebra and Cephenomyia, if the imagoes are considered. Such a divi- sion is, therefore, likewise not a natural one, since it disturbs the natural relations of affinity. Two elements must be considered in order to bring about an approxi- mately natural division: In the first place, the organization of the larve, and, in the second place, their manner of life, and the latter in a subordinate degree, though this is here more important than in other animals, since as yet there is no example of two species of (Estridie of one genus having been found parasitic in different sys- tems of organs. Thus the Cephenomyia larve belong to the wsophagus, the Cepha- lomyia and (Estrus larve to the nasal and frontal cavity, those of Gastrophilus to the intestinal tract, and those of Hypoderma to the subcuticular cellular tissue. Although it is stated that the larva of Gastrophilus has been found in the csoph- agus, this is one of the exceptional cases which are not authenticated. Of course, only the full-grown larva is meant here, since young larve may always be found in other places during the immigrations. So, for instance, the young (Estrus and Cephe- nomyia larve both immigrate in like manner through the nose, and their roads do not separate until they get there, but the former migrate into the frontal cavity and the latter into the @sophageal cavity. 76 INSECTS AFFECTING DOMESTIC ANIMALS. Of the organs in which (stride occur, the skin, or really the subcuticular cellu- lar tissue, is that which is the most strongly attacked; the larvee of four genera— Hypoderma, (Estromyia, Dermatobia, Cuterebra—live init. The nasal and frontal cavity are inhabited by the genera Cephalomyia and (éstrus, the nasal and cesoph- ageal cavity by the genus Cephenomyia, the intestinal canal by the genus Gastro- philus. The transformations cf the other genera of {stride are unknown. It is interesting, further, that many genera occur only as parasites of certain fami- lies of mammals, while others have a somewhat wider or very wide range of distri- bution, and so have for hosts the different mammals, yet not quite without choice, and often even seek man for their breeding places. Thus, until now, the larvie of Cephenomyia have only been found in the throats of cervina, those of the genera Cephalomyia and Céstrus only in tylopoda and cavicornia, those of the genus Gastrophilus in solidungula and multungula (Rhinoceros), but Hypoderma, on the other hand, in cavicornia (Bos, Capra, Antilope), cervina (Cervus, Moschus), and equida, Cuterebra larvze in Rodentia and Marsupialia, and finally those of Dermatobia in dogs, oxen, horses, and even upon man. (p.40) Another picture is formed if the perfect insects are divided according to a peculiar character into those with pectinate antennal bristles (Cuterebra, Derma- tobia), and those with naked antennal bristles (Hypoderma, Gastrophilus, Cephe- nomyia, Cephalomyia), since the larvie of the former are parasitic in ungulate animals as well as especially in Rodentia and Marsupialia, but those of the latter only in Ungulata. This hitherto so convenient and practical division likewise can not be relied upon for an inference, since (strus leporinus belongs to the group of (Estrid:e with naked bristle, but its larva lives upon a rodent. It is seen that such divisions are only artificial and serve for orientation, but that nevertheless nature can not be forced into them. Such divisions are therefore only temporary, and only too often become untrue so soon as new discoveries are published. It is therefore best to treat of the larvee according to their genera, and to limit these as natually as possible, since it has thus far been found constantly in this family that the larve of one genus all have a like life history, and conversely the generic characters of the imagoes can scarcely lead us astray if we wish to draw an inference as to the life history of a larva perhaps not yet investigated. In the case of a new genus, how- ever, we can infer its life history with very little certainty. Experience alone teaches this. The flies are seldom observed except in open sunny places and secrete themselves mostly in low herbage, grass, along roadsides, and other situations where they may gain ready access to their victims. Most or all of them live in this stage strictly without food, the mouth parts, except in a few, being very rudimentary or entirely wanting. All are confined in their attacks to vertebrates, and all, so far as positively known, to mammals. The species are quite numerous, about sixty being known in the adult form, but only the more common ones have been thoroughly studied, and in our detailed discussion of the species we will give particular atten- tion only to those affecting the common domestic animals. THE HORSE BOT-FLY. (Gastrophilus equi Fab.) Bots in horses have been a familiar form of parasite to farmers, stockmen, and veterinarians for we know not how long. Whether they were familiar to the ancients has been a matter of discussion among Bul. 5, new series, Div. of Entomology, U. S. Dept. of Agriculture. PLATE I. © @ GASTROPHILUS EQUI IN STOMACH OF HORSE. Fic. 1.—Bots on the walls of a horse’s stomach. (From a photograph by the author.) Fig, 2.—Portion of stomach wall showing points of attachment of bots. (From a photo- graph by the author.) DIPTERA. “FT learned men, but the mention in ancient writings of the Oéstrus and its habits is now generally considered as referable to some of the flies capable of piercing, such as the gad-flies or horse flies and not the bots. The occurrence of two or three similar species affecting the horse has led to some confusion in their names. Thus the Gstrus equi of Lin- neus appears to correspond with the Gstrus vituli of Fabricius, while the Jatter author includes in Mstrus equi the Uistrus nasalis, dvstrus hemorrhoidalis, and Gstrus veterinus of Linneeus. Without going into a discussion of this synonymy here, it will be seen that all of these forms were apparently familiar to scientific writers more than a century ago as well as the more striking features of their life history. Thus the statement made by Linnzus (Turton’s translation, p. 582) reads as follows: ‘‘ Deposits eggs on the hairs of horses, and always on those parts which are most liable to be licked by the tongue; these, either in the egg or larval state are conveyed by the tongue into the stomach, and passing through the intestines with the food are discharged with the dung.” These larve are commonly known by the name of bots. In 1815 Mr. Bracy Clark published his essay on bots of horses and other animals presenting the results of thorough investigation upon these interesting parasites, and subsequent investigation has but confirmed in large part the conclusions reached by him. NATURE AND EXTENT OF INJURY. Different writers have placed very different estimates upon the injury due to bots, and as great diversity, or perhaps greater, exists in the opinions of practical men and veterinarians, some holding that the presence of the bot in the horse’s stomach does not interfere with its normal activities, while others look upon them as extremely dangerous and sometimes refer almost any serious disturbance of the digestive organs, or death from unknown cause, to bots. The injury to the horse from the larve may take four forms: (1) The attachment to the walls of the stomach causes an irritation which may interfere with the normal action of the glands or reduce the extent of glandular surface; (2) the bots abstract some nutriment from the walls of the stomach, or by absorption, from the contents of the stom- ach itself; (3) by collecting, particularly in the region of the pylorus, they serve as an obstruction to the free passage of food from the stom- ach to intestines; (4) in passage through intestines they may attach themselves at times to walls or in rectum and cause great irritation. Some consider this as the source of most of the serious symptoms from presence of bots. In any of these methods the extent of injury depends in large degree upon the number of bots present, a few probably caus- ing no appreciable damage, while large numbers (sufficient, as we have seen them, to completely cover large patches of the stomach walls) must cause serious disturbance and loss of nutrition and would seem a sufficient cause to produce fatal results, From the nature of the case 78 INSECTS AFFECTING DOMESTIC ANIMALS. no definite statistics can be given for the losses incurred. It is prob- ably safe to say that nine-tenths of all colts and horses that are pas- tured during summer, and a smaller proportion of driving and work horses, become infested with bots each year. Aside from the injuries inflicted by the larve, we must consider the excitement produced by the flies when depositing the eggs as a source of loss, and this in many cases is by no means insignificant. LIFE HISTORY AND HABITS. Adults of this species are about three-fourths of an inch in length, the wings are transparent with dark spots, those near the center form- ing an irregular, transverse band. The body is very hairy, the head brown with whitish front, thorax brown, abdomen brown with three rows of blackish spots, which are subject to considerable variations. In the females the segments are often almost entirely brown with sim- ply a marginal series of yellowish spots, while in males the abdomen may be almost entirely yellow or very light brown, with brown or dark Fia. 37.—Gastrophilus equi: a, egg—enlarged; b, egg—natural size; c, young larva; d, young larva— much enlarged, showing spiny armature; e, oral hooks; jf, body spines; g, full-grown larva—twice natural size; h, adult female (original). spots very distinct. The males are rarely seen, for while it is one of the most common occurrences to witness the female around the horses depositing their eggs, the males evidently hold aloof. They are readily distinguished by the form of the abdomen, which lacks the two tubular segments at the end, and is provided on the under side of the last seg- ment with a pair of dark-brown or black hooks, or clasping organs. Otherwise, except the color of the abdomen, already mentioned, they resemble very closely the females. The eggs (fig. 37, a and b) are light yellow in color and will be found attached to the hairs of the shoulders, ; oa ee ee ee y DIPTERA. 79 forelegs, under side of body, and sometimes even the mane and other parts of the body, most commonly, however, on the forelegs and shoul- ders. The method of deposition has been frequently observed. The female hovers near the horse in a position which appears to be nearly vertical, since the body is bent downward, and the extended abdomen is thrust forward under the body to its full extent. The fly then darts toward the horse, the egg is glued to the hair in an instant and the fly retreats a yard or two to hover till another egg is ready to be deposited. The operation is repeated at very short intervals, so that hundreds of eggs may be deposited upon a horse in a comparatively short time. The eggs are held by a sticky fluid, which quickly dries and thus glues them firmly to the hairs. They are about one-sixteenth of an inch in length, and taper a little toward each end, though the attached end is the smaller. The outer end is provided with a little cap (operculum), which is set quite obliquely to the axis of the egg, though some authors represent it aS cutting the egg square off at the end. This cap or operculum breaks or is pushed off when the grub hatches. Bracy Clark wrote that the eggs do not hatch until twenty-five to thirty days old, while Joly found them to hatch in tour or five days. Verrill says: The eggs contain more or less perfectly developed larve when laid; and when they are mature or have been a few days attached to the hair, they burst open and allow the young to escape almost instantaneously, when moistened. Thus, when the horse licks itself or its companions, the moisture hatches the eggs and the young larve are transferred to the mouth by the tongue or lips, and thence to the stomach, where they fasten themselves to the lining membrane by their two hooks. Evidently some such condition is essential to the hatching of the eggs, as we have removed hairs containing eggs from the horse and keeping them where not subject to moisture they failed entirely to hatch, and even after a year’s time do not appear greatly shriveled. Doubtless they must hatch in a comparatively short time or lose their vitality, for moisture does not effect a hatching in those long kept away from the horse. The empty egg shells may cling to the horse for some time after the hatching of the larve and give it the appearance of being coated with eggs. Examination, however, will readily disclose the absence of the operculum in the hatched eggs. In order to determine more certainly as to the exact condition of hatching and the time involved, I undertook in [893 some observations which were reported in Bulletin No. 32 of the Division of Entomology (pp. 46-49). Eggs collected from a horse while flies were depositing, and therefore probably not long laid, were opened at different times by rubbing them with a moistened finger, simulating as nearly as possible the action of the tongue in licking the body. While the larvie appeared to be fully formed during the first three or four days after deposition, the eggs hatched with difficulty and the larvie seemed quite inactive, and all larvee that were freed in this manner up to the tenth day were hatched with difficulty, though the larve at the end of this time were becoming fairly active. 80 INSECTS AFFECTING DOMESTIC ANIMALS. Four weeks after hatching the eggs opened with the slightest touch of a wet finger, and the larve adhering to the finger were very active, though in some cases they were inactive and apparently dead. About five weeks after collecting the eggs nearly all gave only inactive or dead larvee, though opened with ease on being touched with the finger, and in forty days after collecting no living larvze could be found in the remaining eggs, except one which had succeeded in pushing off the cap of the egg and partially emerging. In view of these results, I coneluded: (1) That the eggs of the horse bot fly do not hatch, except by the assistance of the horse’s tongue. (2) That hatching does not ordinarily occur within ten or twelve days and possi- bly longer, or if during this period, only on very continuous and active licking by the horse. ; (3) That the hatching of the larve takes place most readily during the third to fifth week after deposition. (4) That the majority of the larve lose their vitality after thirty-five to forty days. (5) That larve may retain their vitality and show great activity upon hatching — as late as thirty-nine days after the eggs were deposited. (6) That it is possible, though not normal, for eggs to hatch without moisture or friction. (7) That in view of these results, the scraping off of the eggs, or their removal or destruction by means of washes will be effective, even if not used oftener than once in two weeks during the period of egg deposition, and, probably, that a single removal of the eggs after the period of egg deposition has passed, will prevent the great majority of bots from gaining access to the stomach, or at least so large a proportion that little injury is likely to occur. Wishing to know still more definitely the period of most ready hatch- ing, and the effect of different washes for treatinent, I suggested to a veterinary student, Mr. Harry Shanks, a careful series of observations, which were carried through during the summer of 1894. From this study, which was made under my direction, and so that I had frequent opportunity to note progress, a number of points were gained, which are worth adding to the above record. Three hundred eggs were collected from a horse which had been previously freed from eggs, So that the exact date of deposition was assured. The eggs were tested every day. On the day of collection (first day) the eggs appeared immature. One day later eight eggs opened by picking the operculum off showed three larvee with slight movement, and five immovable. On the third day a half hour of friction failed to hatch eggs, but the larve when freed by picking off the operculum showed two, slight movement; one, no move- ment, and one sufficient movement to get out of the opened shell. On the fourth day the larve in eleven eggs were all active, but had to be freed by picking off the operculum; the same was true up to the seventh day, the only difference being noted in greater maturity and size of larve. 3 | j Sa pet cen er Oh an re he a pcpbetee a Os sed Beker Cie Be ~— ss AEST EG EN A siecle Deets e retine meee: - # » ~ § » 4 DIPTERA. - $1 On the ninth day, or when the larve were eight days from deposi- tion, one larva was freed by seventeen minutes of rubbing with wet finger, another in twenty-two minutes; on the tenth day two others, one in fourteen and the other in eight minutes; and on the eleventh day several were hatched, the time varying from two to five minutes of subjection to the saliva and friction. On the twelfth day it required but one or two minutes, and on the thirteenth eggs would hatch in fifteen to thirty seconds. On the fourteenth day a number of eggs were tried, about one-third of which hatched almost immediately upon being touched with the moist finger, the others in from five to eight seconds. On the fifteenth day all eggs seemed fully mature, and prob- ably nine-tenths would have hatched at once upon being touched by a horse’s tongue in the ordinary motion of licking. From the sixteenth day to the twenty-second the eggs would open with a touch of the finger, but the larve would not adhere except with moisture. On the twenty-third day the first dead larva was noted, and a day later four out of eleven eggs opened had dead larve. On the twenty-fourth day all of the eggs not previously opened were examined with a lens, and only one showed the cap removed, the larva being partly out, but dead. The hatching of but one egg out of three hundred seems to me to establish pretty fully my former opinion, that the eggs require moisture or friction for the release of the young. On the twenty-fifth day, out of 10 eggs three contained dead larve, five could move slightly, and two were quite active. On the twenty- sixth day caps were removed from thirty-five eggs, twenty-seven larve being dead, seven were capable of slight movement, and one was active enough to escape from the shell. On the twenty-seventh day out of forty-three eggs opened only one larva was alive, and on the twenty-eighth day only one out of sixty-five, and on the twenty-ninth day all the remaining eggs, one hundred and three, showed only dead larve. The results of this study, it will be seen, confirm in the main the con- clusion of the former observations, the principal difference lying in the fact that all the larve were dead at a somewhat earlier period. Of course it could not be said that of the eggs opened in the earlier days none would have survived longer than four weeks, but considering the number used and that one-third of them were kept the full four weeks and two-thirds nearly that long before being opened, the presumption is strong that that is the full normal period of survival. It is safe, I think, to sum up the matter by. saying that the eggs nor- mally require friction and moisture to permit of their hatching and trans- fer to the horse’s mouth, that hatching occurs with diffienlty before the tenth day, and most readily after the fourteenth day, and that they lose vitality at a period varying between the twenty-eighth and fortieth days, the bulk not surviving more than four weeks. This.gives a solid foundation upon which to base recommendations as to the time when eggs must be destroyed. 4653—No. 5 6 82 INSECTS AFFECTING DOMESTIC ANIMALS. The newly hatched larva (fig. 37, ¢) is a slender, worm-like creature, so transparent that the internal organs are plainly visible. It grows rapidly at first, its food consisting, probably, of the mucous secretions of the mouth and esophagus. When two days old it presents the appear- ance Shown in fig.37,d. As soon as it reaches the stomach it fixes itself to the walls by the hooks next the mouth and soon undergoes consider- able change in its form and appearance. The body becomes more con- ical, but instead of the head end being widest this becomes more slender, while the tail end broadens. The spiracles at first exposed in two flap- like projections from the last segment are drawn more within the body and are protected by the development of a horny plate. The spines on the segments following the head become more pronounced. When full grown the larva is three-fourths of an inch to one inch in length and of the appearance shown in the accompanying figure (fig. 37, g). At this time they occur in large clusters upon the walls of the stomach, gener- ally more especially numerous at the pyloric portion, where they serve to retain the contents of the stomach. From the fact that the food of the horse does not become completely reduced to fluid, this obstruc- tion may be considerably greater than if only fluid matter had to pass the pylorus. This growth has occupied from late in the fall, through the winter, till late in the spring, and when fully developed the bots loosen their hold and are carried through the intestines and, escaping with the excrement, burrow into the ground to pass the pupa stage. This lasts for several weeks, thirty to forty days, according to some authors, when the fly, which has been already described, issues and is ready to proceed with the business of providing for another generation of bots. The larva of this species has been found in the stomach of the dog, though it can not be considered a normal habitat for it, and it is very doubtful whether the young larve could survive in the stomach of - @ carnivorous animal. Railliet (Comptes Rendus des séances de la Société de Biologie, 1894) cites records by Colin and others of such occurrences, aid details experiments which show the possibility of the survival of nearly mature larve that are swallowed with fragments of the stomach walls attaching to the stomach of the dog and remaining alive and healthy fifteen days after the ingestion. PREVENTION. In dealing with bots in horses, by far the most important point is to prevent the introduction of the larve, and while we have no oppor- tunity, as in the case of the ox bot-fly, to completely exterminate the pest, it is certain that proper attention to preventive measures would in afew years greatly reduce the numbers of the insect and procure _ comparative freedom. The better care usually accorded horses makes it possible to deal with it in some respects more easily than the species infesting cattle. The most vulnerable point of attack lies in the con- spicuous position of the eggs. No horseman, probably, can overlook DIPTERA. 3s these objects when occurring on the horse he is caring for, and colts in pasture sometimes become so covered with them as to give a decided change in color to the parts most affected. Itis evident that removing or destroying these eggs previous to hatching is all that is necessary to prevent “bots” in the horse. With horses kept in stables or used daily there is little trouble; the flies have less opportunity to deposit eggs upon them, and the ordinary grooming of the animal serves to remove some of the eggs, or being constantly under observation the eggs attract the attention of the person in charge and he removes them, if not to prevent bots at least to avoid the unsightly or ill-kept appearance they give the animal. With colts or horses in pasture, however, the case is very different. Not knowing the currycomb or card through the whole summer, and perhaps hardly seen from one week’s end to the other, the eggs deposited on them by hundreds have every possible chance to transmit larvie to the alimentary canal where they commence their growth. During July, August, and September, or as late as eggs appear on the horses, those kept in pastures should be examined once every two or three weeks and the eggs destroyed or removed. This can be accomplished in several ways. By using washes of dilute carbolie acid, about one part carbolic acid to thirty parts water, or rubbing the affected parts over lightly with kerosene, by clipping the hair or by shaving the eggs off with a sharp knife or razor. Our own experience leads us to prefer the last. With avery sharp knife or razor (a dull one will glide over the eggs) the affected parts can be very quickly run over without removing much, if any, of the hair. This method leaves no doubt as to whether or not the eggs have been touched, as in washes, and subsequent examinations are not complicated by a lot of dead eggs or shells. Perform once every two weeks, and there can be very few of the larve which gain entrance to the stomach. Will it pay, may natu- rally be asked by the man who has, say, from twenty-five to a hundred colts in the pasture. Possibly not, if but a single season is considered, but the loss of a single horse, or the poor condition of a number, result- ing from bots, or the fretting of the whole number in pasture, would more than equal all the cost of removing the eggs from the entire lot. But when the presence on the farm of the pest year after year is consid- ered with all its attendant evils, we believe most emphatically that it will pay. Quite frequently the flies will be observed at work depositing eggs on the legs or body of a horse at work or in carriage. If not noticed at once the nervous stamping, biting, or often greater excitement of the horse will apprise the driver of their presence. Although the flies are pretty wary and dart away when approached, a few seconds’ watch-. ing will enable one, by striking them down to the ground with hand or hat, to capture and kill the fly and thus stop the deposition of eggs and annoyance to the horse. Whether the larve of this species can mature except upon gaining access to earth seems not to have been determined, and for all the time the horses are in the field or on the 84 INSECTS AFFECTING DOMESTIC ANIMALS. road they have ready access to earth. But as some other forms can pupate successfully in the dung heap, it would seem worth while to subject the droppings of horses known to contain bots to some process that would destroy them and thus prevent maturity of the fly. REMEDIES FOR BOTS. The prescription of drugs for the removal of bots from the stomach when their presence is known or suspected belongs rather to the vet- erinarian than to the entomologist, but it may not be out of place here to call attention to a few of them. It is of course not an easy matter to determine during the life of the horse whether any particular dis- turbance of the digestive organs or lack of nutrition is due to tine presence of bots or to some other agency producing similar symptoms, and even a competent vetermarian may be puzzled in diagnosis. If occasional bots are noticed in the excrement of the animal together with poor condition, their presence in numbers may be inferred. It must be remembered that the bots are capable of withstanding almost any substance that the walls of the stomach can endure, and the safest plan, if intending to dose for them, is to employ a veterinarian. Tur- pentine is perhaps most generally given, but must be used with care. THE Ha:MORRHOIDAL BOv-FLY. (Gastrophilus hamorrhoidalis Linn.) While it is common to speak of the horse bot fly, it should not be in- ferred that there is but one kind parasitic upon the horse. Take the world over there are at least six well-defined species occurring on the horse, ass, or mule, and any of these are liable to be introduced into this country with imported animals. The above-named species is probably next to equi, the most generally distributed in this country. With the other allied species it was well known in Europe during the last cen- tury and received mention or more elaborate description from Linnzeus, DeGeer, Fabricius, and other leading writers on entomology. EXTENT OF INJURY. The losses to be referred to this species are similar to those of the other species, but from the accounts of various authors and what we have heard from persons who were plainly describing the actions of this particular form, it is evident that the excitement and consequent loss due to the attacks of the adult 4y are much worse with this species than the common one. This is described by Clark as follows: At the sight of this fly the horse appears much agitated, and moves his head back- ward and forward in the air to balk its touch and prevent its darting on the lips; but the fly, waiting for a favorable opportunity, continues to repeat the operation from time to time; till at length, finding this mode of defense insufficient, the enraged animal endeavors to avoid it by galloping away to a distant part of the field. If it still continues to follow and tease him, his last resource is in the water where the ce de all em yararegewiy i> - Pepe the y) 7 rae are wer ne oe eM DIPTERA. — «85 (Estrus is never observed to follow him. At other times this (strus gets between the forelegs of the horse whilst he is grazing, and thus makes its attack on the lower lip. The titillation occasions the horse to stamp violently with his forefoot against the ground, and often strike with his foot, as if aiming a blow at the fly. They also sometimes hide themselves in the grass and as the horse stoops to graze, they dart on the mouth or lips and are always observed to poise themselves during a few seconds in the air, while the egg is preparing on the point of the abdomen. LIFE HISTORY AND HABITS. Having discussed pretty fully the habits of the common species, it will be unnecessary to go into details that are similar in other species, but simply call attention to distinguishing characters and such differ- ences in habit as may be of economic importance. Prof. A. E. Verrill (Report on External and Internal Parasites of Man and Domestic Animals, p. 29) gives the following condensed state- ment of its life history and habits: The Gastrophilus hemorrhoidalis, or red-tailed bot-fly, is a small species, easily dis- tinguished by the bright orange-red tip of the abdomen. The thorax above is olive gray and hairy, with a black band behind the suture. The base of the abdomen is whitish and the middle blackish, in strange contrast with the orange red of the end. The larvze have the same habits and are found in the same situations with those of the common bot-fly, which they much resemble, except that they are whiter and smaller, their length not exceeding one-half or five-eighths of an inch. They change to pup within two days after leaving the horse, and the pup are deep red. They remain in the pupa state about two months, and the flies appear from the last of June till the cool weather of autumn. In depositing the eggs the female differs in habit from the common bot-fly, for she selects the lips and nose of the horse as the most suitable place for this purpose.. The eggs are darker colored [some authors say black] than those of the common bot-fly, and contain a nearly developed embryo, so that they very soon hatch, and the young larv are transferred to the mouth by the tongue, and thence get into the stomach. REMEDIES. On account of the shorter time between deposition of eggs and hatch- ing of larve, it is evident that the removal of eggs as for that species would be less successful. Jor horses in use, immediate attention when they give signs of the presence of the fly, the capture of the insect and the removal of eggs already attached would be but the natural method suggested by a knowledge of the insect. For horses in pasture, if exhibiting signs of molestation by this insect, the same attention would be advisable whenever the nature of the case will permit. It would be worth while to try the application of some oil or tar to the hairs of the lips as a prevention to the fastening of the eggs to them. HORSE Bov-FLY oR “CHIN FLY.” (Gastrophilus nasalis Linn.) As already stated, this species has been more or less confused with equi in scientific writings and doubtless still more so in general observation. 86 INSECTS AFFECTING DOMESTIC ANIMALS. It was described as Gstrus nasalis by Linneus (Fauna Suec.) and it was also given the name of veterinus by Clark. It was ineluded by Fabricius with hemorrhoidalis under Gistrus equi. The description in Systema Nature (Turton’s translation) is as follows: Wings immaculate, body ferruginous, sides of the thorax and base of the abdomen with white hairs. Deposits its eggs on horses and cattle, the larvie probably pass through the stomach like the former one. Less than (strus equi. Insertion of the wings and base of the abdomen covered with whitish hairs; second segment of the abdomen with two hairy tubercles, Beneath and legs rusty brown. Female with sometimes a blackish abdomen. Of this species Verrill writes (Ext. and Int. Parasites, p. 28): The Gastrophilus nasalis is a smaller species, densely hairy, with the thorax yel- lowish red or rust-colored. The abdomen is either whitish at base, with the middle black and the apex yellowish brown aud hairy; or the base is whitish and all the rest brown; or the middle is black, with the base and apex whitish, with grayish hairs. The wings are unspotted. The larve are much like those of the preceding [hemorrhoidalis], except that they are smaller, and also live in the stomach of horses. They change to pupx beneath the manure, and the flies appear from June to Sep- tember. It alsu infests the ass and mule, and some authors say that it lives even in cattle. Zurn! ascribes this parasite to horses, asses, mules, and goats, and says the eggs, 1 mm. long, are laid on the lips and margin of nostrils. He describes the full-grown larva as 13 to 14 mm. long, deep yellow or yellow brown, thicker behind than before, and the segments 2 to 9 above and 2 to 10 below with a single row of yellowish, brown-tipped spines. The pupa he described as dark-brown or black, the segments with only a single series of horny spines, its length of life in this stage from thirty to forty-two days. Professor Garman? in a recent paper on the subject gives a record of the occurrence of this species in Kentucky. From this record it would appear that the species is somewhat common and troublesome in that region, and as the species has been recorded from many places in this country, it may be looked upon as having quite a general distribution. The most essential point in habit of this species is the fact that the eggs are laid on the lips or nostrils, within easy reach of the tongue, and as it is quite probable that they hatch more promptly than those of equi, it is more difficult to adopt measures of prevention. Measures must consist in preventing as far as possible the deposition of eggs, for which purpose the application of a little tar and fish oil to the hairs of the under lip may be of service, and where eggs are suspected, the use of a wash of carbolic acid to the lips and margin of nostrils. According to Garman, the eggs are white, and are attached to the hairs of the lip and throat by the greater part of one side. The species occurs in Europe and has been observed in New England, New York, _ Ohio, Kentucky, Kansas, Utah, and probably elsewhere in this country. ! Die tierischen Parasiten, p. 100. 7The Bot Flies of the Horse, Seventh An. Rep. Ky. Ag. Exp. Sta., p. xxvii. ts ee RE My ee Tv eee Mae IY Ay (ae DIPTERA. — RT Professor Garman gives the following key by which the different species of bot-flies may be distinguished : 1. (6) Discoidal cel] closed by cross vein. PP tyes Le Wa irtow B35 o2 oS Oe tae oot eee bay cee eee G. equi. 3. (2) Wings not marked with brown. 4. (5) Anterior basal cell nearly or quite equal to the discoidal cell inlength. G. nasalis. 5. (4) Anterior basal cell markedly shorter than the discoidal cell. G. hemorrhoidalis. ne eMnt OPI OMS 22S le ots oe agen phe Once Sate meer eee tener G, pecorum, Gastrophilus pecorum Fab. We are not aware that this species has been encountered in the United States, and if so it is evidently rather rare. The following paragraph from Professor Verrill’s report would seem to indicafe an acquaintance with specimens collected in this country: The Gastrophilus pecorum is densely covered with yellow hairs, with a band of black hairs on the thorax behind the suture in the male. The female is yellowish brown, the abdomen black, with yellowish hairs at its base, as well as on the thorax: The wings are grayish or light brownish, clouded with yellowish brown. The larve are similar to those of the more common G. equi, and have similar habits. The flies appear at the same time. Osten Sacken’s list of American Diptera records it only from Jamaica on the authority of Walker. THE BoT-FLIES OF CATTLE: WARBLE FLIES. Until a few years ago it was assumed that the common bot-fly affect- ing cattle in this country was the same as the one most common in European countries, and the same specific name was applied to it with apparently little careful examination of either larve or adults to deter- mine the question with certainty. Following the announcement of Dr. Curtice, that the larve reached the backs of the animals through the cw@sophagus, a careful review of all available material was made (Riley, Insect Life, Vol. LV, p. 302), which indicated that the species most abundant,if not the only com- mon form, was not the bovis of Europe, but lineata, which is likewise European in distribution. There is so much in common, however, in the habits and nature of the injury of the two species that it seems appropriate to discuss some of these general features for the two species, and then to give the dis- tinctive features for the two forms with reference to such differences of habit or treatment as may be necessary. A considerable portion of this general matter was prepared prior to the discovery of the identity of our species with lineata, and, while written with bovis in mind, applies properly to the former species. Historically, bovis has been recognized the longer, having doubt- less been known from earliest times, and the larva often mentioned in writings from 1716 on as, possibly, also lineata, but bovis was described 88 INSECTS AFFECTING DOMESTIC ANIMALS... by DeGeer in 1776 under the name of Uistrus bovis, later changed by Latrielle to Hypoderma bovis. In 1815 Bracy Clark, in his Essay on the Bots of Horses and Other Animals, presented probably the first careful study of its life history and habits, and later the researches of Brauer, Taschenberg, Zurn,and | others have added to our knowledge of the species. More recently Miss E. A. Ormerod, consulting entomologist of the Royal Agricultural Society of aloud, has published results of a num- ber of reported and personal observations on its habits, injuries, etc., and during the summer of 1889 the Farmers’ Review, in this county undertook an investigation on much the same plan. The species are, so far as we know, closely confined to the bovine race or nearly related species, lineata being regarded as a parasite of the buffalo as well as the ox. Kollar (Treatise on Insects) speaks of bovis as affecting besides cattle, the stag, roe, and camel, but no authentic record of such occurrence has been noted, and he may have had as a basis for the statement the related species occurring normally on these animals. There are, indeed, records of the rare occurrence of these parasites on man, but such are exceptional, and the species should be considered as restricted, primarily, to bovine animals. On account of this restriction, the-insect is known in the lafval stage only where eat- tle are kept, and can be introduced in a new country only in the larval stage with the animals. It is in this manner and this alone that they have been scattered over the world with domestic breeds of cattle. EXTENT AND MANNER OF INJURY. The losses from warble flies must be considered from three distinct points, only one of which can be estimated with any great accuracy. They are (1) the loss incurred on the hides perforated by the maggots, subjecting them to discount or rejection in the markets; (2) the loss in milk and beef supply caused by the fretting and stampeding due to the presence of the flies when laying eggs, and (3) the loss to the vitality of the animal, its weakened condition, and consequent loss in milk or ‘beef due to the presence of the warbles, with accompanying ulcers in the back, sometimes, it is asserted, resulting in the death of the animal. LOSS ON HIDES. This will vary in different countries, both from the actual differences in abundance of warbles and consequent perforation of the hides and from the different rates of discount applied by different dealers. That it is by no means insignificant will appear from the following condensed statements of statistics and evidence on the subject: As a result of many inquiries and testimony from numerous sources, Miss Ormerod estimated the loss in England at $5 per head for cattle. RT El aa tne cer eae DIPTERA. —6© 89 The results obtained by the Farmers’ Review in its recent investi- gation are summarized as follows (Insect Life, Vol. I], p. 157): From the reports received the approximate percentage of grubby cattle and the average loss on grubby hides for the principal stock-raising States of the Mississippi : Valley have been estimated as follows (August 7, 1889): grubs. The average loss on a grubby hide is one-third. Iowa.—Seventy-one per cent of the cattle in the majority of counties are grubby in the season specified. Loss on grubby hides one-third. Indiana.—Forty-eight per cent of the cattle grubby. Loss on hides one-third. Wisconsin.—Thirty-three per cent of cattle grubby. Loss on hides one-third. Ohio.—Fifty-six per cent of cattle grubby. Loss on hides one-third. Missouri.—Fifty-seven per cent of cattle grubby. Loss on hides one-third. Kansas.—Sixty per cent of cattle grubby. Loss on hides one-third. Kentucky.—Fifty-seven per cent of cattle grubby. Loss on hides one-third. In Minnesota and Dakota grubs are practically unknown among cattle. In Nebraska they are not very bad where found; twelve counties report an average of 40 per cent. The rest heard from are free of the pest. Grubby hides are ‘‘ docked’ one-third of their value. In Michigan 61 per cent of the cattle are infested with grubs in the southern and middle counties. In the northern counties they are unknown or very scarce. Grubby hides sell for one-third less than sound ones. Illinois.—_Seventy-three per cent of the cattle marketed in the grubby season are infested with ; > The amount of this loss can be better appreciated perhaps by reproducing in con- densed form the approximate estimate of the loss on the hides of cattle received at the Union Stock Yards of Chicago during the grubby season, which includes the months from January to June. Using the reports by States above given as a basis it is estimated that 50 percent of the cattle received are grubby. The average value of a hide is put at $3.90; and while from the report referred to one-third value is the usual deduction for grubby hides in this estimate, but $1 is deducted, or less than one-third. The number of cattle received in 1889 for the six months indicated was 1,335,026, giving a loss on the 50 per cent of grubby animals of $667,513. When to this is added the loss from depreciated value and lessened quantity of the beef, the amount for each infested animal is put at $5, indicating a total loss on these animals from the attack of the fly of $3,337,565. LOSS IN MILK AND BEEF FROM ATTACK OF BOT-FLIES. In trying to present any estimate of loss from this source we are con- fronted by the fact that many other flies with these serve as a constant source of annoyance to cattle in pasture, exciting them at times to a wild frenzy, when they go chasing about trying to avoid their enemies, and not only losing the opportunity to feed peaceably, but using up in useless activity the nutriment which should go to form milk or flesh; at other times driving them into ponds or streams of water or into the Shade of trees or sheds, where they remain for hours at a time, only partially relieved from the torments of their foe and losing the oppor- tunity for feeding which is essential to growth or production of milk. It is, of course, impossible to separate the losses due to each kind of fly, and even if it were possible it would be difficult to state in exact figures the sum lost. The following note, quoted by Miss Ormerod, is perhaps as good an illustration as we can select to show approximately this loss as estimated by a practical breeder and dairyman: ys We all know, to our cost, how greatly these irritating flies torment and madden the cattle, causing them to gallop or run asif for their lives to get away from the buzz and presence of their tormentors. Feeding cattle can not grow in flesh with- out quiet and rest, and milking cows must suffer to a greater extent than we are rt _ er EE eee eee 90 INSECTS AFFECTING DOMESTIC ANIMALS. aware of. To use a common remark, they soon ‘‘bate”—i.e., give less milk. To drive a cow fast or cause her to be excited reduces the quantity and quality of the milk. Without perfect quiet and rest they can not do their best for us. This leads me to one important point. What is our loss in the cheese tub caused by the warble and gad flies? I have tried to estimate the loss during the four or five summer months or even the eight months that a cow is supposed to be in profit. There are certain times of unrest when the cow will give about half of her usual flow of milk. These tormenting flies and the presence of the prickly-coated warble maggot must keep up a perpetual uneasiness and retard the growth of our feeding cattle, to our loss, it may be, of £2 per head. In the dairy cows the loss will be greater. The daily loss of milk may make a ditference of a hundredweight of cheese per cow per annum. Half a hundredweight, or 12 per cent of milk less in a dairy, making 4 hundredweight at 70 shillings, comes to 35 shillings. But 12 per cent is too low an estimate. It may in some cases be put at £5 per head, and in a dairy of 100 cows would show a loss of £300. , This source of injury, however, lasts but a few weeks during summer, and probably does not compare with the loss due to the presence of the maggots. This must be a constant source of irritation to the animal. and a drain upon its energies from the time the warble begins to grow until the sore heals after the departure of the maggot. .~It extends through at least one-third of the year, while the whole period of inva- sion probably lasts for eight or nine months. Imagine some fifteen or twenty boils or carbuncles located along the back producing a reg- | ular supply of muco-purulent matter due to the inflammation and sup- plying nutriment to a healthy grub which grows to be three-fourths of an inch in length, and suppose, if possible, that these are no discom- fort or cause of loss to the creature affected with them. ? The occasional attacks of one or more species of bots upon man and the discomfort caused by them in such cases would seem to be sufficient proof of the irritation caused in the lower animals, even if we allow something on the ground that these lower animals are less sensitive to pain. Omitting, however, the creature’s comfort as a matter of mere sentiment and considering the question from the practical standpoint of money returned, it requires only the very modest estimate of the loss of $1 per head to the cattle of the United States to show a loss of about $36,000,000 sustained by the country on the basis of the census of 1880 (doubtless between fifty and sixty millions at the present time). Young. animals are injured more than old ones, and many writers assert that deaths are not infrequent from the effects of warbles. Without considering the lessened quantity, the inferiority of the beef of animals infested by the grub is strikingly shown in an article on the subject in which the testimony of retail butchers and buyers of meat in Chicago and other cities is given. It is shown that the buyers of the highest class of meat, who supply hotels.and res- _ taurants, will not on any account purchase carcasses showing traces of warble attack. Such beef has to be sold, therefore, at a price below that obtainable for good beef, free from grub damage, and the lessened value per animal was put at from $2 to $5. The appearance known as licked-beef, which, resulting from the presence of the grub, may be described as a moist or running surface of a greenish-yellow color, is certainly unwholesome in look, if not in fact. The description of such meat as given in the Farmers’ Review, quoting again largely from Miss Ormerod, is almost sufficient to turn one against beef altogether.—(INsEcr LIFE. ) DIPTERA. 91 If we take the estimates as a whole, some of which have been pub- lished since the first writing of this chapter, it is evidently a modest estimate to consider the losses from the different sources of injury to hides, loss in milk and beef, and lessened vitality to be $2.50 per head of cattle for the whole United States, making a grand total of $90,000,000 on the basis of the census of 1880. Were this loss something unavoid- able or requiring the expenditure of much time or money to prevent, there might be some excuse for its continuance, but since it can by simple and inexpensive methods be not only wholly prevented from year to year, but practically exterminated from the country, thereby avoiding both the loss and the trouble of applying remedies in the future, it would seem of the greatest utility to adopt those necessary measures without further delay. The preventive measures necessary become at once apparent by knowledge of the life history and habits of the insect. OCCURRENCE OF WARBLES IN MAN. There are many instances of the occurrence of the warble in man, and these records contain instances which are to be referred to both of the species, Dr. Riley having positively identified one such case at least for lineata, and Dr. William Schoyen being authority for the European records of bovis. In all these cases there seems to have been a large amount of migration on the part of the larva and usually an emergence from the_skin before complete maturity, which would suggest that the larva does not find the conditions exactly normal. The following instance observed by a physician who is also a trained entomologist is of special value as showing the conditions of such an occurrence: Several years ago I saw, professionally, a boy 6 years of age who had been suffering for some months from the glands on one side of his neck being swollen and a fetid ulceration around the back teeth of the lower jaw of the same side. Three months treatment was of no avail, and the end seemed near; one day a white object, which was seen to move, was observed in the ulcer at the root of the tongue, which on being carefully extracted proved to be a large grub, which, from having frequently seen them, I recognized as a full-grown larva of Hypoderma. It was of the usual tawny color, about half an inch long when contracted, about one-third that thick- ness, and quite lively. The case ended fatally. This boy had been on a farm in Illinois the previous fall, where probably the egg was in some way taken into his mouth, and the larva found between the base of the tongue and the jaw suitable tissue in which to develop, coming to maturity at the same time with those bred in cattle. (Dr. John Hamilton, in Entomological News, Vol. LV, p. 219.) LIFE HISTORY AND HABITS. In certain points of life history and habit the two species agree. The adult flies are about half an inch in length and bee-like in appearance, the two species separated easily by characters to be detailed later. They appear during the summer months and deposit their eggs upon cattle, the act of oviposition being frequently accompanied by a great amount of annoyance to the animals, in some cases inspiring them with 92 INSECTS AFFECTING DOMESTIC ANIMALS. such terror as to result in costly stampedes, prevention of feeding, and nervousness that is very injurious to the animal. The flies probably mate in the vicinity of their pupation, and the females seek the cattle in open pasture for the purpose of depositing their eggs. It is claimed by good observers that they will not fly over water or follow cattle when they seek protection in ponds or other bodies of water, and also that they do not enter sheds or trouble cattle in the shade. The method of deposition has been a subject of much discussion. The earlier writers asserted that the insect punctured the skin and laid the egg beneath, basing the assertion, it would seem, on the great terror and apparent pain of the animal when attacked and the position of the grub when first distinguishabie. Réaumur even describes the boring apparatus by means of which it is able to pierce the tough hide of the ox. Clark and others, however, held with equal strength to the view that the eggs are simply deposited on the skin, and the larve begin at once upon hatching to burrow beneath. Williston (Stand. Nat. Hist., Vol. I!, p. 427) says: ‘“‘The eggs of Hypoderma are deposited on the hairs about the front shoulders, neck, and groins of artiodactyls only. It was thought for a long while that the female thrust the eggs within the skin, but such is now known not to be the case.” Miss Ormerod, after careful study of the very young larvee and course of their channels, says: ‘‘ From the presence of these small cav- ities just below the cuticle, and the fine canal running downward from them or from the surface, as the case may be, to the young warble cell beneath the hide, I think we shall find that the egg is fixed just beneath the cuticle and that the young maggot works its way through the hide to where we find it in the early stage. It does not seem possible to me that the fly could pass the egg through the hide by means of her egg- laying apparatus (or ovipositor), because, as observed, the passage down the maggot cell is sometimes of a shape that could not have been caused by the ovipositor.” It seems hard to believe that all the fright and apparent pain exhibited by the cattle is due simply to the alighting of the flies and deposition of the egg on the hair. They can not bite, for, as already stated, their mouth parts are rudimentary, and to suppose that the cattle are aware of the true nature of the pest and exhibit fear simply because of a knowledge that they will cause them future trouble is to accredit them with a wisdom rather beyond that usually granted to any of the loweranimals. Neither does it seem that all this fright could be due simply to their resemblance to bees, for cattle are not so frequently stung by them as to develop such an intense fear of them. The structure of the ovipositor clearly excludes the possibility of puncture, for, though horny, it has a blunt, trifid tip, and is beset at the end with certain minute hairs, and structure of this character is a very safe guide to habit. (Riley.) Until recently it was assumed as a matter of fact that the larve entered through the skin, but the discoveries of Dr. Curtice have proven, for lineata at least, that the normal course is by way of the DIPTERA. 93 mouth and alimentary canal, as will be discussed more fully under /in- eata. While from analogy it seems very probable that a similar habit will be proven for bovis I know no positive obser- vations, but Miss Ormerod adheres to the belief that the entrance for that species is through the skin. In either ease the maggots, as a rule, must be within the animal as early as October (for lineata much earlier), and by January the lumps or swell- ings along the back denoting their presence be- come appreeiable, and growth continues as late as April and possibly May, varying with latitude. We have quite fully developed specimens (of lineata) taken March 25, from the backs of cattle at Ames, lowa, at which time they were mostly well grown and some of them apparently about Fig. 38.—Hypoderma lineata: ready to escape from the ulcer. After working ovipositorof female: a, from their way through the opening in the hide,in “4°” 8P: ftom below— enlarged (from Insect Life). which they are assisted by the prickly tubercles covering the body, they drop to the ground. The full process is thus described by Dr. Williston (Stand. Nat. Hist., pp. 427-428): They have the peculiar ability to contract either end into an elongate cylindrical form, which not only serves them in their egress, but also to bore into the ground. A few days before they are ready to emerge they begin to enlarge the opening by this expansion and contraction; when they have enlarged it sufficiently, a ring-like contraction of the body that begins at the posterior part and progresses toward the head enables them in a few minutes to free themselves, which they usually do in the morning hours. Upon the ground they creep about until they meet some obstruc- tion, when they burrow from 1 to 2 inches below the surface, and remain as in the Gastrophiius species. They remain in the ground as pupe for about a month and then issue as flies. REMEDIAL MEASURES. Knowing that the insect occurs, during nearly three months of the year at least, in no other place than in the backs of cattle, it is evident that the destruction of all the grubs in the back of every animal between January and April must result in the extermination of the pest. That there are measures sufficient to accomplish this destruction is certain, and at an outlay of time and trouble that makes them prac- ticable with every man who owns cattle, whether one or ten thousand. Indeed the insect is open to attack in at least three different ways: (1) Measures to prevent the deposition of eggs; (2) measures to destroy the eggs or young grubs; (3) measures to destroy the grubs after passing under the hide. : To prevent the deposition of eggs the application of some persistent sticky substance may be recommended, or this may be combined with some substance of obuoxious smell, 94 INSECTS AFFECTING DOMESTIC ANIMALS. Coating the back from neck to loins with tar or with a mixture of sulphur, 4 ounces; spirits of tar, 1 gill; train (whale) oil, 1 quart, once a week. ‘Train oil alone two or three times in the season and one application of spirits of tar, carbolic acid, sulphur, and linseed oil combined, are reported in Miss Ormerod’s pamphlet as effective for bovis. Animals that are housed are said not to be attacked, and furnish- ing sheds in pastures or access to shade of trees or to bodies of water is considered as helpful. We doubt, however, if these measures can be used as satisfactorily in large herds of cattle or on the ranches of the Western States as measures directed against the grubs. And unless the substance serves to catch and kill the fly it will of course simply seek animals not pro- tected or possibly be driven to deposit eggs on some other part of the body. In January the warbles become large enough to be detected by pass- ing the hand along the back, and at this time a little kerosene rubbed into each one or the application of mercurial! ointment will destroy the grub, which rests with the breathing pores directed toward the surface, securing its supply of air through the small channel connecting the cavity with the outer surface. The sore heals up and the hide in a short time becomes perfect, so no loss need be incurred if the animal is to be slaughtered in late winter or early spring, and for milch cows the drain upon their vitality and productiveness is stopped. , Even if these measures have been adopted every animal should be examined during March and any grubs found should be destroyed. They are by this time quite conspicuous, being felt by running the hand along the back, or in many cases can be distinetly seen as promi- nent lumps. The hole through which they breathe and finally escape is now large enough, so that by careful pressure the maggot may be forced out unbroken. If necessary, the opening may be enlarged a little by using a round stick bluntly pointed, as a probe. If late in the spring, all grubs pressed out should be crushed to prevent possibility of their getting into suitable places to pupate and finally reach the adult stage. For cattle in stables it is a very simple matter, while handling or feeding them, to run the hand along the back, and on detection of a grub to press it out, and all farm hands should be instructed to lose no opportunity to relieve the cattle from these annoyances. While it is certain that this insect could be practically exterminated in the United States in a single year, we realize fully the great diffi- culty in getting every person owning cattle to know or appreciate the need of using the necessary means; and two or three scrub cows in a county unecared for will of course perpetuate the species. Nevertheless, this should not debar anyone from attending to the matter with his own stock, for, since the flies travel but short distances, every farmer / elieinemrleninlccitahdiiies:: masa Dies i Se Cie |S ea DIPTERA. | - 95 may secure practical immunity in his own herds, and after the first year’s thorough work have scarcely any trouble in attending to them. He should, of course, examine carefully every anima! brought to his farm, and rid it of grubs before the time of their maturity. Many farmers are careful to attend to this matter already, but there is no systematic attention to it, and the only permanent check to their increase at present lies in the fact that millions of them infesting cattle slaughtered between October aud April perish with their hosts, and hence only those in cattle kept over from year to year survive to con- tinue the species. We ean not close this sketch of remedies without presenting a plan which, though it may be styled fanciful or ideal, must if carried out result in the extermination of the pest and a saving, we believe, of not less and probably more than $50,000,000 per year to the farmers of the United States. Let every man owning kine of any grade be posted by a general proc- lamation. inserted in every newspaper in the land that in a certain winter, say 1900, he is to examine every animal in January and apply kerosene or mercurial ointment to all lumps discoverable on the back from the neck backward, and down halfway on the ribs; that in March or at latest before the middle of April he must go over every animal again, and press out and destroy any warbles remaining. Then the following winter if any warbles whatever are to be found to repeat the processes. This, with the destruction of grubs in all cattle imported from other countries, must prove successful. Even if a few escaped by the neglect of some shiftless stock owner, or by accidental oversight in searching for them, the result would repay over and over again, and for many years, the grand effort of that year. Ox Bot-FLY OR WARBLE FLY. (Hypoderma bovis DeG. ) As previously stated, this species was formerly supposed to be dis- tributed over America, but the utter fail- efiaig eee AS ed\ ure to find a single specimen of the larva Za) ox or adult in the mass of material that has been examined in the last few years makes it doubtful if even the earlier records of its occurrence in this country can be relied upon, and therefore it seems necessary to define its distribution as covering the countries of the Old World surrounding the Mediterranean. Brauer \ gives its European distribution as from pyc. 39,— Hypoderma bovis — enlarged Scandinavia to the southernmost por- after Brauer). tions, and also saysitis distributed over Asia, Africa, and North America, 96 INSECTS AFFECTING DOMESTIC ANIMALS. The adult fly, shown enlarged in the accompanying figure, is half an inch cr a little more in length and not very different in general appear- ance from a honeybee. It is quite hairy, and, although the surface of the body is black, except the front of the face below the eyes, the color of the hairs gives it a banded appearance, the face white, the front part Fic. 40.—Hypoderma bovis: a, egg; b, full-grown larva, ventral view; c, puparium, ventral view; d, newly hatched larva, side view; ¢, anal stigmata of larva—all enlarged (after Brauer). of the thorax yellow, middle of the thorax black, hind part of the thorax whitish, base of abdomen whitish, middle of abdomen black, and apex of abdomen orange red. The eggs are elongate oval, with an appendage for attachment to the hair (fig. 40, a). +]. A “Th a | FF 7 i ad 5 ‘|. i =] ® a 5 he . . . ify : Ae a the u LC Pia Ba : :3 5 a Saeco Coe Its fideo Bae *. sy i oe Pr a | Bund be pe ° we rs Sy .) *, of a “4. ea (5 qe. s a 5 ts 8 eee tthe, ne) be 5) ee Ay BA om oe he Te .° FS . 5 « tte cp bat : a fs hy pales ee od eck os fi x se 4 Do : * AY Gch Sey BE ar IF 9 bo =f: . on f i . I wee 8 bin Fia. 41.—Hypoderma bovis: diagram of spiny armature (after Brauer, from Insect Life). The larva of this species is only known in the later stages, that of the first stage not being described. Brauer describes the second and third stages, the latter form being carefully figured, and the figure is here reproduced from an illustration in Insect Life. 3 3 . ie ‘ x DIPTERA. — 97 This larva is thick and fleshy, of a yellowish white color, becoming darker as it approaches maturity, but the most distinetive characters are found in the disposition of the spines which cover most of the sur- face of the body. The last two segments are entirely naked, and also the dorsal and lateral prominences of the ninth segment are free from spines. This arrangement of spines is clearly shown in the diagram, which is a device adopted by Brauer to indicate the difference in spine dis- Fia. 42.—Hypoderma bovis: a, tribution in the different species. Comparison nya it aatoghalarane of this figure with that for lineata will serve to of adult; ¢c, cap which splits Metermine at once the identity of a specimen. eee ced The wide spaces represent the dorsal (the left) and the ventral (the right) surface, and the narrow spaces the three rows of lateral protuberances. The spines on the upper and lower border of the segments are represented by dots. The pupa is an oval dark body formed from the contracted larva, the anterior end of which is removed when the imago issues. It is clearly illustrated in the annexed figure (fig. 42). The treatment of the species is discussed under the general treatment for both species. Ox BotT-FLY OR HEEL FLY. (Hypoderma lineata Villers. ) The synonomy and distribution of this species has been very fully discussed by Dr. Riley in Insect Life (Vol. LV, p. 302), along with a dis- cussion of the distinctions of the species and I shall extract largely from this article as well as from the one by Dr. Curtice, (Journal Com- parative Medicine and Veterinary Archives, Vol. XII, pp. 265-274, June, 1891). The species was described in 1789 by Villers (Ent. Linn., Vol. III, p. 249), and later (from larva) by Brauer as bonass?. Much confusion has existed, particularly because of the assumption that the common warble of this country should be referred to bovis, but the matter has been definitely set to rest by the researches de- tailed in the above-mentioned papers, which may be consulted for full details. Aside from the occurrence in the buffalo, which appears to have been not uncommon, it is evidently a parasite normal to cattle. Which of these animals, if either of them, was the primary host of the species can not be stated, although the evidence seems to me to favor the opinion that it was primarily a parasite of the ox and that its occur- rence on buffalo followed the introduction of cattle into this country. 4653—No. 5— ~-7 98 INSECTS AFFECTING DOMESTIC ANIMALS. In Europe it is said to occur in Switzerland, Norway, Crimea, the Balkans, the Caucasus, England, Lower and Upper Austria, etc., but it has not been noted in Styria or Hungary. In America it is known from all parts of the United States, but is especiaily abundant in the southern portion and extending north to Illinois, lowa, and Nebraska. The amount of terror inspired by the adults is sometimes very great, and the following graphic account of its attacks in Texas by a gentle- man who has given much time to them will serve to show its manner of work and the loss entailed: I believe that here the fly invariably deposits its eggs on the hair around the heel, although the popular notion is that the fly actually stings the animal. The cattle lick themselves, thus conveying the eggs into the mouth, the larve making their way in between the walls of the gullet. Here they remain some months, when they finally make their way up to the skin along the back, where they bore through, Temaining in the hole a little over two months. When they first reach the skin they are quite white, but gradually color and become a dark brown or black, and forcing themselves out of their sacks fall tothe ground. The skin of the larva becomes dark and shell-like, and at the end of about six weeks the perfect fly emerges. Although I know that in Pennsylvania the backs of the cattle are often badly infested with these larve, showing that the fly is by no means rare, yet I never saw that its presence caused any fright or even uneasiness, while here it is so dreaded by the cattle as to cause at times heavy loss to stockmen. The time of the fly begin- ning and ending its attack is very variable. I have seen cattle running from it as early as December, while this year up to date (February 15) I have seen no indica- tion of its presence. Cattle seem to become absolutely frantic from terror; a steer will be quietly graz- ing, when suddenly he will spring forward, head erect, tail arched, and in a moment he will be madly rushing across the pasture, probably to the creek, into which he will plunge, remaining for hours. If the streams running through the pasture have muddy bottoms many weak animals become mired and perish miserably unless dis- covered and pulled out. As the fly generally appears toward the close of winter, when cattle are often comparatively poor and weak, the loss in this way would be very serious but that stockmen have their men ride daily along the banks of any boggy streams in order to rescue mired animals. When a cowboy finds one unable to get out he uncoils his lariat, deftly thows it over the horns, gives a turn or two around the pommel of his saddle, and calling on his pony, the animal, unless very badly mired, is soon on the bank and in safety, and hereafter often comes the most difficult part of the business—the letting go. In getting hold the cowboy has it all his own way, but once the animal is on solid earth again it forgets its former peril, remembering only the terrible wrench to head and neck, and proceeds to get even with its tormeutor, with the result that the man has sometimes to drop his rope and ride off trusting to its becoming loosened and drop- ping off. Can any one suggest the reason why the fly has such terrors for a Texas cow, whilst in Pennsylvania she cares nothing for it?—(George W. Holstein, in Entomological News, Vol. IV, p. 299.) LIFE. HISTORY. The egg.—The egg, including the pedicel or clasping base, is 1 mm. long and 0.2 mm. wide at the greatest diameter. In color it is dull yellowish white, and the surface is smooth and shining. As may be seen by the illustrations (fig. 43, a, D, ¢, d, the egg consists of two distinct parts, viz., the egg proper and the clasping base, which firmly secures it to the hair and connects with the egg proper by a thin but rather wide pedicel. This base is made up of two lips or valves, which close over the hair DIPTERA. — 99 and thus give a very secure attachment. The egg is narrow, ovoid, broadest at its middle, and larger at the base than at the tip, which is more or less abruptly and obliquely truncate (fig. 43d). The striking results of the researches of Dr. Curtice, which showed that the larve are taken into the mouths of the animals and pass by way of the cesophagus to the subcutaneous tissue along the back, have already been mentioned, and it now remains to give in detail the stages of the larva during this strange career. The time occupied by the larva is sometimes quite long, occupying several months in reaching the skin, while the development after reaching this location is more rapid. va Sept ch ie yese° Ea enter tT ft RS See oe ett ietee a Fic. 43.—Hypoderma lineata: a, eggs attached to hair; b, ¢, d, dorsal, ventral, and lateral view of egg; e, embryonic or first larva, as seen in the egg; /, g, mouth-parts of same—enlarged; fh, anal seg- ments of same—still more enlarged (from Insect Life). The larva, first stage.—This stage (fig. 43,e) when ready to leave the egg, or when first hatched, is 0.08 mm. long by 0.02 mm. in width, tapering above. Within the egg it fills the cavity and may be seen through the shell and quite readily removed. It is dull white in color, with the surface from the second to the twelfth joints dis- tinctly and densely spinose. The armed area occupies the entire surface of these joints, except a narrow lateral free space. The arrangement of the spines on these joints, except the last, is uniform, with perhaps a slight increase in the size of the spines from the second to the eleventh joint. The armature of these joints and of the anterior half of the twelfth consists of a rather prominent and posteriorly directed row on the anterior margin of each joint, followed by numerous smaller prickles, which decrease in size and abundance toward the posterior margin of the joint. The posterior half of the terminal joint is armed with very much larger and slightly curved prickles or spines, which point posteriorly on one side and anteriorly on the other(see fig. 43,h). Theanal spiracles are represented by dark cireular spots, and terminate in two prominent spines. The anterior spiracles appear as two minute elevations, and the mouth parts consist of two dark crescent-shaped hooks, the upper extremity of which projects, and two long supporting rods which fureate basally, and on the tips of which the hooks articulate (fig. 43, f, g). 100 INSECTS AFFECTING DOMESTIC ANIMALS. Second stage.—In the absence of any knowledge of an intermediate form, the larva found in the esophagus may be considered as the second stage (fig. 44). The indi- viduals vary in length from 11 to 1£ mm. and are quite smooth and devoid of prickles, except some minute ones, which appear like black specks partly : surrounding the anal spiracles (fig. 44, d) and a few extremely a minute ones just above the mouth parts (fig. 44, ¢). The former, 4 or those around the anal spiracles, are of peculiar structure, and consist of a circular, brownish-black, slightly elevated base, in the center of which arises a short, stout, posteriorly curved very minute spine, less than one-half the diameter of the base in length. The mouth parts are more prominent than in the first stage, and the apical portion is broadened and fur- cate near the base (fig. 44, b, c). This stage does not differ in any essential way from the stage first found under the skin in the back before the perforation to the surface 1s made. (See fig. 45, a, b, c.) Fic. 44.— Hypoderma Third stage.—In this stage, which is the second form of the lineata: Secondstage larva found in the back (fig. 45, d, e, f), the larva again diverges of larva from cso- markedly from the second or preceding stage and acquires many phagus; a, larva; b, of the characteristics of the mature larva. It tapers, however, eee aes considerable toward the posterior extremity, rather than the Herne Satine reverse, and the spinous armature varies considerably in differ- d, enlargedend view ent specimens, but ventrally is similar to that of the adult, the of anal segment, spines being, however, morenumerous and less prominent. ‘The showing spiracles Jateral armature is sometimes almost wanting, but occasionally and spines (from In- : : Seob Lite). occurs to the amount shown in the figure (fig. 45, d). The dor- sal armature is much more scanty, and is either limited to the first and second joints or frequently entirely wanting. Fourth stage.-—The fourth and last larval stage is shown with characteristic arma- ture at, fig. 45 g, i, dorsal and lateral views. Its chief difference from the larva of bovis (as shown in the diagram) is that the penultimate segment ventrally and also Sp RoR ROYER Nm cee *t O86 a cael ae mele i SRSA res NEE Fia. 45.— Hypoderma lineata: a, second stage of larva from back; b and ¢, enlargement of extremi- ties; d, ventral view of third stage, with details of extremities at e and /; g, dorsal view of mature larva, with enlargement of anal spiracles at h; 7 ditto, lateral view—natural size indicated by side lines (from Insect Life). dorsally is spinose, as the preceding ones on the posterior margin, while in bovis it is distinctly unarmed. The full-grown larva when escaping from the back is of a gray- ish-white color and ranges in length from 22 to 25 mm. DIPTERA. 101 Puparium.—Once out of the back the larva rapidly darkens and contracts, and the puparium, which is merely the contracted and hardened larva, becomes dark brown, almost black, but otherwise possesses all the characteristics of the larva. Imago (Fig. 47).—Length, one-half inch (five-eighths with ovipositor extended) ; : general color, black; body more or less clothed with yellowish-white, reddish, and | brownish-black hairs. The front, sides, and back of the head, the sides of the thorax, is — oo Aa nn f-& me b&w Fia. 46.—Hypoderma lineata: diagram of spiny armature. a band across the base of the scutellum, and the basal segment of the abdomen are covered with long yellowish-white, almost white, hairs. The head above, central thoracic region, including prothorax and mesothorax, middle segments of the abdo- men above, and legs, clothed with brownish-black hairs, which on the head and thorax ure more or less intermixed with whitish hairs. The covering of hairs is shorter and Fia. 47.— Hypoderma lineata: female—natural size indicated by side line (from Insect Life). scantier on the head and thorax, and the tip of the scutellum and following parts of the thorax, together with four prominent lines on the thorax, indicated in the draw- ing by the high light, are smooth and highly polished. The hairs of the terminal seg- ments of the abdomen are reddish-orange, which color also predominates on the hind tibix. a ES 102 INSECTS AFFECTING DOMESTIC ANIMALS. THE SHEEP BOT-FLY OR HEAD MaceorT.! (@strus ovis Linn.) This insect, like the other members of the family, has been known for centuries, and has been equally dreaded by the animals it infests. It was mentioned by the Greek physician, Alexander Trallian, as far back as the year 560. Notwithstanding that it has been so well known, very different estimates have been placed upon the injury it may cause. Indeed, some writers have gone so far as to claim that no injury results from its presence, and to ridicule the idea that sheep die of “ grub in the head.” Even so high an authority as Mr. Youatt declares: It is incompatible with the wisdom and goodness that are everywhere evident, in proportion as the phenomena of nature are closely examined, that the destined resi- dence of the @strus ovis should be productive of continued inconvenience or disease. Mr. Randall is correct in saying that “ this is as farfetched as a con- clusion as the reasoning on which it is founded.” If the grub in the head is not productive of inconvenience or disease, whence the suffer- ing condition, the loss of appetite, the slow, weak gait, the frequent coughing, the purulent matter, sometimes so profusely secreted as at times to almost prevent the animals breathing? Whence the tossing and lowering of the head, and the fits of frenzy to which so naturally quiet and gentle an animal as the sheep is subject? All these symptoms result from grub in the head, and the animal frequently gets too weak to rise, and finally dies. These effects of the grub were well recognized and understood by such old writers and close observers as Réaumur and Kollar, while numerous flock masters of close observation who have suffered from this pest agree in ascribing these symptoms to this cause. It would be as reasonable to believe that those parasites are beneficial which are so injurious to man either internally or externally, or those which prey upon our caterpillars and other insects, and invariably destroy them. For although when there are but few grubs in the head the injury may not be perceptible, they can never be beneficial, and when numerous will undoubtedly cause death. They can notlive in the head of the sheep without causing great irritation by the spines with which the ventral region is covered and the hooks with which they cling to such a sensitive membrane as that which lines the sinuses. Moreover, when numerous enough to absorb more mucus than the sheep secretes the grubs will feed on the membrane itself, and (according to the evidence of some practical sheepmen) will even enter the brain through the natural perforations of the ethmoid bone, through which pass the olfactory nerves, in either of which cases they must cause the most excruciating pain. The natural fear also which the sheep have of the fly and the pains they take to preventits access to the nose are of themselves proof that itis obnoxious to them. The pest appears to have been more abun- - 1 Adapted in part from Riley’s Mo. Rep. I, pp. 161-165. iT DIPTERA. (103 dant in the Mississipp1 Valley than in the Eastern States, at times grubs being found in the head of almost every sheep that died. While it is possible that the disease produced by this insect may be confused with the “ gid” or ‘“‘ staggers ” produced by an entozoan parasite, the Tenia cenurus, it is doubtiess true that many cases of death from these bots are assigned to other causes. And,on the other hand, undoubtedly many other diseases are cloaked by the popular verdict of ‘** grub in the head.” The flies which are represented in figure 48, 1 and 2, life size, make their appearance in June and July, and deposit living maggots in the nostrils of the sheep. This point may be considered as well established by competent observers, although the older authorities all speak of the deposition of anegg. It may be possible, however, that eggs are deposited in cases where the flies are particularly fortunate in finding their victim with- out delay, but in such cases the eggs doubtless hatch almost im- mediately after deposition. The larve at once commence to work their way up the nostrils and nasal passages, causing great irritation on their way until they reach the frontal sinuses, cavities located be- tween the two plates of the skull and lying one on each side of the central line of the head and be- tween and a little above the eyes. There they attach themselves by Fie. 48.—@strus ovis: 1 and 2. Adult fly. 3. the little hooks or tentacula, placed papa. 4. Full-grown larva, dorsal view. 5. each side of the head, to the mem- _— Same, ventral view. 6. Young larva. 1 and 2 : . 1 natural size, the others enlarged (from Riley). | branes which line the cavities, feeding on the mucus which is always to be found in them. Until they attain their growth they are of a creamy white color with two brown spots placed side by side on the posterior segment. ‘These spots (fig. 48,6,¢) are spiracles or stigmata, through which the worm breathes. The segment with these two spiracles is retractile, and can be drawn in and hidden at the worm’s pleasure. When full grown the grub ) becomes darker, particularly toward the tail, the white of the first two ) or three segments becoming dirty white on the fourth or fifth, and growing darker on each successive segment until the last, which is a very dark brown. (See 4 and 5 of fig. 48.) It has two small parallel hooks or tentacula at the head (a), and above these two very small tubercles, not very easily shown in the engraving. It also has small brown elevated round spots on each of the segments along the sides, which might at first be taken for spiracles, but which are not, and also two small corneous appendages (5, b, and 6, ¢ of fig. 48) on each side of the anus. The ventral region has a band of small elevated ee 104 INSECTS AFFECTING DOMESTIC ANIMALS. dots running the breadth of each segment in their middle, whick, under the magnifier, appear to be minute brown spines all pointing posteriorly (fig. 48,5). These aid the maggot in its movements. When ready to contract into a pupa it passes down the nasal passages of the sheep and falls to the ground, where it quickly buries itself, and in about forty-eight hours contracts to half its former size, and becomes smooth and hard and of a black color, tapering, as in the larve, toward the head. It remains in this state from forty to fifty days or more, according to the weather, when the fly pushes open a little round ecap- piece at the head and thus arrives at maturity. In this stage it looks something like an overgrown house fly. The ground color of the upper part of the head and thorax is dull yellow, but they are so covered with little round spots and atoms (searcely distinguishable without the aid of a magnifier) that they have a brown appearance. The abdomen con- sists of five rings, is velvety and variegated with dark brown and straw color. On the under side it is of the same color, but not variegated in the same way, there being a dark spot in the middle of eachring. The feet are brown, the under side of the head is puffed out and white. The antenne are extremely small and spring from two lobes which are sunk into a cavity at the anterior and under part of the head. The eyes are purplish brown, and three small eyelets are distinctly visible on the top of the head. It has no mouth and can not, therefore, take any nourishment. The wings are transparent and extend beyond the body, and the winglets (calypteres), which are quite large and white, cover entirely the poisers. Its only instinct seems to be the continua- tion of its kind. It is quite lazy, and except when attempting to deposit its eggs its wings are seldom used. PREVENTION AND REMEDY. To prevent it from depositing its young, different means are resorted to. Mr. Randall says ‘‘some farmers turn up the soil in portions of pasture so that the sheep may thrust their noses into the soft ground on the approach of the fly, while others smear their noses with tar or cause them to do so themselves.” But as the fly is very persevering, and generally attains her object, the means to be most depended on is the dislodging of the larve or grub, and so far lime has been thought the most effectual and should be given them so that by sniffing it they . may be made to sneeze, and thus dislodge the grub in many cases. Some Sheep keepers even shut their sheep up for several nights in a tight barn when first taken up in the fall, believing that the close and heated atmosphere induces the grub to descend, and is therefore more easily dislodged, and that the injury accruing from such foul air is trifling compared to the benefit received from dislodging the grubs. Other sheep breeders are in the habit of fixing salt logs in their pas- tures, of sufficient length to enable all the sheep to get at them. Into these logs, at intervals of 5 or 6 inches, holes are bored with a 2-inch DIPTERA. 105 auger, and during the season a little salt is kept in these holes, while every few days a little tar is smeared around them with a brush. The sheep in obtaining the salt tar their noses and the odor of the tar keeps the fly away. In severe cases, where the grubs are already in the head, they may be dislodged in a measure by a feather dipped in turpentine, which should be run up the nose and quickly turned. This, of course, can be but partially effective, as it is difficult to reach the extremity of the tortuous canals, and it is in such localities that they must cause greatest difficulties. For the same reason and on account of the great pain caused the animal the use of a wire to remove the larvee as recommended by some should be discountenanced entirely. The burning of sulphur or other destructive substances in a closed room is likely to kill the sheep before reaching the larve in their retreats. In would be interesting, however, to determine what effect pyrethrum would have upon them. Valuable animals may be treated by trephining, to remove the grubs from the sinuses—an operation that should be performed by a veterinarian or skilled operator. THE REINDEER Bor. (G@demagena tarandi Linn.) This species is recorded as a parasite of the reindeer in Europe and North America and is doubtless of no little economic importance where this animal is an essential domestic species. Its habits are similar to those of Hypoderma, and it is recorded that the presence of the para- sites is a source of great annoyance to their hosts. No observations have been made, so far as I know, to determine the manner of intro- duction, but there would seem to be the same probability of their introduction by the mouth as exists for the species of Hypoderma. DEER Bogs. Species of bots are recorded from deer, elk, and antelopes, the flies being included in the genus Cephenomyia. Two species of this genus are credited to America, but it is probable that careful collecting from these animals would increase the number. THE EMASCULATING BOT-FLY. (Cuterebra emasculator Fitch.) In the supplement to his third report as State entomologist of New York Dr. Fitch presents the history of a bot-fly which is of remarkable interest, and though it does not affect any domesticated animal (except as Squirrels may be kept as pets), the subject is of such interest that we can not pass it unnoticed in this connection. It would be interest- ing to reproduce Dr. Fitch’s notes entire, but they are too lengthy for anything but a brief synopsis. 106 INSECTS AFFECTING DOMESTIC ANIMALS. He reared the fly from which his description is made from a larva obtained from the striped squirrel or chipmunk (Tamias striatus lysteri). The larva occurred in the scrotum, causing it to become unnaturally enlarged, and when found lay with tail end next a small opening ‘“Jarger than the head of a large pin, the testicles being entirely con- sumed.” This larva buried itself August 13, 1856, and issued as fly July 29, 1857. So far as we know, this is the only adult of the species which has ever been reared. Some notes upon the species were published by Riley and Howard in Insect Life (Vol. I, p. 214), with figures of the larva, a few paragraphs of which we reproduce here, with the figures. Fie. 49.—Cuterebra emasculator: a, full-grown larva from above; b, same, from below—enlarged; ec, head of same; d, anal end of same; ¢, portion of integument of same—still more enlarged (from Insect Life). Dr. Fitch published a painstaking description of the different stages and gave the species the name of Cuterebra emasculator from the larval habit which he supposed characteristic. He mentions the fact that hunters in the vicinity of Lakeville, N. Y., where the first specimen sent him was found, had long been familiar with the fact that at least one-half of the male gray squirrels shot in that vicinity were found to be castrated, and that it was the opinion of hunters that the deformity was caused by the squirrels seizing and biting out the testicles of their comrades. In support of this idea he gives the testimony of Mr. Hurst, taxidermist of the New York State Cabinet of Natural History, who ciaimed to have seen a half dozen red squirrels unite in mastering a gray one and castrating him. Dr. Fitch queries whether the bot-fly may not be attracted by the wounds so made, if this habit prove common, but concludes that the object of the joint attack of several upon one is rather to kill the grub which is engaged in emasculating him, we . . DIPTERA. 107 Unfortunately there is yet some doubt as to whether Fitch’s species will hold. Brauer, in his Monograph of the (stride, page 232, quotes Fitch’s description at length, and states that he can not separate the species from Cuterebra scutellaris Loew, a North American species, the habits of which do not seem to be known. If this interesting insect has not attracted much attention of late years from entomologists, it has not failed to be noticed by zoologists and taxidermists, although we are not aware that observations have been published, The following statement was written at our request by Dr. Merriam, the ornithologist of the Department, as we had learned by conversation that he had made notes some years ago on the abun- dance of the insect in New York State: “In reply to your inquiry concerning the occurrence of Cuterebr in squirrels, I would state that during many years collecting in the Adirondack region of northern New York, particularly along its western border, in the Black River Valley, I fre- quently found Cuterebre in or near the scrotum in the gray squirrel (Sciurus carolin- ensis leucotis), red squirrel (Sciurus hudsonius), and chipmunk ( Tamias striatus lysteri). I have observed the same thing at East Hampton, Mass., and in other localities. The most extraordinary instance of the prevalence of this disgusting parasite that has fallen under my observation was at the south end of Lake Champlain, New York, in October, 1885. On the 7th and 9th of that month I killed more than fifty chipmunks (Tamias striatus lysteri) within a few miles of old Fort Ticonderoga and on the rocky side hill behind the town of Whitehall. Of these a very large percent- age—I think fully one-half—were infested with ‘‘wabbles” (Cuterebr). More females than males were thus afflicted. The ‘‘ wabbles” were usually situated near the median line, and anywhere from the umbilical region to the genitals. In a few cases they were in the axilla, and in one or two instances in the upper part of the foreleg. In a number of individuals two Cuterebre were found and in a few cases as many as three. “Dr. A. K. Fisher tells me that he collected a number of chipmunks about the south end of Lake George, Warren County, N. Y., during the latter part of August and first of September, 1882, a considerable proportion of which were infested with Cuterebrie. As many as three were found, in different stages of development, in one animal, A gray squirrel killed at Sing Sing, Westchester County, N. Y., con- tained a Cuterebra in the left pectoral region.” It is very possible that the larve of more than one species of the genus Cuterebra were concerned in the cases noticed by Drs. Merriam and Fisher, but this point can not be decided at the present time. * * * Concerning the capture of the specimen, which was from a female chipmunk, Mr. Starkweather wrote, October i9, 1888: “About noon on the 13th my children’s pet kitten came in from the grove near our house, in the Rock Creek region, with a ‘chippy’ in its mouth. They rescued it at once, but, although warm, life was extinct. The strange appendage, or abnor- mal growth which they noticed on the under side, caused them to lay it away care- fully in an empty covered cigar box ‘to show papa.’ ‘“‘My attention was called to it twenty-four hours later, when the dark-colored maggot was found in one corner of the box nearly motionless. They described the ‘swelling’ as about an inch long and of the shape of a mulberry. ‘There seemed to be a natural opening at its apex over a sixteenth of an inch in diameter with a tinge of a dark liquid about it.” Subsequent inquiry has revealed the fact that squirrel hunters in this vicinity report that these grubs are very abundant around Washington in the common gray squirrel, one gentleman, with that freedom from fact-bias characteristic of the amateur hunter, stating that he never shot a squirrel which was not infested by grubs. We will doubtless, therefore, have opportunities for rearing the adult and comparing it with Loew’s scutellaris. The larva has already been well described by Fitch, and our figures will illustrate its appearance. The specimen from which they were drawn was evidently full- grown, and has entered the earth in a breeding jar. 108 INSECTS AFFECTING DOMESTIC ANIMALS. It will be noted that all the cases so far cited show the larve to be mature in the latter part of summer or in fall, and in the specimen reared by Dr. Fitch pupation lasted through the winter and until the follow- ing July, which is quite different from the period of pupation in most of the bot-flies, ordinarily the pupa stage lasting but a few weeks and the winter being passed in the larval stage in the bodies of the host ani- mal. It 1s hardly to be supposed that eggs laid by an adult the last of July could mature by the middle of August, so we must infer more than one year as necessary to the life cycle of the insect, in some cases at least. July 31, 1885, Mr. George K. Cher- Fic. eee ore eg ee line rie, then a student in the Iowa A gri- Ree ee eae Pee cultural College, took two larve from the scrotum of a chipmunk, the testicles being entirely consumed. These he placed in alcohol, and the specimens now in hand correspond perfectly with the description of larva given by Dr. Fitch, except that Dr. Fitch states that the head end presents no appearance of jaws or other appendages, while in these spec- imens the hook-like appendages are distinct. Thesemight beso retracted, however, as to be inconspicuous and easily overlooked. The figures here presented (fig. 49) were drawn from specimens received through the kindness of Mr. George B. Starkweather. The details con- cerning their capture, etc., we repro- duce (see p. 107) from Insect Life - Fie. 51.—Cuterebra cuniculi: side view T 9 (Vol. II, p. 216). (ena, If it is allowable to detail a life eycle from the records at hand it would seem that full-grown larve are found from the 1st of August until in October, and that within this time, probably, they escape from the host and burrow in the earth to pupate, remaining in the pupa stage until July of the following year, eggs then deposited requiring at least one full year for the growth of the larvee, and the life cycle being completed in not less than two full years. . THE RABBIT BOT-FLY. (Cuterebra cuniculi Clark.) Rabbits are infested with a very large bot, which attracted attention a century ago, the fly being named Gstrus cuniculi by Clark, and later, 2 ki : DIPTERA. 109 in the Essay, 1815, referred to the genus Cuterebra, while at the same time he described another form as horripilum. The adults of these two forms are so nearly alike that Brauer believes them to be the same, the cuniculi being described from a ; slightly denuded specimen. Without b attempting to settle this question, we e may proceed on the supposition that Hi there is but one species and then ' call attention to the specimens which : have exact correspondence with the q description of horripilum. The adult is a large fly, almost as large and having some resemblance to a bumblebee. The head is black, the thorax above covered with a yellow-brown hair, the first segment of the abdomen with yellow hair, and a * pe Fic. 52.—Cuterebra cuniculi: a, larva, ventral aspect; b, pupa, lateral view; ¢, anterior ex- the rest of the abdomen of a blue- tremity; d, hooks and anterior spiracles of black eolor. larva—all enlarged (original). The egg and early stages of larva are unknown, but the full-grown larva is a large, black, spiny creature, found under the skin of the rabbit, where it forms a large tumor. Fic. 53.—Cuterebra horripilum: adult—natural size (original). The Department records show these larvze to have been collected at Oracle and Florence, Arizona; Tuscola, Fla.; Savannah, Ga.; Riy- Fia. 54.—Outerebra larva, collected at Ames: a, ventral; }, lateral; c, dorsal aspect (original). erside, Cal., and Estes Park, Colo., while specimens from St. George, Fla., referred doubtfully to this species, were taken from the necks of rats. 110 INSECTS AFFECTING DOMESTIC ANIMALS. In the accompanying figures, 50 and 51, from specimens belonging to the National Museum, the adult is shown in dorsal and side view, while figure 53 represents a specimen captured at Ames, Iowa, and which agrees perfectly with the form described as horripilum. The points of difference will be noted as pertaining to the fullness of the head in front of the eyes and in the form of the abdomen. The larva shown in figure 52 is from a partially contracted specimen, which probably accounts for the difference between them and the fuller specimens shown in figure 54. The latter figures are from specimens collected by Mr. George K. Cherrie from the common rabbit at Ames, lowa. ' While the material at hand so far favors the belief that we have here but one species, it is desirable that a larger number of both larve and adults should be examined, and especially that more specimens be bred in order to establish beyond doubt the connection between certain forms of larve and the adults. THE COTTON-TAIL Bot. (Cuterebra fontinella Clark.) This species was originally described by Clark from specimens taken in Illinois, but it remained practically unknown until the descriptions by Townsend in Insect Life (Vol. V, pp. 317-320). It is a large species, the flies being four-fifths of an inch and larve an inch in length. (See the full description by Townsend already noted.) OTHER SPECIES. Cuterebra buccata Fab. is another species that has been recorded at various times in this country (Kentucky, Pennsylvania, Carolina, Mas- sachusetts, Washington, D. C.) and is doubtless a fairly common para- site of squirrels and possibly other small mammals. Aside from these that have been mentioned there are a number of species in the genus Cuterebra from Ainerica which are known only in the adult stage, and to discuss them here would not only too greatly extend the paper, but would be of little value, since for monographic purposes the student will naturally refer to the works of Clark and Brauer. Bot-FLY OF MAN, MONKEYS, DOGs, ETC. (@strus hominis L.) The question whether there is a bot-fly peculiar to the human species has been much discussed, but the burden of evidence at present avail- able leads to the view that the species occasionally infesting man occurs also on dogs, monkeys, etc., and we therefore consider the Species under the above heading. DIPTERA. 111 The first record that can be considered as referring to this form is the description of Linnzus, Systema Natura, and which in Turton’s translation, 1802 (Vol. III, p. 583), reads as follows: Hominis.—Body entirely brown Inhabits South America. Linnéap. Pall. Norl. Beytr., p. 157. Deposits its eggs under the skin on the bellies of the natives; the larva, if disturbed, penetrates deeper and produces an ulcer, which frequently becomes fatal. Subsequent authors failed to verify Linnzus’s account and concluded it was a myth, though Clark (Rees, Cyclopedia, article Bots), while considering it probably a spurious species, attempts to account for the record by saying that it is “perhaps merely an accidental deposit of Wstrus bovis in the human body, of which there are numerous instances.” Fabricius ignored itentirely inthe Systema Antliatorum, and Latreille considers that the larve referred to were those of Musca carnaria or some analagous species. Say, however, in 1822 described specimens which he had received from South America, and gives quite a detailed account of the habits as detailed by Dr. Harlan, who sent the specimens. (Jour. Acad. Nat. Sci. Phil., Vol. II, pp. 355-360; Complete Writings, Vol. II, pp. 52-38.) To the account published in Say’s Writings Dr. LeConte adds a description of his own experience witk the insect and states that it is supposed to be the Dermatobia noxialis of Goudot. Previous to this Keferstein (Uber @strus hominis, Verh. Zool.-Botan. Gessells. in Wien, 1856, p. 637) had collected all the known facts regard- ing the bots infesting the human body, and Coquerel in 1859 had described larvee taken from the human body in Cayenne, Mexico, and New Orleans (Revue et Magas. Zool., sér. 1859, T. 11, pp. 356-361), and with Sallé (361-367) and Laboulbéne in 1861 a similar larva from Cayenne. Other authors mentioning it are Hill (N. T.), account of the larva of a supposed (strus hominis or gad-fly, which deposits its eggs in the bodies of the human species (Edinb. new Phil. Jour., 1830, pp. 284-288; Isis, p. 917, 1832), and Goudot (Observations sur un diptere exotique dont la larve nuit aux beeufs. Cuterebra noxialis. Ann. Sci. Nat., ser. 3, 1845, T. 3, pp. 221-230. Extr. Ann. Soc. Ent. Fr., ser. 2, 1844, T. 2, Bull., pp. 40-42.) Brief mention is made of this species in the American Entomologist (Vol. I, p. 86) under the name of (strus hominis Gmelin, and in Pack- ard’s Guide (p. 406) occurs the tollowing condensed paragraph on the subject accompanied by figures: The genus Dermatobia includes the Ver macaque, of Cayenne and Mexico, found beneath the skin of man in tropical America, and it is disputed whether it be a true indigenous ‘ @strus hominis” or originally attacks the monkey, dog, or other ani- mal. In Cayenne the species attacking man is called the Ver Macaque; in Brazil, (Para) Ura; in Costa Rica, Torcel ; in New Grenada, Gusano peludo or Muche. The D, noxialis Goudot? Ver moyocuil lives on the dog and is found in Mexico and New Grenada. The larve are long, cylindrical, S-shaped, differing greatly from others of this family in form. ‘Ihe flies are closely allied to those of the preceding genus, Se, INSECTS AFFECTING DOMESTIC ANIMALS. Professor Verrill (Ext. and Int. Parasites Dom. Animals, p. 24) men- tions Dermatobia noxialis as laying eggs in the backs of sheep and cattle, and that ‘it also attacks men in the same way, forming painful tumors beneath the skin. The same or a similar species also affects the dogs in tropical America.” In a note appended to Professor Verrill’s report there is a record of the occurrence of what is conjectured to be larve of the same insect, taken from a young woman in Mississippi. And, quite recently, in an interesting article by Dr. Matas, published in Insect Life (Vol. I, pp. 76 and 80), we have an account of the extrac- tion of three parasites from a man who was oviposited in while bathing during a trip in Spanish Honduras. The account agrees in all partic- , Py : son re . Fs CBE n uy ne Fia. 55.— Dermatobia noxialis: larva; a, ventral aspect and appearance of tephalic and caudal extrem- ities, also the three rows of spines, single below, and the point where the double dorsal rows end; b, dorsal view shows that the three rows of spines single below are double above—greatly enlarged (from Insect Life.) ulars with previous accounts of infection from this pest and emphasizes the fact of its injurious nature. We do not wish to attempt here a solution of the mixed synonomy of this species, or ake any dogmatic assertions as to the accounts, all referring to one and the same insect. That should be demonstrated by the rearing of flies in the region where bots abound. It may be said in passing, however, that when occurring in man the larva must in the great majority of cases be killed before maturing, and hence the multi- plication of the species be accomplished by the infection of some of the lower animals. Treating the accounts in a body, there is certainly no doubt as to the injurious nature of the pest, for, while most reports are devoted natu- rally to presenting its injuries to man as of greatest interest, enough is said to prove that dogs and other animals are greatly troubled by them. AAP MERRY ome - >» ct etearg a . you DIPTERA. 113 Upon man, all accounts, except that of Dr. LeConte, represent them as Serious annoyances and some of them as fatal. Dr. LeConte says in the infested natives they seemed to produce but little uneasiness, and that the parties were not aware of the time when the eggs were depos- ited. Headmits that “they produce a swelling having the appearance of an ordinary boil, in which at times is felt for a few seconds an acute pain when the worm moves.” Apparently no one has as yet obtained the adult fly from larve infest- ing man, either by rearing them from larvee extracted or escaping from beneath the skin or by capturing them when depositing eggs. Lin- neus’s description refers to the larva. In many accounts there is no reference to a distinct sting at the time of egg deposition, this being determined by subsequent location and development of tumors; but Dr. LeConte, already cited, remarks espe- cially upon the victims not being aware when the eggs were laid, and this might give color to the existence of more than one species. Fia. 56.—a, Braner’s figure of entire Dermatobia larva, supposed to be closely allied to specimens shown in fig. 55; b, cephalic extremity; c, caudal extremity of same specimen; d, Dermatobia larva figured by Coquerel, and closely related to, if not identical with, preceding. only seen under lower power and perhaps in earlier period of development—enlarged (from Insect Life). It appears quite certain that in some cases at least the eggs are so fastened to the skin that the deposition is attended with pain. The larve evidently hatch very soon after and develop with consid- erable rapidity, but since in all recorded cases the larva has been extracted before maturity nothing is known of 1ts pupation. The form is quite peculiar and renders the accounts at least all referable to one genus of Cistride. We reproduce from Insect Life the figures presented in the paper by Dr. Matas. The usual remedy consists in the forcible expulsion of the larva, sometimes assisted by incisions, the application of tobacco ashes, ete. In a recent paper Blanchard! gives an extended account of the - 1R. Blanchard, Sur les (strides américaines dont la larve vit dans la peau de Vhomme. Annales de la Société entomol. de France, Vol. LXI, p. 109, 1892, 4653—No, 5 8 114 INSECTS AFFECTING DOMESTIC ANIMALS. species affecting man, and refers to two species, Dermatobia noxialis and D. cyaniventris, the species common throughout tropical America. In the former the second and third segments are provided with fine spines, while in the latter these segments are smooth; and in the former, also, the posterior border of segments 4 10 7 are without a range of hooks dorsally, while cyaniventris has these segments and also the eighth, sometimes, with a row of crooked hooks pointing forward on the pos- terior border dorsally. Railliet speaks of these bots as at times a veritable scourge to cattle, aside from their attacks on man and dogs. Family MUSCID2. (House Flies and Allies.) These are robust-bodied, usually hairy flies, the larvee of which are fleshy. footless maggots, living in decaying matter, ordure, etc. THE HorRN FLY. a (Hematobia serrata Rob.-Desy.) In the introduction and rapid spread of this insect we have an excel- lent illustration of the importance of giving attention to the injurious insects of other countries and of taking all possible means to prevent their importation. ; Fig. 57.— Hematobia serrata: a, egg; b, larva; c, puparium; d, adult in biting position—all enlarged (from Riley and Howard). The species in hand has been a common insect in Europe, and with other members of the same genus recognized as a troublesome insect, though apparently no careful study of its life history has been made there. a a ae IPTERA. 115 It was first noticed as troublesome to cattle in this country in 1887, and while we can not say with certainty just when it was introduced we may be pretty sure that it was during the year 1886, or at most not earlier than 1885, It is even possible that it may have been brought over in the spring of 1887, as its powers of reproduction are such that a few weeks would suffice to make it a conspicuous pest in a limited area. Within two years from the time when it was first recognized in seri- ous numbers it had become so numerous and had spread over so large a region that it was made the subject of a very careful and successful study by Messrs. Howard and Marlatt of the Division of Entomology. The results of these investigations were published in Insect Life (Vol. IJ, p. 93) and in the Annual Report of the Commissioner of Agricul- ture for 1889. It was also made a subject of study at the New Jersey Experiment Station, and Professor Smith’s report in Bulletin 62 of that station gives the results of the season’s observations and trials of remedies. Since these papers appeared the insect has spread over practically all of the United States east of the Rocky Mountains, and also into a large por- tion of Canada, and numerous articles have appeared in the bulletins of experiment stations and in agricultural journals with reference to it, the greater portion of them being based on the original studies above mentioned. INTRODUCTION AND SPREAD IN AMERICA. All accounts agree in placing the first serious occurrence of this insect in the vicinity of Philadelphia, and it appears probable that it was at that port that the flies first landed. From there as a center it spread in all directions, though at first mainly southward, and by 1889 it had covered most of the State of New Jersey, portions of eastern Pennsylvania, a considerable area in Maryland, and also a portion of northern Virginia. In 1891 it had been reported from New York, Ohio, Kentucky, Georgia, Florida, and Mississippi, and in 1892 from Connecticut, Massachusetts, Canada, Michigan, Indiana, Lowa, Louisiana, and Texas. More recent records refer more particularly to its increase and local distribution in the various States, but it may be said to occupy now practically all of the United States east of the Rocky Mountains and the Provinces of Ontario and Quebee in Canada. NATURE AND EXTENT OF INJURY. As with most new pests, the nature and amount of damage caused by the insect was the subject of much exaggeration and wild specula- tion. As usual in such cases extreme views were taken, both of which wereerroneous, Those who asserted that no damage whatever resulted 116 INSECTS AFFECTING DOMESTIC ANIMALS. from its presence were soon proven to be wide of the truth, while the exaggerated tales of death to animals, the destruction of horns, and many other wild statements were easily recognized as imaginative. That the loss from their presence is very considerable is recognized by most practical stock breeders who have everyday association with the affected animals, the loss showing in reduced vitality, lack of growth, or in loss of milk. Mr Fletcher, the entomologist of the Dominion of Canada, estimated the loss in Ontario and Quebec at one-half the product. The loss is the direct result of the irritation to cattle, which keeps them in a perpetual worry and interferes with their feeding and with the normal digestion of food, and to some extent from the loss of blood, which, when the flies occur by the thousands on a single animal, is an item not to be ignored. When at rest upon the horns, at which time they are most conspicuous, they are in reality the least harmful, as they then cause neither irritation nor loss of blood. The larvee are of course entirely harmless and it is only the adults that affect the animals. Injury to other animals than cattle seems to be very slight, and while a number of records have been given of the insect occurring upon horses these seem to be exceptional. POPULAR NAMES AND POPULAR ERRORS. Upon this subject Riley and Howard say: The popular name which is here adopted—the ‘‘horn-fly”—has the sanction of popular use. It is sufficiently distinctive, and we therefore recommend its adoption. The name of ‘Texas fly” and ‘‘ buffalo-fly ” and ‘‘ buffalo-gnat” are also in use in some sections and indicate an impression that the insect came from the West. Dr. Lintner uscs the term ‘‘cow-horn fly.” Objections may be urged to all of these. The most prominent of the popular errors is the belief that the fly damages the horn, eats into its substance, causes it to rot, and even lays eggs in it which hatch into maggots and may penetrate to the brain. There is no foundation for these beliefs. As we shall show later, the flies congregate on the bases of the horns only to rest where they are not liable to be disturbed. While they are there they are always found in the characteristic resting position, as shown in fig. 60, and described later. Where they have been clustering thickly on the horns, the latter become ‘“flyspecked”’ and appear at a little distance as though they might be damaged, and it is doubtless this fact which has given rise to the erroneous opinions cited. HABITS AND LIFE HISTORY. The adults of the horn-fly are about half as large as the common house fly and very much like it in shape and color. The accompanying figures will serve to distinguish it, while the following technical descrip- tion by Dr. Williston should be used for the exact discrimination of the species: Male.—Length, 3.5 to4 mm. Sides of the front gently concave, its least width equal to one-fourth of the distance from the foremost ocellus to the base of the antenne; in the middle a narrow dark-brown stripe; a single row of slender gt Bhi, ? ~ 2, LRT Near ea oi 2 jetacdpiae. Se ate woe Anee DIPTERA. a i bristles on each side. Antennzw brownish red; second joint slightly tumid; third joint a little longer than broad, with its inferior angle rectangular; arista swollen at the base (which is black), the pectination long. The narrow sides of the front and the still narrower facial and genal orbits silvery gray, with a slightly yellow- ish cast; facial fovex and cheeks blackish, the latter clothed with yellowish hair. Palpi black, the inner surface and immediate base more yellowish; gently spatulate in shape, nearly as long as the proboscis and extending two- thirds of their length beyond the oral margin. Mesonotum sub- shining black in ground color, but mostly concealed beneath a brownish dust, which, on the pleure, is more grayish. Abdo- men with similar dust; in the middle with a brownish, more subinterrupted stripe and nar- row darker posterior margins to the segments. Femora black or very deep brown, first two pairs of tibiz and tarsi brownish yel- low or luteous, the hind tibize ‘ and tarsi blackish brown; hind > tibiz on the posterior surface with a noticeable, erect, subap- ical bristle; hind tarsi about as long as their tibiz, the first three joints widened from their base to tip, so as to form a distinct serration on their inner, acute angles, each of which terminates in a long hair. Wings with a light blackish tinge (due to microscopic pubescence), the imme- diate base yellowish, the first posterior cell rather symmetrically narrowed to terminate broadly at the extreme tip of the wing. Female.—Front straight on the sides, its width about equal to one-half of the dis- tance from the foremost ocellus to the base of the antenne; the median deep brown stripe about as wide as the pruinose sides. Palpi yellow, with the margins and tip blackish. Legs more yellowish; hind tarsi regular; pulvilli and claws small. Fic. 58.—Hematobia serrata: adult in resting position— enlarged (from Insect Life). The flies are observed in greatest number in July, but appear as early as May, and remain till cold weather, the full time depending upon the season or latitude. The characteristic habit of clustering about the base of the horn seems to exist only when the flies are quite abundant. When they average only a hundred or so to a single animal, comparatively few will be found on the horns. Moreover, as a gen- eral thing the horn-clustering habit seems to be more predominant earlier in the season than later, although the flies may seem to be nearly as numerous. The clus- tering upon the horns, although it has excited considerable alarm, is not productive of the slightest harm to the animal. Careful study of the insects in the field shows that they assume two characteristic positions, one while feeding and the other while resting. It is the resting position in which they are always found when upon the horns. In this position the wings are held nearly flat down the back, overlapping at base and diverging only moderately at tip. (See fig.58). The beak is held in a nearly horizontal position and the legs are not widely spread. In the active sucking posi- tion, however, the wings are slightly elevated and are held out from the body, not 118 INSECTS AFFECTING DOMESTIC ANIMALS. at right angles, but approaching it, approximately an angle of 60° from the abdomen. The legs are spread out widely, and the beak, inserted beneath the skin of the animal, is held in nearly a perpendicular position, approaching that in figure 59, c. The fly before inserting its beak has worked its way through close to the skin. While feeding, however, the hairs which can be seen over its body do not seem to interfere with its speedy flight when alarmed, for at a fling of the tail or an impa- tient turn of the head the flies instantly rise in a cloud for a foot or two, returning again as quickly and resuming their former positions. Fic. 59.—_Hematobia serrata: a, head of female, front view; b, head of male, front view; c, bead from side—all enlarged (from Insect Life). The horns are not their only resting places, for with the horns black for 2 inches above their base we have seen the flies toward nightfall settle in vast numbers upon the back between the head and foreshoulders, where they can be reached by neither tail or head. When feeding they are found over the back and flanks and on the legs. During a rain storm they flock beneath the belly. When the animal is lying down a favorite place of attack seems to be under the thigh and back belly, around the bag. With certain animals the dewlap seems to be badly attacked, while with others this portion of the body is about exempt. Certain cattle, again, will be covered with flies and will lose condition rapidly, while others are troubled but slightly. Fia. 60.—Haematobia serrata: cow horn showing band of resting flies—reduced (from Insect Life). On the horns the flies settle thickly near the base, often forming a complete band for a distance of 2 inches or more. (See fig. 60.) They seem to prefer the concave side to the convex side of the curve of the horn, probably for the reason that the cow can not scrape them off so readily, and one cow was noticed in which they reached nearly to the tip of the horn on the concave side of the curve only. DIPTERA. 119 The time and method of the deposition of the eggs were for some time a puzzle, but it was clearly shown in the investigations of the Division of Entomology that the eggs are placed in fresh cow manure in daytime, mostly between 9 a.m.and 4p.m.,and that in laying them the females dart only for an instant from the cattle, immediately after the dung is passed, and that within a little more than a minute afterward all had returned to the animal. They are laid singly, and never in clusters, and usually on their sides on the surface of the wet dung; seldom inserted in cracks. (Fig. 57, a.) Egg.—Length, 1.25 mm. to 1.37 mm.; width, 0.34 mm. to 0.41 mm. Shape, irregular oval, nearly straight along one side, convex along the other. General color, light reddish brown, lighter after hatching. General surface covered with a hexagonal, epithelial-like sculpture, each cell from 0.027 mm. to 0.033 mm. in length by about half the width. In the unhatched egg, even in those just deposited, a long, rather narrow, ribbon-like strip is noticed along the entire length of the flat- tened side, rather spatuloml in shape. In hatching this strip splits off, remaining attached at one end, and the larva emerges from the resulting slit. Larva.—After the eggs hatch, the larve descend into the dung, remaining, how- ever, rather near the surface. Newly hatched larva.—Length, 2.45 mm., and greatest width, 0.48 mm. Color, pure white. Joints of segments rather plainly marked, venter with slightly elevated ridges at ends of abdominal segments, the ridges with delicate sparse rugosities. Resembles in main full-grown larva. Full-grown larva.—Length, 7 mm.; greatest width, 2 to 2.5 mm. Color, dirty white. Antenne, 3-jointed, last joint pointed. Head with a lamellar or ridged structure shown in figure; divided by cleft at tip; skin behind lamellar struc- ture coarsely granulated, while that of thoracic and abdominal joints is nearly smooth. Thoracic stigmata pedunculate with six pedunculate orifices. Ridges on venter of abdominal joints not strong, fainter than in young larva. Anal stigmata q large, slightly protruding, very dark brown, nearly round, flattened on proximal borders, slightly longer than broad, 0.14 mm. in length, with one central round opening, and a series of very delicate marginal tufts of cilia, four tufts for each spiracle, each issuing from a cleft, but none on the proximal edge. Anal segment below with a dark yellow chitinous plate showing six irregular paired tubercles; the surface of the skin surrounding the plate rather coarsely granulated (fig. 57, D). The larval stages are passed in from four to six days. Puparium.—W hen ready to transform, the larve evidently descend from the dung into the ground below from a half to three-quarters of an inch. Actual observa- tions were made on larve in dung in breeding cages where the soil was fine sand, affording ready entrance to the larve. Where the dung has been dropped upon hard ground the probabilities are that they will not enter so deeply, and may indeed transform upon the surface of the ground at the bottom of the dung. Description.—The puparium is from 4 mm. to 4.5 mm. in length, by 2 mm. to 2.5mm. in width, regularly ellipsoidal, the head rather more pointed; dark brown in color. The segments are plainly separated. The anal stigmata are darker in color than the rest of the skin; are slightly protruded and preserve the same shape as in the larva. The central opening is still visible, as are the slight indentations of the border. The ventral plate, noticed at the base of the anal segment of the larva is still noticeable as a series of tubercular elevations. (See fig. 57, ¢.) The pupa stage may last from five to eight or ten days, so that the full time from egg deposition varies from ten to seventeen days, esti- mated for the average as about two weeks. As the flies doubtless SSeS. 88888888 SSS... >> 120 INSECTS AFFECTING DOMESTIC ANIMALS. begin egg laying soon after issuing from the pupa stage, there is room for a number of generations during even a northern summer, probably from six to eight being common. REMEDIAL MEASURES. While the injuries of this pest have abated after the first two or three years in all localities where it has appeared, it is doubtless here to stay, and must be looked upon as a permanent source of damage, theamount of injury varying with favorable or unfavorable conditions. For its treatment two lines should be followed, one directed toward the protection of the cattle from the direct attacks of the flies, the other to the destruction of the larve, with a view to lessening the number of flies. AOR S are PES OORT Ot DED Gas Aan 20 000? 4 > (Ce > \ Re \ LH WS GF ; Fia. 61.--Hematobia serrata: a, side view of head of larva; b, ventral view of head of larva, show- ing antenne and thoracic stigmata; c, dorsal view of analend of larva, showing anal stigmata; d, anal plate of puparium; e, ventral view of anal end of larva, showing anal plate—still more enlarged (from Insect Life). For the direct protection of cattle, the remedy most generally adopted, and which can be strongly recommended, is the daubing of the parts most affected with some sticky, offensive substance to repel the flies. Of these, a mixture of fish oil and tar, equal parts, is found one of the most permanent and effectual. Axle grease is used with good results. Spraying the animals with kerosene emulsion has been recommended, and if adopted should be applied at evening when cattle are yarded, a convenient method being to drive them through a gate at each side of which stands a man with spraying nozzle, so as to spray the flies of both sides at once. If only one nozzle is available the original sug- gestion of driving the cattle through a gate and then immediately back, so as to get the flies on the unsprayed side, may be adopted. et RS Oe nnn ene ss ee” ~— DIPTERA. 121 A plan which has been going the rounds of the agricultural papers is to arrange a trap in the doorway to a stable, the cattle, after passing the doorway, going through a set of brushes which dislodge the flies, which, with a properly arranged window above the door, collect at the light, and are here trapped and die. A recent number of the Denver Field and Farm mentions a similar device being patented. It is intended for the capture of all flies gath- ering upon cattle, but would be especially useful for this species. The principle has been used so generally that there may be doubt as to its being patentable. (See chapter on remedies.) For the destruction of the larve, which is probably the more effective way of preventing damage, two principles have been established. The first involves the killing of the maggots by introduction of some destructive agent; the other, the prevention of their maturity by the rapid drying of the mass of dung which supplies their food. The use of lime, as originally suggested in Insect Life, is a very effective plan, and where not prohibited by expense should be generally adopted. Professor Smith’s suggestion to spread out the droppings of manure so that they may dry rapidly is applicable during dry weather and in some localities is accomplished by drawing brush across the fields, a method which must necessarily fail to be complete in its operation, but much less expensive than the use of a shovel by hand. THE FLESH FLY. (Sarcophaga carnaria Linn.) While this species is perhaps better known as a household pest attacking fresh meat, the fact that it often deposits its eggs in the wounds of living animals makes it an important pest of domestic animals. It has been a familiar insect probably ever since man began to appreciate the insect foes to his com- fort, and has been a common subject of treatment in writings upon insects from a very early date. It was technically described by Lin- neus in 1761, and its habits were already doubtless well known. Its life history is easily told, and to some extent probably familiar to every- one who has had to do with the handling of fresh meats. Fig. 62.—Flesh fly, Sarcophaga carnaria Living larvze are deposited by the Sop OF teas het ore females upon any available bit of fresh meat, including wounds of animals, and these feed and develop with astonishing rapidity, soon consuming large quantities of flesh and, upon attaining their growth, crawl away, secrete themselves in the first convenient shelter, remain a few days in the pupa stage and issue as adults. 132 INSECTS AFFECTING DOMESTIC ANIMALS. It is evident that in the primitive conditions of nature, or in locali- ties where people are indifferent to the exposure of the carcasses of dead animals, these creatures may perform an important function, dis- posing of carcasses in a short time which otherwise would contaminate the atmosphere for many days. When infesting the storehouse, however, or attacking the wounds of domestic animals, the case is very different and the insect requires prompt subjection. For stock it is important to prevent, as far as possible, the occurrence of cuts, bruises, or wounds of any kind which may furnish an attraction for the flies, and to guard against.injury from barbed-wire fences or the horns of cattle. Wounds when formed should be dressed with dilute carbolic acid and coated with tar to prevent deposition of eggs, whileif already infested with the larve the wounds should be carefully cleaned, washed out with the carbolie acid solution and dressed with tar to pre- vent further egg deposition. Probably the most common American species is S. sarracenie Riley. THE STABLE ELY. (Stomoxys calcitrans Linn. ) This well-known species is widely distributed and a familiar pest in many countries. It was described by Linneeus in 1761 (Syst. Nat., 2, 1004) and has been mentioned in numerous works since then, Geoffroy, DeGeer, Fabricius, and many others noticing it, and it is unnecessary to go into detail with regard to its bibliography here. Its bite is severe and it causes a great amount of annoyance to cattle, horses, and other domestic animals, and it is frequently very troublesome to people working in places where it abounds. It is not confined to stables or the quarters of domestic animals, but occurs frequently in shady places, groves, and in dwellings, especially in cloudy weather, and puts the occupants to great inconvenience. Its bite is not poisonous, and aside from the pain given and the possibility of it disseminating disease, it is less injurious than some other mem- bers of the group. When abundant, however, this annoyance may be very great, and they all deserve attention. Indeed, it is especially charged against this species that they have been the means of trans- mitting glanders from diseased to healthy horses and anthrax among cattle, a charge which appears very reasonable from the fact that it inflicts a deep bite and does not gorge itself at a single animal, but may fly from one to another in securing a meal. It does not appear that the life history of this species has been fully recorded, although it has been stated that the stages are probably passed indung. In connection with the studies of the horn-fly by the Division of Entomology this species was reared with others from horse manure, aud it may be considered as established that the eggs are laid in dung and the larval stages passed there, requiring greater or less time for tm ee te nite 2s Se Re DIPTERA. 425 their development, a number of generations being produced each year. The prompt disposal of dung would therefore help greatly in reducing the numbers of this pest. THE MEAT FLY oR BLow FLY. (Calliphora vomitoria Linn. ) This fly agrees quite closely with the flesh fly in habits, except that it deposits eggs instead of living larve. The eggs, however, hatch very quickly after deposition, so the effect is very much the same. Like that species it has long been known as a troublesome insect and was described by Linneeus. It is a large species and familiar as the large blue fly which so noisily frequents the window or seeks entrance to pan- tries, cellars, and storerooms where eatables are kept. With that species also it is credited with attacking fresh wounds, and Packard states that during the war of the rebellion they were griev- ously tormenting to our soldiers, laying their eggs in the wounds, especially of those left on the field over night. On domestic animals where these “fly blows,” as they are commonly called, occur, the same treatment suggested for the flesh-fly may be practiced. BLUE-BOTTLE FLY. (Lucilia cesar Linn.) In history and habits this species is very similar to the preceding species and it is unnecessary to go into detail with regard to it. It is one of the first to put in its appearance in spring, having lived through winter in some sheltering corner. Its eggs are deposited upon any available fleshy matter and the larve mature rapidly. Packard, in mentioning its habits, says: Dr. Chapman, of Apalachicola, writes to Mr. Sanborn that this fly, attracted by the stench of a mass of decaying insects which have perished in the leaf of Sarra- cenia, ventures in and deposits its eggs, and the larve devour the festering heap. These in turn, on becoming flies, are unable to get out of their prison, perish, and are added to the putrefying mass that had nourished them. (Guide, p. 104.) THE SCREW-WoRM FLY. (Compsomyia macellaria Fab.) The screw-worm is unquestionably one of the most important of all the insects that affect domestic animals, and while the literature of the subject deals largely with its attacks upon man, on account of its very general fatality when gaining entrance to the openings of the face, by far the greater number of its attacks are upon the lower animals, and it is principally in this connection that we purpose to discuss it here, inelud- ing such reference to its hominivorous attacks as may furnish aid in understanding its mode of work. Tren ee 124 INSECTS AFFECTING DOMESTIC ANIMALS. The recognition of the injurious nature of the insect appears to have been in the early days of American settlement, and its description has occupied the attention of numerous naturalists. Indeed, it has an appalling synonymy, no less than twenty-six names having been applied to forms which are considered gh good authorities as representatives of this species. It will be useless to attempt Hees a discussion of this synonymy, but I may quote from an article by Dr. Williston ' the more important points in this connection, along with an extract from a Spanish article on the subject, and simply add here that valuable contributions have been made to the knowiedge of its attacks on domestic animals by Prof. H. A. Morgan,’ of the Louisiana Experiment Station, Prof. H. EK. Weed,* of the Mississippi Experiment Station, and Dr. M. Francis,‘ of the - Texas Station, whose papers will be drawn from in discussing certain phases of the subject. Dr. Williston’s article is as follows: In connection with Professor Snow’s article on this fly® it seems worth while to give a brief synopsis of papers published in the past few years by the able dipterol- ogist of South America, Dr. E. L. Arribdlzaga, of Buenos Ayres. From his studies he has ascertained no less than twenty-six different specific names that this fly had received. It is possible that some of these names would apply to distinct species were their types examined, but it is a thankless task to endeavor to make order out of the chacs in which Walker, Macquart, and Robineau-Desvoidy have involved the subject, and the results of Arribdlzaga’s thorough studies can with propriety be adopted. To these results, however, Mr. J. Bigot, of Paris, has recently taken _ exception in a note® on Professor Snow’s paper. This author’s penchant for making synonyms himself may perhaps have something to do with his wishing to preserve species founded on inadequate grounds. His argument that ‘‘il me semble fort hasardeux d’avancer qu’un seule et méme espéce se retrouve, en permanence, depuis les confins de la Patagonie jusqu’au dela des provinces centrales de ’ Amérique du Nord, vivant indifféremment sous les zones torrides, tempérées et méme froides!”’ is of little value, when the author himself should know that other American flies do have a similar range of habitat, to say nothing of the nearly allied Musca domestica. The specimens which Professor Snow sent me for examination, although somewhat injured, certainly seem to me to be Compsomyia macellaria (Fab.) E. Leh. A. The species may, with tolerable certainty, be recognized by its having a bright metallic green or coppery color on the abdomen and thorax, the latter above with three black stripes; the bristle of the antennze feathered to the tip, and the head, except the eyes, chiefly yellow. In size it varies from 7 to 10 millimeters. However, these systematic details will be of less interest than the following, which I translate from the Spanish of Arribdélzaga:7 ‘‘During the pleasant days of spring or the hotter ones of summer, these flies may be seen covering in great numbers, now umbelliferous flowers, now all sorts of filth; or, resting, there glistens in the sunlight the iridescent surface of their half-opened wings, and the blue, the green, the violet, the copper, and the gold of their metallic colored bodies. ‘Psyche, Vol. IV, pp. 112-114. 2? Bulletin No. 2, 2d series, Louisiana Experiment Station. > Bulietin No. 14, Mississippi Experiment Station (1891). 4 Bulletin No. 12, Texas Experiment Station (1890). 5 Psyche, Mar.—Apr., 1883, Vol. IV, pp. 27-30. 6 Bull. Soc. Entom. France, 12 Sept., 1883, No. 17, pp. 154-155. 7 Anales de la Soc. Cientifica Argentina, Vol. X, pp. 80-84. setae SA BR Mtn Fi eta VK sts esta eee EME ap: ae, ier 4 * ‘ 5 t : DIPTERA. 125 ‘Our fly deposits its egg, commonly called ‘‘ queresa,” in dead bodies, in manure, in fresh meat reserved for food, and soon there appear immense numbers of voracious larve that rapidly consume the objects in which has begun their active life. Not content with these habits, common to all the species of the group to which it per- tains, it deposits the germs of its posterity in the wounds of man and of animals, at the entrance of openings of the human face, and, in its anxiety for propagation, will deposit them in the wool of sheep. “‘Azara was, I believe, the first observer who noted cases of human myiasis in South America. Coquerel, many years later, called the attention of plysicians and naturalists to the frequent and fatal accidents which this evil produces among the exiles of Cayenne. According to this author, Dr. Chapuis, physician in chief of the French marine, attended one case in which the larve of C. macellaria had penetrated to the frontal sinuses, causing the death of the patient; also one very unclean person attacked in the nasal fosse and the pharynx, who succumbed after he had ejected one hundred and twenty larve. There were, as M. St. Pair observed, in the same country, six similar cases, of which three terminated in the death of the patients after cruel sufferings; in two the nose was destroyed, and in the last there was a deformation of the olfactory organ. In another case observed by M. St. Pair there were removed, by means of injections, more than three hundred larvz, but he was not able to obtain them all, and the remainder soon penetrated the ball of the eye, destroying the lower 4 eyelid in consequence of gangrene, invaded the mouth, corroied the gums, and laid bare the inferior maxillary. The victim died seventeen days after his entrance into the hospital.” After giving records of numerous other cases, he further adds: *‘To Dr. Lesbini, of Cordova, are due the better observations upon cases of myiasis produced by C. macellaria. The first case presented itself in an old foreigner who had an ulcer in his leg filled with these larvx; the second case occurred in Cordova, in a boy of 7 years, attacked in the left ear; the third and last case was in a girl of 16 years, also of Cordova, affected in the nasal fosse by the presence of two hundred and fifty larve. All these patients were saved. -“Ttis probable that, attracted by the fetid odor of unclean individuals, these flies hover over the mouth or the nose, and thus deposit their eggs. Some affirm that they at times enter the passages for this purpose. “The area of distribution of Compsomyia macellaria is very great, and will be, I believe, yet greater with time, since their habits facilitate their transportation by man from one region to another. Hitherto they have been observed in the following countries: Islands of America (Musca macellaria F.), North America (Chrysomyia tibialis, C. Vherminieri, C. carulescens, C. decora, C. plai R.-Desv.), Mexico (Lueilia hominivorax), Cuba, Colombia, Venezuela, Cayenne, Brazil, Peru, Chile, Uruguay, Argentine Republic, and New Holland.” DISTRIBUTION. It will be noted in the preceding paragraph that the species is credited to all of America between Patagonia and Canada, but the territory within which the greatest damage occurs is within the tropical and subtropical belt. Weed states that the fly is killed by cold winters, which, if correct, means a barrier to its northward extension beyond what is possible in each season by migration of the flies. HABITS AS A PEST OF MAN. In discussing the habits of the species it will be convenient to discuss it with reference to the attacks upon the human species.and domestic animals independently. 4 es 126 _ INSECTS AFFECTING DOMESTIC ANIMALS. The attacks upon man are usually due to deposition of eggs in the nostrils or mouths of sleeping or unguarded individuals, though no doubt exposed sores or bruises having a bloody surface would be equally attractive. Professor Snow! has given a very careful description of the attacks and results in a number of cases, and it will be useful here to extract from his paper some of the especially typical cases as showing the mode of attack, the effects of the presence of the larv, and the treat- ment resorted to: Ihave from time to time had occasion to note the depredations of the screw-worm upon horses and cattle in this State, but until recently have not received positive evidence of its attacks upon human subjects in any locality so far north as Kansas. But early in September, 1882, I received from Mr. 8. D. Osborn, the postmaster at Varck, in southeastern Kansas, specimens ‘‘of the worms which came from the nos- trils of Milton Carter.” ‘These proved to be the larve of Lucilia macellaria Fab., the so-called ‘‘screw-worm.” Upon further inquiry, I learned that upward of one hun- dred full-grown maggots escaped from the nose of this patient, who finally recovered from the serious illness consequent upon their ravages. I also ascertained that Mr. Carter had long been afflicted with an offensive nasal catarrh, which made his nos- trils an attractive place for the oviposition of the fly, and that he had fallen asleep in the woods in the daytime only a few days before the first appearance of the symp- toms produced by the presence of the larve. Several other instances of the attacks of Lucilia upon man soon came to my knowl- edge, most of which led to fatal results. Among these I will select the case attended by Dr. J. B. Britton, of Mapleton, in southeastern Kansas, who reported it in full at the session of the Southeast Kansas District Medical Society, in January, 1883. From this report I condense the following account: “On the evening of August 22, 1882, Mr. M. E. Hudson complained of a eeu sensation at the base of the nose and along the orbital processes, which was first fol- lowed by inordinate sneezing, and later by a most excruciating pain over the os frontis, also involving the left superior maxillary. This patient also had suffered, and was still suffering, from an aggravated form of nasal catarrh. The discharge was quite purulent, of a yellowish color, frequently tinged with blood, with a disa- greeable odor and at times intolerably offensive. On the 24th there was a profuse discharge of much purulent matter from the nostril and month, when all pain instantly subsided. ‘This discharge continued for three days, during which time as much as 16 ounces escaped, increasing in consistency until it was pure pus. The odor becoming much more offensive, his cough was more troublesome, and fever increased to such an extent as to produce slight delirium for twelve hours. What was thrown off was with much difficulty expectorated, and was sanious, containing microscopic particles of osseous matter, together with flakes of plastic exudation. The os hyoides was evidently destroyed. The patient had spoken with difficulty for thirty-six hours and there was much trouble in swallowing. The soft palate had evidently given way, and there was an entire inability to protrude the tongue or use it in speech. “‘About this time a worm similar toa maggot dropped from his nose. That was the first indication or suspicion that there was anything of the kind present. There was not, as in some other cases reported, any swelling, or movements traceable under the skin, nor was there at any time any complaint of the patient calculated to lead to a knowledge of their presence. After the appearance of the first I expected more, and was surprised to see them drop from the nostrils and wiggle from the mouth without any discomfort to the patient until they came in contact with the 1 Psyche, Vol. IV, p. 27 (1883). sae saab DIPTERA. ‘ee Schneiderian membrane, when they annoyed him greatly, and every effort was made on his part to expel them; but so soon as expelled no further trouble was manifested until another would get into the nostril. Every effort was made on my part to dis- cover them under the tissue, but the soft palate being destroyed to a great extent, and the palatine arch apparently lowered, it was with much difficulty that an examination could be made. The worms were evidently burrowing under the pala- tine fascia, as it presented a honeycombed appearance and in places patches were totally destroyed as large asa dime [18 mm.]. They continued to drop irom the mouth and nose, forced from the nostrils by the efforts of the patient, for the follow- ing forty-eight hours, during which time 227 were counted and the estimated num- ber exceeded 300. At this time tae whole of the soft palate was destroyed. The patient lived four days after the iast worm came away. ‘T put five of the worms in dry earth, and in fourteen days from the time they dropped from the nostri] there hatched out three flies. ‘‘Upon a very minute and careful examination after death I was sstouidala to find that all the tissue covering the cervical vertebrx, as far down as I could see by throwing the head back and compressing the tongue, was wholly destroyed and the vertebra exposed. The palatine bones broke with the slightest pressure of the finger. The os hyoides was destroyed and the nasal bones loose, only held in position by the superficial fascia. ‘My own theory is that the fly deposited the eggs while the patient was asleep, probably the day previous to the peculiar sensation and sneezing first complained of. At that time they had acquired vitality enough to annoy him while in contact with the sound flesh. So soon as they came in contact with the unsound flesh, or that affected with the catarrh, being, as itmust have been, gangrenous, they gave no further trouble.” * * * In the Peoria (Ill.) Medical Monthly for February, 1883, Dr. Joshua Richardson, of Moravia, Iowa, has an article upon ‘‘ The Screw Fly and its Ravages,” from which I make the following extracts: ‘While traveling in Kansas in the latter part of last August, a citizen of this place had the misfortune to receive while asleep a deposit of eggs from this fly. He had been troubled for years with catarrh, hence the attraction to the fly. He returned home a few days after the accident and shortly after began complaining of a bad cold. Growing rapidly worse, I was called to attend him. Monday, my first day, his appearance was that of a man laboring under a severe cold. Had slight con- gestion of the lungs, and moderate grade of fever. His nose seemed greatly swollen and he complained of a smarting, uneasy feeling in it, and general misery through the head. Gave him treatment to relieve the congestion and fever. Tuesday, saw him again. His nose and face were still more swollen, and in addition to the other symptoms he was becoming slightly delirious and complained a great deal of the intense misery and annoyance in his nose and head. A few hours after, I was sent for in haste with the word that something was in his nose. I found on examination amass of the larve of this fly (or ‘‘screw-worms,” as they are commonly called in the South) completely blocking up one nostril. On touching them they would instantly retreat en masse up the nostril. Making a 20 per cent solution of chloroform in sweet milk I made a few injections up both nostrils, which immediately brought away a large number, so that in a few hours I had taken away some 125 of them. By Wednesday evening erysipelas had begun, implicating the nose and neighboring portions of the face. Another physician was called. By continual syringing with a strong antiseptic solution of salycilate of soda, bicarbonate of soda, and carbolic acid we hoped to drown out the remaining larve. But they had by this time cut their way into so many recesses of the nose and were so firmly attached that we were unable to accomplish much. Finally we resorted to the chloroform injections, which immediately brought away a considerable number. Friday I was able to open up two or three canals that they had cut, extracting several more that had literally packed themselves, one after another, in these fistulous channels. His 128 INSECTS AFFECTING DOMESTIC ANIMALS. speech becoming suddenly much worse, I examined the interior of his mouth and found that a clear-cut opening had been made entirely through the soft palate into his mouth and large enough to insert the end of a common lead pencil. Saturday the few remaining larve began changing color and one by one dropped away. On Sunday for the first time hemorrhage from both nostrils took place, which continued at intervals for three days, but was not at any time severe. On this day the patient began to improve, the delirium and erysipelas having subsided, leaving but little or no annoyance in his head. In a few days he became able to go about home, and y even to walk a distance of half a mile to visit a friend and return. But while there he began complaining of a pain in the neighborhood of his left ear, apparently where the eustachian tube connects with the middle ear. It proved to be an abscess. Being already so reduced by the first attack, he was unable to withstand the second, and died after an illness of nearly three weeks, completely exhausted by his pro- longed sufferings. Three days before his death the abscess discharged its contents by the left nostril. The quantity of pus formed was about 24 ounces [78 grams]. “In all about 250 larve were taken away from him during the first attack, and, as the visible results, not only had they cut the hole through the soft palate, but had also eaten the cartilage of the septum of the nose so nearly through as to give him the appearance of having a broken nose. The case occupied, from the first invasion of the fly to its final result, nearly two months. He doubtless would have recovered but for the formation of the abscess, which, from all the symptoms, was caused by one or more of the larve having found their way up the left eustachian tube.” Dr. Richardson also quotes the Rev. William Dixon, of Green, Clay County, Kans., as giving the following account of his own experience: “While riding in his buggy a few years ago in Texas a screw fly attacked him, flying up one nostril. He blew it out, when it dashed up the other and deposited its eggs before he was able to expel it. Not realizing the danger, he did nothing for about three days, when the pain became so great that he hastened to Austin to con- sult a physician. His soft palate was almost destroyed before the larve, over 200 in number, were expelled.” This was the only one of twelve cases known to Dr. Richardson in which the patient recovered. AS A PEST OF DOMESTIC ANIMALS. Until recently the references to the attacks of this species on domes- tic animals have been of a very fragmentary character, but the papers by Morgan, Weed, and Francis have brought its true importance into prominence. Its greatest injuries for the United States have occurred in Texas, and the Texas Experiment Station early began the study of its habits. Prof. G. W. Curtis, formerly director of that station, wrote to me at considerable length regarding the pests, kindly sending me specimens of the various stages, and I can hardly better present the relation of the pest to the stock industry of that State than to extract from a letter dated December 15, 1888: I am sorry I have not more time to answer your questions about the so-called “screw-worm” of Texas. Ihave been closely interested in practical stock raising in this county for nearly six years; always in charge of the college stock and part of the time privately with stock of my own, and I am free to confess that the man who can find a cheap, expe- ditious, and effective preventive or remedy of the screw-worm will confer a blessing fitly measured by the enormous firancial benefit which would accrue. DIPTERA. 129 My observations have been mainly concerned with the practical side of the sub- ject, and not until the past year or two have I taken much trouble to investigate the life history of the insect. As a rule, the fly begins its work in June, but nothing like vigorous business activ- ity is reached until July, when for three or four months the time of the stockman 1s kept constantly absorbed in attending to animals with ‘‘ wormy’’ sores. This year (1888) the most trouble was experienced during September and October, and out of some 200 head of cattle and 60 or 70 head of hogs we had as many as 15 or 20 cases under treatment in a space of less than two weeks. The trouble starts usually by some little scratch, perhaps caused by barbed wire ' or by a stroke from a horn; sometimes, frequently in fact, it starts by an undue accumulation of ticks and consequent rubbing of the animal, which, while removing some of the ticks, leaves an opening in the skin through which a little blood will exude. In either case the basis of the operation seems to be a raw or slightly bloody surface, and the rapidity with which the work is carried on is wonderful. The eggs are deposited and the larve appear in a very short time; from what I have noticed I should say in less than thirty-six hours after the egg is deposited. I have been told, time and again, by those who assume to know, that the ‘‘screw- worm fly” does not deposit the eggs—that they are hatched within the body and the young larva deposited after hatching. There is a gray fly which does this, but the female deposits only a few larvz, and they are not by any means to be dreaded so much as the green fly (brown head), which deposits eggs by the wholesale. I have never seen a ‘‘screw-worm” (larva) which I could trace directly to a gray fly. All of the worms which I have bottled up and hatched under positive guard against error have turned into the same kind of fly, specimens of which (in alcohol) are herewith transmitted for your examination. It is said, however, that the gray fly works earlier in the season. This may be true, as the flies I have hatched out have been from worms taken from sores during September and October. In October of this year a house cat which I have had his foot injured, presumably by fighting. When we next saw him, about three days later, his foot was swollen and filled with screw-worms. We took out over 60 screw-worms from his foot within six days. All of these were placed in a bottle with a little earth and covered by a wire screen. The worms pupated and transformed in twelve days, about 30 flies coming out; all like the flies sent you. During the few days that the worms were in the cat’s foot they divested the bone of almost every particle of flesh and caused one of the phalangeal bones to come out entire. About a week after this I bought a thoroughbred Hereford calf and had him shipped down from the northern part of the State. On arrival I found screw-worms in the cleft of the right front foot (between the toes), produced by some fly in Dallas, as he was shipped directly from that point, and had been there for two weeks or more prior to date of shipment. I took out some 12 or 15 of these worms and ‘‘planted” them very carefully. I did not know but the fly in north Texas might prove to be the gray one, and I was anxious to satisfy myself on this point. Some 10 or 12 of the number ‘“‘planted” transformed and the flies appeared in eleven days from date of planting, all green with brown heads, exactly like the ones I had found in the cat’s foot, and which must, of course, have been deposited by flies in this immediate vicinity. ~*~ ~*~ * Dr. Francis (Bull. 12, Tex. Exp. Sta.) states that no cases in man _ have fallen under his notice, and says: Of all our domesticated animals cattle suffer the most from its ravages. They occur in wounds from horns, castrating, spaying, branding, dehorning, barbed-wire injuries, and often where ticks have burst on the brisket, flank, or just behind the 4653—No, 5 9 130 INSECTS AFFECTING DOMESTIC ANIMALS. udder of cows. They often occur in the vulve of fresh cows, especially if there has been a retention of the placenta or afterbirth. Young calves are almost invariably affected in the navel, and often in the mouth, causing the teeth to fall out. One case occurred in the first stomach (paunch or rumen) that is worthy of mention. Last September the writer had occasion to kill a Jersey bull calf probably two months _ old that had screw-worms in both hind legs just above the hock joint. On opening the abdomen I found hair balls in the stomach (rumen), and, to my surprise, about twenty-five fully matured screw-worms almost buried in the wall of that organ. I placed some of the worms in moist earth, and in ten or twelve days they hatched out genuine screw-worm flies. How did they come there? My opinion is that the calf licked the sores on his legs, and in doing so took some eggs that hatched and developed in the stomach. Horses and mules are not so often attacked. In them they are usually found in barbed-wire injuries, and occasionally in the sheaths of horses and the vagine of mares and the navels of colts. Hogs are more liable to become affected than horses. They are frequently wounded by dogs and by fighting, or there may be barbed-wire injuries, wounds from castra- tion, etc. Sheep are comparatively free from the attacks unless injured by dogs. Weed considers that next to the attacks upon man those upon cattle are of most importance, and he estimates that half of the cases in cat- tle occur where ticks have been crushed. He also states that ‘‘sheep are attacked when injured by dogs, or when the sheep are in poor con- dition the eggs are laid upon the wool and when the larve hatch they immediately bore into the skin. In many cases the sheep are attacked within the nasal cavities and the worms eat into the head.” On hogs he says the favorite seat of attack is upon the ears. LIFE HISTORY. The fly which produces all this trouble is a small species less than half an inch in length (10 mm.) and of a bluish green color with metal- Fic. 63.—Compsomyia macellaria: adult, wings expanded—enlarged (after Francis). lic reflections. It is particularly distinguished from related forms by the presence of three longitudinal black stripes on the thorax. The head is reddish or yellow and the body is covered with stiff black hairs. DIPTERA. 131 The fly appears in early summer (June or July for Texas), the time doubtless depending on the latitude, it having passed the winter as adult presumably either in a latitude free from extreme cold or a pro- tected location in houses. There is no impossibility of the migration Fic. 64.—Compsomyia macellaria: adult, wings at rest—enlarged (after Francis). of these flies from localities several hundred miles south of the place of their appearance in early summer, as aside from the powers of flight they could easily be transported on boats or cars. I know of no obser- vations, however, to establish such a means for their distribution. In depositing its eggs it selects some wound or decaying matter and lays a mass of eggs at once; at least three or four hun- dred may be deposited by a single female within a space of a very few moments, and the same fly may oviposit at different times and in different places hundreds or even thousands of eggs. ; The eggs are cylindrical, like those of other flies, about 1 mm. in length, white. ‘Under the microscope : the eggs show a prominent ridge on one side.” (Weed.) ae The eggs hatch within a few hours. Francis says: vie w—enlarged (after Francis). My present opinion is that if the eggs are laid in a moist place and on a warm day it requires less than one hour; whereas if laid in a dry place they seem to dry up and lose their vitality. Weed considers the time required for hatching about nine hours. The idea that they may be deposited in living condition is combated by all careful observations. The larva, or maggot, is a whitish footless grub, rather slender and quite active, burrowing into the tissues of the affected animal or into the mass of putrid flesh or decaying matter that furnishes it food. They grow rapidly and mature in five or six days (Weed) or about a week (Franeis). When mature they escape from the wound they have infested or wriggle away from the mass of matter T= 132 INSECTS AFFECTING DOMESTIC ANIMALS. in which they have developed, and bury themselves in the ground to transform. The puparia are brown in color, cylindrical, rounded at the ends, and about two-fifths of an inch in length. (See fig. 69.) The length of time passed in the pupa stage appears to vary, but observers agree on from nine to twelve days as the usual time; Francis Says nine for the shortest and fourteen for the longest period observed by him. From this history it is evident that there may be a succession of many generations during a season, which for different individuals so Fig. 66.—Egg of C. macellaria—great- ly enlarged (after Francis). Fig. 68.—Larvaof OC. macellaria—enlarged (after Francis). Fic. 67.—Egg mass of 0. macellaria (after Francis). overlap and combine that there are hosts of the insects in all stages, from their appearance in the early part of the season till checked by return of cold weather. As Francis says: While the larve are thus developing, the flies are constantly laying fresh eggs in the wounds, so that the young worms take the places of the matured ones, and thus keep up a constant and progressive loss of tissue. REMEDIES. It is evident from the above accounts that the fatal cases in man are due to the deposition of eggs, mainly in the nostrils, sometimes in the Fie. 69.—Puparium of C. macellaria—en- Fia. 70.—Puparium of C. macellaria, showing larged (after Francis). broken end where fly has emerged—enlarged (after Francis). mouth, and that such deposition is most liable to occur to persons sleep- ing in the open air or to those suffering from catarrh. The evident precaution is to avoid these sources of danger by the use of mosquito netting or wire gauze for sleeping rooms and of a protection for the nostrils when exposed in places where the flies are common. If once infested, medical attention should be sought at the earliest DIPTERA. 133 possible moment, and in case of delay a prompt syringing out of the nasal passages with dilute carbolic acid, L part acid to 200 parts water, should be resorted to to dislodge or kill the worms. For the general abatement of the pest, attention to the destruction of garbage, carcasses, or filth of any kind is to be commended, while pre- vention of bruises, cuts, barbed-wire scratches, and especially the punctures of ticks, are among the most important measures. Weed and Francis agree that ticks furnish the greatest number of cases, and the former advocates the feeding of salt and sulphur as a preventive of ticks on this account. Francis, however, considers the sulphur treat- ment of no avail, but depends upon killing ticks with dipping, a proc- ess which must serve to kill ticks, lice, serew-worms, and all external parasites at once. (See section on dipping methods. ) As a direct application for the sores infested with worms, a wash of carbolie acid is advised. The acid should be diluted with thirty times its bulk of water, and its value would, I suspect, be enhanced if a little glycerin were added. A final dressing of pine tar or in deep sores a packing with oakum and coating with tar are recommended. Dr. Francis writes me that since the publication of his Bulletin on serew-worms they have found a very practical method of applying sub- stances to destroy the larve. Itis to use creoline, or any of the car- bolic sheep dips, in a machinist’s oiler, by which means one can deliver a few drops in the holes without waste. ‘They use an ordinary conical zine oil can of about 4 ounces capacity, and find it very satisfactory. SUMMARY. In brief, if may be said that the serew-worm fly, which is distinguished by blue body, red front to head, and three black lines on the thorax, is distributed through all of tropical and much of temperate America; that it deposits eggs (not living young) in refuse matter, carcasses of animals, flesh wounds, or even minute drops of exuded blood, and the exposed openings of the body; that the eggs hatch within a very few hours at most, and larvee grow to maturity rapidly, consuming all tissues adjacent to them, and in cases of attack upon the limbs often laying bare the bones; that pupation lasts about ten or twelve days and is passed underground; that adults are found through nearly all the summer months, but for the southern United States more par- ticularly from July to October; that for prevention and remedy reliance must be placed upon the prevention, as far as possible, of all wounds and filth on animals, and when infested, prompt treatment with washes of dilute carbolic acid and subsequent coating with pine tar. THE TSETSE FLY. (Glossina morsitans Westw.) This famous fly of the central plains of Africa can hardly be omitted from a work of this character, especially since there is a possibility of 134 INSECTS AFFECTING DOMESTIC ANIMALS. its distribution to other countries. Even now it is thought to exist in Australia. Its attacks upon cattle, horses, mules, sheep, as well as numerous wild animals—zebras, antelopes, buffaloes, etc.—are said to be most deadly in result, and even man is attacked with severity, though it is claimed that these attacks are less injurious to man than to animals. , Other species of the genus have similar habits, but are less known. , THE HIPPELATES FLIES. (Hippelates spp.) Under the title of The Hippelates Plague in Florida! Mr. HB. A. Schwarz has called attention to a group of insects that must have a very important place in the list of animal plagues, though they seem to have been pretty generally neglected. His treatment of the pest is Fia. 71.—Hippelates flavipes —much enlarged (from Schwarz). almost entirely from the. standpoint of their attacks upon human beings, but it is clearly shown that they must be a dangerous pest to domestic animals as well. There can be no doubt that these insects have been commonly met with and noticed as a source of annoyance, but no one seems to have made a study of them from the economic standpoint before Mr. Schwarz. The species especially mentioned are: Hippelates plebejus Loew, flavi- pes Loew, and pusio Loew, two of which are figured and the figures are here reproduced. The annoyance caused by the flies is due to their darting into the eyes and other parts of the body after the moisture or perspiration, and also by a constant humming. They prove very irritable. Further, a ‘Insect Life, Vol. VII, pp. 374-379. EO DIPTERA. 135 théy attack sores, scratches, ulcers, etc., and by passing from one per- son to another, or from dogs, cats, or other animals with sores to healthy individuals, become a most dangerous source of disease contagion. So far as described the plague is greatest in the Southern States, especially Florida, Alabama, and Texas, and as similar species are common to many parts of the country, there 1s little doubt that when investigated many of the annoying gnats will be found to come within this group. Indeed, I feel confident that in years past insects of this character have been often encountered in the Mississippi Valley, as the hard bodies and persistent efforts to enter eyes have been noted, when no attempt was made to collect specimens or place them entomologically. The flies are strictly diurnal, and continue to be troublesome from early morning till near sunset, being most aggressive during the bot and sultry hours of the after- noon. They preferably frequent open and sunny places, while in the shade of dense Fic. 72.— Hippelates plebejus—much -nmarged (from Schwarz). forests their presence is not noticeable. They are equally troublesome in the coun- try away from human habitations, and in the streets of small towns, but I do not recollect having seen them in any number on the streets of the larger cities. They enter the houses, but evidently do not feel at ease in the 100ms, for they do not attack people, but congregate on the panes of windows, if these happen to be closed. The life histories are unknown, but Mr. Schwarz suggests the stems of reedy plants or the piles of decaying reeds along shores of lakes or marshes as possible breeding grounds. With regard to remedial measures Mr. Schwarz says: Until some light is thrown on the life history of the tlies 1t is impossible to sug- gest any remedial measures to be adopted for the general abatement of this pest in agiven region. Very little can be said regarding protective measures. To kill the flies, as we instinctively do the mosquitoes, by a slap of the hand, is of no avail against the Hippelates, because they are too numerous and for other obvious reasons, 136 INSECTS AFFECTING DOMESTIC ANIMALS. A close-fitting veil would no doubt protect the eyes, but in the hot days of a south- ern summer the wearing of a veil is a torture almost equal to that of the flies. For the same reason applications of oil of tar, oil of pennyroyal, and similar sub- stances, which are more or less satisfactorily used in the North against the mosqui- toes, black flies, and sand flies, is hardly bearable in the South. Smoking cigars or a pipe offers a good protection to those who indulge in this vice, but even an invet- erate smoker can not smoke constantly when he is out of doors. A good smudge also drives away the flies, but of course can not be classed among the remedies that are handy and available at every hour and at every place. Sprinkling the coat collar and other parts of the clothing with Eucalyptus oil (and no doubt, also, other strongly smelling etheric oils), as lately recommended as a good repellent against house flies, should be tried, and promises, in my opinion, good results. This sketch of the flies is naturally very incomplete, as, were the attempt made to include all that may at times annoy domestic animals, it would require a volume by itself. The common house fly, for instance, may often prove a serious pest to domestic animals, and its annoyance in houses is too well known to need any comment. The effort has been to give a fairly adequate treatment of those species which are of greatest concern to the stock raiser, especially in the United States. Family HIPPOBOSCID 2. (Forest Flies, Ticks.) This remarkable and interesting group of insects contains two species of special interest to the stock breeder, both of which are old and familar pests. The species of the family at large oceur on a number of animals, but the greater number occur on birds, and especially upon birds of prey, and therefore have no relation to our present discussion. They are horny-bodied, flattened flies with tubular mouth parts fitted for suction, and having, except the sheep tick, well-developed wings. They are therefore somewhat migratory in their habits. They are especially remarkable and abnormal in their method of reproduction, the eggs hatching and the larve developing within the body of the adult, so that when extruded they have almost reached the pupa stage. The extruded larva changes almost immediately to the pupa, the larval skin forming a hard pupa case, and in this con- dition they resemble seeds. This stage is quickly passed, and the adult appears, assuming at once its mature form. Williston remarks that the genus Lipoptena is remarkable in that in the earlier state the flies have wings and live on birds, but later they seek quadrupeds, where they remain, and having no further use for their wings, they lose them. It must be inferred that the young flies issuing on mammals migrate by means of their wings to birds and later return to a mammal host. pO SO er DIPTERA. 137 It is commonly stated that these flies produce but one or two young, but Dr. Curtice is authority for the statement that the sheep tick may produce from five to eight young, one after another, which would make the multiplication more rapid, and better account for the occasional abundance of this pest. THE BrrRD TICKS. The species occurring on birds are included in the genera Olfersia and Ornithomyia, the former being distinguished by the absence of ocelli and the presence of two teeth under each claw. Olfersia americana Leach is a rather common species on owls and other raptorial birds and also the partridge or ruffed grouse. It is described and figured by Packard as Hippobosea bubonis, in the Guide, p. 433. O. albipennis occurs somewhat commonly on herons, and ardee is recorded from the same class of birds. Other species listed by Ostén Sacken are brunnea, mexicana, propinqua, and suleifrons. Ornithomyia contains eight species, of which nebulosa is recorded from an owl, Strix nebulosa; and pallida Say from Sylvia sialis. THE DEER TICK. (Lipoptena depressa Say.) This interesting form was described by Say from specimens taken from the common deer (Cervus virginianus). It is wingless, as usually found on this host, but according to Williston is provided with wings and occurs on birds during the early period of its existence. At this time the wings are weak, the veins slender. THE FOREST FLY oR HORSE TICK. (Hippobosca equina Linn.) Linneus described this species in 1761, but it must have been a familiar form to observers of insects long prior to that date. Since then it has received frequent notice, and mention of it occurs in numerous general works and in all treatises on Diptera or on the parasites of the horse. Its injuries consist in the irri- tation produced by the move- ments among the hairs, their punctures of the skin, and loss of blood occasioned when occur- ring in numbers. It would seem to be far less common in this country than in the Old World, and | have yet to hear Fia. 73.—Hippobosca equina (copied from Packard). | es 138 INSECTS AFFECTING DOMESTIC ANIMALS. of a case where it has occurred in serious numbers. It is listed by Osten Sacken, on authority of Kirby and Loew. It is of course possible that the species may multiply so as to become a pest, and this possibility should be recognized. It might, from the ability to fly, be more difficult to handle than the sheep tick, but doubt- less the careful grooming of horses affected would prevent undue increase. Dusting pyrethrum in the hair would be useful, and this could be resorted to with horses in pasture as well as those that are stabled. THE SHEEP TICK. (Melophagus ovinus Linn.) Linneeus described this species in 1761 under the name of Hippobosea ovinus, but in the later division of this genus, which at first covered all the forms included in the family, this species was assigned to the genus Melophagus. It differs from the other members of the family in never possessing wings. The head is small and sunken into the prothorax. The middle portion of the thorax is rather slender, contrasting with the development of this region in the winged forms. It is of a reddish or gray brown color, about one-fourth of an inch long, and easily detected when present in any numbers on sheep. Theynever migrate from the original host PRON except it be to attach to an- AS ag other animal of the same spe- Minar cies, and probably the principal movement is that which occurs after sheep are sheared, when the ticks tend to migrate to lambs. On the sheep, if abundant, they may cause considerable dam- age, indicated by lack of growth or poor condition, and when massing upon lambs they may cause great damage, resulting in the death of the victims if not promptly relieved. | They are distributed over the world generally where sheep are kept, and are too well known by sheep breeders to make it necessary to emphasize the injury they may cause. All breeds of sheep seem alike subject to attack, but I know of no record of their occurrence upon other animals. Curtice has determined that each female may produce from five to eight young, the seed-like brown puparia of which are often to be met with among the more numerous adults that adhere to the wool or skin. Fie. 74.—Melophagus ovinus: a, adult; b, puparium— enlarged (original). DIPTERA. 139 REMEDIES. While the ticks may be greatly lessened in number by the vigorous use of pyrethrum—a most available remedy during winter—the most practical plan to adopt, and one which if thoroughly followed will make all others unnecessary, is to dip the sheep each year after shearing. Of the numerous dips which are in use, and which are discussed more fully in the chapter on remedies, the kerosene emulsion is recom- mended for this form, and several of the patented dips on the market are gcod, while tobacco dips, tar dips, etc., may be used, if preferred. ' It is of course desirable to use a dip that will eftectually destroy not only these ticks but the two forms of lice and the scab mites, in case any of these are present. A dipping tank is an essential part of the equipment for sheep raising, and its construction is described in the chapter on remedies. A flock once freed from the pests will not be again infested except by the introduction of infested animals; hence care should be taken in making additions to the flock to free the newcomers from parasites. It is also well to keep the sheep fora few days after dipping in a differ- ent inclosure from what they occupied before, to avoid possible infes- tation from any stragglers that may have been caught on wool upon posts or brush, and if the wool is charged with them when clipped it i" ‘Should be stored where the ticks could not easily return to the sheep. 4 The ticks can not travel any distance independently, and will soon die a when removed from the sheep, but proper care here will assure success. 4 With due care to have an efficient dip one operation should suffice, but F it is a good plan to examine the herd a week or ten days after dipping, and if any parasites are found to have escaped, or to have issued from pup that survived, to repeat the operation. A BAT HIPPOBOSCITD. Under the title of ‘‘ A remarkable new hippoboscid from Mexico,” Mr. C. H. T. Townsend describes a species which he names Trichobius dugesit and which he received from Dr. Dugés, of Guanajuato, Mexico, taken from a bat, Glossophaga soricina. (Entom. News, Vol. LI, pp. 105-106, 1891.) 140 INSECTS AFFECTING DOMESTIC ANIMALS. Family IN Yi@@EiEE TE pear (Bat Flies.) These very remarkable Diptera seem to have gone a step farther even’ ; than the Hippoboscide in their adaptation to parasitic life, the known forms being totally wing- less and constantly confined to their hosts. The latter are various species of bats, and the species have been observed in various parts of the world, three only being recorded for this country, the Strebla vespertilionis Fab., credited to Jamaica, San Domingo, Cuba, and South America; the Megistopoda pilatei, from Cuba, and an unnamed species of Nycteribia, from California. The Strebla vespertilionis is credited with occur- ring on pigeons and parrots, but considering the normal habits of all the known species these must be looked upon as stragglers. Fic. 75.—Nycteribia sp. (after Packard). | i CHAPTER III. SIPHONAPTERA. Fleas. This group of insects, including the well-known fleas, has by many writers been considered as related to the Diptera, but in most recent works on systematic entomology it is given separate rank under the above name. It is unnecessary here to discuss the question of their zoological position, but it may not be out of place to remark that, while they are avery distinct group and doubtless well deserve to have this distinction indicated systematically, there is much to indicate that they have had a remote relationship to the dipterous branch. This is shown not only in-the mouth parts and feet of the adults, but in the larve, which are footless, slender, worm-like creatures. The insects of this group are characterized by the entire absence of wings, by having the bodies compressed, the legs long and stout, the Fic. 76.—Pulex irritans: a, larva; b, pupa; c, imago—all enlarged (from Van Beneden). cox being remarkably developed, giving them great leaping power. The mouth parts are well developed and adapted for suction, all the species in the adult stage feeding upon the blood of mammals or birds. The antenne are small, usually sunken in a pit or groove in the side of the head and of peculiar form, the third, or terminal, segment being annulated, or, in some cases, even divided into leaf-like plates. The eyes are simple when present, but in many cases they are reduced to mere rudiments or even completely wanting. The tarsi are 5-jointed. They undergo a complete metamorphosis, the early stages being passed in places adjacent to the resorts of the host. The eggs, while sometimes laid upon the hairs of the host animal, are loosely attached 141 ~= a 142 INSECTS AFFECTING DOMESTIC ANIMALS. and must ordinarily be scattered in places where the host forms sleep or nest. The larvee, so far as known, live in dust or litter in similar locations. They are slender, worm-like, footless objects, with a sparse covering of hairs. The pup form in similar locations, inclosing them- selves in cocoons. Westwood says When full grown, which occurs in summer in about twelve days, the larve inclose themselves in a small cocoon of silk, often covered with dust, and attached to sur- rounding substances. Rdosel, however, observed that some of the larve underwent their transformations without forming any cocoon. In most of the available works the group is made to contain but a Single family, the Pulicidse, but more recent systematic works sepa- rate them into three families, the Sarcopsyllide, including the small forms, with large heads, which are confined to the host animal while in the gravid condition; the Vermipsyllide, in which the gravid females are not stationary, but the abdomen becomes swollen, and in which the labial palpi are 10-jointed; and the Pulicide, including most of our common forms, in which the female abdomen does not become swollen, and the labial palpi are from 3 to 5 jointed. While the fleas are essentially parasitic in the adult stages, they are by no means so strictly confined to the host as are the Pediculidz or most of the Mallophaga, but wander from the host at times, and may -even be found on different species of animals than those which are evi- dently their normal hosts. Probably these stragglers do not, as a rule, maintain a permanent habitat upon the new host, and therefore, with the exception of one or two species, little attention need be given to prevention of migration or of transfer from one animal to another. In the further discussion of species, which will be limited mostly to - the American forms of economic interest, we will disregard these divisions and treat the species simply under their respective genera. THE JIGGER FLEA, OR CHIGOE. (Sarcopsylla penetrans Linn. ) Linneeus described this species more than a century ago (1767) under the name of Pulex penetrans, and it has been treated in many different works since that time. The various names of “ jigger,” ‘“jigger flea,” ‘“‘chigoe,” and ‘‘chique,” applied to it in various localities, are evidently, in part at least, associated with its annoying habit. In distribution 1t covers all of tropical and subtropical America. Baker says ‘this flea is undoubtedly found throughout the tropical and subtropical regions of both hemispheres.” Railliet states that it was introduced into Africa about the year 1872, and that it has propagated there with astonishing rapidity. While most of the records of its injuries have been with reference to its occurrence on man, it is a notable pest of inferior animals, and doubtless occurs much more frequently as a parasite of some of these than of man. SIPHONAPTERA. 143 The dog and cat are among the species that are specially subject to its attack, but other mammalia are affected, and Railliet mentions sheep, goats, cattle, horses, asses, and mules, and even birds as hosts, and cites particularly a case where a hog was very seriously infested. The foot examined by R. Blanchard had been obtained from Liberia <> << = ‘g & Ade SONAR AERA OH OOOO! oa Sek ees <<<< KEE SESE SESE —a wvewes ry *. (Q°RGSoS eee eere m4 > SIPHONAPTERA. | 147 THE HouskE FLEA. (Pulex irritans Linn.) This, perhaps the best known species of flea, was described by Lin- neus in 1746. It is distributed widely over the globe, and often becomes a serious pest in houses, sometimes even in spite of the most careful attention and cleanliness. It is easily distinguished from the common flea affecting dogs and eats, and which is almost as frequent an inhabitant of houses, by the fact that there are no combs of spines upon the borders of the head or pronotum. From the much less common species just mentioned which occurs on the opossum, and which is most nearly allied to it, it is to be separated by the greater length of the mandibles and hypopharynx, which reach more than halfway the length of the anterior coxe, by the the single row of bristles on each abdomi- nal segment, the large male claspers, and the dark-reddish or piceous color. The habits and life history of this spe- cies have long been known and frequently described. They occur particularly in houses, secreting themselves in bedding and clothing, and, especially at night, make their attacks on their human vic- tims for the purpose of drawing blood. Their eggs are deposited in out-of-the- way places, in the dust or lint under car- vet peer Pall pine ne gee ea pets, and the larve are said to feed upon —_¢embs (original). the particles of organic matter which may be found in such localities. Railliet states that each female deposits 8 to 12 eggs, which are whitish and ovoid and 0.7 mm. long by 0.4 mm. thick; further, that in summer the larve issue in four to six days, become pupe eleven days later, and after about twelve days in this stage become adult; the time for development from egg to adult being, therefore, about four weeks, while in winter, in a warmed room, it occupies about six weeks. While no amount of personal cleanliness will protect an individual from their attacks in a building which is infested by them, careful attention to the removal of all dust and refuse which may harbor the larve will assist in keeping them in check. The use of pyrethrum is very effectual in destroying them, and may be dusted in places which harbor them. (See also remarks under “The Dog and Cat Flea.”) t THE BriRD FLEA. (Pulex avium Tasch.) According to Taschenberg, the common fleas, affecting a great variety of birds, including the domestic fowls, are all representatives of a single species, and although some of the forms were described as early o 2 ee re 148 INSECTS AFFECTING DOMESTIC ANIMALS. as 1832 to 1835 he brings them all together, and, discarding the various names referring to particular hosts, as galline Bouché, columbe Ger- vais, hirundinis Sam., sturni Dale, and fringille Walk., proposes a new name, avium, to stand for the species. It belongs to the series with no comb of spines on the head, but with a comb on the pronotum. The mandibles are short, not reaching to the ends of the anterior coxe, and there are 24 to 26 spines in the’ pronotal comb. The hind femora have a row of minute bristles on the side, and the first two of the abdominal segments have minute teeth on the disk above. Length, 3 to34 mm. Dark brown in color. THE RAT AND MOUSE FLEA. (Pulex fasciatus Bose d’ Antic.) This species seems to have received pretty general recognition, and has been recorded from quite a number of different hosts. Whether i can be said to be primarily a parasite of the rat and mouse I do not pretend to say, but since it has been noted a number of times from these animals, and so far only from these in this country, I have assigned it here. Nothing has been recorded regarding its life history, but doubtless it is like its congeners. The adults are elongate. with the head evenly rounded in front, with- out any comb of spines on the lower border, while the hind border of the pronotum bears a comb of strong spines, 18 in number. The mouth parts are of normal length, not extending beyond the anterior cox, a character which will separate it from its nearest allies, the sciurorum and avium. Taschenberg has collected a list of the known hosts, and enumerates Myoxus, Oricetus frumentarius, Mus musculus (mouse), Mus decumanus (rat), and Canis lagopus; and adds that he has also two examples from the Mammoth Cave, Kentucky. I have col- lected it from Mus decumanus at Ames, Iowa, which appears to be the only record from a definite host in America, but it is doubtless of com- mon occurrence. SQUIRREL FLEAS. Several species of fleas have been described from the squirrels, and while they do not occur indiscriminately on all species it will serve our purpose here to consider them together, referring for full descrip- tion to the technical papers of Taschenberg and Baker. Pulex sciurorum Bouché, the flea which infests squirrels in Europe, has not been found to occur on our American species of squirrels. Pulex howardi Baker, recorded from the red squirrel, Ithaca, N. Y., ‘‘ squirrel,” Tallula Falls, Ga., gray or fox squirrel and nest of field mouse, Lincoln, Nebr., is apparently the most generally distributed of the American species, _ PY * 4 ms q : us ji . ; SIPHONAPTERA. ‘149 There are no spines upon the head, but a comb of 18 spines is on the pronotum. The male claspers are armed with short, black teeth which very readily separate this species from its nearest allies. Specimens from fox squirrel, Caddo, Ind. T., sent tome by Prof. W. W. Cooke, probably belong to this species, as Baker mentions several specimens in my collection without host, and as several of these speci- mens were sent him the labels of which may have been lost. The speci- mens being remounted I can not positively recognize them now. Baker also describes Pulex wickhami from the flying squirrel ( Sciu- ropterus volans), at Iowa City; Pulex gillettei from the red squirrel (Sciurus canadensis), Portland, Mich.; Pulex coloradensis from Fremont’s chickaree, Georgetown, Colo.; Pulex hirsutus, from prairie dog (Cynomys di i stein ek \ Fia. 81.—Pulex howardi: a, female; b, genitalia of male—greatly enlarged (original). ludovicianus), Stove Prairie, Larimer County, Colo.; P. longispinus, from Fremont’s chickaree, Colorado, and Pulex montanus, from the large gray squirrel (Sciurus alberti), foothills west of Fort Collins, Colo. THE SPERMOPHILE FLEA. (Puiex bruneri Baker. ) The common spermophiles, Spermophilus 13-lineatus and S. franklini, are very commonly infested with a large reddish-brown flea which has been recorded so far from Lincoln, Nebr., and Fort Collins, Colo., as well as Ames, lowa, where I have taken it frequently during a number of years past. The head is without spines beneath, but the pronotum bears a comb of about 16 spines. Baker describes it as follows: Apical spines on joint 2 of hind tarsi long as joints 3 and 4 together; antennal groove in middle of head; maxillary palpi in female with joint 2 three-fourths of 4, and 3 two-thirds of 4, labial palpi reaching to one-third of anterior femora; pro- notal comb of 16 spines; in anterior tarsi joint 2 longer than 1 and one-third longer than 3; in middle tarsi joint 1 equals 5 and 4 together and shorter than 5, while 5 is 150 INSECTS AFFECTING DOMESTIC ANIMALS. twice 4; in posterior tarsi joint 1 equals 2 and 3 together, 5 a little longer than 3 and less than one-half of 1, while 2 1s three times 4 and less than 4 and 5 together; hind femora with a row of bristles on the side; color, light reddish brown, darker dorsally on the abdomen; length, 2 to 2.5 mm. . Fic. 82.—Pulex bruneri: male—enlarged (original). While this species has been noted as so common on its ordinary hosts it has never been observed as occurring upon any of the domestic animals. THE DoG AND CAT FLEA. (Pulex serraticeps Gerv.) The common flea, affecting the dog and cat, was described by Duges! under the name of Pulex canis in 1852, and by Bouché? under the name of Pulex felis in 1835, these names referring to the forms infesting the dog and the cat, respectively. The reference of the two to one species under the above name by Gervais? was made in 1844. It is one of the most abundant species known, and is distributed practically over the entire world. Asa house pest it rivals the irritans, and in many places even seems to be about the only species occurring. Howard states that from the specimens sent to the Division of Ento- mology itis this species rather than irritans that is usually troublesome. It may be easily distinguished from that species by the presence of the combs of spines on the border of the head and pronotum, those on the head being usually 6 to 9 in number and those on the hind border of the pronotum 14 to 18 in number. The adults seem to adhere quite closely to their hosts, as cats and dogs infested by them will be found to carry them quite constantly, 1 Ann. des Sciences Naturelles, Vol. XX VII, p. 157. ?Nov. Act. Acad. Leop. Carol., Vol. XVII, i, p. 505. 3 Hist. Nat. des Ins. Apt., Vol. III, p. 371. ; SIPHONAPTERA. 151 and their eggs may be found adhering very lousely to the hairs of these animals. They drop off, however, at tke slightest touch, and must therefore be distributed in a great variety of places besides the sleep- ing places of their hosts, which would naturally receive the greater number. Dr. Howard suggests that for experimenters who may wish to follow out for themselves the life history of the species an easy way to collect the eggs is to lay a strip of cloth or carpet for the animal to lie and sleep upon, and afterwards to brush the cloth into a receptacle, in which the eggs will be found in numbers if the animal is infested. Verrill gives the following condensed account of the life history of this species: The female cat flea lays her eggs among the fur of the cat, to which they are but slightly attached. These eggs are very small, white, and long oval. As the cat walks or runs about, the eggs are constantly being scattered around, often in great numbers. On one occasion I was able to collect fully a tea- spoonful of these eggs from the dress of a lady in whose lap a half-grown kitten had been held for a short time. The places where cats sleep be- come well filled with eggs. These hatch inabout two weeks into little, white, footless, maggot- like larve, which have small tufts of hairs along the sides. They are at first about one-sixteenth of an inch long. The head is pale yellow and the posterior end of the body bears two spines. These larve feed upon decaying particles of ani- mal and vegetable matter always to be found in the dirt where they live. They move about by means of their hairs and spines. They grow rapidly in warm weather, and in about twelve days, when they mature, spin a slight silken cocoon and change to a pupa, which is inactive. This looks more like the mature flea and has the legs free. In a short time, varying from ten to sixteen days or more, according to the temperature, the pupa matures, and the full-formed flea comes forth from the cocoon, ready and willing to take care of itself. * * * They pass the winter both in ‘lie mature and larval states, and perhaps also as eggs and pupx. There are several broods each season. Fic. 83.—Pulex serraticeps: front part of body, showing combs on head and pronotum—enlarged (original). REMEDIES. A very concise statement of the remedies to be applied for fleas is given in cireular No. 13, by Dr. L. O. Howard: The larve of the dog and cat flea will not develop successfully in situations where they are likely to be disturbed. The use of carpets and straw mattings, in our opinion, favors their development, since the young larye can penetrate the inter- stices of either sort of floor covering and find an abiding*place in some crack where they are not likely to be disturbed. It is comparatively easy to destroy the insect in its early stages (when it is noticed), as is shown by the difficulty of rearing it, but the adult fleas are so active and so hardy that they successfully resist any but the most strenuous measures. Even the persistent use of California buhach and other pyrethrum powders was ineffectual in one case of extreme infestation, as was also, and more remarkably, a free sprinkling of floor mattings with benzine. In this instance it was finally necessary to take up the floor coverings and wash the 152 INSECTS AFFECTING DOMESTIC ANIMALS. floors down with hot soapsuds in order to secure relief from the flea plague. In another case, however, a single liberal application of buhach was perfectly success- ful, while in a third a single thorough application of benzine completely rid an infested house of fleas. To sum up: Every house where a pet dog or cat is kept may become seriously infested with fleas if the proper conditions of moisture and freedom from disturbance exist. Infestation, however, is not likely to occur if the (bare) floors can be fre- quently and thoroughly swept. When an outbreak of fleas comes, however, the easiest remedy to apply is a free sprinkling of pyrethrum powder in the infested rooms. This failing, benzine may be tried, a thorough spraying of carpets and floors being undertaken, with the exercise of due precaution in seeing that no lights or fires are in the house at the time of the application, or for some hours afterwards. Finally, if the plague is not thus abated, all floor coverings must be removed and the floors washed with hot soapsuds. This is a useful precaution to take in any house which it is proposed to close for the summer, since even a thorough sweeping may leave behind some few flea eggs from which an all-pervading swarm may develop before the house is reopened. * * * Provide a rug for the cat or the dog to sleep on and give this rug a frequent shak- ing and brushing, afterwards sweeping up and burning the dust thus removed. As all the flea eggs on an infested animal will not, however, drop off in this way, and those which remain on it will probably develop successfully, it will be found wise to occasionally rub into the hair of the dog or cat a quantity of pyrethrum powder. If thoroughly applied, it will cause the fleas to fall off in a half stupefied condition, | when they, too, may be swept up and burned. In the observations made at this Department upon this species of flea during the summer of 1895, some difficulty was found in preserving just the right degree of moisture to enable the insect successfully to transform. An excess of moisture was found prejudicial to the development of the species, as was too great dryness. The observations showed, however, that at Washington in summer an entire generation may develop in a little more than a fortnight. Hence a housekeeper shutting up her house in June, for example, with a colony of fleas too small to be noticed inside it need not be surprised to find the establishment overrun when she opens it up again in September or October. RABBIT FLEAS. SE ee ie Ne ce te ek ee ee Be The different kinds of rabbits are very abundantly supplied with fleas, as doubtless any one who has handled these animals will willingly testify. According to authorities, however, there are at least three different species of fleas which may infest them. The species infesting the European hares is known as Pulex goniocephalus Tasch., and this has not as yet been recognized in America. Pulex gigas of Kirby was originally described from Canada, and Baker has recorded it from the cottontail rabbit, at Lansing, Mich. It is Fic. 84.—Puler inaequalis. described as having the head rather evenly head and forepart of body— rounded in front, the eyes in the anterior half of Bere the head, mandibles reaching two-thirds of the coxe, the comb on the border of the head of one or two spines, pro- notal comb of 20 spines, light reddish-brown, the female 4 mm. long. SIPHONAPTERA. 153 Pulex inaequalis Baker, described from cottontail and jack rabbits near the Grand Canyon, Arizona, is thought by Baker to be the North American representative of goniocephalus. It is distinguished from gigas by having the head obtusely angulated in front, the head spines 5 or 6in number and pronotal spines 16. Length of the male, 1.5 mm. ; female, 1.75 to 2.25 mm. A variety called simpler is indicated as having 8 spines in the head comb, 14 in the pronotal comb, and being slightly larger in size, 2.5 mm. in length. This variety seems to be the common form on Lepus sylvaticus in Lowa. Pulex goniocephalus has sharply angulated forehead and pronotal comb of 14 spines. It has a length of 2 mm. THE MOLE FLEA. (Typhlopsylla assimilis Tasch. ) This species, described by Taschenberg from the European mole in 1880, appears to be identical with the species found on our common moles Scalops aquaticus and argentatus. Fia. 85.—Typhlopsylla assimilis: a and b, head and met segment of female; c, male—enlarged original). The eye is very rudimentary, scarcely visible under the microscope, the head with a comb of 3 spines on the lower border and the pronotum with acomb of 7 to 9 spines on each side. ‘Male claspers boot-shaped, the sole turned up.” Color rather dark brown, more intense along the dorsum. Length 2.5 mm. It is recorded from Sorex vulgaris, Talpa europea, Mus sylvaticus, and Arvicola arvalis by Taschenberg, and Baker records it from the mole, Lincoln, Nebr., and the “common garden mole,’ Lansing, Mich. I have taken it repeatedly from the prairie mole (Scalops argentatus) at Ames, lowa, and have specimens from Prof. A. W. Bitting from Scaleps aquaticus, Lafayette, Ind. From these records it would appear to be quite closely confined to the mole as its particular host, and the rudimentary nature of its eyes might be looked upon as a parallel adaptation with that of its host. 154 INSECTS AFFECTING DOMESTIC ANIMALS. ’ THE POCKET GOPHER FLEA. (Typhlopsylla americana Baker; also Pulex ignota Baker.) This species, described by Baker (Canadian Entomologist, Vol. XXVIII, p. 186), I have taken repeatedly from our common pocket Fia. 86.—Typhlopsylla americana: male; a, antenna—enlarged (original). gopher (Geomys bursarius) during the past ten years, and it must be a common resident of their burrows. Mr. Baker records it from a“ large Fia. 87.—Typhlopsylla americana: female—enlarged (original). brown mole,” and states that he has seen specimens collected by Pro- fessor Gillette on the pocket gopher at Fort Collins, Colo., and by Professor Aldrich at Moscow, Idaho, on Thomomys talpotdes. | SIPHONAPTERA. 155 Vertex evenly rounded from occiput to mouth, slightly flattened above in male; head with very weak bristles; bristles on joint 2 of antenn# longer than third joint, which is without bristles; mandibles attaining three-fourths of anterior cox; pro- notal com) of 18 to 22 spines; legs with strong spines on tibiw and hind tarsi; hind femora with a row of bristles on the side; in middle tarsi joint 2 is longer than 5; in hind tarsi joint 1 is about as long as 2 and 3 together, while 5 is shorter than 3; abdominal segments each with two dorsal and two ventral rows of numerous bris- tles, the second dorsal row with 12 to 14 bristles, the ventral row with nearly as many, ventral bristles not stronger than dorsal; male claspers long, linear, edges not parallel, end somewhat obliquely cut off, rounded; color, brown; length of male, 2.25 mm., of female 3 to 3.25mm. (Baker.) The form described as Pulux ignota by Baker is evidently a female of this species, and, since it appears to be a Typhlopsylla, the name americana had better be retained. Aside from the species mentioned above in the genus Typhlopsylla, Kolenati has described octactenus, hexactenus, pentactenus, and dictenus occurring on bats in Europe, Tacshenberg wnipectinata on bat in Europe, musculi from rats and mice in Europe, caucasica on Spalax typhlus in the Caucasian Steppes, gracilis on Talpa europea and Sorex vulgaris in Europe, and Baker has described alpina from mountain rat, George- town, Colo., and fraterna from garden mole, Lansing, Mich., and Brook- ings, S. Dak, host unknown. CHAPTER IV. HEMIPTERA. Bugs and Lice. SUBORDER HETEROPTERA. Insects with suctorial mouth parts; four wings, unless altogether wanting, the upper or front pair being thickened or leathery at the bases. The young resemble the adults except in size and in wanting wings. They live upon the juices of plants or animals, which they procure by suction. Family ACANTHIID ™®. (Bed Bug and Allied Forms.) THE COMMON BED Bu6gG. (Acanthia lectularia Linn.) This species, described by Linnzus a century and a half ago, has been a most familiar insect to man, though for how long a time it is quite difficult to determine. Westwood (Introduction, Vol. II, p. 475) Says: , [ts introduction into this country (England) has been a subject of discussion. It was well known to Pliny (Hist. N., 29, 17), Dioscorides, Aristophanes, and Aristotle (Hist. An. Ed. Bek., p. 148,12); but it has been generally asserted to have been brought from America to England, whence it passed to the Continent of Europe, and that it was not known here until 1670. Mouffet, however (Ins. Theatr., p. 270); mentions its having been seen in 15°3. It has, however, been noticed as a singular fact, and as showing that this disgusting visitant must have been comparatively little known in the days of ‘‘Good Queen Bess,” that, although the word ‘‘ bug” occurs five or six different times in Shakspeare’s plays, it is in every instance syn- onymous with bugbear, and does not designate this insect (Patterson’s Shakspeare Letters, p. 59). It is by no means easy to estimate the amount of injury caused by this insect, for so far as man is concerned it consists of loss of time and comfort, while its effects upon other animals are involved in too much obscurity to allow of any estimates being formed: As found in houses infesting man it can only be considered as semi- parasitic, living for the most part secreted in cracks and crevices and attacking its victims during the night. Probably its attacks upon other animals are of a similar nature, although it is referred to by some authors as a parasite of domestic fowls, = vi 158 INSECTS AFFECTING DOMESTIC ANIMALS. The eggs are oval in shape, of a whitish color, slightly narrowed at one end, and will be found in great numbers in the cracks which furnish shelter for the adults. The young bugs escape from the eggs by push- ing off a circular lid at one end. They are similar to the adults except in color and in the proportions of the body regions. At first nearly white, they gradually assume the reddish and finally the dark reddish brown color of the adults. The body is at first more slender and the head larger in proportion to the rest of the body, but gradually the abdomen widens until the insect acquires the shape and size pe in the figure. Professor Uhler says (Standard Natural History, Vol. II, p. 205): This species has been distributed over most parts of the world, chiefly by the agency of man, and, as might be expected under such circumstances, is subject to much variation in the relative size, proportions, and forms of most parts of the body. Full-favored gross specimens are often quite coarsely punctured and_ hairy, while their half-starved brethren have a much thinner outside integ- ument and finer punctures, with less conspicuous pubescence. Some specimens have the wing pads hang- ing loose as if ready to change into wing covers, but generally these are run together into one piece on the middle line. Thus far no indi- Fia. 88.— A canthialectularia: a, young ; b, adult—enlarged vyjidualsof this insect have been met (from Riley). with fully winged. There is some confusion as concerns the attacks of the bedbug or its parasitism on other animals than man. Packard (Guide to the Study of Insects, p. 551) states that “it lives as a parasite on the domestic birds, such as the dove,” and further, same book and page, that ‘ Mr. James MacDonald writes me that he has found a nest of swallows on a court-house in Iowa swarming with bugs.” In the American Ento- mologist (Vol. I, p. 87) the following statement occurs: Ordinarliy the bed-bug is confined to the dwelling places of man, and lives on the blood of us great lords of creation, but we have known it to swarm in prodigious” numbers in a chicken house, where it must have fed exclusively upon chickens’ blood, and it is said to occur also in European pigeon houses. As other species of the same genus have been described as infesting pigeons, swallows, and bats, respectively, it might be that these state- ments are based upon observations which did not take into considera- tion the specific distinctions. Still another source of confusion exists so far as birds are concerned, and that is the occurrence upon the swift (Chetura pelasgia), frequently called “swallow” or ‘chimney swallow,” a species of louse {Nitzschia pulicaria) which, though smaller, has so much of a resemblance to the bed-bug as to mislead an observer not familiar with the characters separating the divisions of insects to which these belong. HEMIPTERA. 159 Whatever its foundation, there is a widespread belief that birds and bats carry bed-bugs from place to place, and considering the suddenness with which they appear in new buildings and sometimes in buildings never used for dwellings, it seems hard to otherwise account for their appearance. Still, to those fa- miliar with the habits of the bed-bug and its opportunities for transportation, there will be no insuperable difficulty in ac- counting for all such appear- ances. Another impression seems to be that bed-bugs occur in the woods and under bark. A foot- Mite cei fen note in Westwood’s Introduc- DN ace tion (Vol. I, p- 475) reads: Fic. 89.—Acanthia lectularia: head and prothorax— much enlarged, showing form and clothing (origi- Southall states that its first ap- nal). pearance took place after the great fire in 1666. ‘‘ Learned men,” says he, ‘‘united in thinking they were imported with the new deal timber, as the bugs were naturally fond of turpentine woods.” — It is certain that they swarm in the American timber employed in the construction of new houses; and it is said that they feed upon the sap of that wood. We fail to find, however, any authentic record of such occurrence from personal observation, and since we have never met it in collecting under the best conditions for observing it we are inclined to think that the impression is due entirely to other insects closely resembling the bed-bug having been mistaken for it. In 1839 Mr, Leonard Jenyns published a paper in the Annals of Natural History (Vol. 5, pp. 241-244) on three undescribed species of the genus Cimex, closely related to the common bed-bug (C. columbarius, hirundinis, pipistrelli). These are stated to infest, respectively, the pigeon, the swallow, and the bat. The occurrence of any of these but hirundinis has not yet been re- corded in the United States, although, for reasons already stated, they might fail to be recorded even were they fairly common. PREVENTION AND REMEDY. Cleanliness and the application of the common remedies, such as ben- zine, corrosive sublimate, and hot water will usually suflice to keep. these pests reduced in ordinary dwellings, but in large buildings more general measures may sometimes be necessary, and in such cases there is probably nothing more effectual, when it can be done, than thorough fumigation with sulphur, brimstone, or perhaps bisulphide of carbon. “T have known a house which had long stood empty, and yet swarmed with them, thoroughly cleansed by.fumigation with brim- stone” (Westwood). We know personally of an instance where a large building, badly 160 INSECTS AFFECTING DOMESTIC ANIMALS. infested with this pest, on being thoroughly fumigated with sulphur as a disinfectant against scarlet fever remained for some time compara- tively free from bugs. : Attention to the cracks in the walls and around casings, as well as to the joints of bedsteads, will do much to keep pests under control. For immediate relief in a sleeping room pyrethrum is most available, since it can be used while a room is occupied. Dusted between the sheets of a bed, it will protect the sleeper from the most voracious hotel bug. THE “CORUCO,” OR MEXICAN CHICKEN BuG. (Acanthia inodora Dugés.) In 1892 Dr. Alfredo Dugés, of Guanajuata, Mexico, described! and figured a species of bed-bug infesting poultry, and the same, or a very closely related form, is recorded from southern New Mexico by Prof. C. H. Tyler Townsend, who says: There exists in southern New Mexico a Cimicid, known by the Mexican name of - coruco, which is an unmitigated pest of poultry in this region. When the insect once gains access to the hen- house it soon swarms in great numbers, infesting the inmates and roosts, and covering the eggs with the excrementa, which show as black specks. It is a very difficult pest to exterminate, and has been fre- quently known to spread from roosts to dwelling houses, where it proves more formida- insect also exists in western Pexag,? 6, Seo Dr. Dugés mentions applica- tions of vinegar as a remedy,’ doubtless to be applied ta the poultry to alleviate the bites, as well as to deter the corucos from biting. Here burning of sulphur in the henhouses and spraying of kerosene have been tried with doubtful results. About the only way to keep poultry uninfested is to keep them entirely out of doors and not to house them at all. The corucos infest and stick to the houses and roosts, awaiting the return of the hens at night. They began to appear in Las Cruces the present year (1893) before the middle of April. Iam informed that the corucos often swarm in immense numbers in houses, com- ing up through the floors and cracks. In such cases it is almost impossible to get rid of them, the easiest and most economical way being to desert the house. They Fia. 90.—Acanthia inodora: female; a, outline of egg—en- jarged (original). 1La Naturaleza, 2d series, Vol. II, 1892, Pl. VIII, 8 figs. ble than the bed-bug. This - a Soe ere, HEMIPTERA. 161 have been known, according to one informant, to swarm in military posts in former times in southern New Mexico to such an extent that the soldiers were ordered out and formed in two lines, one line with brooms to sweep the corucos en masse up against an adobe wall, where the other line stood ready with trowels and mud and plastered them into the wall alive—a novel but effective means of riddance! I have not seen Dr. Dugés’s original article, but he has very kindly sent me specimens of the insect, and from these the accompanying drawing has been prepared. It will be seen that the form is quite distinct from that of the ordinary house bug, especially in the excava- tion of the prothorax in front, which is very slight, the lateral angles not projecting forward on the sides of the head. THE BARN-SWALLOW BUG. (Acanthia hirundinis Jenyns.) This species has occurred in great numbers in the nests of the com- mon barn swallow at Ames, lowa, the occurrence being noted by Prof- fessor Gillette (Entomological News, Vol. I, pp. 26-27) and by the writer in the Canadian Entomologist, Vol. XXIV, p. 264. The bugs appear to be confined to the swallow nests or upon the parts of the barn adjacent to them, some being ob- served on the sides of the barn nearly down to the ground. They were very abundant after the swal- lows hac left in autumn, and specimens kept in a bottle corked with a rubber stopper were alive the fol- lowing summer. It would be an easy matter for them to survive in the nests or in cracks and corners of the building near the nests during the winter absence of the hosts. The nests contained immense num- bers of empty eggshells, showing that the eggs were deposited directly in the nests, and where the young bugs in hatching would at once gain access to the birds. While it is impossible to say at just what time the eggs were laid, it is safe to conjecture that they are laid some time during the early part of the summer, probably soon after the appearance of swallows in the spring, and that the young become partially grown at least before fall. It is of course possible that they may use other food than the blood 4653—No. 5——11 Fic. 91.—Acanthia hirundinis—enlarged (original). 162 INSECTS AFFECTING DOMESTIC ANIMALS. of the swallows, but it is evident that they are closely associated with this bird as a host. The figure will indicate the distinctive characters of the species, and comparison with the lectularia and inodora will reveal sufficient basis for considering it a distinct form. The species occurring upon the pigeon and the bat have not been recorded for America so far as I am aware, but it is quite probable that they may occur. They are evidently quite distinct species, and it would be a matter of interest to determine their occurrence here. Acanthia columbaria Jenyns is specially characterized by the rounded form of the abdomen, the slightly excavated prothorax, and the third joint of the antenne being longer than the fourth. Acanthia pipistrelli Jenyns has the abdomen narrowed, the prothorax moderately deeply excavated, the antenne intermediate, between lectu- laria and columbaria. a Fic. 92.—Antenne, showing comparative length of joints in a, Acanthia hirundinis; b, A. lectularia; c¢, A. inodora—enlarged (original). Considering the inaccessibility of the original descriptions to many students, it may be useful to repeat here the full technical descriptions as given by Jenyns (Annals of Natural History, 1839, Vol. III, pp. 241-244): C. lectularius: Ferrugineo-ochraceus; thorace profunde emarginato, lateribus reflexis; abdomine suborbiculato, apice acuto; antennis articulo tertio quarto longi- ore. Long. 24 lin. Hab. In domibus. C. columbarius: Ferrugineo-ochraceus; thorace profunde emarginato, lateribus reflexis; abdomine orbiculato, apice subacuto; antennis articulo tertio quarto paulo longiore. Long. vix 24]lin. Hab. In columbis. C. hirundinis: Fusco-ferrugineus; thorace leviter emarginato, lateribus planis, abdomine ovato, apice subacuto; antennis brevibus, articulo tertio et quarto sub- aequalibus. Long. 1}lin. Hab. In nidis Hirundinis urbice. C. pipistrelli: Ferrugineo-ochraceus, nitidus; thorace profunde emarginato, lateri- bus paulo reflexis; abdomine ovato, postice attenuato; antennis articulo tertio guarto longiore. Long. 2lin. Hab. In Vespertilione pipistrello. C. columbarius: On comparing this species with the common house bug it will be found to be smaller and of a more circular form. The antennz are shorter and the joints are not quite so slender, and the difference in length between the third and fourth joints is not so considerable. The thorax is rather less hollowed out in front, the anterior angles less produced, and the sides less reflexed. The abdomen more nearly approaches the round, the lateral margins being very much curved and the greatest breadth exactly in the middle; whereas in the house bug the lateral margins are at first but little curved, and the greatest breadth rather behind the middle, The colors as well as the degree of the pubescence are similar in the two species. HEMIPTERA. 163 C. hirundinis: This species is rather less than C. columbarius ana in respect to form different from both this and the C. lectularius. The antennwe are comparatively short, and the third joint is scarcely if at all longer than the fourth. The eyes are not so prominent, the thorax is much less hollowed out in front, the anterior angles but: little produced, and the sides scarcely at all reflexed. The scutellum is wider at the base or more transverse and does not project so far backward; the elytra are less coarsely punctured; the abdomen is not so broad, and more rounded at the apex, the sides regularly curved. The whole insect is more pubescent. The color is ferru- ginous, inclining to testaceous, darker than in the common bed-bug, and the head and thorax are much clouded with fuscous. In one specimen the legs are spotted at or near the joints with this last color. There are also some fuscous spots on the abdo- men. The young or pupe have the abdomen much narrower than the perfect insect, inclining to oblong. C. pipistrelli: The antenne of this species are of an intermediate length between those of the C. lectularius and those of the C. columbarius, and the third joint is obviously longer than the fourth. The eyes are prominent. The thorax has a mod- erately deep excavation in front, and the sides are partially reflexed. The abdomen is narrower than in either of the above-named species, and much more attenuated posteriorly, the greatest breadth being rather before the middle. The thighs are more incrassated. The whole insect is more pubescent, approaching to hispid, and rather coarsely punctured. The color is dark ferruginous ochre, glistening with a faint metallic or subaeneous hue, not perceptible in any of the other species. The legs and antenn2 are a shade paler than the abdomen, and, as well as this last, with- out spots. Family REDUVIID2. This family contains a large variety of bugs, the majority of which appear to be strictly carnivorous in habit, many of them being of no little service in destroying injurious insects. They are provided with stout curved beaks; the antenne have the terminal joints smallest; the head is cylindrical, the neck usually long and the bodies generally slender, while the legs are strong and often armed with spines. Many species are capable of inflicting severe wounds, but probably very few of them do so except in self defense. One species, however, has been So many times recorded as attacking individuals of the human species for the purpose of sucking blood for food that it should be mentioned, at least, in this connection. THE BLOOD-SUCKING CONE-NOSE. (Conorhinus sanguisuga Lec.) This species, sometimes called the “big bed-bug,” is distributed throughout the southern United States and has been reported as fre- quently occurring in beds, attacking the sleepers and sucking their blood. The following from the American Entomologist (Vol. I, p. 88) sums up its habits: While taking his meal, as we are informed, he fairly spraddles himself out, and seems to enjoy it hugely. In the more southerly parts of Illinois, namely, in Madi- son, Jersey, and Union counties, we know of no less than eight specimens having been found in beds, and it must also occur as far north as Adams County, for we saw it in a collection of insects made at Quincy and exhibited at the State fair in 1868. Mr. Uhler, as he informs us, formerly received a specimen from southern Ohio, near Marietta, at which place it was said to be occasionally found in beds, and to cause ES Se : 164 INSECTS AFFECTING DOMESTIC ANIMALS. severe inflammation by its puncturing. Dr. E.S. Hull, of Alton, Ill., was once, as he tells us, bitten in three places in the arm by one of these eroabuves, and the arm became so inflamed in consequence that for three days afterwards he almost lost the use of it. In the northerly parts of the United States, so far as we are aware, it does not occur. Like many of its allies it passes the winter in the perfect state, for we have ourselves captured it in south [llinois under loose bark in November, in company with its pupa (fig. 93, bd). Fia. 93.— Conorhinus sanguisuga: a, pupa; b, adult (from Amer. Entom.). All the species of this genus, most of which are South American, fly into houses by night, according to Burmeister, and live upon the blood of mammals, the puncture ot their beaks causing great pain. In the larval and pupal states they probably suck the juices of insects; for being wingless in those states they would have no means of reaching the larger animals. The single pupa that we found under bark in winter time occurred in a place that was about half a mile from the nearest house; so that at all events it certainly could have had no chance there to suck human blood. SUBORDER PARASITA. This group includes the suctorial lice, confined to mammals; they are strictly parasitic insects, being confined to their hosts constantly and deriving all their nourishment from them. They are wingless, and the mouth parts consist of a tubular suctorial organ. This suborder contains but two families, the first of which, the Poly- ctenidz, contains, so far as known, but two species, both of ahr are confined to bats, one in Jamaica and the other in China. These do not properly fall within the province of this paper, and it will not be neces- sary to give them further consideration. Family PE DICULID A. (The Suctorial Lice.) This family includes nearly all the species of the suborder and all that come within the limits of this paper. We need only add to the character above given the short rostrum without joint and the tarsi adapted to clasping and holding to hairs. 4 et Se Sap ea ean 2 aC ead egmonicg ine niet eth: “aT . ve HEMIPTERA. 165 The eggs—“‘nits”—are attached to hairs by a glue-like substance, and the young lice when hatched resemble the adults except in size. As the entire life of the parasite is passed upon the same animal or on another animal of the same kind, its range of habit is easily stated. But very few of the species are ever found upon any other species of animal than that which they normally infest, and if so always upen very nearly related species. Whether this is due to differences in the thickness of the skin, of tem- (4 perature, of the size of the hair to which they must adhere and to which their feet are adapted, or to some subtle difference in the odor or taste peculiar to their particular host which leads them to dis- card all others, we are unable to say. The mouth parts are necessarily capable of great extension in order to reach the blood of their hosts. Uhler says (Standard Nat. Hist., Vol. II, p. 209): “A fleshy unjointed rostrum, capable of great extension by being rolled inside out, this action serving to bring forward a chaplet of barbs which embed themselves in the skin to give a firm hold for the penetrating bristles, arranged as chitinous strips in a long, slender, flexible tube, terminated by four very minute lobes, which probe to the capillary vessels of asweat pore. The blood being once reached a current is maintained by the pulsations of the pumping ventricle and the per- istaltic movements of the stomach.” The species infesting man are so nearly related to the others that we can not well pass them by without notice. THE CRAB LOUSE. (Phthirius inguinalis Leach.) If we may depend upon ancient writers, this / species has long been a companion of man.