114 



Insects injurious to Domestic Animals. 



Vol. IX. 



Insects injurious to Domestic Animals. 



By Willis Gaylord. 



It must be considered a singular circum- 

 stance, that scarcely an animal of any kind 

 can be named, which is not made the prey 

 in some form of animals parasitical or other- 

 wise, lower in tlie scale of being than them- 

 selves. Even man himself suffers in this 

 way, and the animals domesticated by him, 

 not unfrequently fall victims to some of the 

 various insects that seek their food, and pro- 

 vide for their offspring by preying on the 

 living. The hair, the skin, th« flesh, the 

 intestines, all have their injurious insects, 

 and even the vital parts are not ahva3's ex- 

 empt. Lice multiply in the hair and fea- 

 thers ; grubs infest the nostrils, skin and 

 stomach ; the entozoa are found in the flesh 

 of the living and apparently healthy beasts; 

 and one species, the filaria, has in more in- 

 stances than one taken up its abode in the 

 eye itself; worms of numerous varieties har 

 hour in the intestines, and in many ways 

 cause irritation, disease and death. Where 

 the field is so large, it cannot be expected 

 that every part of it shall have been fully 

 explored; but much useful information has 

 been gleaned, which, if spread before the 

 farmer, can scarcely fail of being beneficial 

 to him. 



The horse is one of the most valuable of 

 our domestic animals, and y^erhaps the one 

 most liable to danger from the attacks of in- 

 sects. Many good horses are lost every 

 year from hots, or diseases connected with, 

 or produced by them. Some of the best 

 writers on the horse and the insects inju- 

 rious to the animal, divide the horse-bot into 

 three kinds, all the progeny of a species of 

 CRstrus or horse-fly. The first and the one 

 most common, is the parent of the bot com- 

 monly observed in the stomach of the horse. 

 The name of this fly is the Gaslerophihis 

 equi. This fly deposits its eggs on the legs 

 of the horse, and when the horse bites or 

 licks the spot covered by the nits, the young 

 larvfB adhere to the tongue and are carried 

 into the stomach, where they fasten them- 

 selves to its coat, and remain until ready to 

 assume the pupa state, when they cease to 

 adhere to the coat of the stomach, are ex- 

 pelled with the dung, pass into the earth 

 and through the clirysaJis state, and finally 

 emerge perfect insects. This bot-fly is too 

 well known to need description. Any per- 

 son may satisfy liimself of the manner in 

 which this worm is produced from the egg 

 by scraping some fresh deposited ones from 

 the hair, and placing them in Iris closed 

 hand, first moistening it with saliva; or he 

 inay place his hand thus moistened on the 



leg of the animal, so as to cover a quantity 

 of the nits, and in either case he will soon 

 find his moistened hand covered with living 

 larvae. 



Another bot-fly, the Gasierophilus hcEino- 

 rhoidalis, deposits its egg on the lip of the 

 horse, whence the larvae are taken to the 

 stomach. It also, and perhaps more fre- 

 quently, deposits its eggs, during the evacu- 

 ation of the dung, and the subsequent pro- , 

 trusion of the intestine. These bots are 

 frequently found within the verge of the 

 anus, whence their name. They are less 

 injurious to the horse than the other kind, 

 but sometimes occasion no little itching or 

 irritation, when an injection of the linseed 

 oil may be used to dislodge them. 



A third bot-fly is the Gastercphilus vele- 

 rinus. The horse, while feeding or stand- 

 ing in the harness, will at times be observed 

 to fling up his head suddenly, as if hurt or 

 alarmed; and frequently, if at liberty, will 

 run off" to some other place. The trouble 

 is occasioned by this fly, which, poising 

 itself under the belly of the animal for a 

 moment, darts between the fore-legs and 

 strikes the throat of the horse immediately 

 between and above the upper curve of the 

 jaw, depositing an egg at each blow. This 

 is done by a sharp-pointed ovipositor, and 

 hard swellings are sometimes caused at that 

 point, from the repeated stingings inflicted. 

 It is supposed the red bot, found occasionally 

 in the stomach of the horse, proceeds from 

 this fly : but in what manner the larvae 

 makes its way into the stomach, after the 

 egg is deposited in tliis way, is not very ob- 

 vious. We have found bathing the stung 

 part or the swelling, with spirits of turpen- 

 tine, to act favourably, either by allaying 

 the irritation, or, perhaps from its penetrat- 

 ing qualities, destroying the young larvas. 



In what manner the bot in the stomach of 

 a horse causes its death, does not seem to 

 be well understood ; and from the fact that 

 horses in perfect health, when accidentally 

 killed, have had their stomachs found filled 

 with bots, some have denied that they ever 

 do injure the horse or cause death. It is a 

 law of nature, however, that all parasites, 

 whether on plants or animals, do inflict in- 

 jury and may occasion death ; and the bot 

 docs not seem to form an exception to this 

 law. And from the facts that they do some- 

 times fix themselves in tlie upper part of the 

 windpipe and produce a fatal irritation and 

 cough ; that they sometimes collect in such 

 masses in the first intestine as completely to 

 clioke it up and fatally obstruct it; and that 

 when death attributed to bots has happened, 

 the stomach immediately on death has been 

 found perforated in a multitude of places, it 



