BOT-FLIES. 



BOT-FLIES. 



troublesome to horses. Bots are the larvae or 

 maggots of a species of gad-fly (the (Estrus 

 equi), which deposits its eggs on the legs, mane, 

 or those parts of the horse that the animal is 

 most apt to lick. The egg is immediately 

 hatched by the warmth and moisture of the 

 tongue, and the little worm conveyed into the 

 mouth, whence it crawls down the oesophagus 

 into the stomach. It adheres to the cuticular 

 coat of the stomach by means of little hooks, 

 with which its mouth is furnished ; and there 

 it remains from the summer of one year to the 

 spring of the next, nourished by the mucus of 

 the stomach, or the food which it contains. 

 Then having attained its full size as a maggot, 

 it loosens its hold, and is carried along the in- 

 testines with the other contents of the stomach, 

 and evacuated with the fceces. Before it drops, 

 it generally clings for a while to the verge of 

 the anus, and tickles and teases the horse to a 

 very great degree. Except they exist in most 

 unusual numbers, bots do neither good nor 

 harm during their residence in the stomach of 

 the horse. It is the habitation which nature 

 has assigned to them; and the safety of so 

 noble an animal as the horse would not have 

 been compromised for the sake of a maggot 

 and a fly. The best advice that can be given, 

 therefore, is to let them alone, or at most to be 

 content with picking them off when they appear 

 under the tail. There are two good reasons 

 for this. The first is, that there is not any me- 

 dicine that will expel them ; the strongest and 

 even the most dangerous purgative is insuffi- 

 cient. The second reason is, that if the bots 

 are let alone, they will, in due time, come all 

 away without our help or meddling. (Clater's 

 Farriery, p. 168 170.) Green food, however, 

 expels them readily, as does common salt in 

 the proportion of two to four ounces to a quart 

 of water. The most simple and efficient reme- 

 dy is a quart of milk, mixed well with a quar- 

 ter of a pound of honey or brown sugar, given 

 fasting. This is much better than aloes. 



BOT-FLIES. The various insects, impro- 

 perly called bot-bees, are two-winged flies, be- 

 longing to the order Diptera and the family 

 (EstridcE. Bot-flies do not seem to have any 

 mouth or proboscis ; for, although these parts 

 do really exist in them, the opening of the 

 mouth is extremely small, and the proboscis 

 is very short, and is entirely concealed in it, 

 so that these insects, while in the winged state, 

 do not appear able to take any nourishment. 

 The larvae or young of bot-flies live in various 

 parts of the bodies of animals. They are thick, 

 fleshy, whitish maggots, without feet, tapering 

 towards the head, which is generally armed 

 with two hooks, and the rings of the body are 

 surrounded with rows of smaller hooks or 

 prickles. When fully grown, they drop to the 

 ground and burrow in it a short distance. 

 After this, the skin of the maggot becomes a 

 hard and brownish shell, within which the in- j 

 sect turns to a pupa, and finally to a fly, and 

 comes out by pushing a little piece like a lid 

 from the small end of the shell. 

 $ More than twenty different kinds of bot-flies 

 are already known, and several of them are , 

 found in the United States. Some of them have 

 been brought here with our domesticated ani- , 

 214 



mals from abroad, and have multiplied ar.l 

 increased. Three of them attack the horse. 

 The large bot-fly of the horse (Gastrrophilus 

 equi} has spotted wings. She lays her eggs 

 about his knees ; the small red-tailed species 

 (G. hcemorrhoidalis), on his lips; and the brown 

 farrier bot-fly (G. veterinus), under his throat, 

 according to Dr. Roland Green. By rubbing 

 and biting the parts where the eggs are laid, 

 the horse gets the maggots into his mouth, and 

 swallows them with his food. The insects 

 then fasten themselves in clusters to the inside 

 of his stomach, and live there till they are fully 

 grown. The following are stated to be the 

 symptoms shown by the horse when he is 

 much infested by these insects. He loses flesh, 

 coughs, eats sparingly, and bites his sides; at 

 length he has a discharge from his nose ; and 

 these symptoms are followed by a stiffness of his 

 legs and neck, staggering, difficulty in breath- 

 ing, convulsions, and death. No sure and safe 

 remedy has yet been found sufficient to remove 

 bots from the stomach of the horse. The pre- 

 ventive means are very simple, consisting only 

 in scraping off the eggs or nits of the fly every 

 day. Bracy Clark, Esq., who has published 

 some very interesting remarks on the bots of 

 horses and of other animals, maintains that 

 bots are rather beneficial than injurious to the 

 animals they infest. (Dr. Harris.) 



If a piece of the maw or stomach of a horse 

 that has died while affected with bots be 

 cut out, it may be held under the jet of the 

 strongest fountain or hydrant, without the 

 maggots or bots leaving go, or loosing their 

 hooks. Experiments have been made to de- 

 stroy them out of the body with spirits of tur- 

 pentine, alcohol, and a great many of the most 

 stimulating and acrimonious substances, in 

 liquid and other forms, all, however, with little 

 apparent effect upon an insect so very tena- 

 cious of life. The bot-maggot is even said to 

 live a considerable length of time in oil of vi- 

 triol and nitric acid or aquafortis. After such 

 results, the chance of destroying them in the 

 body must be small, through means which 

 would not destroy the horse. The following 

 ingenious method has, however, been pursued 

 with success. A full drench has been admi- 

 nistered, consisting of a mixture of milk sweet- 

 ened with molasses, followed soon after by an 

 active purgative drench. The milk and mo- 

 lasses tempt the bot-maggots to let go their 

 holds in order the better to partake of the milk, 

 in which condition they are worked off quickly 

 by the brisk operation of the medicine. 



The maggots of the (Estrus bovis, or ox bot- 

 fly, live in large open boils, sometimes called 

 wornils or wurmals, that is, worm-holes, on 

 the backs of cattle. The fly is rather smaller 

 than the horse bot-fly, although it comes from 

 a much larger maggot. The sheep bot-fly 

 (Cephalemyia oin's) lays its eggs in the nostrils 

 of sheep, and the maggots crawl from thence 

 into the hollows in the bones of the forehead. 

 Deer are also afflicted by bots peculiar to them. 

 Our native hare, or rabbit, as it is commonly 

 called, sometimes has very large bots, which 

 live under the skin of his back. The fly 

 ((Estrus buccatus) is as big as our largest 

 humble-bee, but is not hairy. It is of a reddish- 



