FAEMERS' INSTITUTES. 



165 



Fig. 1. 



Gasirojjhilus equL- 

 Horse bot-flv. 



natural Hisfory. 



The flies (Fig. 1*), which may be soon from early summer even till autumn, 

 are thickly set with brownish hairs, while the wings are 

 plainly specked with darker spots. The eyes are black and 

 wide apart, while the face in front of them is whitish. The 

 thorax has a central spot of black, and the abdomen, between 

 tlie segments, is darker than tlie general color, and it is also 

 flecked with darker spots. The abdomen of the female is 

 tapering, and terminates in an extensible ovipositor, which 

 bends down imderneath the abdomen. The male has 9, 

 _ more oval abdomen, and is also of a deeper brown than is 

 the female. The female deposits her eggs beneath the lower 

 jaw, along the mane, upon the shoulder, and even more abundantly along the 

 forward legs, within and below the knees. Does the female remember when she 

 herself was young, and what were then her needs? Else what teaches her to so 

 place her eggs that the young hot, now soon to issue therefrom, will most readily 

 be taken into the mouth and carried to the stomach, upon which event their 

 very lives depend. The light yellow ovoid eggs are glued one at a time to the 

 hairs, much to the annoyance of the horse, as denoted by the quick jerking 

 movements of the head and stamping of the feet. The young are already nearly 

 developed in the eggs, from which they soon issue, though the empty shells may 

 remain away into the winter. As the horse licks itself or its companions, some- 

 times impelled, perhaps, by a tickling sensation induced by the movement of 

 the wee bots, these latter are lapped up and conveyed to the throat or stomach. 

 The bots (Fig. 2 ) are stout, lieshy larvae, nearly egg-shaped, the mouth being- 

 at the tapering end. They are whitish, becoming darker with age. 

 When full grown they are about one incli long. About tlie mouth 

 are hooks by which they maintain their hold, while the spines are in 

 double transverse rows, extending around the anterior border of each 

 These spines are reddish, with dark tips, and point backwards. There 

 are no spines on the two posterior segments. The last segment is truncate, and 

 has fleshy lobes which conceal the spiricle plates. These bots attach for the 

 most part to the mucous membrane of the left side of the stomach, though they 

 are often found in the throat, on the right side of the 

 stomach, in the small intestine, and when full grown in 

 and about the anus. When found their head is buried in 

 small depressions (Fig 3). I recently examined the throat 

 of a horse which was supposed to have been killed by bots, 

 and found it quite full of these pits, each with its bot. f 

 In spring and early summer these maggots pass from the 

 alimentary canal of the alfected horse, enter the ground 

 and within their own skin assume the pupa state. They 

 remain as pupre between one and two months, when the 

 mature fly again appears. 



Effect Upon the Horse. 



In the throat, when numerous, the bots may cause much inconvenience ; 



Flu. 2. 

 Horse-bot. 



rmg 



Fig. 3. 

 Horse-bots at work. 



*The figures iu this article are all from the valuable work of Prof. James Law, of Ithica, New 

 York, — " The Farmer's Veterinary Adviser," who generously gave us the use of the engravings from 

 which to procure electrotypes. 



*Professor Law writes me that there are well authenticated cases of horses having died from 

 such attacks. 



