PAEASITES 



429 



for the purpose of leather. Miss Ormerod calculated the 

 loss in Great Britain and Ireland was not less than two 

 millions a year. It has been suggested it should be made 

 a scheduled disease, and all owners of warbled cattle com- 

 pelled to dress them during the spring, at a time when the 

 disease is practically under control, for it is obvious if the 

 larvse are then killed no fly develops. 



For this purpose the following should be used every few 

 days to the holes in the back, viz., a mixture of Sulphur, 

 Creosote, and Train Oil. This placed on the openings into 

 the tracheae suffocates the larvffi ;* the same results from 

 the application of mercurial ointment. It is better, how- 

 ever, to squeeze out the larvse in 

 the spring and kill them. As a 

 preventive measure cattle before 

 being turned out to grass should 

 be dressed along the back and 

 shoulder blades with Stockholm 

 tar, I or butter and tar mixed with 

 sulphur. Sheds give protection 

 against fly attacks, and it is said 

 the flies will not cross water. 

 This is a common characteristic 

 with some of the most formidable 

 fly pests, for example Tse-tse. ^is- W2--^gf oi GastrovUhis 



'' ^ _ . eqiii attached to hairs oi horse 



Gastrophilus equi or Horse Bot and showing larva just hatched 



Fly is about half to two-thirds of (°^%™fl«d). 

 an inch long, with reddish hairs on a dark banded thorax, 

 and yellowish brown hairs on the abdomen. The eggs are 

 deposited on the hair (Fig. 182), principally in the region 

 of the fore-limbs, and are about yV inch long. When the 

 egg is hatched, the larvse pushing off the lid, and their 

 wriggling causing irritation, the horse rubs by the lips or 

 licks the place, and so the larvae are conveyed to the mouth. 

 In the stomach the larvse attain their full size, about 

 I inch. They are provided with two hooks around the 

 mouth, by which they anchor themselves to the wall of 



* Eeoommended by Mr. Thomson, M.K.C.V.S., Aspatria. 



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