witli brownish-] )lack hairs. There are four raised Hnes on the thorax, 

 which are pohshed and shinino-, as shown in the ilhistration (fig;. 1). 

 The hairs on the tip of the body are reddish brown. 



The European bot-fly {Hy poderma hovis) is a much hirger insect, 

 and is strongly banded with yellow and black, 

 ^^ as indicated in fig. 2, the light areas repre- 

 sentins: the vellow color. 



r,. 



cc 



J> 



Fig. 9. — Hypoderma hovis: a, 

 puparium, from side; b, same, 

 from above, showing exit hole 

 of adult; c, cap which splits 

 oil to allow the adult to issue— 

 natural size (after Clark). 



PREVENTIVES AND REMEDIES. 



It is possible to greatly diminish the loss 

 occasioned by the ox bot, and this is notably 

 true of the smaller herds belonging to the 

 general farmer, dairyman, and to the raiser 

 of improved breeds, which are better cared 

 for and more easil}^ handled. For the great 

 herds of half-wild cattle covering the extensive grazing districts of 

 the West and Southwest, any treatment becomes a matter of extreme 

 difficulty and will often be impracticable. Even in such cases, how- 

 ever, it may be possible to prevent excessive loss, as will be indicated 

 below. 



The common means of preventing the attacks of this fly and of 

 killing the larvae after they have reached their final location in the 

 back are of very ancient origin, having 

 been referred to, in fact, by Pliny, writ- 

 ing in the first century of our era, and 

 were probably known much earlier. 

 Nothing better has been found for the 

 purpose in modern times, although the 

 methods are perhaps more effective 

 now on account of the better knowledge 

 of the habits of the insect. 



The substances used are any strong 

 smelling oils and fats, by means of 

 which it is possible to prevent the fly 

 from depositing its eggs on the animal 

 and also to kill the larvie in their final 

 stages in the back. The larvae, during 

 their earl}^ and wandering stages, are 

 out of reach, and it is impossible to 

 kill them. 



The oils commonly used for the pur- 

 poses mentioned are the train oils or fish oils, either alone or with 

 sulphur or carbolic acid mixed. The addition of the latter is espec- 

 ially favorable to the healing of sores and diseased places left by 

 the grubs. Common axle grease may be used for the same pur- 



FiG. 10.— Larva, probably of Hypo- 

 derma lincala, takeu from boy: o, 

 ventral surface; b, anterior end; c, 

 anal end— all enlarged (from Insect 

 Life) . 



