402 THE MANAGEMENT AND FEEDING OF CATTLE 



bing it onto the affected parts with the hand or with a 

 cloth; the second should be applied every other day with 

 a small brush ; the third and fourth every day with 

 the hand or with a cloth. A few days of faithful treat- 

 ment will check and remove the disease. Isolation of 

 the affected animals is not necessary when treatment is 

 promptly administered. 



Warbles on cattle. — Warbles are grubs which 

 mature in the flesh of cattle immediately underneath the 

 skin and usually in the region of the back. It was for- 

 merly believed that they were produced by the ox bot fly 

 of Europe (Hypoderma bovis), but it has been satisfac- 

 torily demonstrated that the tgg which produces warbles 

 is laid by another species, Hypoderma lineata, which more 

 or less resembles the former in appearance and habits. 

 The general color of the fly is black, and in conforma- 

 tion it resembles a bee. For many years it was be- 

 lieved that the fly laid its eggs in the body of the 

 animal after piercing the skin. The preponderance of 

 evidence, however, points to the fact that the eggs are 

 laid somewhere in the hairs of the body, supposedly in 

 the region of the heel, though this is by no means cer- 

 tain, and that they are conveyed to the mouth by the 

 tongue of the animal when licking itself. In the first 

 stages of development the larvse have been found in 

 considerable numbers in the esophagus of cattle in the 

 month of November. Usually by the latter part of 

 January they have all disappeared from the esophagvis 

 and by that time the small lumps traceable on the skin 

 of the back indicate their presence. In the interval it is 

 thought that they have worked their way through the 

 tissues. They continue to grow in their final home and 

 then work their way through the skin frequently as late 

 as April or May, when they fall to the ground, into which 

 they burrow, pupate and emerge in about a month as a 

 fly. When the grubs leave the body they are about three- 

 quarters of an inch long, and they quickly change from 



