THE SCREW-WORM is an important pest of nearly all stock 

 in the Southwest. In some sections the rearing of young 

 calves is practically prevented by its ravages. Some grown 

 stock are killed outright and some are maimed permanently, 

 while infested sheep always lose llesh and their milk produc- 

 tion decreases. The expense of watching herds and treating 

 infested animals also is considerable. 



Several kinds of Hies infest wounds and blow soiled wool 

 on sheep. These flies may occur in any part of the United 

 States. 



All of these flies breed in decaying animal matter, espe- 

 cially in carcasses of large animals. If all dead animals could 

 be disposed of properly, no cases of infestation of living 

 Rnimals would occur. 



Complete destruction of carcasses by burning is the ap- 

 proved method. This lessens danger of the spread of such 

 diseases as anthrax and tuberculosis from animal to animal 

 in pastures and prevents all breeding of flies in carcasses. If 

 burning can not be carried out properly, bury carcasses, cov- 

 ering them with at least 2 feet of soil, 4ppiy i liberal ([uan- 

 tity of quicklime prior to covering, especially if i possibility 

 exists that the animal died of some contagious disease. 



Other steps to prevent infestation are avoiding injury to 

 stock, having calves come when flies are not abundant, destroy- 

 ing ticks, performing surgical operations in winter or early 

 spring, and poisoning or trapping flies. To prevent attack 

 of the wool-maggot, lamb early, avoid diarrhea, tag sheep 

 if dirty, and breed hornless types. 



In treating stock watch for the first signs of infestation, use 

 chloroform to kill maggots, and follow with pine tar to repel 

 flies. 



For further information about the screw-worm fly and other 

 flies infesting wounds, with accounts of their habits and the 

 methods of controlling them, consult the following pages. 



