SHEEP INSECTS 145 



wool; also exporters suffer loss because American 

 live stock are prohibited from Europe. 



Scab is caused by small mites that work in the 

 skin causing the wool to fall off and producing large 

 scabs over the body; there are four varieties of 

 mites that work on sheep and cause scab — the mite 

 causing the common or "body scab"; the mite cans-- 

 ing the ''head scab"; the mite causing the ''foot 

 scab" ; and the mite causing the "follicular scab" 

 affecting the eyelids. 



The common or body scab is a severe itching dis- 

 ease and occurs most often on the backs and sides 

 where the wool is longest; it is the worst form of 

 the disease in this country ; the mites multiply with 

 wonderful rapidity; one female lays 15 to 24 eggs 

 which hatch in a few days, and in 15 days the young 

 become adults ; in a few months a single female can 

 produce an enormous number of progeny. 



Control — When far advanced, soften the scab 

 with some kind of grease or oil, and then apply 

 some of the common "sheep dips"; the active in- 

 gredients in most "dips" are tobacco, arsenic and 

 carbolic acid ; each sheep will require from a quart 

 to a gallon; use the dip at a temperature of 100 de- 

 grees in summer and 10 degrees warmer in winter; 

 a simple method of treating a few sheep is to turn 

 them on their back and pour the dip along the mid- 

 dle line of the venter; where large numbers are to 

 be dipped, special tanks are made ; a kerosene emul- 

 sion is also a good sheep "dip" ; a second or third 

 dipping may be necessary, as the dips do not often 

 kill the eggs, and another brood may appear later. 



The sheep "tick" ^ {Melophagiis ovinns) 

 Order — Diptera. Manual, p. 488 



A curious, degraded, wingless insect belonging 



^ Imes— U. S. Dept. Agr., Ear's' Bull. 798. 



