SHEEP AND SWINE PARASITES 441 



by having all sheep brought from infested regions dipped before 

 delivery. 



Sheep tick {Melophagns ovinus). — Reddish or gray brown, flat- 

 tened, wingless flies that infest sheep of all ages, but are most in- 

 jurious to lambs. They remain on the sheep throughout their 

 whole life cycle. The young are nourished within the mother until 

 full grown, and are ready to pupate when born. 



Treatment. — The nicotine-and-sulfur dip has given the best results 

 in the control of this pest ; many of the commercial cresol and coal-tar 

 creosote dips are also effective. The lime-and-sulfur dip will not kill 

 the ticks. When only a few are to be treated, kerosene emulsion may 

 be used as a spray and rubbed into the wool. 



Swine. Hog louse (Hcematopinus suis). — Lousy hogs are likely 

 to be in a stunted, unthrifty condition, and when badly infested the 

 skin becomes covered with scales and sores. 



Treatment. — Clean and whitewash the pens and sleeping quarters, 

 adding 1 pint of crude carbolic acid to each 4 gallons of the wl ite- 

 wash. Spray or dip infested animals with 10 per cent kerosene 

 emulsion, or use the tobacco-and-sulfur sheep dip. Repeat the ap- 

 plication in two weeks to kill any lice that may have escaped. A 

 wallowing trough containing five to eight inches of water on which is 

 floated a thin layer of crude oil is frequently used with success. 



