SOME PESTS OF OHIO SHEEP 



75 



live under these conditions in order to make recommendations con- 

 cerning the use of such sheds and pastures. Various authorities 

 place the length of life of the mites when removed from the body of 

 the host at from 2 weeks to as many months. Pastures may be 

 safely occupied at an earlier date than buildings and pens. Two 

 months may safely free open pasture, but it is thought that a much 

 longer time should elapse before healthy sheep are introduced into 

 once-infested buildings. In fact, the safest plan consists in a re- 

 moval of all the bedding and loose material of the sheds to land that 

 is to be plowed and thoroughly spraying the walls, floors and racks 

 with a slightly stronger solution of the dip than is used on the 

 sheep. 



An advanced case of common scab. 

 From Bui. No. 21, Bureau of Animal Industry, U. S. D. A. 



HEAD SCAB MITE 



Symptoms. — This tiny mite confines its attacks almost ex- 

 clusively to the parts which are not covered with wool. Its pres- 

 ence is usually first observed on the lips, in the vicinity of the 

 angles of the mouth and on the edges of the nasal openings ; more 

 rarely it may show itself first around the eyes and ears. The 

 mites penetrating into the skin cause little watery pimples to arise 

 at the point of attack. The itching appears to be intense, for the 

 animals rub the infested portions vigorously against the rack, on 



