DIPTHRA OF MINNESOTA. 



101 



is not found on animals other than sheep. The insect is about one- 

 sixth of an inch long, a wingless fly, and is apt to be common where 

 sheep are in crowded quarters, for it is only when sheep are crowded 

 together that this parasite craAvls from one animal to another. The 

 female brings forth }'oung in the pupal stage, and the species is most 

 abundant in spring and summer. Lambs suiTer particularly just 

 after the older sheep have been sheared, for in the hair of the un- 

 sheared lambs the ticks find a safe retreat and succulent food close 

 at hand. As many as lOO ticks can be found sometimes upon one 

 lamb. 



Treatment. 



Scrubbing or combing" or washing with water will do but little 

 good. Dipping with some insecticide is the only sure remedy. At 

 the State Experiment Station at St. Anthony Park dips made from 

 coal tar or creosote products are used one gallon of dip to one hundred 



Fig. 157. Head of sheep tick, much enlarged. Lugger. IJelow, uterus-like enlargjment of 



oviduct. After Leuckart. 



gallons of water, once in the spring immediately after shearing, 

 and again in the fall before going into winter quarters. If they are 

 not so dipped, the ticks, as mentioned above, will migrate as soon 

 as possible to the unshorn lambs. They should be kept in the liquid 

 at least one minute. Sheep added to the flock from the outsid< 

 should be dipped before they join the home flock to prevent the in- 



