8 FARMERS^ BULLETIN 798. 



the ATool fibers, usually from one-half inch to an inch from the skin. 

 Consequently when the sheep are shorn the majority of the eggs are 

 removed with the fleece. 



Sheep ticks when feeding attach themselves temporarily to the 

 skin of the sheep by burying their sucking tubes in the tissues ; when 

 not feeding they move about in the fleece. During cold, inclement 

 Aveather they remain deep in the fleece close to the skin for shelter 

 and warmth, but when the days are warm they are found near the 

 surface and often can be seen in great numbers crawling over the tips 

 of the wool. Sometimes they are dislodged from this position and 

 thus temporarily infest trails, pastures, corrals, bed grounds, and 



premises. ^Yhen dis- 

 lodged from a sheep 

 they crawl upon an- 

 other at the fii-st op- 

 portunity. 



The sheep tick does 

 not transmit an 3^ 

 knoAvn disease to the 

 sheep, but it harbors 

 a very small one- 

 celled animal organ- 

 ism, related to forms 

 which are transmitted 

 by insects to various 

 animals, including 

 man, andAvhich cause 

 serious diseases. 

 Open -fleece sheep, 



■k, flout view ; enlarged. SUCh aS the COarse- 



wool and medium- 

 wool breeds, are subject to ravages by the tick. The fine-wool sheep 

 usually are not affected to any great extent, as the parasites do not 

 seem to be adapted to existence in the greasy, tight fleeces of such 

 breeds. When the flock is heavily infested the ticks may be found 

 on any part of the bod}', but they usualh' select locations Avhere 

 the wool is thin and occur in greatest numbers on those parts 

 where they are protected from the efforts of the sheep to dislodge 

 them. The neck, breast, shoulders, belly, and thighs are the favorite 

 locations. 



Many of the ticks are removed with the fleeces at the time of shear- 

 ing, especially if machine shearing is practiced. The freshl.v shorn 

 sheep ofl'ers very little })rotection for the ticks, and conse(iuently, 

 during the shearing season, the ticks migrate to the lambs in large 

 numbers. The lambs of the flock suff'er most from the ravages of 



