ERADICATION OP THE EOCKY MOUNTAIN SPOTTED FEVER TICK. 5 



On the lambs, ticks were found attached in several different places : 

 Some were in front of the ears, some in the wool on top of the neck, 

 others in the wool on the top and sides of the shoulders, and one was 

 attached, as stated before, on the chest. In no case were the ticks on 

 lambs found attached on the hind quarters or beneath the body. 



The ticks referred to as crawling were no doubt those males and 

 females which had recently gotten on the sheep, or perhaps they were 

 males seeking females. Besides the females referred to in Table I as 

 " engorged one-half or more," there were some other females which 

 had fed slightly but had never become as much as one-half engorged. 

 This division at one-half engorged is made because females less than 

 about that size seldom lay eggs. Should ticks less than one-half full 

 get rubbed off, it is extremely doubtful if they would ever deposit 

 eggs. Just how many ticks were rubbed off or killed before complete 

 engorgement it is impossible to say, but a few cases of this kind were 

 observed. In all cases in which females are referred to " with males 

 beneath," such pairs were in the correct position to effect fertilization. 

 The " engorged females recovered from sheep," except one, were 

 picked from the host when they had reached full or nearly full 

 engorgement. 



It seems probable that the dead unfed ticks found in the wool were 

 for the most part killed by the lanolin, although the heat of the wool 

 may have been a factor. It was found in a number of cases that ticks 

 died after attaching. This factor was indicated by a reddish spot on 

 the skin near the place where the tick was found dead. The ticks, 

 however, were usually found loose in the wool. Both living (at- 

 tached) and dead ticks were found at times in the same fold. 



To show the location of the ticks recovered and the relation between 

 shearing and the development of the ticks, certain data in Table I 

 have been rearranged in Tables II and III. 





Table II.- 



— Location of ticks recovered from 



sheep. 







Dead. 



Alive. 



Head 



31 

 28 

 30 

 23 

 3 



45 



Neck . 



29 





15 



Sides. ..'. 







Underneath 



2 3 







1 On the shoulder. 2 Two on leg. 



Table III. — Relation between shearing and attachment of ticks. 



Dead 

 females. 



Engorged 

 females. 



Lambs not sheared 



Sheep not sheared 



Sheep sheared (including ram) 



