338 The Diseases of Animals 



TICKS 



Ticks and mites are closely related, to the spider- 

 tribes. They are not insects. Most of the ticks are 

 only partially parasitic; that is, only a part of their 

 lives is spent upon the bodies of other animals. 



The most injurious parasitic tick is the southern 

 cattle tick (Margaropus annulatus) . Fig. 52. This crea- 

 ture is important, not only because of the 

 losses resulting from its attacks, but also 

 because it is the carrier of the germs of Texas 

 or southern cattle fever from southern to 

 susceptible northern cattle. The southern 

 cattle tick is reddish or grayish in color; the 

 adult female's body is about one -third of 

 an inch in length, and resembles in shape 

 Southern a small castor bean. It attaches itself to the 

 natural ^ize. skin of cattle, particularly in the regions 

 S3?? 'owe?! where it is thin, as between the thighs, on the 

 belly, between the fore -legs and on the neck. 

 The female, when fully developed and distended with 

 blood and eggs, looses her hold on the animal, drops 

 to the ground, and deposits a large number of eggs, 

 which cover her body. The eggs hatch in from two to 

 six weeks. The young ticks, crawling up on grass, 

 are brushed off by grazing cattle. They crawl up the 

 legs of the animals and attach themselves so firmly to 

 the skin that they can be pulled off only with difficulty. 

 The southern cattle ticks are found in all the southern 

 states. They are more numerous in a brushy country 

 than on the high, open prairies. 



