INSECT ENEMIES OF LIVE STOCK 171 



Ticks in a cage, when blown upon vigorously, fall to the 

 ground ; and perhaps this happens in nature, when a beast 

 breathes upon the shrub on which the larval ticks have 

 taken up their position, and, by falling to the ground, they 

 avoid being eaten. It is probable therefore that ticks are 

 informed of the presence of their hosts by shadows and 

 by the slight breeze they make in walking along. It 

 is absolutely essential for the larval tick to find a host, 

 for failure to do so means eventual starvation, though 

 a beneficent provision of nature enables them to live for 

 nearly eight months without feeding, if necessary. During 

 the whole of the time spent on the vegetable support, no 

 food is taken by the larvae, and, as a natural corollary, no 

 growth takes place. When once the host is reached, the 

 larva begins its parasitic life, and, becoming attached to 

 dewlap, inside of thighs and flanks or escutcheon, it immedi- 

 ately starts to draw blood. In a few days the rich brown 

 colour gives place to white, and in five to twelve days the 

 skin is shed, and, instead of a six-legged larva, an eight- 

 legged nymph continues to deplete the host of its blood. 

 In another five to ten days a second moult takes place, 

 and, as a result, the ticks attain sexual maturity. 



The male has now attained his full development, but 

 the female is only on the threshold of hers. The male is 

 quite active, and moves from place to place over the host's 

 skin to mate with the female ticks, which, in contradis- 

 tinction to the males, are exceedingly sluggish, rarely 

 moving from the point of attachment. After mating, the 

 female increases enormously in size, and in from three to 

 nine weeks after first attachment to the host as a seed 

 tick, she becomes fully engorged and drops to the ground 

 to oviposit and start the life-cycle over again. 



If, during the life-cycle, any of the ticks become attached 

 to cattle suffering from red water, the parasites causing 

 this disease are taken up by the ticks, along with the 

 blood on which they feed. Within the tick's body the fate 



