28 



Insects and Disease 



pointed and starve before their host appears, but 

 as they are able to live for a remarkably long time 

 without taking food their patience is often rewarded 

 and the long fast ended. 



Those species which drop to the ground to molt 

 must again climb to some favorable point and wait 

 for another host on which they may feed for a 

 while. Then they drop to the ground for a second 

 molt and if they are successful in gaining a new 

 host for the third time they feed and develop until 

 fully mature and the female is ready to lay her 

 eggs. The Texas fever tick, and some others, as 

 we shall see, do not drop to the ground to molt but 

 once having gained a host remain on it until ready 

 to deposit their eggs. 



The young ticks have only six legs (Fig. 1 5) but 

 after the first molt they all have eight. 



TICKS AND DISEASE 



Texas Fever, Ever since stockmen began driving 

 southern cattle into states further north it has been 

 noted that the roads over which they were driven 

 became a source of great danger to northern cattle. 

 Often 80% to 90% of the native cattle died after 

 a herd of southern cattle passed through their 

 region and the losses became so great that both 

 state and national laws were passed prohibiting 



