SHEEP TICK AND ITS ERADICATION BY DIPPING. 



4. — Young sheep tick just after emerging from the 

 puparium ; enlarged. 



dipping should not be done before all the pupij3 which were in 

 the wool at the time of the first dipping have had time to hatch, 

 otherwise they may 

 hatch after the sec- 

 ond dipping and re- 

 infest the flock. Con- 

 sequently, it is im- 

 portant to allow a 

 proper interval of 

 time between the first 

 and second dippings 

 if the results are to 

 be successful. The 

 first dipping prob- 

 ably destroj's many 

 of the pupae that are 

 less than 4 da3^s old, 

 and the dip remain- 

 ing in the wool has a 

 tendency to prevent 

 the development of 

 young ticks and 

 probably kills many of them. Under average conditions during 

 early fall dipping, 24 daj^s should elapse between the first and 



the second dipping. 



NATURE AND 

 HABITS. 



True ticks, such, 

 for example, as the 

 Texas-fever tick, do 

 not pass their entire 

 life on the animal 

 which they infest, but 

 always drop to the 

 ground to lay their 

 eggs. The life his- 

 tory of the sheep tick 

 is more simple. It 

 does not drop off the 

 sheep to lay eggs, but 

 deposits its pupae in 

 the fleece. Each fe- 

 male deposits an aver- 

 , one being laid about 

 eggs, are attached to 



Fig. 5. — Mature male sheep tick, back view ; enlarged. 



age of from 12 to 15 pupa3 during her lifetime 

 every T or 8 days. These pupa.', or so-called 



