62 OHIO EXPERIMENT STATION: BULLETIN 356 



emerges eager for a meal of blood. The time between the deposit- 

 ing of the pupa and the emergence of the young tick varies, depend- 

 ing upon the temperature in part at least. This time has been var- 

 iously estimated at from 10 to 19 days in summer and 24 days or 

 even longer in winter. Young ticks have been observed to emerge 

 from pupae on the host animal 19 days after the pupae were de- 

 posited. When taken off the host animal and kept in vials young 

 ticks have emerged in 20, 25, 27 and 29 days after the pupae were 

 collected. The temperature during this time ranged from 65 de- 

 grees to 80 degrees. The young tick develops very rapidly reach- 

 ing sexual maturity in a few days. The female deposits her first 

 pupa about 14 days after emerging from the puparium which the 

 hard shell is called. 



The longevity of the young and adult ticks is of practical inter- 

 est, since this point will determine how soon it will be safe to turn 

 sheep dipped for ticks into pens or pastures formerly occupied by 



infested sheep. Young ticks 

 have been observed to live for 5 

 days away from sheep, while 

 adults have lived from 4 to 7 

 days. Those ticks recently en- 

 gorged with blood generally live 

 longer when removed from sheep 

 than those not so engorged. 

 The ticks spread from one 

 Sheep Tick sheep to another through con- 



Melophagus ovinus, adult and tact both with infested sheep or 

 puparium with tagg Qf wqq] {rQm infested 



sheep. During cold weather when sheep are placed in sheds in 

 close contact the conditions are favorable for a rapid spread of the 

 ticks. They pass readily from one sheep to another, especially 

 from the ewe to her lamb. 



Control. — The points of practical interest then in the life his- 

 tory and habits of the tick bearing on its control are: — (1) length 

 of pupal stage, generally 19 to 24 days; (2) period before female 

 deposits her first puparium, about 14 days; (3) longevity of tick 

 when removed from host, 4 to 7 days ; the pupae of course when re- 

 moved would hatch out in 19 to 24 days or even longer into ticks 

 capable of reinfesting animals ; (4) the ticks pass readily from 

 infested animals to other animals. There is even danger of the at- 

 tendants spreading them. Ticks have been found upon the trous- 

 ers of attendants several hours after the handling of infested 



