HAEMAPHYSALIS : MANIPULATION 647 



of A. hebraeum the success of any experiment with the adults depends 

 on having both sexes on the animal, for the female wanders about 

 looking for the male and will not become replete. with blood until after 

 copulation. 



Those species of Amblyomma which are parasitic on the larger animals 

 may be experimented with in the same way as that described for the 

 species of Rhipicephalns and Margaropns. It is just as easy to apply 

 ticks to a horse as it is on a goat, provided that the feeding habits, 

 particularly the sites of attachment, are known. Those species of 

 Amblyomma which are parasitic on reptiles may be manipulated in the 

 way described for the species of Aponomma, to be mentioned presently. 



With the exception of Dermacentor nitens, D. nigrolineatits and 

 D. albipictus, all the species of Dermacentor drop off their host for each 



of the two moults. The life histories and habits of the 



Genus Dermacentor 

 more important species have been studied by Hunter 



.and Hooker, and Bishop and Wood. Dermacentor andersoni may be 

 bred on cattle in all its stages ; it leaves its host to undergo both 

 moults. Dermacentor nitens, the ' Tropical horse tick ' as it is called 

 in America, attaches itself almost exclusively in the ears of horses ; 

 it ma)-, however, occasionally be found attached to the neck under the 

 mane. It can be manipulated with great ease if it is remembered that it 

 only leaves the host when the female is replete with blood ; ear bags are 

 therefore only required to place the larvae on the host and again just 

 before the females become full-fed. Dermacentor albipictus, though 

 usually parasitic on the moose and elk, is often found on the horse 

 and on cattle ; the ticks attach themselves on the neck and along the back, 

 on the abdomen, between the legs and sometimes near the base of the 

 tail. On cattle the larvae moult on the 8th day, the nymphs about the 

 20th day, and the females begin dropping off about the 40th day after the 

 larvae are placed on the animal ; an abdominal or scrotal bag is used 

 just before the females become full-fed. Dermacentor nigrolineatits, like 

 albipictus, passes both moults on the host ; it can be bred in the same 

 way on cattle. The larva moults about the 10th day, the nymph from the 

 18th day onwards ; the females begin dropping off about the 30th day- 

 after the larvae are placed on the host. 



In experimenting with the species of Haemaphysalis the worker should 

 remember that most of them are feeble ticks and are very slow in their 

 movements. They are easily dislodged, and when this happens it is 

 almost impossible to get them to fix themselves again. The life 

 history of H. leachi has been studied in great detail by Lounsbury 



