CONTRASTING EFFECTS OF SERA FROM RABBITS AND CATTLE INFESTED WITH TICKS ON THE INVITRO FEEDING PERFORMANCE OF THE TICK RHIPICEPHALUS-APPENDICULATUS

The in vitro feeding activity of partially engorged Rhipicephalus appe ndiculatus (Neumann) (Acari: Ixodidae) females fed on sera from uninfe sted hosts was compared to that of ticks fed serum of hosts which had previously been infested with ticks. Although ticks fed best on sera f rom bovid hosts which had no prior exposure to this ectoparasite, two infestations of a bovid had no significant effect on the acceptability of its serum. In contrast, ticks fed sera from rabbits which had twic e been infested with ticks gained significantly less weight than those fed serum obtained from the same animals before the infestations. Cle arly there is a difference between natural host resistance and that of laboratory animals.