Apparent host selection by some african tick species.

1. Four cattle were exposed to tick infestation in a game-dominated territory for 21 months. All ticks seen crawling on two of the cattle were collected; the other two were thoroughly deticked once daily. The results estimate the gross daily pick-up and the nett daily infestation. 2. The overall gross/nett ratio, the loss-rate, of ticks picked up was 1.76:1. 3. The four main species present separate into two categories, A (R. evertsi and R. appendiculatus) with loss rates of 1.48:1 and 1.53:1, and B (A. hebraeum and H. truncatum), rates 2.25:1 and 2.29:1. Less extensive data for H. rufipes and R. simus put them in categories A and B, respectively. 4. The degree of specialization to predilection sites for attachment is measured, and corresponds to the observed adaptation of the species to domestic cattle. 5. It is suggested that the greater proportion of successes in infestation by category A species results from a higher receptivity to specific bovine stimuli for attachment; about 30% of category B ticks on the other hand reject cattle.