Abstract Blacklegged ticks (Ixodes scapularis) require a single bloodmeal from one of many potential host species during each of their three life stages. However, host species vary tremendously in their permissiveness for ticks. Given the variation in host permissiveness, we would expect ticks to have evolved mechanisms that increase their probability of feeding on highly permissive species. However, we know little of what happens during an encounter between a tick and a passing host. To explore the influence of host and tick qualities on tick adhesion to hosts, we constructed an apparatus in which an artificial host passed over I. scapularis larvae, simulating hosts walking over ticks. This allowed us to control isolated qualities of the host and ticks and observe how many larvae adhered to hosts. In one experiment, larvae were twice as likely to adhere to mouse fur than opossum fur and even less likely to adhere to drag cloth corduroy. However, fur type had no apparent effect in a second study. Instead, the probability larvae adhered to a host increased rapidly with the duration of contact, saturating by ∼1 s regardless of fur type, and was slightly influenced by host speed. Even with the longest contact times, only ∼2/3 of larvae adhered to a host. This probability declined with larval age. Collectively, our results suggest ticks may attempt to adhere to any host they contact, perhaps because contacts are rare and often brief, but not all host-seeking ticks are in a state where they can or will adhere.
Burton et al. (Mon,) studied this question.