Responses of three species of adult ticks (Acari: Ixodidae) to chemicals in the coats of principal and minor hosts.

In laboratory bioassays, host-seeking adult blacklegged ticks, Ixodes scapularis Say, lone star ticks, Amblyomma americanum (L.), and American dog ticks, Dermacentor variabilis (Say), were exposed to substances from the pelage of dogs and white-tailed deer, Odocoileus virginianus (Zimmermann). Male A. americanum exhibited an arrestant response to all samples of deer tarsal gland substances tested, whereas female A. americanum, female I. scapularis, and male and female D. variabilis responded to samples from certain deer and not others. Female I. scapularis, D. variabilis, and A. americanum of both sexes also showed an arrestant response to substances rubbed from the dorsal surface of dogs' ears. These findings suggest that, although these 3 species of ticks are associated with certain host species as adults (A. americanum and I. scapularis with white-tailed deer, D. variabilis with dogs), their repertoires of host-finding behaviors are broad, and use of minor host species may not be purely accidental.