| abstract | Argas (Argas) monolakensis, n. sp., is described from adults, nymphs, and larvae collected from under and around nests of California gulls, Larus californicus Lawrence, on islands in Mono Lake, Mono County, California, and from specimens reared in the laboratory. This species is closely related to A. cooleyi Kohls and Hoogstraal, a parasite of cliff swallows, Hirundo pyrrhonota Vieillot, but is easily distinguished by hypostome dentition and roof of Hallerʼs organ in all stages and chaetotaxy of the larvae. This tick was successfully reared and maintained in the laboratory by feeding them on domestic chickens. Larvae require 5-8 d to feed, whereas all postlarval stages feed rapidly within 9-62 min. At Mono Lake, ticks are aboveground and seek hosts only at night. The number of nymphal stages varies from 2 to 5 depending on the developmental temperature and sex of the tick. Ticks overwinter at Mono Lake as second- to fifth-stage nymphs and adults. Ovarian diapause is common with preoviposition periods in extreme cases lasting up to 20 mo. This tick will readily feed on humans and has the potential to transmit Mono Lake virus, which has been isolated from an estimated 2-8% of ticks on various islands. To date, A. monolakensis is known only from islands in Mono Lake, California. |