The subgenus Persicargas (Ixodoidea: Argasidae: Argas). 27. The life cycle of A. (P.) robertsi population samples from Taiwan, Thailand, Indonesia, Australia, and Sri Lanka.

To provide background data for an investigation of biological interrelationships between Argas (Persicargas) robertsi Hoogstraal, Kaiser and Kohls and 3 arboviruses (Kao Shuan, Pathum Thani, and Nyamanini) isolated from this tick species, domestic pigeons were used as experimental hosts to study the life cycle of population samples from Taiwan (TA), Thailand (TH), Indonesia (IN), Sri Lanka (SR), and Australia (AU). The life cycle (at 28-30 degrees C and 75% RH) required 2-10 months. Biological data for the different population samples varied possibly owing to atavistic retention of seasonally adjusted properties associated with diapause and the migratory habits or breeding cycles of wild hosts, or to different rearing times of the various samples. There were 2-4 nymphal instars in SR and AU samples and 2-5 instars in TA, TH, and IN samples. Nymphs and adults fed within a few days after molting or oviposition and usually emitted coxal fluid while feeding. Males molted from earlier nymphal instars than females.