Abstract
This study examined geographic variation of adult body size and voltinism in the kleptoparasitic spider Argyrodes kumadai in three regions (Boso peninsula in Japan mainland, Amami-oshima Island, and Okinawa Islands) to see how climatic conditions and host use affect life history of this spider. Adult body size differed significantly between populations; Amami-oshima population was larger than the other populations. Voltinism also differed between populations; Boso population was univoltine, Amami-oshima population was probably univoltine with partial bivoltine, Okinawa population seemed to be bivoltine or multi-voltine. The variation of body size appeared to have been created by the combination of the differences in developmental period, food availability in different hosts, and voltinism.
