Notes on the Life History of Zelotes asiaticus (BOESENBERG et STRAND) (Araneae: Gnaphosidae).

Abstract

Life history of Zelotes asiaticus (BosENBERG et STRAND) was estimated by means. of laboratory rearing and field investigation. This species is likely to mature after 8 molts during more than a year after emergence from an egg sac. It seems that this species has a two-year life cycle as follows : Eggs are deposited by the overwintered adult females from spring to early summer; spiderlings emerge from the egg sacs in summer and develop to 2nd-5th instar by winter; juveniles which hibernate their first year develop to penultimates in summer and mature in autumn; and adults overwinter. Possibility of copulation between two populations in which the generation cycles differ from each other is discussed. Spiders of the Gnaphosidae are hunters usually living under stones and in plant litter on the ground. Our knowledge about life cycle of these spiders it very poor. Many gnaphosid species are likely to have a one-year life cycle, but it may be possible that a two-year life cycle also occurs in the region where warm season is relatively short (GRIMM, 1985). The life history of Zelotes asiaticus (BOSENBERG et STRAND, 1906), a common gnaphosid species in Japan, is not clear. I conducted a laboratory rearing and a field investigation of this species in order to ascertain its life history.