Abstract
The venom apparatus in female Euplectrus kuwanae consists of two spheroidal venom reservoirs and a gland. A number of crystals which are rhomb in shape are observed in the venom reservoir. Although venom reservoirs of newly emerged females are small and contain no venom fluid, they develop rapidly until the fourth day of adulthood. When the hosts, Argyrogramma albostriata larvae, were injected with a venom equivalent to 1/2-1/10 of the volume of the venom reservoirs of one female, they failed to molt and died. This indicates that the venom of E. kuwanae has a specific effect on the host's endocrine system.
