Primary Parasitism, Development and Adult Biology in the Wasp Taeniogonalos Venatoria Riek (Hymenoptera: Trigonalyidae)

Abstract

The biology of the Australian wasp Taeniogonalos venatoria Riek was investigated using populations in the Adelaide Region during 1986-90. This species is unusual for a trigonalyid because it is a primary parasitoid of a pergid sawfly and can act facultatively as a hyperparasitoid. The wasp oviposits onto foliage, eggs are ingested by host larvae, eggs then hatch, and the larva penetrates the gut wall. Saline, acid saline, cathepsin and physical manipulation were effective in triggering eclosion. Eggs were viable on foliage for up to 5 months. Larval instars 1-3 are endoparasitic; 4-5 are ectoparasitic. Populations are univoltine, and adults emerge between February and April in synchrony with early-stage host larvae. Adult wasps are relatively short lived (8 days), but survival is increased by access to water and food. Female wasps contain over 6000 eggs at emergence. Aspects of the biology of T. venatoria are discussed in relation to other species of trigonalyid wasps.