Comparative biology and functional response of Trissolcus spp. (Hymenoptera: Scelionidae) and implications for stink bugs (Hemiptera: Pentatomidae) biological control

The biological parameters and functional responses of populations of Trissolcus basalis, Trissolcus brochymenae, Trissolcus teretis and Trissolcus urichi, from central Brazil, attacking Euschistus heros eggs were studied, in order to establish their potential for stink bug biological control. Life table analyses and functional response experiments were used to evaluate and analyze the performance of species when using E. heros eggs as host. There was substantial variation in the ability of different Trissolcus spp. to exploit resources from E. heros eggs. Fecundity measures of Trissolcus spp. when compared to that of E. heros showed that the parasitoids have potential for faster population increase than the stink bug. The four species studied showed type III functional responses. The species of Trissolcus evaluated in this work are potentially effective as natural enemies of E. heros, and can potentially be used in a multi-species approach. Interference competition and other ecological and behavioral effects of more complex environments can occur, as in multiple-species introductions or when alternative hosts are present.