Effect of host quality ofCallosobruchus maculatus(Coleoptera: Bruchidae) on performance of the egg parasitoidUscana lariophaga(Hymenoptera: Trichogrammatidae)

Abstract

AbstractDevelopment and reproductive success of the solitary egg parasitoidUscana lariophagaSteffan were examined after development in eggs of the bruchid storage pestCallosobruchus maculatusFabricius reared at either low or high densities on cowpea seeds and laid at day 1 and 4 of maternal life. Both bruchid larval competition and maternal age negatively affected egg size, but the latter more than the former.Uscana lariophagareared in small hosts developed slower, were smaller and produced fewer eggs compared to parasitoids reared in large hosts. Fecundity of the parasitoid was heavily influenced by host egg size. This was reflected in the values for the intrinsic rate of increase ofU. lariophaga, which differed for wasps that developed in host eggs laid by bruchid females of different age. Wasps allocated marginally more female offspring to larger hosts.