The role of Pimpla hypochondriaca venom in the suppression of pupal Noctuid host immunity

When pupae of the Tomato moth (Lacanobia oleracea L.) (Lepidoptera: Noctuid ae) are injected with venom from the endoparasitoid wasp Pimpla hypochondri aca Retzius (Hymenoptera: Ichneumonidae), they show an increased susceptibi lity to the fungal entomopathogen Metarhizium anisopliae Sorokin (Fungi Imp erfecti: Deuteromycotina). This observation, coupled with the fact that was p eggs are comparatively unlikely to be encapsulated when implanted into en venomated pupae, suggests that venom of P. hypochondriaca suppresses the ce llular immune defense mechanisms of L. oleracea. Injection of host pupae wi th the venom of P. hypochondriaca has a rapid, adverse effect on the normal respiration pattern of L. oleracea. It is possible that severe disruption to host-metabolism may contribute to a general failure in the hosts' normal immune response repertoire.