Dissertation Research: Implications of a Symbiont-Induced Physiological Interaction on Parasitoid Evolution

Cox-Foster IBN-9800892 Insect hosts and their parasites are valuable study systems, research from which contributes to invertebrate physiology, basic ecology and evolution, and pest management alternatives. Certain groups of parasitic wasps attack specific caterpillar hosts. They are protected from the normal host immune response by polydnaviruses, whose mode of action is not well understood physiologically or evolutionarily. This study hypothesizes that polydnavirus mechanisms are different among wasp groups, and that points of divergence can be identified by comparing results of biological assays for interspecific protection with physiological assays of host response to polydnavirus. The proposed project will allow comparison of physiological responses to virus from other parasitic wasps of differing relatedness, and ask if the mechanism we previously described in one group is the same or different. Additionally, work allowing direct comparison of viral DNA will be initiated. Results from the proposed project will provide important contributions to: 1.) understanding the immune physiology of polydnavirus-mediated host/parasite relationships, and 2.) determining the impact of divergent polydnavirus evolution on wasp success and long-term evolution. The results of the proposed study are also relevant to biological control since physiological parameters used may be useful predictors of host range.