Previously it was determined that the New Wold pyralid stemborers, Diatraea saccharalis and D. grandiosella, as well as the Old World crambid stemborer Ostrinia nubilalis, are variably suitable for development of the braconid endoparasitoids of the Cotesia flavipes-species complex. Experiments on host suitability, total hemocyte counts, chronology of encapsulation, etc., indicated that parasitoids that are taxonomically, behaviorally and ecologically very similar may differ in their ability to utilize a host of the same species. One of the most important host factors involved in parasitoid recognition and killing is the encapsulation response by the host’s hemocytes. Here I present studies on the differential hemocyte counts, and the functioning of plasmatocytes and granular cells, for the different host-parasitoid combinations at various stages of parasitism. Hemolymph was analyzed by flow cytometry, a method that readily distinguishes plasmatocytes and granular cells by the physical property of large angle light scattering. The differential hemocyte counts and the functioning of the different hemocyte morphotypes were compared to the encapsulation response of the host and to overall host suitability.
Species 1: Hymenoptera Braconidae Cotesia flavipes
Species 2: Lepidoptera Pyralidae Diatraea saccharalis (sugarcane borer)
Species 3: Lepidoptera Crambidae Ostrinia nubilalis (European corn borer)
Keywords: immune response, flow cytometry
The ESA 2001 Annual Meeting - 2001: An Entomological Odyssey of ESA