Nearly half of all North American mosquito species belong to the genus Aedes. Many species are aggressive biters, carriers of vertebrate pathogens and known to evolve insecticide resistance frequently (Harwood and Jame 1979, King 1975). It is important to understand the reproductive biology of this group of medically important mosquitoes. Elucidation of the process of vitellogenesis has been a long term goal for many insect biologists. We hope to initiate a new approach to the subject by exploring the potential of monoclonal antibodies as specific biological probes for vitellogenin. The specific aims of this proposal include the development and characterization of hybridoma antibodies to Aedes vitellogenin and vitellin. Enzyme and radioimmunoassays utilizing these target-specific antibodies will be developed as routine analytical methods. The availability of such a sensitive and specific technique is crucial for in vitro and in vivo studies of the hormonal control of mosquito vitellogenesis. The monoclonal antibodies can be used with affinity chromatography for the purification of vitellogenin from haemolymph and vitellin from soluble yolk extracts. The physical biochemical properties of these two preparations will be compared. Affinity purified and labelled vitellogenin can also be used to study the process of uptake by the follicle cells. Aedes vitellogenin-specific antibodies developed in this study will be a useful tool for ecologists and epidemiologists to monitor population quality. A panel of these well characterized hybridoma antibodies will be made available to other researchers.