. Competition due to limited food and high larval density occurs commonly among mosquitoes that occupy container habitats and influences their survivorship, growth, development, and adult size. Little is known, however, as to how competitive interactions among larvae influence the susceptibility of adult females to infection and transmission (i.e., vector competence) of mosquito-borne pathogens. This proposal tests whether variation in mosquito performance known to arise from larval competition is associated with variation in vector competence for dengue virus. A series of experiments varying larval density will test for effects of competition on vector competence of natural populations and laboratory colonies of Aedes aegypti and Aedes albopictus, the two most important transmitters of dengue virus in nature. Adult mosquitoes derived from competition experiments will be given a dengue-infectious blood meal, and vector competence will be measured with standard virological procedures. Progress to date using Sindbis, a model virus, showed that uncrowded larval conditions consistently resulted in superior mosquito performance compared to crowded conditions but, counterintuitively, resulted in decreased infection with Sindbis. The proposed experiments with dengue, an unrelated virus, will indicate the generality of results and whether mosquitoes from the laboratory and natural populations differ in responses. This research is novel for exploring how ecological factors in an early life stage may influence vector competence in adult, blood-feeding insects.
