By killing their prey, predators have an obvious direct affect on prey populations. Predators also have important indirect effects on prey, and these indirect effects are less well understood than are the direct effects. Predation can effect prey behavior by selectively killing individuals that engage in activities that increase the chance of capture. Prey individuals may also modify their behavior by adopting low-risk behaviors when predators are nearby. Prey such as insects that go through distinct larval and adult stages can also alter their exposure to predation by altering the time and body size at which they transform from larva to adult. Although all of these indirect effects of predation are possible, the integration of all of these behavioral and life history responses to predation is not well understood. The proposed research tests for fixed (always expressed) and flexible and flexible (expressed only when predators are nearby) behavioral and life history responses to predation in larvae of a tree-hole dwelling mosquito. Populations known to differ in exposure to predation, behavior, and vulnerability to predation are compared. The results of this study will show how fixed and flexible behavioral and life history traits are integrated into an overall life style, and how this life style is related to predation. These experiments will provide an explicit test of the predictions of a mathematical model for the evolution of life history in response to predation. Because the bite of this mosquito sometimes transmits LaCrosse encephalitis, understanding how this species responds to predation, and how these responses affect populations of adult mosquitoes, may also be important for understanding the medical impact of this species.
