Effects of container size on competition between Aedes mosquito larvae

Aedes albopictus is an important invasive species of mosquito that has become widespread across the eastern and southern United States, where it is a strong competitor with resident mosquitoes. One such resident mosquito is Aedes triseriatus, a native tree-hole mosquito of eastern North America. The impact of A. albopictus invasion on native species varies, with resident mosquitoes being driven to extirpation in some areas, but capable of persistence in other areas. This example of context dependence in the outcome of invasion suggests there may be some environmental effect reducing the impact of larval competition in sympatric populations of mosquito larvae. I seek to determine experimentally how impacts of invasion and resistance of native A. triseriatus to invasion vary with the size and shape of the larval environment.

Current experiments focus on the competitive response of larvae kept at varying densities across a range of morphology of the larval habitat. Larvae were held in containers of varying sizes that result in variation in the amount of wall surface area available for browsing relative to volume. Smaller containers have relatively more wall surface area available for browsing per larvae then larger containers of similar form. Because browsing the sides of these containers is a more profitable way of feeding than feeding within the water column, I predicted that smaller containers would exhibit lower intensity of competition. Preliminary work has focused on intra-species interactions between Aedes triseriatus larvae, and supports the hypothesis that competition is relatively more important in larger containers.