Influence of detritus amounts and organic pollution on interspecific resource competition between larval Aedes albopictus and Culex quinquefasciatus (Diptera: Culicidae)

The Asian tiger mosquito (Aedes albopictus), a recent invader to North America, and the southern house mosquito (Culex quinquefasciatus), are two of the most common mosquito species inhabiting water-filled tries in the southern United States. Although Ae. albopictus is known to be a superior resource competitor to several resident species, the nature of any interactions between larval Ae. albopictus and Cx. quinquefasciatus has not been studied. We conducted several laboratory experiments to 1) quantify the degree of competitive effects between Ae. albopictus and Cx. quinquefasciatus, and 2) determine the effects of organic pollutants on competitive interactions between these two species. For the first experiment, microcosms were established containing three levels of organic detritus (Quercus virginiana leaves and Drosophila melanogaster carcasses) and eight density combinations of Ae. albopictus:Cx. quinquefasciatus larvae. For the second experiment, microcosms were established containing a constant amount of detritus, three levels of a ten-chemical blend representing organic pollution, and eight larval density combinations. Microcosms were maintained in an incubator at 27 °C for 45 days. For both experiments, multivariate analysis of variance (MANOVA) was used to test for effects of treatment (i.e., detritus amount or pollution concentration), larval density combinations, and a treatment x density ratio interaction on survivorship, days to pupation, and adult size (i.e., wing length) for both mosquito species. Results from these experiments will help to determine the nature of interactions between these two species and further define the role of organic pollution on each species.