Mosquito species often cooccur in ephemeral aquatic communities (treeholes, artificial containers, etc.) as larvae. Interspecific competition among larvae is postulated to play a key role in the abundance and distribution of these mosquitoes, and competition experiments between pairs of species indicate a fairly consistent competitive hierarchy. In other organisms, notably plants and algae, resource competition theory has been successful in predicting competitive hierarchies. The principal predictive tool is estimation of R*, the resource availability necessary for zero growth. For container mosquitoes, it is not known what mechanism of competition (resource, interference, etc.) determines competitive hierarchy, or whether R* can predict the competitive hierarchy. We raised the mosquitoes Aedes albopictus, Aedes aegypti, and Ochlerotatus triseriatus at standard larval densities, standard environmental conditions, and four levels of detritus, which serves as the resource for the bacteria these mosquitoes consume, to test for species differences in R*.
Results/Conclusions
Survival to eclosion (S) showed a significant interaction of species with resource abundance, and estimated cohort rate of increase (r’) was significantly different among species and resource combinations. Species competitive rankings, as determined by S and estimated R*, were consistent with data from previous competition experiments. Our data indicate that species differences in resource use as quantified by R* is likely the mechanism that determines the outcome of interspecific competition among these species. We are currently conducting concurrent R* and competition experiments to compare more directly R* and interspecific competitive hierarchy for additional species of container mosquitoes.
