Larval habitat age and prior exploitation affect female life history in the mosquito Aedes triseriatus

Many mosquito species in the genus Aedes occupy discrete and ephemeral aquatic container habitats as immatures. A characteristic of these larval habitats that is important for determining the habitat’s ability to support the growth and development of larvae is the quality and quantity of resources in the habitat. Resource availability is likely to be influenced by the age of the habitat, as detritus, which forms the base of the food-web in these habitats, either changes in quality over time or new detritus inputs collect over time. Resource availability is also likely to be influenced by the density of larvae, both current density and resource competition and  delayed resource competition resulting from previous non-overlapping cohorts that exploit the available detritus resources. We manipulated habitat age and prior resource exploitation in a field experiment using the mosquito Aedes triseriatus and white oak leaves (Quercus alba) as the detritus source. We found that mosquitoes performed better when reared in older larval habitats, which yielded higher larval survival, faster development rate, higher value of a composite performance index, and greater adult female longevity than younger habitats. Larvae that developed in previously exploited habitats had significantly delayed development compared to larvae in habitats not previously exploited. We postulate that extended conditioning of leaf detritus in the older aquatic habitats may have enabled fungi to make recalcitrant resources in leaves available to mosquitoes, and thus improved the quality of the habitat for larvae. We also conclude that delayed resource competition has minimal effect on mosquito population dynamics.