Effects of Habitat Permanence Cues on Larval Abundance of Two Mosquito Species

Abstract

Fluctuations in mosquito populations can often be correlated with the level of rainfall in the short term, however, rainfall rarely corresponds to mosquito abundance in the long term. Here, we present results of a field based mesocosm experiment designed to test how variables associated with drought influence larval abundance of two species of mosquitoes. We used two water volumes (2 and 4 l) and two drought water concentrations (high and low). The two mosquito species present in these ponds, Ochlerotatus notoscriptus and Anopheles annulipes, differed markedly in larval abundance. The number of larvae of O. notoscriptus observed was significantly greater in high drought water treatments regardless of water volume, and did not co-vary with any water chemistry parameters measured. In contrast, A. annulipes larvae were significantly more abundant in the greater water volume treatments regardless of drought water concentrations. This pattern co-varied with the pH of the pond water. These results indicate that mosquito species may show variances in their oviposition site selection and larval development depending on water depth and drought history.