Seasonal Patterns of Abundance among Three Species of Culex Mosquitoes in a South Florida Wastewater Lagoon1

Abstract

We monitored over 16 months the density of immature mosquitoes in a settling lagoon receiving dairy wastewater. Within microhabitats containing floating or emergent vegetation, 75% of all samples were positive for mosquitoes and the mean number per sample was 102.9. The vast majority of the mosquitoes collected during the annual cycle was of the Culex (Culex) group. During the summer and fall, Culex nigripalpus Theobald was the most abundant. With the onset of winter, C. nigripalpus's density dropped to a low level where it remained until summer. In contrast, immatures of Culex salinarius Coquillett and Culex quinquefasciatus Say were generally rare or uncommon for most of the summer and fall. Peak densities for both species occurred between January and April. The scarcity of immature C. quinquefasciatus in the lagoon during the summer and fall was not associated with reduced nutrient levels in the aquatic habitat.