POPULATION AND COMMUNITY ECOLOGY Environmental Correlates of Abundances of Mosquito Species and Stages in Discarded Vehicle Tires

Discarded vehicle tires are a common habitat for container mosquito larvae, although the environmental factors that may control their presence or abundance within a tire are largely unknown.We sampleddiscardedvehicle tires in six sites locatedwithin four counties of central Illinois during the spring and summer of 2006 to determine associations between a suite of environmental factors and community composition of container mosquitoes. Our goal was to Þnd patterns of association between environmental factors and abundances of early and late instars.Wehypothesized that environmental factors correlated with early instars would be indicative of oviposition cues, whereas environmental factors correlatedwith late instarswouldbe those important for larval survival. We collected 13 species of mosquitoes, with six species (Culex restuans, Cx. pipiens, Aedes albopictus, Cx. salinarius,Ae. atropalpus, andAe. triseriatus) accounting for 95% of all larvae. Therewere similar associations between congenerics and environmental factors, withAedes associatedwith detritus type (Þne detritus, leaves, seeds) and Culex associated with factors related to the surrounding habitat (human population density, canopy cover, tire size) or microorganisms (bacteria, protozoans). Although there was some consistency in factors that were important for early and late instar abundance, there were few signiÞcant associations between early and late instars for individual species. Lackof correspondencebetween factors that explain variation inearly versus late instars,most notable for Culex, suggests a difference between environmental determinants of oviposition and survival within tires. Environmental factors associated with discarded tires are important for accurate predictions of mosquito occurrence at the generic level.