Larvae ofAnopheles punctipennis(Say),Culex territansWalker,Aedes atlanticusDyar&Knab, andPsorophora ferox(von Humboldt) were collected and 13 water-chemistry variables were measured at permanent and semipermanent pools in Duplin County, N.C., during 1982 and 1983. Stepwise logistic regression was used to identify water-chemistry variables associated with habitats and to predict the occurrence of each species. Models based on pH and concentrations of Cl, K, and Na ions gave reasonable predictions of occurrence.