Habitat segregation of dengue vectors along an urban environmental gradient

Differential distributions of Aedes aegypti and Ae. mediovittatus (potential inter-epidemic dengue vector) and other mosquitoes colonizing bamboo pots in San Juan, Puerto Rico were studied along an urban-rural gradient. City regions (urban, suburban, and rural) and landscape elements within regions (forest [F], low-density housing [LDH], and high-density housing [HDH]) were identified using satellite imagery. Aedes species extensively overlapped in LDH of urban, suburban, and rural areas. Mosquito species showed their high specificity for landscape elements (96.6% correct classification by discriminant analysis); absence of Ae. mediovittatus in HDH or absence of Ae. aegypti in forests were the main indicator variables. The gradient was explained using a canonical correspondence analysis, which showed the association of Ae. aegypti with HDH in urban areas, Culex quinquefasciatus with LDH in suburbs, and Ae. mediovittatus and other native mosquitoes (Cx. antillummagnorum, Toxorhynchites portoricencis) with less disturbed habitats (forests, LDH).