Bromeliad-inhabiting mosquitoes in south Florida: native and exotic plants differ in species composition.

At several locations in south Florida, water impounded by the leaf axils of native or exotic bromeliads was sampled for immature mosquitoes. Culex biscaynensis was the most commonly collected mosquito from exotic bromeliads at study sites in southeastern Miami-Dade County, whereas at nearby sites with native bromeliads, immature Wyeomyia mitchellii were more abundant than immature Culex biscaynensis. Aquatic habitat size and persistence may be important factors favoring Culex biscaynensis in exotic bromeliads. Leaf axils of exotic bromeliads had a greater water-holding capacity than those of the native bromeliads; and because the exotic bromeliads were located on the ground usually near lawn watering sprinklers, their aquatic habitats may persist longer than those of the native, epiphytic bromeliads that received only rainfall. In the exotic bromeliads, the frequency of occurrence of Culex biscaynensis was similar in tree-shaded and in open-sunlit areas. The distribution of Culex biscaynensis currently is limited to Miami-Dade County, and at sites in other south Florida counties, Wyeomyia spp. were the dominant mosquitoes in collections from exotic bromeliads. Aedes aegypti, Aedes albopictus and Culex quinquefasciatus were occasionally found in exotic bromeliads, usually in low numbers; however, these mosquitoes were not collected from native bromeliads.