A Predevelopment Mosquito Survey in the Mahaweli Development Project Area, Sri Lanka: Immatures

Abstract

Sixty-four species of mosquitoes were recorded during a 16-mo baseline study of mosquito breeding ecology in forest habitat due to be developed for irrigated agriculture under System C of the Mahaweli Development Project of Sri Lanka. Thirty species bred in container habitats in the forest, of which the dominant species were Aedes albopictus (Skuse), a secondary vector of dengue fever, and Ae. novalbopictus Barraud. Groundwater habitats yielded 49 species, of which the most abundant anophelines were An. culidfades Giles, the only established vector of human malaria in the country, and An. barbirostris van der Wulp. The culicine fauna was dominated by Culex mimulus Edwards and included potential vectors of Japanese encephalitis (Culex tritaeniorhynchus Giles, Cx. gelidus Theobald, Cx. fuscocephala Theobald, Cx. pseudovishnui Colless) and Brugian filariasis (Mansonia annulifera (Theobald), Ma. uniformis (Theobald), Ma. Indiana Edwards). Some of the more prevalent species differed significantly in relative density levels among the major types of container and groundwater habitats, as well as in relation to gross water quality and light-shade parameters. The densities of potential vectors of malaria and Japanese encephalitis are likely to increase as a result of new breeding habitats created by development.