Anopheles subpictus complex: distribution of sibling species in Sri Lanka.

To determine the sibling species composition of An. subpictus complex in Sri Lanka polytene chromosomes of ovarian nurse cells were examined. Samples of An. subpictus s.l. were collected from 65 of the 73 Health Areas surveyed. Of 3095 ovaries collected 869 polytene chromosomes preparation were identified as sibling species A and 77 B. Species B was present only in coastal localities of the Island whereas species A was found both in coastal and inland areas with predominance in inland areas. This is the first report on the occurrence of two sibling species of An. subpictus in Sri Lanka. Some biological characteristics of coastal and inland populations such as susceptibility to different insecticides, human blood index and human biting rates are discussed.