Evidence for a new malaria vector species, species E, within the Anopheles culicifacies complex (Diptera: Culicidae).

Female Anopheles culicifacies Giles from Ramanathapuram district, Tamil Nadu state, India, were examined for oocysts and sporozoites and their larval progeny for mitotic karyotype. Collections were made from Mandapam and Uchipuli on the mainland, and Thangachimadam and Pamban on Rameshwaram Island. Of the 451 An. culicifacies females that were collected and dissected, 24 were found positive for Plasmodia (21 for sporozoites and 3 for oocysts). Both acrocentric and submetacentric Y-chromosome karyotypes were observed among the progeny of females from all villages. All 11 iso-female lines whose parental females were positive for sporozoites or oocysts had progeny with submetacentric Y-chromosomes. Total absence of sporozoite-positives among mothers of acrocentric males was evidence of assortative mating between these 2 sympatric populations (i.e., 2 species). We propose that the nonvector population with acrocentric Y-chromosome sons retain the original designation of species B and that the vector population with the submetacentric Y-chromosome sons be designated as species E, a new species.