Molecular identification of the Anopheles nili group of African malaria vectors.

Distinction between members of the Anopheles nili group of mosquitoes (Diptera: Culicidae), including major malaria vectors in riverside villages of tropical Africa, has been based mainly on doubtful morphological characters. Sequence variations of the ribosomal DNA second internal transcribed spacer (ITS2) and D3 28S region between morphological forms revealed four genetic patterns corresponding to typical An. nili (Theobald), An. carnevalei Brunhes et al., An. somalicus Rivola & Holstein and the newly identified variant provisionally named Oveng form. Primers were designed based on ITS2 fixed nucleotide differences between haplotypes to develop a multiplex PCR for rapid and specific identification of each species or molecular form. Specimens of the An. nili group from Cameroon, Burkina Faso, Ivory Coast and Senegal were successfully identified to species, demonstrating the general applicability of this technique based on criteria described in this paper.