DNA barcoding for identification of mosquitoes (Diptera: Culicidae) from the Ryukyu Archipelago, Japan

Abstract

The utility of cytochrome c oxidase subunit I (COI) DNA barcoding for the identification of 37 mosquito species belonging to the genera Anopheles (6 spp.), Aedes (14 spp.) and Culex (17 spp.) including subspecies from nine islands of the Ryukyu Archipelago, Japan was examined. A 658 bp fragment of the COI gene was sequenced from 228 specimens. Nucleotide sequence divergences were calculated using the Kimura-two parameter (K2P) distance model and a neighbor-joining (NJ) phylogenetic tree analysis was performed to provide a graphic display of the patterns in divergence among species. The mean intraspecific variations of 35 species including the medically important vector species showed a less than 2% range with 0–1.5% divergences, but higher divergences of more than 2% were detected in Ae. aureostriatus okinawanus Bohart (2.2%) and Cx. hayashii ryukyuanus Tanaka et al. (3.3%). They showed differences in divergence between specimens from different islands. All 37 species were discriminated as distinct clusters in the NJ tree. The results in this study prove the utility of DNA barcoding for identification of mosquitoes from the Ryukyu Archipelago, Japan.