Faunal and genetic studies of mosquitoes on Chichi-jima and Haha-jima, the Ogasawara (Bonin) Islands, Japan

irty years have passed since the last surveillance of the mosquito fauna on the entire Chichi-jima, Ogasawara Islands, Japan. Herein, we report the results of a mosquito study conducted on the Ogasawara Islands in 2015 and 2017. In this study, 2,371 individuals belonging to seven species in three genera were collected, including 262 mosquitoes belonging to ve species in three genera collected in 2015 and 2,109 specimens representing six species in three genera obtained in 2017. e dominant species in dry-ice trap collections were Culex boninensis and Cx. quinquefasciatus, and the latter was dominant in yeast trap collections. Aedes albopictus, Ae. savoryi, and Cx. boninensis were dominant in sweep net collections, while Ae. albopictus and Cx. quinquefasciatus were dominant in the larval collection. Culex boninensis and Ae. albopictus were widely distributed on the islands. Gene sequences of cytochrome c oxidase subunit I from 55 specimens belonging to the seven species in the three genera, including four endemic species (Ae. wadai, Ae. savoryi, Cx. boninensis, and Lutzia shinonagai), were registered in GenBank. Genetic distance analysis showed low intraspeci c variations and low mean genetic distances (between 0.0% and 0.8%), indicating signi cant homogeneity among mosquito populations on the Ogasawara Islands.