Two members of the Culex pipiens subgroup, Culex pallens and Culex pipiens f. molestus, are known to occur in the Republic of Korea (ROK). These species exhibit morphologically similar features and are challenging to distinguish below the species level. Therefore, this study utilized wing geometric morphometrics (GM) on the right wing of the Culex pipiens subgroup, alongside sequencing of the cytochrome c oxidase subunit I (COI) region. Mosquitoes were collected from 11 locations between June and October to minimize regional and seasonal variations. Additionally, Culex pipiens f. pipiens, which is not native to the ROK, was included in the analysis. Culex tritaeniorhynchus, Aedes albopictus, and Anopheles sinensis, the primary vectors in the ROK, were used as outgroups for comparison. All three taxa within the Culex pipiens subgroup could be identified with an 82.4%–97.0% accuracy using GM. However, a comparison of the COI regions of the Culex pipiens subgroup revealed no clear differences between the taxa. These data can be used for accurate identification, contributing to effective mosquito control, in addition to providing a foundation for evolutionary and ecological studies on wing shape differences.

# Jiseung Jeon, Dong Yeol Lee, Yewon Jo, Jihun Ryu, Eunjeong Kim, Kwang Shik Choi. Wing geometric morphometrics and *COI* barcoding of *Culex pipiens* subgroup in the Republic of Korea Pictures of the right wing of an adult female were collected in the Republic of Korea between 2020 and 2022. ## File list (WGM\_ROK\_Jeon et al(2023).zip) Wing data. Jeon et al.(2023).xlsx Right Wing (Cx. tritaeniorhynchus) Right Wing (Cx. pallens) Right Wing (Cx. p. f. molestus) Right Wing (An. sinensis) Right Wing (Ae. albopictus) ## File descriptions Wing data. Jeon et al.(2023).xlsx - Contains data about the location, date, coordinates, and species. Right Wing (Cx. tritaeniorhynchus) - Images of the wings of Cx. tritaeniorhynchus Right Wing (Cx. pallens) - Images of the wings of Cx. pallens Right Wing (Cx. p. f. molestus) - Images of the wings of Cx. p. f. molestus Right Wing (An. sinensis) - Images of the wings of An. sinensis Right Wing (Ae. albopictus) - Images of the wings of Ae. albopictus **Note** - All photos utilize the right wing only and were taken at 20x magnification using an Olympus SZ61 Stereo Microscope.