# Phylogeographic Insights into Aedes albopictus in Korea: Integrating COX1, ND5, and CYTB Analyses

## TL;DR

This study uses genetic markers to understand the spread and diversity of the Asian tiger mosquito in South Korea, identifying key regions for mosquito control.

## Contribution

The study integrates three mitochondrial markers (COX1, ND5, and CYTB) to improve phylogeographic resolution of Aedes albopictus in Korea.

## Key findings

- Southern coastal areas like Busan and Suncheon showed high genetic diversity, suggesting they are entry points for new mosquito introductions.
- CYTB proved to be a useful complementary marker, revealing region-specific haplotypes in Busan and Wonju.
- Busan haplotype H41 connects domestic and international lineages, indicating its role as a likely introduction point.

## Abstract

The Asian tiger mosquito (Aedes albopictus) is an invasive species that can spread medically important arboviruses such as dengue, chikungunya, and Zika. Its ability to expand worldwide is strongly influenced by climate change and human travel. In South Korea, this mosquito is widely distributed, but few studies have integrated multiple mitochondrial markers. In this study, we collected mosquitoes from 13 locations in seven provinces and analyzed their genetic material using three markers: COX1, ND5, and CYTB, which are useful for tracing the relationship among mosquito populations and understanding how they may spread between regions. Our results showed high genetic diversity in southern coastal areas such as Busan and Suncheon, suggesting these regions may serve as entry points for new introductions. The findings also revealed distinct groups in mainland Korea and Jeju Island. Using multiple genetic markers provided an understanding of mosquito diversity and their links to international populations, supporting mosquito surveillance and effective control strategies for Ae. albopictus in Korea and beyond.

The Asian tiger mosquito (Aedes albopictus) is an important vector of arboviruses, including dengue, chikungunya, and Zika. Its rapid global expansion has been facilitated by climate change and human activities. Phylogenetic studies of Ae. albopictus have largely relied on mitochondrial cytochrome c oxidase subunit 1 (COX1) and NADH dehydrogenase subunit 5 (ND5) markers, while the utility of cytochrome b (CYTB) remains underexplored. We collected Ae. albopictus from 13 sites in seven provinces of South Korea and analyzed COX1, ND5, and CYTB sequences. Genetic diversity indices were calculated, and phylogenetic relationships were reconstructed using maximum-likelihood trees and haplotype networks with a dataset obtained from GenBank. COX1 revealed 46 haplotypes, including six novel variants, with the highest diversity in southern coastal regions such as Busan and Suncheon. ND5 showed limited variation, with only two haplotypes. CYTB revealed three haplotypes, including region-specific variants in Busan and Wonju, supporting its role as a complementary marker. The Busan haplotype H41 bridged domestic and international lineages, suggesting Busan as a likely entry point. This study demonstrates that integrating COX1, ND5, and CYTB improves the resolution of Ae. albopictus phylogeography in Korea and highlights the need for continued molecular surveillance to guide vector control strategies.