Environmental DNA in mosqito breeding sites: A monitoring tool for mosquito species and exploration of biological control agents

Mosquito surveillance is crucial for managing mosquito-borne disease and invasive species. Traditional methods, such as trapping and morphological identification, are labor-intensive and lack sensitivity. Environmental DNA (eDNA) surveillance, enabled by molecular techniques, offers a promising alternative for investigating organisms in different environments. In this study, conducted across diverse habitats in Hong Kong, we employed a metabarcoding approach by amplifying the cytochrome c oxidase subunit I (COI) gene from eDNA samples collected at mosquito breeding sites. Next-Generation Sequencing (NGS) facilitated high-throughput identification mosquito species and potential biological control agents, including predatory aquatic insects and parasites. Utilizing the Maximum Likelihood model to construct a phylogenetic tree, we accurately identified 38 mosquito species, including 15 unknown species, and demonstrated that our eDNA method was more comprehensive and sensitive than traditional techniques. Furthermore, we explored potential biological control agents by assessing other aquatic organisms, such as copepods, dragonfly nymphs, and predatory beetles, for integrated mosquito management strategies. Our research highlights eDNA metabarcoding as a valuable, efficient, and non-invasive tool for monitoring mosquito species, investigating biological control agents, and informing public health strategies for mosquito-borne disease prevention and control.