The first attempt to apply environmental DNA analysis to insect biodiversity in Southeast Asia: DNA metabarcoding and physical survey on Trichoptera species

The primary goal of this study was to evaluate the feasibility of environmental DNA (eDNA) metabarcoding for assessing aquatic insect biodiversity in tropical river systems of Southern Thailand, a region where such research has been extremely limited. By conducting the first insect eDNA study in Southeast Asia, we aimed to address the challenge posed by incomplete public DNA databases, which initially resulted in low species detection. To overcome this, we developed a custom DNA reference database and integrated phylogenetic insights from previous studies, significantly improving detection accuracy. This approach demonstrates the critical importance of building regional reference libraries and highlights the potential of eDNA-based methods for biodiversity monitoring in data-deficient tropical ecosystems, contributing to global conservation and ecological research efforts.