Progress of DNA barcoding research in Coleoptera

Coleoptera (commonly known as beetles), the most species-rich order of Insecta, plays an important role in biodiversity assessment, pest management, and biological control. Accurate species identification serves as a fundamental basis for these studies. DNA barcoding, which is primarily based on the mitochondrial cytochrome c oxidase subunit Ⅰ (COI) gene, enables the rapid and reliable identification of species through the analysis of standardized DNA sequences. This review provides a comprehensive summary of DNA barcoding research in Coleoptera, including barcode types and the impact of advances in sequencing technologies on barcoding methods and analytical strategies. It further summarizes applications of DNA barcoding in coleopteran taxonomy, phylogeny, biodiversity assessment, and food web analysis. Moreover, this review discusses potential factors that may affect its accuracy, such as mitochondrial heteroplasmy, nuclear mitochondrial pseudogenes, Wolbachia infection, and introgression. This review highlights future research directions, including expanding DNA barcode reference libraries, re-evaluating species taxonomic status, and promoting the integration of whole-genome sequencing with integrative taxonomy, with the goal of supporting pest management, resource utilization, biodiversity conservation, and ecosystem monitoring in Coleoptera.