Molecular identification of forensically significant beetles (Coleoptera) in China based on COI gene

Precise identification of insect species plays an essential role in the accurate estimation of the postmortem interval (PMI), especially when information on the postmortem phenomenon is not available. Sarcosaphagous beetles infest and colonize human and animal remains in the late stage of decomposition, and their morphological similarity poses a great challenge for forensic entomologists, as an existing key may be incomplete or difficult for non-specialists to use. A method for easy and accurate species-level identification at any life stage is required. In this study, a 272-base pair region of the mitochondrial cytochrome oxidase I (COI) gene was used to explore its utility in the identification of forensically important beetles. Twenty-four specimens were collected from 14 locations in nine provinces of China. Phenogram analysis of the sequenced segments by the unweighted pairgroup method analysis (UPGMA) method showed that all specimens were properly assigned into six species with strong similarity, which indicates the possibility of separating congeneric species with the short COI fragment. These results will be instrumental for implementation of the Chinese database of forensically relevant beetles.