The Application of Mitochondrial COI Gene-Based Molecular Identification of Forensically Important Scuttle Flies (Diptera: Phoridae) in Korea

Abstract

Phoridae are a family of necrophagous flies commonly found in indoor death scene. They account for approximately 19.7% of the entomofauna in human cadavers in Korea. Additionally, this taxon is an indicator of indoor hygiene, and these flies appear in environments where access by other necrophagous insects is difficult, such as enclosed rooms. Thus, they are likely to be used as forensic evidence. Despite their importance in forensic investigations and environmental hygiene, detailed studies on the taxonomy and molecular barcoding for this family are scarce, including in Korea. Because accurate taxonomic information regarding necrophagous insects collected from a death-related scene is essential during medicolegal investigations, molecular barcoding data could be useful as well as reliable. In this paper, full-length nucleotide sequences of genes coding for the cytochrome c oxidase subunit I (COI) in 79 Phoridae larvae collected from 20 medicolegal autopsy cases in Korea were phylogenetically analyzed by comparing their sequences to the foreign barcoding data of Phoridae. Six mitochondrial haplogroups were identified, which two of them matched to foreign Phoridae fly species haplotypes, Megaselia scalaris (Loew, 1866) and M. spiracularis Schmitz 1938. Taxonomies of five other haplogroups, with nucleotide distances ranging from 1.68% to 2.26% from the M. scalaris group, could not be confirmed solely based on the molecular barcoding data. Further research should be performed to determine whether these five haplogroups are diverged conspecifics of M. scalaris or a closely related sister cryptic species of M. scalaris.