COI DNA barcoding for molecular identification of the genus Aphidius (Braconidae: Aphidiinae) in South Korea, with diagnoses of two newly recorded species

[Display omitted] •The genus Aphidius is commercially important species in greenhouse for control pests.•Aphidius is consist of 127 species over the world, while 13 species in South Korea.•COI barcoding could identify Aphidius spp. except for three species into a clade.•We found and confirmed two unrecorded species, Aphidius funebris and Aphidius sonchi. The genus Aphidius is one of the most commercially important species in greenhouse for controlling pests, especially aphids. Although 13 Aphidius species had been recorded in South Korea, it was not carefully surveyed yet. In this study, we surveyed and collected 8 Aphidius spp. including two unrecorded species. Using the DNA barcode region of mitochondrial cytochrome c oxidase subunit I (COI), sequences were newly generated for 16 molecular operational taxonomic units (MOTUs) of 8 species, except for 15 duplicates, in addition of 58 MOTUs of 18 species referred from GenBank for comparison and identification, which were reconstructed in a barcode phylogeny with Neighbor-Joining method. Then, to define each species, both Automatic Barcode Gap Discovery (ABGD) and Bayesian Poisson Tree Processes (bPTP) analyses were performed. As results, although most of Aphidius spp. could be identified by clustering into a clade, we recognized that three Aphdius species were placed in a clade, of which each species was not separated as an independent species. Our data suggested that those species demonstrating a species complex were able to be hypothesized as one species. In addition, diagnoses and illustrations of the two newly recorded species in South Korea were provided.