Notes on the ground beetle Pterostichus togyusanus (Coleoptera: Carabidae): Phylogenetic evidence for species status and new distribution record

A flightless carabid beetle, Pterostichus bellatrix (Tschitschérine, 1895), which is endemic to the Korean Peninsula, had been thought to comprise two subspecies: the nominotypical subspecies distributed in northern and central parts of the peninsula, and the subspecies P. bellatrix togyusanus Park and Kwon, 1996, distributed in the southern part of the peninsula. A recent study upgraded these two subspecies to species level, but no convincing evidence was provided for this taxonomic change. Our comparative morphology of external and male genital characters revealed that these two species are paraphyletic with respect to Pterostichus syleus Kirschenhofer, 1997, which was described from Liaoning Province, China. Thus, separate species status of P. bellatrix and P. togyusanus was confirmed phylogenetically. Although P. togyusanus has only been known from the type locality, Mt. Deogyusan, we newly record this species from Mt. Jirisan, a mountain located south of the known locality. A revised key to species of the Pterostichus opacipennis species group (=the subgenus Koreonialoe (s. str.) Park and Kwon, 1996), which now includes 14 species, is also provided.