Molecular phylogeny of the genus Dicronocephalus (Coleoptera, Scarabaeidae, Cetoniinae) based on mtCOI and 16S rRNA genes

The seven species belonging to the genus Dicronocephalus are a very interesting group with a unique appearance and distinct sexual dimorphism. Only one species among them, Dicronocephalusadamsi, has been known in the Korean fauna. This species is recognized as having a wide distribution from Tibet to Korean Peninsula and is currently represented by two subspecies that have separated geographical ranges. The phylogenetic relationships of Dicronocephalusadamsi were still unclear. The phylogeny of Dicronocephalus is reconstructed with a phylogenetic study of five species including four subspecies based on a molecular approach using mitochondrial COI and 16S rRNA genes. Our results are compared with the results obtained by previous authors based on morphological characters. They show that the tested taxa are divided into two major clades. Clade A consists of two species (Dicronocephalusadamsi + Dicranocephalusyui) and Clade B includes the others (Dicronocephalusdabryi + Dicranocephalusuenoi + Dicranocephaluswallichii). This result generally supports Kurosawa's proposal except that Dicronocephalusdabryi and Dicranocephalusuenoi are newly recognized as members of a monophyletic group. We propose that Dicronocephalusadamsidrumonti is a junior subjective synonym of Dicronocephalusadamsiadamsi. These results show that three members of the Dicranocephaluswallichii group should be treated as species rather than subspecies. However, further research including analyses of different genetic markers is needed to reconfirm our results.