In the present study, the jewel beetle Chrysochroa fulgidissima was taxonomically reassessed based on molecular analyses of cytochrome c oxidase subunit I (COI) and 16S ribosomal RNA (16S) gene partial sequences, and morphological approaches, excluding the subspecies Chrysochroa fulgidissima adachii. Molecular (three data sets, COI, 16S, and COI + 16S in mtDNA) and morphological (quantitative and qualitative characters) evidence suggested that Ch. fulgidissima consists of four independent species found in seven geographical regions, namely Korea, Japan and Taiwan, China (GuangXi and Hainan) and Vietnam, and Okinawa Island. As a result of the large genetic divergences and subtle morphological differences amongst these populations, we were able to infer that the nominotypical subspecies, Chrysochroa fulgidissima fulgidissima, is divided into three pseudocryptic species that have undergone allopatric speciation events. Thus, we propose that the subspecies Chrysochroa fulgidissima alternans should be upgraded to valid specific status. We also provide a description of two new species, Chrysochroa coreana sp. nov. from Korea, and Chrysochroa pseudofulgidissima sp. nov. from China and Vietnam.

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, Dicronocephalus adamsi, 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 Dicronocephalus adamsi 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 (Dicronocephalus adamsi + Dicranocephalus yui) and Clade B includes the others (Dicronocephalus dabryi + Dicranocephalus uenoi + Dicranocephalus wallichii). This result generally supports Kurosawa’s proposal except that Dicronocephalus dabryi and Dicranocephalus uenoi are newly recognized as members of a monophyletic group. We propose that Dicronocephalus adamsi drumonti is a junior subjective synonym of Dicronocephalus adamsi adamsi. These results show that three members of the Dicranocephalus wallichii group should be treated as species rather than subspecies. However, further research including analyses of different genetic markers is needed to reconfirm our results.

The ball-rolling dung beetles of the genus Scarabaeus are very ecologically important for the recycling of feces of large herbivores and the related nature management. There has been a significant decline, however, in the numbers of many species at the population and individual levels. S. typhon is currently thought to be the sole member of Scarabaeus distributed in Korea; however, that species underwent serious local extinctions in the 1970s. Before planning a full-scale species recovery, it is important to have an understanding of the exact species diversity and genetic structures of the focal species. We therefore attempted an integrative taxonomy focused on the Korean population of S. typhon and also on S. pius and S. sacer, which were once thought to be distributed in Korea, using both morphological and molecular approaches. The results of both approaches reveal the Korean species of Scarabaeus to be S. typhon and S. pius. In particular, our molecular results inferred from cytochrome c oxidase subunit I genetic analysis show that S. typhon should be considered a single species despite having various haplotypes throughout its wide geographical range from Europe to Korea. We identified two distinct lineages of S. pius (groups A and B) across a wide distributional range. We conclude that the Korean specimens of S. pius belong to group A and that S. pius is new to Korea under the current taxonomic treatment.