Genetic variations of DNA barcoding region of bumble bees (Hymenoptera: Apidae) from South Korea.

We reassessed species diversity and genetic structure in Korean bumble bees using DNA barcode analyses of 484 cytochrome c oxidase subunit I (COI) sequences from 24 morphospecies. Based on COI, all of the Korean species formed distinct clades in the phylogenetic trees, except for Bombus (Megabombus) koreanus in the maximum likelihood tree. Five species exhibited low interspecific genetic distances (range: 1.2-2.7%), indicating that they are recently diverged species. COI data could not be used to identify bumble bees at the subspecies level. For the dominant species, most local populations in Korea were panmictic and were more closely related to continental populations than to allopatric populations. Furthermore, sympatric haplotypes within Korea could be distinguished. We detected B. (Megabombus) diversus in South Korea for the first time. Our results demonstrate that DNA barcoding is a useful technique for species recognition and for allopatric and sympatric haplotype detection in bumble bees.

A molecular phylogenetic study on South Korean Tettigonia species (Orthoptera: Tettigoniidae) using five genetic loci: The possibility of multiple allopatric speciation.

In Korea, members of the genus Tettigonia have been known as two species, T. ussuriana and T. dolichoptera dolichoptera. However, the taxonomic status of the Jeju Island population of T. ussuriana (JJ-TU) is in question, relative to the mainland population (ML-TU), because of their different body sizes and ratios of wing length. To clarify the relatedness of JJ-TU and ML-TU, we examined the genetic variation and phylogenetic relationships within and between T. ussuriana and related species collected in South Korea, using five genetic loci: three mitochondrial genes (cytochrome c oxidase subunit 1 [CO1], cytochrome c oxidase subunit 2 [CO2], NADH dehydrogenase 1 [ND1]) and two nuclear loci (second internal transcribed spacer [ITS2], and tubulin alpha-1 [TA1]). Unexpectedly, the JJ-TU population is explicitly sister to T. d. dolichoptera, with low genetic distance (0.76-1.22% in CO1), indicating no direct connection with the ML-TU population; this finding suggests a recent divergence involving rapid morphological change without gene flow between JJ-TU and mainland T. d. dolichoptera. The separation of these populations from their common ancestor was caused by geographical isolation during last glacial age. This finding indicates that the JJ-TU population should be elevated to the rank of subspecies, at the very least. Furthermore, the ML-TU population was also revealed to have four genetically divided groups (group A-D) from four localized populations, but no significant morphological differences exist among them. The genetic difference (range 3.19-4.10% in CO1) between group A + B and C + D was especially large, suggesting that cryptic speciation has widely occurred within the mainland areas, caused by allopatric isolations resulting from mountain barriers.

An integrative taxonomy on the locally endangered species of the Korean Scarabaeus (Coleoptera, Scarabaeidae).

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.

Reassessment of Species Diversity of the Subfamily Denticollinae (Coleoptera: Elateridae) through DNA Barcoding.

The subfamily Denticollinae is a taxonomically diverse group in the family Elateridae. Denticollinae includes many morphologically similar species and crop pests, as well as many undescribed species at each local fauna. To construct a rapid and reliable identification system for this subfamily, the effectiveness of molecular species identification was assessed based on 421 cytochrome c oxidase subunit I (COI) sequences of 84 morphologically identified species. Among the 84 morphospecies, molecular species identification of 60 species (71.4%) was consistent with their morphological identifications. Six cryptic and/or pseudocryptic species with large genetic divergence (>5%) were confirmed by their sympatric or allopatric distributions. However, 18 species, including a subspecies, had ambiguous genetic distances and shared overlapping intra- and interspecific genetic distances (range: 2.12%-3.67%) suggesting incomplete lineage sorting, introgression of mitochondrial genome, or affection by endosymbionts, such as Wolbachia infection, between species and simple genetic variation within species. In this study, we propose a conservative threshold of 3.6% for convenient molecular operational taxonomic unit (MOTU) identification in the subfamily Denticollinae based on the results of pairwise genetic distances analyses using neighbor-joining, mothur, Automatic Barcode Gap Discovery analysis, and tree-based species delimitation by Poisson Tree Processes analysis. Using the 3.6% threshold, we identified 87 MOTUs and found 8 MOTUs in the interval between 2.5% to 3.5%. Evaluation of MOTUs identified in this range requires integrative species delimitation, including review of morphological and ecological differences as well as sensitive genetic markers. From this study, we confirmed that COI sequence is useful for reassessing species diversity for polymorphic and polytypic species occurring in sympatric and allopatric distributions, and for a single species having an extensively large habitat.

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.

Two new species of the genus Zorochros (Coleoptera: Elateridae: Negastriinae) from Korea.

Two new species of the genus Zorochros are described from Korea: Zorochros (Zorochros) coreanus sp. nov. and Z. (Z.) mansusanensis sp. nov., belonging to the Z. (Z.) alysidotus species group and Z. (Z.) meridionalis species group, respectively. A key to the Eurasian species for the Z. alysidotus group (nine species) and the Z. meridionalis group (five species) is provided with illustrations of the two new species and their closely allied species, Z. (Z.) mesatiaticus Dolin and Z. (Z.) gurjevae Dolin from Kazakhstan.