The leaf beetle, Chrysolina aurichalcea (Coleoptera: Chysomelidae), is a pest damaging plants of Compositae. In order to understand the genetic diversity and geographic variation we sequenced a portion of mitochondrial COI gene (658 bp) and complete nuclear internal transcribed spacer 2 (ITS2) of the species collected from seven Korean localities. A total of 17 haplotypes (CACOI01 ~ CACOI17), with the maximum sequence divergence of 3.04% (20 bp) were obtained from COI gene sequence, whereas 16 sequence types (ITS2CA01 ~ ITS2CA16), with the maximum sequence divergence of 2.013% (9 bp) were obtained from ITS2, indicating substantially larger sequence divergence in COI gene sequence. Phylogenetically, the COI gene provided two haplotype groups with a high nodal support (≥ 87%), whereas ITS2 provided one sequence type group with a high nodal support (≥ 92%). The result of COI gene may suggest the presence of historical biogeographic barriers that bolster genetic subdivision in the species. Different grouping pattern between COI gene and ITS2 sequences were interpreted in terms of recent dispersal, reflected in the ITS2 sequence. Finally, finding of unique haplotypes and sequence types only from Beakryeng-Islet population was interpreted as an intact remnant of ancient polymorphism. As more samples are analyzed using further hyper-variable marker, further fruitful inference on the geographic contour of the species might be available.

The Scarites aterrimus (Coleoptera: Carabidae), is one of the carabid beetles dwelling exclusively on coastal sandy dunes. Recent habitat deterioration has greatly concerned population declines in several species dwelling on the coastal sandy dunes. Asa first step to establish long-term conservation strategy, we investigated the nation-wide magnitude and nature of genetic diversity of the species. As a first step, we sequenced a portion of mitochondrial COI gene, corresponding to “DNA Barcode” region (658 bp) from a total of 24 S. aterrimus individuals collected over nine sandy dunes belonging to four Korean provinces. The sequence analysis evidenced moderate to low magnitude of sequence diversity compared with other insect species distributed in Korean peninsula (0.152% to 0.912%). The presence of closely related haplotypes and relatively high gene flow estimate collectively suggest that there had been no historical barriers that bolster genetic subdivision. Population decline was postulated on the basis of several missing haplotypes that are well found in the species with a large population size. This interpretation is consistent with field observation of small population size in the coastal sandy dune habitats. The highest genetic diversity estimates were found in the coastal sand dune population of Seogwipo, Jeju Island, justifying a prior attention to the population, in order to sustain overall genetic diversity of the species. Further scrutinized study might be required for further robust conclusion.

The leaf beetle, Chrysolina aurichalcea (Coleoptera: Chysomelidae), is a pest damaging plants of Compositae. In order to understand the genetic diversity and geographic variation of the species we sequenced a portion of mitochondrial COI gene (658 bp) and complete nuclear internal transcribed spacer 2 (ITS2) collected from seven Korean localities. A total of 18 haplotypes (BARCA01 ~ BARCA18), with the maximum sequence divergence of 3.04% (20 bp) were obtained from COI gene sequence, whereas 17 sequence types (ITS2CA01 ~ ITS2CA17), with the maximum sequence divergence of 2.013% (9 bp) were obtained from ITS2, indicating substantially larger sequence divergence in mitochondrial gene sequence. Phylogenetically, the mitochondrial DNA has shown several haplotypes formed independent groups with substantially high node support (≥ 90%), whereas no such grouping was evidenced for ITS2, indicating different behaviors of the two molecules. Such difference may reflect a diverse dynamics of the species such as biogeographic history, mating behaviors, and also possibly different mode of inheritance of the two molecules, but requires further scrutinized examination of the dataset. In terms of population genetic perspective, overall no population subdivision was detected from both molecules, except for locality 7 (Eocheong islet) from mitochondrial DNA. As more scrutinized analysis is performed, further fruitful inference on the geographic contour of the species might be available.

The seven-spotted lady beetle, Coccinella septempunctata (Coleoptera: Coccinellidae), known also as the seven-spot ladybird, is natural enemy for aphids and has a broad ecological range, living almost anywhere there are aphids for it to eat. In order to understand the genetic diversity and geographic variation of the species we sequenced a portion of mitochondrial COI gene (658 bp) and complete nuclear internal transcribed spacer 2 (ITS2) collected from nine Korean localities. A total of 21 haplotypes (CSCOI01 ~ CSCOI21), with the maximum sequence divergence of 4.56% (30 bp) were obtained from COI gene sequence (from 78 individuals), whereas 65 sequence types (CSITS201 ~ CSITS265), with the maximum sequence divergence of 2.06% (11 positions) were obtained from ITS2 (from 79 individuals), indicating substantially larger sequence divergence in mitochondrial gene sequence. Both COI gene and ITS2 shows the distribution pattern that only a few haplotypes or sequence types are widely distributed, whereas majority of them are highly restricted in one geographic location, even represented as a single individual. Unlikely the ITS2 sequence types the mitochondrial COI haplotypes evidenced the presence of two main phylogenetic groups, reciprocally monophyletic to each other. Geographically, these two groups are spread in all localities surveyed. Considering both COI gene and ITS2 sequence together, current our data may suggest the presence of ancestral polymorphism, rather than on-going speciation, but more scrutinized analysis will be performed soon. Due partially by the presence of both COI groups in all surveyed localities, the genetic diversity estimates of all localities are similar from the perspective of COI gene, but ITS data showed extremely lower genetic diversity of one islet locality, Anmyeon-do (locality 2; 0.002530 vs. 0.008054 ~ 0.012060). Analysis of gene flew estimates between localities indicates that most populations are highly interconnected to each other. However, one islet locality, Anmyeon-do (locality) has shown statistically significant distance from the remaining localities on the basis of only ITS2 data (FST = 0.19 ~ 0.34), requiring scrutinized phylogeographic inference on this population with expanded sampling. As more scrutinized analysis is performed, further fruitful inference on the geographic contour of the species might be available.

The dung beetle, Copris tripartitus, (Coleoptera: Scarabaeidae), is one of the insect species listed as endangered wildlife in Korea. In order to establish conservation strategy an investigation on nation-wide genetic magnitude and nature of genetic diversity would be required. In this study, we sequenced each partial sequences of mitochondrial COI (658 bp) and CytB (433 bop) genes and complete internal transcribed spacer 2 (ITS2) of the nuclear ribosomal DNA (411~420 bp) from 70 individuals of C. tripartitus collected from five Korean localities. The sequence divergence of mitochondrial genes was unexpectedly substantial as 5.0% (33 bp) for COI and 4.6% (20 bp) for CytB, whereas that of ITS2 was only 1.9% (6 bp), revealing much higher variability in mitochondrial DNA. In phylogenetic analysis, each 57 and 47 haplotypes obtained from COI and CytB gene sequences was subdivided into two groups (groups A and B), but the node supports for each group was not strong enough to consider each group as independent monophyletic groups in both genes. This interpretation was further supported by the same analysis with ITS2, showing no subdivision at all. These findings reinforce importance for the inference of phylogenetic result using both mitochondrial and nuclear encoded sequences. The C. tripartitus occurring in Korean peninsula was genetically well connected to each other and no obvious population genetic structure was detectable.