Riptortus pedestris (Fabricius) has caused severe agricultural damage in Asian regions. To clarify genetic relationships among different populations of R. pedestris in Korea, 294 COI sequences were generated from 294 individual samples collected in 42 local regions. In total, 36 haplotypes were detected from the 294 COI sequences, and the genetic distances among the 42 local populations ranged from 0.00 % to 1.50 %. In the AMOVA results, a variability of more than 98 % was observed within populations, and the median joining (MJ) networks revealed that R. pedestris has expanded by crossing the nine geographical groups. Most of the samples shared one haplotype, H2; however, some samples obtained from the same regions displayed slight genetic differences. These results indicate that R. pedestris have undergone a series of genetic variations.

The brown marmorated stinkbug, Halyomorpha halys, is an invasive insect pest in North America and Europe that attacks crop species and causes substantial economic damage. To evaluate the genetic diversities and distributions of different H. halys populations in East Asia, North America, and Europe, COI sequences obtained from 79 new specimens from Korea and 10 from the USA were compared with 725 existing COI sequences. In total, 45 haplotypes were detected in populations from 10 countries. Sixteen haplotypes from Korea (H34–.H49) and 2 from the USA (H50 and H51) were novel. Korean populations exhibited the 2nd highest diversity among the 10 countries, with only Greece exhibiting higher diversity. Haplotype H22 was prominent in Korea, H1 was prominent in China, Greece, Hungary, Italy, Canada, and USA, and H3 was prominent in France and Switzerland. Of the 18 haplotypes found in Korea, 1 was shared with China (H2) and 1 with Greece (H22). Haplotype diversity patterns showed that Korean populations were genetically distinct from populations in China, Europe, and North America. This suggested that populations in Europe and North America arose through multiple invasions from China and that (with the exception of Greece), Korean populations did not spread to other countries. This study represents a comprehensive analysis of H. halys populations in Korea and places these populations in a global context that includes other native populations in East Asia and invasive populations in Europe and North America.

Oriental fruit fly, Bactrocera dorsalis, is one of the serious pests of fruit throughout the world. Two regional populations (Bangladeshi and Malaysia) were collected using methyl eugenol lure and one laboratory population was obtained from Thailand. Three populations were compared in cytochrome b (CYB) cytochrome oxidase I (COI) sequences. COI sequences were highly homologous. However, CYB sequences were polymorphic and used to discriminate these regional populations by a phylogenetic analysis. In CYB phylogeny analysis, Malaysia and Thailand populations were clustered and Bangladeshi population was separated

The Hawthorn spider mite Amphitetranychus viennensis is an important pest of various fruit trees as well as a variety of ornamental plants. Its presence has been reported in China, Japan, Korea, and middle east and European countries including Grorgia, Russia, Turkey, Ukraine. Thus, it is a quarantine species in American countries and Australia. Intra-specific variation of A. viennensis was investigated using 555 bp of ITS2 ribosomal DNA and 453 bp of the cytochrome oxidase I (COI) gene. Its variation of ITS2 and COI among China, Japan and Korea were 1.7-2.2% and 0.2-0.7%, respectively. In addition, we collected samples from 14 location in Korea. Intra-specific diversity of ITS2 and COI within Korean populations were ranged into 0.5-0.9% and 0.2-0.5%, respectively. Thus, A. viennensis is not much genetically diverse in different populations.

The JpL species is one of the 31 species belonging to the Bemisia tabaci complex and is distributed in two countries, Korea and Japan. To clarify genetic relationships among different populations of the JpL species in Korea, 83 cytochrome oxidase subunit I (COI) sequences generated from 83 individuals collected from eight Korean provinces were analyzed together with published 16 Korean COI sequences. A total of eight haplotypes were detected from the 99 COI sequences, and 82 COI sequences shared one haplotype, hap-2. The remaining 17 COI sequences were assigned to seven haplotypes, hap-1, 3, 4, 5, 6, 7, and 8. The median-joining networks of the eight haplotypes revealed that the Korean JpL species has undergone genetic variations separately according to two groups, Korean Peninsula and Jeju Island. In addition, the phylogenetic trees constructed based on the 99 COI sequences and published seven Japanese COI sequences were divided into two clades: clade(A) consisted of 97 COI sequences from the Korean Peninsula group, and clade(B) consisted of 19 COI sequences from the Jeju Island and Japan groups. Our study suggests that the Korean populations of the JpL species might have spread and be undergoing genetic variations separately according to the two groups, Korean Peninsula and Jeju Island.

The pear psylla, Cacopsylla pyricola Foerster (Homoptera: Psyllidae), is a serious insect pest of commercial pear crops. The species, which resides on pear trees throughout its life cycle, is rapidly spreading in some regions of the world. Given the life cycle, it is unclear how such a rapid spread has been facilitated. Presently, the population genetic structure of the species including genetic diversity and gene flow was studied to understand the nature of dispersal and field ecology of the species. Pear psylla was collected from several pear orchards in Korea. The 658-bp region of mitochondrial COI gene and the 716-bp long complete internal transcribed spacer 2 (ITS2) of the nuclear ribosomal DNA were sequenced. Unlikely other previously studied insect pests, the COI-based genetic diversity of the pear psylla was extremely low (maximum sequence divergence of 0.15%). This finding allowed us to conclude that the species may have been introduced in Korea relatively recently, possibly with the phenomenon of genetic bottlenecks. ITS2 sequence-based analyses of phylogeny, population differentiation, gene flow, and hierarchical population structure all concordantly suggested that the pear psylla populations in Korea are neither genetically isolated nor hampered for gene flow. These genetic data are concordant with the dispersal of an overwintering winterform morph outside the non-pear habitat in the fall and the possibility of subsequently longer distant dispersal.

The bumblebee, Bombus ignitus (Hymenoptera: Apidae), is a valuable natural resource that is one of the most notably utilized for greenhouse pollination in Korea. In order to understand the nature of genetic relationships, gene flow, and population structure of the species we sequenced a partial COI gene of mitochondrial DNA (mtDNA) corresponding to “animal barcode” region and the complete internal transcribed spacer 2 (ITS2) of the nuclear ribosomal DNA (nrDNA) collected from Korean localities. Although the 658-bp long mtDNA sequence provided only six haplotypes with the maximum sequence divergence of 0.61% (4 bp), the ITS sequences provided 84 sequence types with the maximum sequence divergence of 1.02% (21 sites), confirming better applicability of the ITS sequences to the study of intraspecific variation. The complete ITS2 sequences of B. ignitus were shown to be longest among known insects, ranging in size from 2,034 bp ~ 2,052 bp, harboring two duplicated repeats. Overall, a very high per generation migration ratio, a very low level of genetic fixation, and no discernable hierarchical population/ population group were noted to exist among populations of B. ignitus on the basis of both molecules, thus suggesting that the B. ignitus populations on the Korean peninsula are panmictic, which is consistent with our understanding of the dispersal capability of the species

The bumblebee, Bombus ignitus (Hymenoptera: Apidae), is a valuable natural resource that is one of the most notably utilized for greenhouse pollination in Korea. In order to understand the nature of genetic relationships, gene flow, and population structure of the species we sequenced a partial COI gene of mitochondrial DNA (mtDNA) corresponding to “animal barcode” region and the complete internal transcribed spacer 2 (ITS2) of the nuclear ribosomal DNA (nrDNA) with the individuals collected from Korean localities. Although the 658-bp long mtDNA sequence provided only six haplotypes with the maximum sequence divergence of 0.456% (3 bp, from 91 individuals), but the ITS sequences provided 33 sequence types with the maximum sequence divergence of 0.78% (16 bp, from 35 individuals), confirming better applicability of the ITS sequences to the study of intraspecific variation. The ITS2 sequences of B. ignitus were shown to be the longest among known insects, ranging in size from 2,034 bp ~ 2,045 bp and harbored two duplicated repeats, indicating unusual structure of B. ignitus ITS2 sequences compared with other insect ITS sequences. Overall, a very high per generation migration ratio, a very low level of genetic fixation, and no discernable hierarchical population/population group were noted to exist among populations of B. ignitus on the basis of both molecules, thus suggesting that the B. ignitus populations on the Korean peninsula are panmictic, which is consistent with our understanding of the dispersal capability.

Invertebrate mitochondrial genome contains 13 protein-coding genes and major start codons for them are ATA (Met) and ATG (Met). However, alternative start codons such as ATT (Ile), ATC (Ile), TTG (Leu), and GTG (Val) also have been suggested from a diverse organism. Approximately 120 complete mitochondrial genome reported showed that the start codon for COI gene evidences an array of diverse designation of COI start codon such as typical ATN, tetranucleotide TTAG and ATAA, newly proposed AAT and AAC and so on. In the case of Lepidoptera, many completely sequenced species showed no typical start codon at the start context of COI and even within the neighboring tRNATyr. In order to clarify, we newly sequenced the beginning context of COI gene, encompassing the neighboring tRNATyr and start region of COI gene from 39 species belonging to eight lepidopteran families. We found the newly sequenced 39 species and 14 available complete lepidopteran mitochondrial genomes all possessed CGA (arginine), which is the first non-overlapping in-frame codon in COI gene. Furthermore, this CGA is highly well aligned in terms of both nucleotide and amin o acid sequences with neighboring region. Thus, the CGA (arginine) may be synapomorphic character for Lepidoptera, functionally constrained. We, therefore, propose the CGA sequence as the start codon for COI gene in lepidopteran insects.