In this study, we developed ten microsatellite markers specific to L. angelina using the Illumina NextSeq 500 platform. Forty-three individuals of L. angelina collected from three localities in South Korea were genotyped to validate these markers and to preliminarily assess population genetic characteristics. The observed number of alleles, observed heterozygosity (HO), and expected heterozygosity (HE) at a locus ranged from 4–13, 0.211–0.950, and 0.659–0.871 in the population with the largest sample size (20 individuals), respectively, thereby validating the suitability of the markers for population analyses. Our preliminarily assessment of the population genetic characteristics indicates the presence of inbreeding in all populations, an isolation of the most geographically distant population (Seocheon), and lower HO than HE. The microsatellite markers developed in this study will be useful for studying the population genetics of L. angelina collected from additional sites in South Korea and from other regions. †These authors contributed equally to this paper.

To verify the progenitor of B. mori, we sequenced 14 B. mori strains preserved in Korea and one B. mandarina collected in Korea and conducted phylogenetic analysis of Bombycidae using maximum-likelihood method and concatenated sequences of 13 PCGs and 2 rRNA genes. All B. mori strains, regardless of their origin, formed a strong monophyletic group, with the highest nodal support. This B. mori group was placed as the sister to the two B. mandarina collected each from Korea and Shandong, China with the highest nodal support. Finally, the remaining two B. mandarina, which were collected in Japan were independently placed as the most basal lineage of B. mori and B. mandarina group. These results appear to indicate that an immediate ancestor for the domestic silkworm strains may have been originated from China and Korea.

In this study, we developed 11 microsatellite markers specific to A. crataegi using NGS to investigate the genetic relationships of A. crataegi populations from South Korea to circumferential Asian countries (China, Russia, Mongolia, and Japan). Further, two mitochondrial DNA (mtDNA) gene segments (COI and CytB) were sequenced from the samples. The population- and individual-based Principal Coordinates and STRUCTURE analyses collectively suggested that the South Korean population of A. crataegi is most differentiated from the Japanese population, whereas it was closer to Mongolian and Chinese populations. These results collectively suggest that northern populations, in particular, Mongolian populations can be considered as the most genetically compatible one as donee population, when the reintroduction program is launched. †These authors contributed equally to this paper.

Cymbidium flower is mainly grown for exportation to China and Japan, but detection of a few pests including the cotton aphid, Aphis gossypii (Hemiptera: Aphidae), necessitated post-harvest treatment for casual exportation. Thus, we irradiated electron beam to cotton aphids occurring in cymbidium to establish post-harvest method for casual exportation of the flowers. For cymbidium, six categories of product quality were examined after eight different doses were irradiated (100, 200, 300, 400, 500, 600, 800 and 1,000 Gy). One thousand Gy to cymbidium caused an extreme deterioration only in vase life in both colors compared to control (0 Gy). In the case of cotton aphids, adult longevity decreased from 11.23 (100 Gy) to 4.70 (400 Gy) when four different doses were irradiated (100, 200, 300, and 400 Gy), with control being an average of 20.89 days. The numbers of total first instar nymph produced per adult was not significantly differed among five doses (2.21 ~ 2.74 individuals), but was substantially lower compared to control (an average of 51.46; P < 0.0001). Live F1 nymphs did not develope to adults at all five doses, except for a single nymph at 100 Gy, which was dead right after emergence. The results of probit analysis indicated that majority of adults required 3.33 ~ 7.55 days for 90% mortality at 200 Gy and higher, but at 100 Gy it required 41.56 days. Therefore, higher than 100 Gy might be required for complete control of adult cotton aphids and their F1.

Bombyx mandarina (Lepidoptera: Bombycidae) is generally regarded as the ancestor of the domesticated B. mori. Recently, over 40 mitochondrial genomes (mitogenomes) mainly from B. mori strains preserved in China and wild individuals of B. mandarina were sequenced to verify the progenitor of B. mori. At this point, we also were curious about the origin and the relationships of Korean silkworms to foreign B. mandarina and B. mori. As a first step, we sequenced the complete mitogenome of the B. mandarina collected in Korea and compared it to pre-exsiting data (37 strains of B. mori and 14 individuals of B. mandarina). The complete mitogenome of B. mandarina was 15,694-bp long, consisted of 13 protein-coding genes, two rRNA genes, 22 tRNA genes and one non-coding region. The 494-bp long A+T-rich region possessed the highest A/T content (95.3%) than any other region of the genome. Overall, the general mitogenome characteristics of the genus Bombyx species have an identical gene arrangement, similar A/ T content (average 82.3%) and so on. Phylogenetic analysis, however, showed that B. mori and B. mandarina formed a distant group each with the highest nodal support. For more findings of mitogenome characteristics of Bombyx including the Korean B. mandarina and those preserved in Korea more mitogenomes, particularly from Korea, might be needed.

Currently, phylogenetic relationships of Bombycoidea have been reconstructed using molecular data, but generated several hypotheses on among-familial relationships [(especially, “Satruniidae+Bombycidae+Sphingidae” group)] within Bombycoidea. Thus, in this study, we sequenced 39 mitogenomes from both Bombycoidea and Lasiocampoidea. Consequently, one topology was obtained on the basis of ML and BI methods. It suggested the monophyly of the two superfamilies (Bombycoidea and Lasiocampoidea) consistently with a high nodal support; the sister relationship between Saturniidae and Sphingidae in “SBS”; and the sister relationships between Bombycidae and the Saturniidae + Sphingidae group.

The effects of cold storage temperature and exposure duration on immature stages of spotted-wing drosophila (SWD) Drosophila suzukii (Diptera: Drosophilidae) on ‘Campbell Early’ grapes were examined to establish a phytosanitary control method. The immature stages (eggs, larvae and pupae) of SWD were all dead after a 6-day cold treatment at 1°C and 8-day cold treatment at 1.5 and 2°C. Small-scale tests using pupae, which were the most-cold tolerant stage, confirmed the validity of the selected temperature and exposure durations. Conversely, the 8- and 10-day at 1°C treatments showed 100% mortality, suggesting that these treatments can guarantee quarantine security against infestations of SWD on exported ‘Campbell Early’ grapes.

In this study, we developed 12 microsatellite markers specific to N. pygmaea using Illumina paired-end sequencing. Forty individuals of N. pygmaea collected from three currently known localities in South Korea were genotyped to validate these markers and to preliminarily assess population genetic characteristics. No locus showed significant deviation from the Hardy–Weinberg equilibrium (HWE). Our preliminary data indicate an absence of inbreeding in all populations and an absence of obvious genetic difference. The microsatellite markers developed in this study will be useful for studying the population genetics of N. pygmaea collected from other regions, including additional sites in South Korea.

The number of reported mitochondrial genomes (mitogenomes) from the monotypic Lasiocampoidea has been limited until recently. In this study, we sequenced the complete mitogenome of the lappet moth, Kunugia undans (Lepidoptera: Lasiocampidae), and compared it to those of other lasiocampid species and macroheteroceran superfamilies (59 species in six superfamilies). The 15,570-bp long K. undans genome had the typical set of genes found in animal mitogenomes, with the exception of one additional trnR that are located between trnA and trnN loci. Considering that the two trnR copies are located in tandem with proper secondary structures and identical anticodons, a gene duplication event might be responsible for the presence of the two tRNAs. In summary, the general mitogenome characteristics of Lasiocampoidea did not differ greatly from the remaining macroheteroceran superfamilies, but it did exhibit some unique features.

Currently, phylogenetic relationships of Macroheterocera with the inclusion of Bombycoidea have been reconstructed using molecular data, but generated several hypotheses on familial relationships within Bombycoidea and among-superfamilial relationships within Macroheterocera. Thus, in this study, mitogenome-based superfamilial relationships of Macroheterocera and familial relationships among macroheteroceran superfamily, Bombycoidea, were tested with different algorithms and partition schemes. Additionally, two unrecorded species of Bombycoidea (Saturnia jonasii and Kentrochrysalis streckeri) detected in Korea using morphological and molecular data are presented.

In this study, we tested the effect of a range of insect orders including Trichoptera as outgroups for lepidopteran phylogeny. Phylogenetic analyses performed with four different partitioning schemes using the maximum-likelihood method provided four different topologies (T1-T4) and topological test most supported T1 topology. When the means of first principle component for nucleotide frequency between A/T and G/C of PCGs was considered Trichoptera, Diptera, Coleoptera, and Orthoptera tended to result in T1 topology more frequently in the given ingroup taxa and outgroups tested. This result contradicts to the general view that the sister taxon might be the best outgroup. The T1 topology was largely consistent with a recent large molecular dataset-based lepidopteran phylogeney, presenting the relationships ((((((((((Noctuoidea + Geometroidea) + (Bombycoidea + Lasiocampoidea)) + Drepanoidea) + Mimallonoidea) + Pyraloidea) + Gelechioidea) + Papilionoidea) + Tortricoidea) + (Gracillaroidea + Yponomeutoidea)) + Hepialoidea).

We sequenced the complete mitochondrial (mt) genome of Camponotus atrox (Hymenoptera: Formicidae) that is distributed only in Korea. This genome is 16,540 bp in size, contains typical sets of genes (13 protein-coding genes, 22 tRNAs, and two rRNAs). The C. atrox A+T-rich region is the longest in the sequenced ants as 1,402 bp and is comprised of an identical tandem repeat consisting of six 100-bp copies and one 96-bp copy. A total of 315 bp of intergenic-spacer sequences were spread over 23 regions. An attempt to align spacer sequences in ants turned out that alignment was mostly feasible among congeneric species, with a substantial sequence divergence, indicating the potential of these sequences as congeneric molecular markers. The A/T content in first and second codon positions of PCGs are similar in ants including C. atrox (73.9 vs. 72.3% on average). Estimation of degree of genetic divergence (e.g. non-synonymous substitution rate) with an increased taxon sampling among hymenopteran superfamilies indicated the presence of different rates of divergence between the suborders Symphyta and Apocrita as has previously been reported. The C. atrox mt genome has a unique gene arrangement, trnI-trnM-trnQ at the A+T-rich region and ND2 junction (underline for inverted gene), possibly originated from tandem duplication of trnM-trnI, resulting in trnM-trnI-trnM-trnI-trnQ and loss of first trnM and second trnI, resulting in trnI-trnM-trnQ.