DNA barcoding and morphological analyses of Korean Lymantria (Erebidae, Lepidoptera) were conducted for quarantine inspection. In DNA barcoding, Lymantria dispar identified through quarantine inspection was distinguished as three species, L . dispar asiatica , L . albescens , and L . xylina . Lymantria monacha , which is known as a single species in Korea, is revealed as containing three species, L . monacha , L . minomonis , and L . sugii . At the subspecies level, L . dispar dispar formed a single cluster, whereas L . d . asiatica and L . d . japonica formed a cluster containing both subspecies. In morphological re-examination on DNA barcoding results, L. dispar was distinguished from L. albescens by wing pattern, and from L. xylina by papillae anale. L. monacha and the related species were hard to be distinct from each other by using wing pattern, but it was easily distinct through comparison of genitalia. Therefore, DNA barcoding led to accurate identification in species level, but in subspecies level, only a taxon showing geographically far distance was discriminated from the others. These results may provide a taxonomic outline of the Korean Lymantria fauna and may be used as an identification reference for Lymantria species during quarantine inspection.

Infestation of phosphine (PH₃) resistant insects threatens global grain reserves. PH₃ fumigation controls rice weevil (Sitophilus oryzae) but not highly resistant insect pests. Here, we investigated naturally occurring strains of S. oryzae that were moderately resistant (MR), strongly resistant (SR), or susceptible (wild-type; WT) to PH₃ using global proteome analysis and mitochondrial DNA sequencing. Both PH₃ resistant (PH₃–R) strains exhibited higher susceptibility to ethyl formate-mediated inhibition of cytochrome c oxidase than the WT strain, whereas the disinfectant PH₃ concentration time of the SR strain was much longer than that of the MR strain. Unlike the MR strain, which showed altered expression levels of genes encoding metabolic enzymes involved in catabolic pathways that minimize metabolic burden, the SR strain showed changes in the mitochondrial respiratory chain. Our results suggest that the acquisition of strong PH₃ resistance necessitates the avoidance of oxidative phosphorylation through the accumulation of a few non-synonymous mutations in mitochondrial genes encoding complex I subunits as well as nuclear genes encoding dihydrolipoamide dehydrogenase, concomitant with metabolic reprogramming, a recognized hallmark of cancer metabolism. Taken together, our data suggest that reprogrammed metabolism represents a survival strategy of SR insect pests for the compensation of minimized energy transduction under anoxic conditions. Therefore, understanding the resistance mechanism of PH₃–R strains will support the development of new strategies to control insect pests.

Lycorma delicatula (White) suddenly arrived in Korea where it rapidly spread out in the central region of Korea and caused serious damage to grape vineyards. To trace the source region of its invasiveness, population genetic structures were compared between the native region, China, and the introduced regions, Korea and Japan. We examined 762 individuals from 38 different population collections using 15 microsatellite loci. Both principal coordinate and structure analyses displayed that the Chinese populations were separated into three subgroups which were located significantly far apart from each other. Among them, the Shanghai population was located closest to most Korean populations. Based on the genetic relationships and structures, it was revealed that the multiple introductions into Korea occurred at least three times. In addition, the Shanghai population was strongly estimated to be a source of initial invasive populations of Korea. In addition, analysis of the approximate Bayesian computation suggested simultaneous spread from two distant locations early in the invasion by artificial transportation of the host plants bearing egg masses. Our population genetics study can provide a precedent case with regards to identifying spreads by anthropogenic outcomes in other invasive regions.

We analyzed the population genetic structure and demographic history of 20Lymantria disparpopulations from Far East Asia using microsatellite loci and mitochondrial genes. In the microsatellite analysis, the genetic distances based on pairwiseF_STvalues ranged from 0.0087 to 0.1171. A NeighborNet network based on pairwiseF_STgenetic distances showed that the 20 regional populations were divided into five groups. Bayesian clustering analysis (K = 3) demonstrated the same groupings. The populations in the Korean Peninsula and adjacent regions, in particular, showed a mixed genetic pattern. In the mitochondrial genetic analysis based on 98 haplotypes, the median‐joining network exhibited a star shape that was focused on three high‐frequency haplotypes (Haplotype 1: central Korea and adjacent regions, Group 1; Haplotype 37: southern Korea, Group 2; and Haplotype 90: Hokkaido area, Group 3) connected by low‐frequency haplotypes. The mismatch distribution dividing the three groups was unimodal. In the neutral test, Tajima's D and Fu's FS tests were negative. We can thus infer that the Far East Asian populations ofL. disparunderwent a sudden population expansion. Based on the age expansion parameter, the expansion time was inferred to be approximately 53,652 years before present (ybp) for Group 1, approximately 65,043 ybp for Group 2, and approximately 76,086 ybp for Group 3. We propose that the mixed genetic pattern of the inland populations of Far East Asia is due to these expansions and that the inland populations of the region should be treated as valid subspecies that are distinguishable from other subspecies by genetic traits.

In this study, we analyzed the potential distribution of red imported fire ant, Solenopsis invicta Buren (Hymenoptera: Formicidae), in response to climate change in South Korea using CLIMEX, a species distribution model. We further attempted to evaluate the risk of the distribution/invasion and subsequent dispersion by considering climatic suitability, and functional characteristics of cities and covered cultivated areas. The climatic suitability has extended from the southern and coastal regions to inland regions due to climate change. The number of areas with EI (Ecoclimatic Index) values of more than 20 was 9 (12%) in the current climate; the value was assumed to increase to 23% (2040), 24% (2060), 42% (2080), and 62% (2100) from the South Korea coast to inland. We predicted that May to October would be the most active period in seven domestic high-habitation areas. We also analyzed the invasive risk of the red imported fire ant into covered domestic cultivation areas. Considering climatic suitability, we determined that Jeju, Pohang, Busan, Ulsan, Mokpo, and Gosan would be the most affected areas. This study can provide baseline data for the management of invasive species nationally and for regional control through predictions of the probability of settlement and direction of spread.

We conducted quarantine insect species diversity monitoring using DNA barcoding with 517 lepidopteran samples that were obtained from quarantine inspections of foreign vessels entering Korea. For species delimitation and species identification of the analyzed samples, we applied a 2% cutoff rule. Consequently, 145 (368 samples) were considered taxonomically identified. Therefore the number of samples that were identified to the species level was relatively low, at approximately 71%. Thirty of 145 species were not known in Korea, three, i.e., Noctua pronuba (Noctuidae), Orthosia hibisci (Noctuidae), and Pieris brassicae (Pieridae), were checked as ‘Regulated pests’ in Korea.