In Korea, both Sympetrum depressiusculum Sélys, 1841 (Odonata: Libellulidae) and Sympetrum frequens Sélys, 1883 are recorded. However, the identity of Korean populations and the validity of listing the two species have not yet been settled. In this study, we collected 74 individuals from Kroea, Russia, the Netherlands, and Japan. These were sequenced for COI, 16S rRNA, and ITS region. Major morphological characters and phylogenetic, network, and structure analyses all consistently suggest that Korean populations form a single species. Consequently, it could be valid to treat Korean populations as one species, S. depressiusculum, by applying the senior name.

The genus Conicera Meigen is a group of necrophagous phorid flies mostly associated with carrion, including C. tibialis, commonly known as the “coffin fly” that breeds in buried corpses. In this study, specimens of the Conicera species collected from South Korea are examined morphologically on the basis of characteristics on male antennae, sensory organ on midfemora, and left and right surstyli on hypopygium. As a result, five species, viz. C. dauci, C. gracilis, C. orientalis, C. pacifica, C. quadrata are newly recorded from South Korea. Photographs of diagnostic characters, a distribution map and a key to males of South Korean species are provided.

Currently 41 valid species of the Pholcus phungiformes-group (Araneae: Pholcidae) have been known from Korea. In this study, four new species of this species-group were discovered from Gangwon-do and eastern Chungcheongbuk-do. These new species have common characteristics with Pholcus socheunensis, such as broad and membranous prolateral process and strongly curved pseudoappendix in male palp. The female of Pholcus montanus in the original description is the misidentification of a new species. Brief diagnosis, photographs and a distribution map of the new species and P. socheunensis with discussion on their sympatric distribution are provided.

Ramulus mikado (Rehn, 1904) is an environmentally problematic species that has recently caused a severe outbreak on the mountainsides of the Seoul metropolitan area, resulting in significant damage to forests and causing inconvenience to people in the city centre vicinity. In this investigation, we analysed the genetic diversity through sampling in the outbreak region. The outcomes confirmed the efficiency of COI for species identification and the usefulness of haplotype analysis in examining regional variation.

Opostegidae is a microlepidopteran family (Lepidoptera: Nepticuloidea) that includes almost 190 species belonging to eight genera worldwide. Since Shin recorded Opostegoides Kozlov in Korea, only two species of the genus have been recorded in Korea among the family. We found the genus Pseudopostega Kozlov, 1988 from Gangwon-do Jeongseon. This study reports the genus Pseudopostega Kozlov, 1985, for the first time. Illustrations of adult and genitalisa are also provided.

The utilization of methyl bromide (MB) for quarantine purposes has been hampered by its designation as an ozone-depleting substance under the Montreal Protocol. The International Plant Protection Convention's (IPPC) call for alternatives to MB and a reduction in its usage. There is an urgent need to explore and implement substitutes. Despite some substitute agents like EDN being developed for wood, EDN has been limited due to various factors such as occupational risks. This study focuses on evaluating the efficacy of Sulfuryl Fluoride (SF) as a viable alternative fumigant against Reticulitermes speratus, one of major wood destroying pests. Experimental trials conducted at ambient temperature (23°C) revealed promising results, with SF demonstrating LCT50 and LCT99 values of 30.87 mg·h/L and 42.53 mg·h/L, respectively. Under low-temperature conditions (5°C), SF remained effective but with slightly higher LCT50 and LCT99 values of 151.62 mg·h/L and 401.90 mg·h/L, respectively. The penetration test, conducted using R. speratus-infested pine wood cubes, further highlighted SF's efficacy, with LCT50 and LCT99 values of 31.59 mg·h/L and 53.34mg·h/L at 23°C, indicating powerful penetration capabilities. When tested at a loading ratio of 90% (v/v) at 5.0mg/L for 24 hours in a 500L chamber as a middle-scale trial, SF achieved a 100% mortality, showing its potential as a suitable replacement for MB. These findings suggest that SF could open new markets as an MB substitute and enhance safety at quarantine sites when applied to imported and exported timber.

The small-sized water strider genus Rhagadotarsus Breddin is known to be widely distributed in Southeast Asia. In a recent survey, we found Rhagadotarsus kraepelini Breddin from Gyeongsangbuk province. This species is known to non-native species in Japan. We provide descriptions and photographs of the external morphology of R. kraepelini. And a key to genera of Korean Gerridae is also provided to facilitate identification.

Chromosomal level genome draft was assembled using a Korean Diadegma fenestrale (Jeju strain, KJ09). This assembly was achieved through a combined approach utilizing Nanopore long-read sequencing (approximately 134X coverage) and Illumina NovaSeq short-read sequencing (approximately 83X coverage). The assembled genome spans 243 Mb, comprises 160 scaffolds, with most of the genome contained within 11 chromosomal level scaffolds. The completeness of the assembly is reflected in BUSCO assessment, with values reaching 99.6%. Gene annotation is not completed. A symbiotic virus, Diadegma fenestrale Ichnovirus (DfIV) genome revealed 62 non-overlapping circular DNA segments the aggregate genome size was approximately 240 kb. Although the frequency of DfIV genome integration into the host’s 11 chromosomes varies from 0 to 32%, it was confirmed that all 62 DfIV genome fragments were inserted into the host genome. A total of 123 ORFs were predicted from the DfIV genome and most of those were expressed in the host’s ovary. This result may be contradictory to existing theories, but we propose a new hypothesis that some genes possessed by viruses may play different roles depending on the type and state of the host. Additionally, this phenomenon can be considered in relation to coevolution with the hosts.

본 연구에서는 영종도에 위치한 인천과학고등학교 주변에 서식하는 개미와 개미집 근권토양을 두 차례에 걸쳐 채취한 것을 활용하여 토양미생물 순수분리 및 동정을 진행하였다. 채취된 개미의 더듬이의 모양, 털의 위치 및 분포 등의 형태학적 동정 및 DNA extraction을 통한 분자생물학적 동정을 통하여 채취한 개미를 Camponotus japonicus으로 결론하였다. 토양미생물을 연속희석법을 이용하여 확인한 결과 채취한 개미집 세 곳에서 각각 12, 18, 10개의 종이 동정되었다. 개미집 근권토양의 비옥도가 상대적으로 높다는 선행연구를 바탕 으로 ‘분리한 토양미생물이 다양한 유기물 분해 효소활성을 보일 것’이라는 가설을 세웠고, 이를 확인하기 위해 분별배지를 제작하여 디스크 확산법을 진행하였다. 실험 결과 개미집 근권 토양에서 분리된 균주가 일반 토양에 서 분리된 균주에 비해 높은 효소활성을 보임을 확인하였으며 개미집 근권 토양 미생물의 불용성인산 가용화능 이 우수함을 확인하였다. 이후 위 실험들을 바탕으로 개미집 근권 토양 미생물이 식물 생장을 촉진시켜 미생물을 접종한 토양에서의 식물의 건조 질량이 증가하였음을 확인하였다.

해충에 이용되는 화학적 기피제는 생태계를 파괴할 수 있으며 내성을 가진 생물체로의 진화를 촉진한다. 같은 종의 생물끼리의 의사소통 수단인 페로몬을 이용하면 다른 종에게 영향을 미치지 않으면서 특정 곤충에 특이적 으로 작용하는 방충제를 제작할 수 있을 것이라 생각된다. 본 연구는 초파리(Drosophila)의 페로몬 2종류를 추출 하여 초파리의 기피도 및 유인도와 번식률을 확인하고자 한다. ℃, 광주기 12h/12h의 동일한 조건에서 사육하 며 10마리당 헥세인 10를 사용하여 암컷의 표피에서 CHC 페로몬과 수컷의 페로몬샘에서 cVA 페로몬을 추출 한다. 연령, 성별, 교배 여부에 따라 관찰통에 각각의 페로몬을 처리하여 지정구간에 분포하는 초파리의 수를 계수하여 기피도 및 유인도를 확인한다. 관병에 암수 1쌍을 투입하고 하루에 1번 선정한 페로몬을 투여하며 산란 수을 측정한다. 이 연구를 통해 CHC가 수컷 초파리에 대한 기피 효과가 있음을 확인하였으며 추출되는 수컷의 연령이 높을수록 cVA에 의한 번식률 감소가 크게 나타났다. 본 연구를 통해 페로몬을 통한 초파리의 방제 가능성 을 확인하였으므로 다른 곤충의 방제에도 적용할 수 있을 거라 기대한다. 페로몬은 생물 농축과 같은 환경적 영향이 없으며 소량으로 유의미한 결과를 도출했다는 점에서 의의가 있으며 상용화를 통해 해충에 의해 피해를 해결할 수 있을 것이라 기대한다.

Immune priming is an increased immunity after prior exposure to a specific pathogen as a kind of adaptive immunity and occurs in insects. However, its underlying mechanism is elusive in insects. Immune priming was detected in a lepidopteran insect, Spodoptera exigua. Prior infection with a heat-killed pathogenic bacterium, Xenorhabdus hominickii, increased survival upon the second infection of the live bacteria compared to larvae without pre-exposure. Plasma collected from larvae with the prior infection significantly up-regulated cellular and humoral immune responses compared to the similar treatment without prior exposure. However, when the active plasma exhibiting immune priming was heat-treated, it lost the priming activity, suggesting a presence of protein factor(s) in the immune priming. Lipocalin is a lipid carrier protein and is well known in vertebrates for diverse physiological functions including immunity. An apolipoprotein D3 (ApoD3) is known to be a lipocalin functioning in immune priming in a mosquito, Anopheles gambiae. A homologous ApoD3 (Se-ApoD3) was identified in S. exigua. Se-ApoD3 was expressed in all developmental stages and larvae, it was highly expressed in hemocytes. RNA interference (RNAi) of Se-ApoD3 expression was performed by injecting its specific dsRNA. The larvae treated with the RNAi were impaired in cellular and humoral immune responses. Furthermore, the plasma collected from RNAi-treated larvae lost the immune priming even at the prior exposure. These suggest that Se-ApoD3 mediates the immune priming in S. exigua.

The Asian longhorned tick, Haemaphysalis longicornis, is an ectoparasite of domestic and wild animals, which transmit various pathogens including Severe Fever with Thrombocytopenia Syndrome Virus (SFTSV). They are the predominant hard tick species in Republic of Korea (ROK) and widely distributed throughout ROK. It is known that H. longicornis produce their offspring via two reproductive strategies, bisexual and parthenogenesis. It might affect their population maintenance and vectorial capacity. Parthenogenesis H. longicornis had the insertion of two thymine ‘T’ in mitochondrial 16s rDNA. In this study, we analyzed the proportion of bisexual and parthenogenesis H. longicornis in ROK including thirteen cities: Goseong[GS], Sokcho[SC], Chuncheon[CC], Ganghwa[GH], Samcheok[SCH], Sangju[SJ], Boryeong[BR], Ulsan[US], Gochang[GC], Jinju[JNJ], Jindo[JD], Jeju[JJ], and Seogwipo[SG]. Parthenogenesis individuals predominated from the northeastern are of ROK including Goseong, Sokcho, Chuncheon, Ganghwa, Samcheok, Sangju, Ulsan, and Jinju. Whereas bisexual individuals predominated from the southwestern area in ROK including Boryeong, Gochang, Jindo, Jeju, and Seogwipo. The analysis of haplotype diversity using concatenated sequences of mitochondrial Cytochrome c oxidase subunit I (COI) and Cytochrome B (CytB) revealed that H. longicornis were grouped into two major haplotypes. Two major haplotypes were correlated with bisexual and parthenogenesis, respectively. Likewise, H. longicornis individuals were divided into two clades and each clade were indicated by bisexual and parthenogenesis. The current study provides us an understanding of the genetic characteristics of two reproductive strategies for H. longicornis, which will be led to expand knowledge of the life cycle and population maintaining for H. longicornis.

The salivary glands of hard ticks consist of three types (type I, II, and III) of acini according to their functions and location. The type II and III acini play critical roles in tick salivation, which is likely controlled by a variety of neuropeptides or neurotransmitter via interaction with their receptor, G protein-coupled receptors (GPCRs). Orchestration of dopamine receptor (D1) and invertebrate specific D1-like dopamine receptor (InvD1L) located in type II and III acini precisely control tick salivary secretion via collection of primary saliva in the lumen and expulsion of collected saliva, respectively. The two dopamine receptors (D1 and InvD1L) in Haemaphysalis longicornis were identified as 1278 bp (426 aa) and 1362 bp (454 aa) in length, respectively. Both dopamine receptors were functionally analyzed through Ca2+ and cAMP assay using the heterologous expression system. The transcripts of D1 and InvD1L were profiled from synganglion and salivary glands of female ticks (unfed, 3/18/60/96 post blood meal and replete). D1 and InvD1L were significantly upregulated in the early phase of blood feeding from female H. longicornis. Salivary secretion induced by dopamine was significantly reduced by RNAi of D1 and InvD1L. Interestingly, RNAi of two dopamine receptors induced a significantly longer period of blood feeding in female ticks, which were significantly lighter after feeding than control. Taken together, it was suggested that D1 and InvD1L play critical roles in early and late phase of tick blood feeding for feeding capability.

The soluble epoxide hydrolase (sEH) plays a crucial role in insect immunity and development by metabolizing oxylipins such as EpOMEs and EETs. This study investigates sEH's involvement in insect antiviral response against Autographacalifornicanuclear polyhedrosis virus (AcNPV) infection. Viral infection assays were performed on Plutellaxylostellaand Marucavitrata, utilizing occlusion bodies (OB, via feeding) and budded virus (BV, through injection). Insect mortality was monitored every 12 h for up to 7 days. Our findings demonstrated a dose-dependent impact of both virus forms (OB and BV) on insects. Additionally, the sEH inhibitor, AUDA (12-(3-adamantan-1-yl-ureido) dodecanoic acid), was employed alongside the virus. The results indicated that combining AUDA with the virus increased insect mortality. Furthermore, fluorescence assays revealed the gradual movement of the virus from the gut to hemolymph and fat body. AUDA was observed to expedite virus infection. Moreover, sEH expression rapidly increased along with the viral infection in Spodoptera exigua. RNA interference of sEH expression enhanced the viral virulence against S.exigua. These suggest that EpOMEs play crucial roles in immune resolution against viral infection in insects.

The western flower thrips, Frankliniella occidentalis, is a significant economic pest among thysanopterans because of its massive feeding damage and ability to spread tospovirus to hundreds of plant species worldwide. To control this pest, chemical insecticides have been used but become unsatisfactory in the control efficacy due to the rapid resistance development of F. occidentalis. The cost-effective chitosan-based nanoparticle (NP) formulations as dsRNA insecticide gave > 80% mortalities in 7 days in the field condition. Nevertheless, the usage of NP-based dsRNA is hindered by the conflict between the excessive expense of producing dsRNA and the massive quantity of materials required for field application. Many research reports have demonstrated microbial-based dsRNA production using the L4440 vector and HT115 (DE3) Escherichia coli for application to vertebrate and invertebrate systems. In this study, we aimed to compare chitosan NP and bacterial formulation-based dsRNA control tactics against F. occidentalis using RNAi against the vacuolartype ATPase (vATPase) gene.

Eicosanoids represent a category of oxygenated C20 polyunsaturated fatty acids that play a crucial role in regulating various physiological functions in insects. These compounds are synthesized from phospholipids through the enzymatic activity of phospholipaseA2 (PLA2). In this study, we investigated four PLA2 genes encoded in the western flower thrips, Frankliniella occidentalis, with a focus on understanding their specific functions through a variety of experimental approaches. Among the four PLA2s identified, Fo-PLA2A and Fo-PLA2B fall under the category of Ca2+-independent cellular PLA2 (iPLA2), while Fo-PLA2C and Fo-PLA2D are classified a secretory PLA2 (sPLA2). Enzyme activity assays showed that all developmental stages of the thrips exhibited significant activity against both types of PLA2 substrates (arachidonic acid (AA) and non-AA), albeit with variations in enzyme kinetics across different developmental stages. Further examination revealed that all four PLA2 genes were expressed in every developmental stage. Fo-PLA2B and Fo-PLA2C displayed higher expression levels in larvae, while Fo-PLA2A and Fo-PLA2D were predominantly expressed in female and male adults, respectively. These findings support the hypothesis that PLA2s likely serve specific functions during distinct developmental stages. Our results indicated that PLA2s play pivotal roles in mediating various physiological processes such as immunity, development, and reproduction. So, the differential expression of certain PLA2s in various stages suggests that each PLA2 may have a specific role during different stages. Additionally we conducted flouorescens in situ hybridization (FISH) analysis to localize PLA2 transcripts in different tissues, shedding light on their specific functions within these tissues. In summary, the four identified PLA2s are associated with distinct catalytic activities and exhibit differential expressions across developmental stages and tissues, collectively contributing to various physiological processes.

Two bacterial genera, Xenorhabdus and Photorhabdus, are mutually symbiotic to the entomopathogenic nematodes, Steinernema and Heterorhabditis, respectively. Success parasitism of the nematode-bacterial complex depends on the host immunosuppression by the bacteria via their secondary metabolites. Lrp (Leucine-responsive regulatory protein) is a global transcriptional factor of the bacteria and play a crucial role in the parasitism. However, its regulatory targets to suppress the insect immunity were not clearly determined. This study investigated the regulatory target genes and subsequent secondary metabolites by Lrp in Xenorhabdus hominickii. Lrp expression occurred at the early infection stage in a target insect, Spodoptera exigua. Among eight non-ribosomal peptide synthetase (NRPS1-NRPS8) genes, six gene (NRPS3-NRPS8) expressions were positively correlated with Lrp expression in the infected larvae of S. exigua. Exchange of the Lrp promoter with an inducible promoter altered the production of the secondary metabolites along with alteration of the NRPS expression levels. The immunosuppressive activities of X. hominickii depended on the Lrp expression level. The metabolites produced by Lrp expression possessed the eicosanoid-biosynthesis inhibitors and hemolytic factors. A cyclic dipeptide (= cPF) was produced under Lrp control and identified to inhibit phospholipase A2 activity of S. exigua in a competitive inhibitory manner. These results suggest that Lrp is a global transcriptional factor of X. hominickii and plays crucial role in insect immunosuppression by modulating NRPS expressions.

Rice serves as the staple food for many Asian countries. However, it faces a significant threat from various Hemiptera species, including Nilaparvata lugens, Sogatella furcifera, Laodelphax striatellus, and Nephotettix cincticeps, which can cause devastating diseases. These species are economically significant pests of rice. Traditional morphology-based methods have proven inefficient in accurately distinguishing these pests at the species level. In this study, we present a successful approach for designing species-specific primers and their application in both general and multiplex PCR as well as loop-mediated isothermal amplification (LAMP) assays, widely adopted molecular tools for species identification. Each primer set incorporates a species-specific sequence of at least 2 base pairs in both the forward and reverse primers. These primers have demonstrated exceptional diagnostic accuracy in conventional and multiplex PCR. Additionally, our study showcases the high sensitivity of LAMP, successfully achieving positive amplification with genomic DNA quantities ranging from 100pg to 10pg. In summary, these techniques provide an efficient means of diagnosing planthoppers in a large number of field-collected or individual samples.

담배가루이(Bemisia tabaci)는 국내 주요 농업 해충으로서 고추, 오이, 토마토 등의 시설재배 작물에 큰 피해를 입힌다. 담배가루이는 작물을 흡즙하여 식물체의 상태를 악화시키고 TYLCV(tomato yellow leaf curl virus)등 100 여 종의 바이러스를 매개하며, 배설물을 통해 그을음병을 유발한다. 가장 일반적인 담배가루이의 방제방법은 빠르고 높은 효과를 지닌 살충제 살포이다. 하지만, 지속적인 화학적 방제는 해충의 살충제 저항성을 야기한다. 살충제 저항성은 방제 효율 감소와 농가의 경제적 손실을 일으킨다. 본 연구는 국내 지역별 시설 고추 재배지에서 발생한 담배가루이의 약제별 저항성을 조사하여, 지역별로 효과적인 약제 선정 및 대체 약제 추천 등 지속 가능한 해충관리법을 제시하고자 한다. 담배가루이는 전국 13개(파주, 양평, 화성, 횡성, 당진, 천안, 공주, 예천, 구미, 사천, 남원, 나주, 고흥) 지역에서 채집되었다. 작용기작 별 사용량이 많은 8종을 선정하였으며, 엽침지법을 사용 하여 살충률을 확인하였다. 곤충생장조절제(insect growth regulators, IGR)인 피리프록시펜계 약제는 알을 대상 으로, 그 외 7개 약제는 2령약충을 대상으로 살충률을 확인하였다. 높은 살충력을 보인 약제는 아버멕틴, 밀베마 이신계, 스피노신계, METI살충제, 디아마이드계 약제이다. 아버멕틴, 밀베마이신계는 권장사용농도로 처리 시 최소 84.5%, 최대 100% 살충률을 보였다. 스피노신계는 최소 86.3%, 최대 90.6% 살충률을 보였으나 천안, 파주, 사천에서 각각 59.7%, 66.6%, 79%로 다른 지역에 비해 상대적으로 낮은 살충률을 보였다. METI살충제는 최소 81.1%, 최대 98% 살충률을 보였으나 나주, 예천, 천안, 사천이 각각 61.6%, 68.8%, 68.9%, 69.2%의 상대적으로 낮은 살충률을 보였다. 디아마이드계는 최소 83.9%, 최대 91.9% 살충률을 보였으나 천안과 구미가 각각 56.6%, 59.8%로 상대적으로 낮은 살충률을 보였다. 낮은 살충력을 보인 약제는 네오니코티노이드계, 설폭시민계, 테트 론산 및 테트람산 유도체, 피리프록시펜계 약제이다. 네오니코티노이드계는 최소 14.1%, 최대 41.9% 살충률을 보였다. 설폭시민계는 최소 17%, 최대 42.8% 살충률을 보였다. 테트론산 및 테트람산 유도체는 최소 30.5%, 최대 54.9% 살충률을 보였으나 천안이 14.4%로 특히 낮은 살충률을 보였다. 피리프록시펜계는 최소 55.3%, 최대 64.3% 살충률을 보였으나 횡성이 72.2%로 상대적으로 높은 살충률을 보였으며, 파주가 35%로 상대적으로 낮은 살충률을 보였다. 실험 결과를 통해 살충제 별 살충력의 차이와 지역별로 살충률의 차이를 확인하였다. 본 연구결 과를 통해 효과적인 약제 추천과 지역에 따라 다른 방제 전략 제시에 도움이 되고자 한다.

Since 2007, diamide insecticides have been widely used in Korea to control various types of lepidopteran pests including Spodoptera exigua. For nearly a decade, diamide resistance in field populations of S. exigua across 18 localities has been monitored using bioassays. Based on the LC50 values, some field populations showed a high level of resistance against chlorantraniliprole, although regional and temporal variations were observed. To investigate resistance at a molecular level, mutations (Y4701C, I4790M, and G4946E) were examined in the ryanodine receptor (RyR), which is the primary mechanism underlying diamide insecticide resistance. As a result, only I4790M mutation was found in most of field populations. As resistance levels varied significantly despite the uniform presence of the I4790M mutation, we considered the presence of another resistance factor. Further, the I4790M mutation was also found in S. exigua specimens collected prior to the commercialization of diamide insecticides in Korea as well as in other countries, such as the USA. This finding led us to hypothesize that the I4790M mutation were predisposed in field populations owing to selection factors other than diamide use. For further clarification, we conducted whole-genome sequencing of S. exigua (449.83 Mb) and re-sequencing of 18 individuals. However, no additional non-synonymous mutations were detected in the RyR-coding region. Therefore, the high level of diamide insecticide resistance in Korean S. exigua is not caused by mutations at the target site, RyR, but is attributed to other factors that need to be investigated in future studies.