The tribe Tropidocephalini Muir, 1915 (Delphacidae: Delphacinae) comprised 37 genera 204 species worldwide. In Korea, only three species, Epeurysa nawaii Matsumura, 1900, Tropidocephala brunnipennis (Distant, 1906), T. nigra (Matsumura, 1900), have been reported. In this study, one species, Epeurysa distincta Huang & Ding, 1979, is reported for the first time from Korea. We provide the morphological characteristics, photographs and taxonomic keys of the four species belonging to the tribe Tropidocephalini.

Solenopsis invicta, known as the red imported fire ant, is an insect native to South America. This species was unintentionally introduced into Australia, New Zealand, several Asian countries, Caribbean countries, and the United States. It shows a high survival rate and settlement potential in human-habitable and non-living areas such as tropical rainforests, disturbed areas, deserts, grasslands, and roads. In Korea, invasions of red fire ants have been reported every year since 2017, and two invasions were discovered in 2023. Quarantine agency analyzing the haplotype and colony social type of S. invicta for surveillance and control. Population genetic analysis using Microsatellite Alleleic data of 66 loci to trace the origin of the invasion. Through research cooperation with the United States Department of Agriculture (USDA), we have received samples and expanded our genetic information database. This study analyzed genetic differences between 15 invasive populations and 44 reference groups. As a result of microsatellite analysis, the domestic invasive population showed a genetic structure similar to those in Guangzhou, China, and Florida, USA.

The genus Icerya Signoret, 1876 has 38 species distributed in the world, and some are known to cause damage to valuable crops. The Seychelles scale, Icerya seychellarum (Westwood) (Hemiptera: Coccomorpha: Monophlebidae) was found on Cycas revoluta located in the province of Seogwipo-si, Jeju Island, South Korea. This species is highly polyphagous and has been reported to attack host plants of 136 genera, it is widely distributed in tropical and subtropical regions. In South Korea, the species was presently considered a quarantine pest and it seems that control is needed. In this study, I. seychellarum is recorded for the first time in South Korea, we provide information on the distribution, host plants, and description of this species.

Ctenoplusia agnata (Lepidoptera: Noctuidae) is a polyphagous pest that damage on crops belonging to the Fabaceae and Brassicaceae, and it is known as a migratory pest. In this study, we investigated pattern of occurrence to trace invasion characteristics using sex pheromone traps and conducted genetic analysis of captured individuals while also exploring their correlation with air currents. Our findings suggest that C.agnata exhibits an annual occurrence of four generations in Korea, with the second or third generation, primarily active from July to September, posing a significant threat to soybean. Genetic analysis revealed the presence of 17 haplotypes, and trajectory modeling confirmed the influence of air currents from Kyushu, Japan and Zhejiang, China etc. These results are expected to be used as a comprehensive management of C.agnata and other migratory moth species.

The fall armyworm (FAW), Spodoptera frugiperda, is an invasive pest species in Africa and Asia, which is native to the Western hemisphere. Invaded FAW was corn feeding strain. We study the developmental and biology of the corn strain FAW on the rice plants compare the result with corn feeding up to F2- generation. The development periods of F0, F1 and F2 generations of the rice-fed colony were 21.7%, 18.3% and 18.9% longer than corn-fed colony. The rice-fed colony was significantly lower in the body weight of larvae and pupae, and pre-adult survival rate and the fecundity than corn-fed colony. Our results showed that the corn strain FAW can survive and complete its life cycle by feeding rice plants up to several generations under laboratory condition, but their development and fecundity were reduced in comparison to the corn feeding colony. However, this study suggests potential impact of invaded FAW to the infestation of rice fields in Asian countries.

Reticulitermes speratus (Kolbe) is economically important pest in East Asia including Korea, Japan and China where they infest wooden structures in urban areas. In this study, we report the first record of R. speratus speratus from Korea, which was verified using soldier morphology and molecular characteristics obtained from a mitochondrial gene. R. speratus speratus Kolbe, 1885 (Blattodea: Rhinotermitidae) are found in several provinces, mainly southern regions in Korea, whereas R. speratus kyushuensis are distributed throughout the country. Our morphological comparison showed that R. speratus speratus can be distinguishable from R. speratus kyushuensis by the ratio of the posterior postmentum width to length. In the molecular comparison, R. speratus speratus revealed genetic differences of 3.06% (range 2.60–4.10%) from R. speratus kyushuensis using cytochrome oxidase subunit II gene sequences.

The aphid genus Macromyzus Takahashi is a small East-Asia genus of the tribe Macrosiphini (Hemiptera: Aphidinae). Globally, there are five recognized species: Macromyzus (Anthracosiphoniella) maculatus (Basu), Macromyzus (Macromyzus) indicus David & Narayanan, M. (M.) manoji Raha & Raychaudhuri, M. (M.) spinosus Su & Qiao, and M. (M.) woodwardiae (Takahashi). In this study, we report the first record of the aphid genus Macromyzus Takahashi in Laos. We present a decription of a new species of this genus associated with Diplazium esculentum (Retz.) Sw. (Athyriaceae). Additionally, for the first time, we conducted scanning electron microscopy research on the morphology and sensilla of representative of this genus.

Anoplophora horsfieldii (Hope, 1843), 국명 노랑알락하늘소(가칭)는 아열대 지역에 주로 분포하는 종으로 2019 년에 제주도 용연계곡에서 처음 발견되었으며, 2023년에 국내 정착이 보고되었다. 국내에서는 팽나무에서 발생 하는 것으로 알려졌으나, 섭식방식, 산란 선호성 등 생태적 특성에 대해서는 국내외 연구가 전무하다. 따라서 본 연구에서는 노랑알락하늘소의 기초적인 생태정보를 제공하고자 실내 산란 선호성 조사 및 야외조사를 진행 했다. 산란 선호성 실험은 기주식물로 알려진 팽나무, 멀구슬나무와 제주도내 대표 수종인 동백나무, 종가시나무 을 대상으로 했다. 이 중 팽나무에서만 산란이 확인었으며, 상대적으로 굵은 팽나무에서 더 많은 산란이 확인되었 다. 야외조사에서는 최대 발생지인 용연계곡을 기준으로 반경 3 km 내에서 노랑알락하늘소의 탈출공이 확인된 32 그루의 팽나무를 대상으로 피해를 조사하였다. 나무의 굵기는 흉고직경이 20-40 cm인 팽나무에서 탈출공이 많이 확인되었고, 높이는 지면으로 부터 0-100 cm 구간에서 가장 많은 탈출공이 발견되었다.

Spodoptera litura Fabricius, 1775 (Lepidoptera: Noctuidae) is a serious crop pest with a long-distance migratory flight. To date, the DNA barcode region has been widely used in genetic diversity analysis studies of Spodoptera litura. However, the DNA barcode region showed maximum variation rate of S. litura, which from 18 regions in South Korea, was 0.608% (nine haplotypes) in previous study. In this study, four mitochondrial genes (ND4, ND4L, ND1, 16s rRNA) have higher intra-specific variation rates than the DNA barcode region. Among the four genes, The variation rate of the 16s rRNA region was confirmed to be a minimum of 0.203% (2bp) and a maximum of 1.824% (18bp). Finally, the 16s rRNA region with the highest PCR amplification efficiency and highest variation rate was selected as a high-efficiency molecular marker.

The genus Norbanus Walker 1843 (Pteromalidae: Pteromalinae) consists of 38 species distributed worldwide. Among them, 13 species have been described from the West and Central Palaearctic (Noyes 2003). Norbanus is one of several pteromalid genera that shares the character of a narrow spicula on the clava. In Korea, only one species in the genus Norbanus is recorded. In this study, we report Norbanus meridionalis for the first time in South Koera. We provided description and diagonostic illustration of Norbanus meridionalis.

The yellow mealworm, Tenebrio molitor L. (Coleoptera: Tenebrionidae), is an important industrial insect commercially produced around the world as food and feed. Temperature and nutrition are the two most influential environmental factors determining the rearing conditions in insects, but little is known about how these two factors interact to affect the performance of T. molitor larvae. In this study, we investigated the combined effects of temperature and dietary protein:carbohydrate (P:C) ratio on key performance traits in T. moltior larvae. Throughout their larval stage, the insects were reared on one of 36 treatment combinations of six temperatures (19, 22, 25, 28, 31, 34 °C) and six protein:carbohydrate ratios (P:C = 1:5, 1:2, 1:1, 2:1, 5:1, 1:0) and their survivorship, development, growth rate, and pupal mass were monitored. Survivorship was high at low temperatures (< 25°C) and high P:C ratios (>1:1), but decreased with increasing temperature and decreasing P:C ratio. Increase in rearing temperature accelerated larval development but resulted in a reduced pupal mass. Thermal optimum for pupal mass (19.3°C) was thus lower than that for development time (28.1°C). The growth rate was maximized at 27.9°C and P:C 1.65:1 and decreased as both the temperature and the P:C ratio deviated from their optimum. All four key performance traits (survivorship, development time, pupal mass, growth rate) were optimized at temperatures between 25.7 and 27.4°C and P:C ratios between 1.17:1 and 2.94:1. Our data provide insights into how the production and nutritional value of T. molitor larvae can be improved through adjusting their rearing conditions.

Stilbene-based fluorescent brighteners (FB) have been shown to enhance insecticidal activities of entomopathogenic viruses but little is known its effect on entomopathogenic bacteria. We investigated the effect of two FBs (FB 28 and FB 71) on the insecticidal activity of B. thuringiensis var. kurstaki (Btk) as well as the Lymantria dispar multiple nuclear polyhedrosis virus (LdMNPV) in Lymantria dispar asiatica. FB 28 increased the mortality at the combination with low concentration (1.6×102 IU/ml) of Btk, but FB 71 slightly reduced the mortality with middle and high concentrations (1.6×103 and 1.6×104 IU/ml) of Btk in comparison to Btk alone. Both FB 28 and FB 71 increased mortality in combination with LdMNPV at all concentrations (3×102, 3×104, and 3×106 POBs/ml) compared to LdMNPV alone. Our findings suggest that FBs enhanced pathogenic activities but depend on chemical nature of FBs.

The striped fruit fly (SFF), Zeugodacus scutellata, is an agricultural pest species with a strong and rapid reproductive ability that can cause significant harm. To control the population of these kind of pests, the sterile insect technique (SIT) is being used as one of the effective methods. SIT involves the introduction of sexually transmitted factors that reduce the reproductive capacity of males. This study shows that knocking down the testis-specific serine/threonine protein kinase 1 (Zs-Tssk1) gene alters male fertility and male-initiated types of communication. Since Zs-Tssk1 influences the physiology of the testes, spermatogenesis is also affected, which in turn alters the lifespan of Zs-Tssk1 knock down group in comparison with the control. Based on these results, Zs-Tssk1 may be crucial in reproductive function, and its down-regulation may be helpful in controlling SFF through SIT.

In Korea, the Asian honey bee (Apis cerana) and the European honey bee (Apis mellifera) (Hymenoptera: Apidae) are the two most common honey bee species. These two closely related species are known to have different sensitivity levels to various insecticides due to millennia of exposure to different pests and pesticides. It is reported that A. cerana is known to be more sensitive to several insecticides, such as amitraz, fenitrothion, and fipronil, than A. melllifera. Multiple studies investigated toxicological responses and related CYPome in A. mellifera, but little is known in A. cerana. The goal of this study is to elucidate the underlying mechanism of different toxicological responses between two bee species, with an emphasis on cytochrome P450 (P450), a significant enzyme involved in metabolic activities. The differences in basal P450 expression patterns were investigated by comparing the relative expression levels of P450 orthologs in several dissected organisms of each species. To compare the sensitivity against major insecticides, lethal doses of major insecticides relevant to both honey bee species were assessed by topical and oral ingestion bioassays. The determined sublethal doses of insecticides were applied to honey bees, and the inducibility of P450s was investigated by comparing the expression patterns of multiple P450s. From these results, this study eventually attempts to compare the toxicological differences between two Apis species with differences in induced cytochrome P450 expression levels.

Riptortus pedestris has established symbiotic interactions with specific bacteria from soil environment in every generations. The soil environment is extremely heterogeneous with microbial diversity, suggesting that bacterial composition of the R. pedestris can be affected by surrounding environments. Therefore, we investigated spatiotemporal variation of bacterial communities in wild R. pedestris collected from five mainland areas and Jeju Island in South Korea across insect generations. Among the 390 R. pedestris adults collected, we detected a total of 28 bacterial genera from the symbiotic region of insects. Among the bacterial genera, genus Caballeronia bacteria was the most abundantly detected regardless of sampling site and generation. Nevertheless, bacterial richness varied among the insect generations with 10 genera detected in overwintered generation, 15 genera in the 1st generation and 18 genera in the 2nd generation. Moreover, we found five bacterial genera that were exclusively detected from the Jeju island compared to the mainland areas surveyed.

The Varroa mite, Varroa destructor, a parasitic mite that afflicts honey bees, has become increasingly resistant to acaricides like fluvalinate due to its widespread use. The target site insensitivity mechanism, mediated by the L925V/M/I mutations in the voltage-gated sodium channel, plays a major role in resistance. Additionally, cytochrome P450 monooxygenases (Cyp450s) appear to function as a metabolic resistance factor; however, no Cyp450-mediated resistance mechanism has been reported to date. The aim of this study was to identify and characterize Cyp450s associated with fluvalinate resistance. A synergistic bioassay confirmed the involvement of Cyp450s in conferring tolerance or resistance to fluvalinate. Correlation analysis between mortality data and the expression levels of Cyp450 genes led to the identification of several candidates that may play a crucial role in fluvalinate resistance. Analysis of tissue distribution patterns revealed that these genes were most abundantly expressed in the cuticle and synganglion. This suggests that, despite their relatively low expression level, they may play a critical role in protecting the target site from fluvalinate due to its predominant expression in neuronal tissues. Functional analysis, in conjunction with baculovirus expression, demonstrated that fluvalinate has high inhibition rates against the recombinant candidate Cyp450s, suggestive of their strong interaction with fluvalinate. We discussed the potential utilization of their expression levels as a molecular marker for diagnosing metabolic resistance in field-collected Varroa mites.

The aphid genus Tuberaphis Takahashi belongs to the tribe Cerataphdini (Hemiptera: Hormaphidinae) and comprises 17 valid species. Generally, its species are distributed in East and South East Asia, where they primarily feed on Styrax spp. (Styracaceae) and utilize species within the Loranthaceae family as their secondary hosts. They form various shapes of galls on Styrax, looking coral and broccoli etc. Currently, the only aphid species reported to exclusively produce gall forms resembling broccoli head-shaped is Tuberaphis takeouchii (Takahashi). For the first time in Korea, an aphid species forming gall structures with a broccoli-head-like appearance has been discovered. We confirmed that the species discovered in Korea is a new species through morphological and molecular comparisons with T. takenouchii (Takahashi). To comprehend the life cycle of this new species, we conducted a year-long study investigating how the gall forms change and examined aphid polymorphism across different seasons. The results of this study additionally include as followings: 1) Species identification, 2) DNA barcoding, 3) population genetic analyses, and 4) morphological comparison using SEM

Nutrient acquisition by insect herbivores affect all aspect of the the lifespan of individauls. For seed-sucking insect herbivores, they face challenges with nutrient acquisition due to requirement for extra-oral digestion of seed contents into a readily-ingestible state. In this study, we demonstrated environmentally-transmitted Caballeronia insecticola allow seed-sucking R. pedestris to overcome challenges with extra-oral digestion. Through the evaluation, first, we found symbiotic insects exhibited enhanced feeding efficiency by consuming significantly larger amount of food per feeding attempt compared to apo-symbiotic insects (P<0.05). Then, we observed feeding behavior modification in the symbiotic insects from the behavior tracking evaluation. Symbiotic insects displayed dichotomic behavior which can be generally divided into early focused feeding and later subdued resting periods. By contrast, apo-symbiotic insects displayed unordered behavior by frequent switches between feeding and walking behavior.

Honey bees are crucial pollinators for agricultural and natural ecosystems, but are experiencing heavy mortality in Korea due to a complex suite of factors. Extreme winter losses of honey bee colonies are a major threat to beekeeping but the combinations of factors underlying colony loss remain debatable. Finding solutions involves knowing the factors associated with high loss rates. To investigate whether loss rates are related to Varroa control and climate condition, we surveyed beekeepers in korea after wintering (2021–2022 to 2022–2023). The results show an average colony loss rate of 46%(2022) and 17%(2023), but over 40% colony loss before wintering at 2022. Beekeepers attempt to manage their honey bee colonies in ways that optimize colony health. Disentangling the impact of management from other variables affecting colony health is complicated by the diversity of practices used and difficulties handling typically complex and incomplete observational datasets. We propose a method to 1) Varroa mite population Control by several methods , and 2) Many nursing bee put in hive before wintering.

The Varroa mite, Varroa destructor is an ectoparasite that parasitizes honey bees. The widespread usage of acaricides, particularly fluvalinate, has resulted in the emergence of resistance in Varroa mite populations all over the world. The goal of this study is to track fluvalinate resistance in Varroa mite field populations in Korea using both bioassay and molecular markers. To accomplish this, a residual contact vial (RCV) bioassay for on-site resistance monitoring was developed. Early mortality evaluation in the RCV bioassay was effective for reliably separating mites with the knockdown resistance (kdr) genotype, but late mortality evaluation was useful for distinguishing mites with additional resistance factors. The RCV bioassay of 14 field mite populations collected in 2021 revealed potential resistance development in four populations. Quantitative sequencing was used as an alternate method to examine the frequency of the L925I/M mutation in the voltage-gated sodium channel (vgsc), which is related with the fluvalinate kdr phenotype. While the mutation was not present in Varroa mite populations in 2020, it appeared in 2021, rose in frequency in 2022, and was practically ubiquitous across the country by 2023. This recent emergence and rapid spread of fluvalinate resistance within a span of three years demonstrate the Varroa mite's significant potential for developing resistance. This situation emphasizes the critical necessity to replace fluvalinate with alternate acaricides, such as fenpyroximate, coumaphos, and amitraz. A few novel vgsc mutations potentially involved in resistance were identified. Potential factors driving the rapid expansion of resistance were further discussed.