The genus Margarinotus Marseul, 1854 is one of the highly diverse groups of Histeridae (Histerinae), consisting more than 100 described species in the world. About 80 species are known to distributed in Palaearctic region, among them, 11 species have been reported from Korea. In this study, we report a new species, Margarinotus pseudoboleti sp. nov. and a new record, Margarinotus yezoensis Ôhara from Korea. Also, we provide a revised taxonomic key for Korean Margarinotus, including above two species and images of adults.

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 box tree moth, Cydalima perspectalis (Walker, 1859) (Lepidoptera: Crambidae), is a native species in East Asia specialized in box trees (Buxus sp.) but has recently invaded most European countries. Due to the absence of its natural enemies in Europe, the economic impact is serious in most countries. In order to find parasitoids as biological control agents in Korea, C. perspectalis larvae were collected from ornamental and native box trees from various regions of the country from 2022 to 2023. While rearing them in the insectary, several parasitoids emerged from the larvae. We found at least six larval parasitoids, including five wasp species and one fly species. Molecular diagnosis using the nucleotide sequences of the mitochondrial cytochrome oxidase subunit I (COI) showed that most samples were 90–97% identical to the data in the NCBI database. Further studies are required to determine biological and parasitic characteristics, such as developmental rate, fecundity, host specificity, and parasitic rate, to clarify the suitability of parasitoids as biological control agents.

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

Miridae show remarkable diversity (>11,700 spp.), accounting for a quarter of all Heteroptera. However, their phylogeny and evolutional history is still remain unclear. In this work, we provide new suggestions for the phylogeny of Miridae using a larger dataset than previous studies. In addition, we suggest an alternative evolutionary history based on newly calibrated divergence dates for Miridae and its subordinate groups, and present probable factors of the family’s success in terms of species diversity. The entire dataset comprises 16 outgroups and 188 ingroup taxa including all seven known subfamilies and 37 out of 45 known tribes. Each species is aligned as 3,577 bp with six molecular loci (COI, 16S rRNA, 18S rRNA, 28S rRNA D3 region, H2A, and H3A).

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.

사막이리응애(Neoseiulus californicus)는 칠레이리응애에 비하여 고온건조한 조건에서 유리하고 점박이응 애, 차응애, 차먼지응애 등 응애류 뿐만 아니라 가루이, 총채벌레 등 다양한 미소해충을 포식 포식하는 광식성 천적으로서 전세계적으로 산업화되고 있다. 사막이리응애를 농가수준에서 증식하기 위하여 간단한 대량생산 방법을 개발하였다. 천적의 먹이원인 가는다리고기진드기와 배지로서 밀기울(70%) 및 팽창질석(30%)을 멸균 팩에 넣고 사막이리응애를 사육하였다. 그 결과 사막이리응애의 밀도는 3주차에 18배로 증식되었다. 증식된 사막이리응애를 딸기 농장에 2월초부터 4월초까지 8주간 매주 투여한 결과 잎당 점박이응애의 밀도는 무처리구 에서 41.5마리이고 천적처리구는 7.0마리로서 점박이응애 방제효과가 83%로 나타났다. 본 연구를 통하여 자가 생산한 사막이리응애를 활용하여 딸기농가의 점박이응애 방제에 효과적으로 사용할 수 있을 것으로 판단된다.

경북대학교 친환경농업연구센터에서는 농업인들의 효과적인 천적 활용을 증진시키기 위하여 2016년부터 경상북도 농민사관학교의 지원을 받아서 친환경천적 교육과정을 개설하고 천적 자가생산 및 현장적용 기술의 실습교육을 실시하였다. 그동안 토양 포식성 천적인 총채가시응애(Gaeolaelaps aculeifer)와 뿌리이리응애 (Stratiolaelaps scimitus), 그리고 점박이응애의 포식성 천적인 칠레이리응애(Phytoseiulus persimilis)와 사막 이리응애(Neoseiulus californicus)의 간편하고 경제적인 대량생산기술을 개발하고 그 기술을 약 180명의 농업 인에게 전수하였다. 즉, 농업인들이 스스로 천적을 자가생산하여 시설재배지에 적용함으로서 비용절감 및 청정 농산물 생산 효과를 높히는데 기여했다. 또한, 간편한 천적생산기술을 전국적으로 농업기술원, 농업기술센터, 그리고 친환경농업인단체 등 20여개 기관에 전수하였다. 최근, 경북의 농업기술센터(안동, 고령, 경주)에서 농업 인을 대상으로 천적 대량생산 시스템 보급 시범 사업을 실시하면서 뿌리이리응애 및 칠레이리응애 등의 천적 자가생산시설을 구축하고 자체적으로 생산함으로서 지속적인 천적 활용이 가능하게 되고 해충 방제 효과를 증가시킬 수 있었다. 즉, 농업인들이 직접 천적을 생산하고 활용하게 함으로서 천적농업의 성공사례가 증가하였 을 뿐만 아니라 국내 천적 공급 시스템이 다양화되어 천적농업의 활성화에 크게 기여한다고 판단한다.

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.

Recently, as the possibility of unexpected outbreaks of alien insects has increased due to climate change such as global warming, the importance of early control through rapid and accurate spread of exotic forest pest and change prediction diagnosis is required. This study summarizes and reports the followings: the establishment of monitoring strategy for exotic insects by the investigation of species distribution range through field surveys and others, the development of new diagnostic technique through microstructures and life-cycle, the dispersal of exotic insects, and ecological impact assessment using ecological methods and with the expansion of exotic insects and development of ecosystem impact prediction model.