Honey bee plays an important role in pollinating plants. Recently, however, declines in honey bee populations have been reported in many countries, and pesticides have been pointed out as one of the factors contributing to honey bee loss. To determine the effects of pesticides on honey bee behavior, we investigated the homing ability of honey bee exposed to four pesticides (acetamiprid, imidacloprid, fenitrothion, and carbaryl). In addition, the changes in expression levels of genes associated with ‘learning and memory’ (cGMP-dependent protein kinase foraging, Kruppel homolog 1, Adenlyate cyclase 3, Early growth response protein 1, Hormone receptor 38) were examined after pesticide treatment in forager bee. The four pesticides tested in this study generally reduced the homing ability of foragers. In the examination of gene expression, learning and memory-related genes were induced by the exposure to acetamiprid, imidacloprid, and carbaryl, whereas fenitrothion decreased the expression of these genes in honey bee. Although further studies are needed, this suggests that pesticides may have negative effects on honey bee behavior and behavior-related gene expression.

Scabies, caused by an infestation of the skin with the itch mite (Sarcoptes scabiei), is highly contagious and classified as a prevalent neglected tropical diseases. The current diagnostic approach relies solely on clinical judgment based on symptoms, history, and microscopic observation by an experienced dermatologist. To enhance sensitivity and specificity, we developed an alternative method based on mite-derived DNA. Our method involves a quick DNA release from skin scraping samples and Loop-Mediated Isothermal Amplification (LAMP) targeting the scabies mite-specific DNA sequences, enabling diagnosis within 30 minutes. Importantly, no cross-reactivity was observed when the sample was contaminated by two house dust mite species, and false positives were barely detected. Currently, we are in the process of developing a Point-of-Care Testing (POCT) kit for a scabies survey targeting school-age children in Timor-Leste as a global health project.

본 연구는 검거세미밤나방(Agrotis ipsilon) 성페로몬 트랩에 혼재하여 유살되는 은무늬밤나방아과 형태적 분류와 동정법 수립을 위해, 날개 무늬의 형태계측학 분석을 실시하였다. 은무늬밤나방아과 개체는 2023년 11월 부터 12월까지 제주도 애월읍 일대에서 채집되었으며, 콩 해충으로 알려진 콩은무늬밤나방(Ctenoplusia agnata) 을 비롯하여, 다양한 농작물을 가해하는 것으로 알려진 붉은금무늬밤나방(Chrysodeixis eriosoma)의 수컷 성충이 포획되었다. 앞날개의 형태 및 무늬를 가지고 현장에서 쉽게 동정할 수 있는 형태적 특징을 도출하기 위하여, 각 성충 개체의 앞날개를 잘라 현미경 카메라로 촬영하고, 앞날개의 내횡선, 아외연선, 반점 크기 등 15개의 형질 을 측정하였다. 또한 각 형질 간의 상관관계를 분석하였으며 빈도분포를 통하여 두 종간 분리되는 형질을 파악하 였다. 최종적으로 다변량 분석법을 적용하여 두 집단이 어떻게 군집을 이루는지 분석하고, 날개형태만으로 붉은 금무늬밤나방과 콩은무늬밤나방을 구분할 수 있는 방안을 제시하였다.

Tropilaelaps mercedesae Anderson and Morgan, 2007 (Acari: Laelapidae) is a serious ectoparasite of the brood of several honey bee species. Among the four recognized species of Tropilaelaps, Korean population was renamed as T. mercedesae from T. clareae on the basis of morphological evidences and genetic data. In this study, we report the complete mitochondrial genome (mitogenome) sequence of T. mercedesae. The 15,119-bp long mitogenome has an identical gene arrangement to that of Chinese sample reported previously. Comparison of two geographic samples showed COII, ND5, ND4, ND6, CytB, and ND1 to have higher number of variable sites than COI, which is often used for population-level study, suggesting these genes to have potential usefulness for population genetic study. The mitogenome sequence of T. mercedesae from Korea could be useful for species identification for geographic samples, trace of the origin of local populations, and illustration of evolutionary distinction among Tropilaelaps species either using part of or whole genome.

The genus Acronicta Ochsenheimer, 1816 is known as a forest pest. The acronictine species is widely distributed across the Afrotropical, Oriental, Australian, and Neartic regions. This study presents a new record of an acronictine species from Korea, including descriptions, illustrations, and diagnostic characteristics. Additionally, the CO1 barcode data of the newly recorded species is compared with the global barcode reference at the species level. New data on the recently recorded species has been obtained from this study. This information will aid in the prompt identification and preparation for potential pest outbreaks.

Stathmopodidae, in the superfamily Gelechioidea, was first described by Edward Meyrick in 1913. This family has various characteristics, such as feeding on crops, moss, spores of fern, aphids, etc., but there is a lot of difficulty in identification due to morphological similarities between species. Therefore, it is necessary to understand the genitalia structure through dissection, but this process necessarily involves damage to the type specimen. To solve these problems, Micro-CT(Computed Tomography) which allows observation of internal structures without damage, was utilized to create a 3D model of the genitalia. In this study, the genitalia structure of Stathmopoda pedella (Linnaeus, 1761), the type species of Stathmopodidae, was imaged using Micro-CT under a resolution of 4 um conditions, providing a 3D description.

동물의 종 유지에 있어서 교미행동은 매우 중요한 위치를 차지함. 교미과정에서 수컷의 경우 모든 암컷에 대해 성행동을 보이는반면, 암컷은 가장 적절한 교미의 시기를 정하며, 적절한 수컷을 선택하고 교미행동을 보이기 때문에 암컷의 교미행동을 유도하는 과정은 생물학에서 매우 중요한 의미를 지님. 본 연구에서는 초파리 (Drosophila melanogaster) 전자현미경자료와 총신경망분석 (Connectomics)을 이용하여 초파리 뇌에서 암컷의 교미행동을 조절하는 것으로 알려진 pC1신경의 하부신경 pC1b,c가 성적 성숙과정에서 교미를 하고자 하는 욕구 (sexual drive)를 증가시키는 기능을 하는 것을 처음으로 밝힘. 본 연구에서는 처음으로 pC1b,c 신경 내의 cAMP 수준이 교미의 욕구변화를 보여주는 중요한 물질이라는 것을 밝혔고 cAMP의 수준이 오르기 위해서는 신경펩티 드인 Dh44와 그 수용체 GPCR인 Dh44R1과 Dh44R2가 필요하다는 것을 확인함. 또한 cAMP의 변화는 신경내의 CREBB를 통하여 하위 유전자인 pyx (pyrexia)의 발현을 유도한다는 것을 밝힘. 본 연구로 종 유지 메커니즘을 좀 더 이해할 수 있음.

From invertebrate to vertebrate, females uptake sperm for a specific duration post-copulation known as the ejaculate holding period (EHP) before expelling un-stored sperm and the mating plug through sperm ejection. Our study uncovered that encountering males or mated females after mating substantially shortens EHP, a phenomenon we term ‘male-induced EHP shortening (MIES)’. MIES requires Or47b+ olfactory and ppk23+ gustatory neurons, activated by 2-methyltetracosane and 7-tricosene, respectively. These odorants raise cAMP levels in pC1b and c neurons, which are responsible for processing male courtship and regulating female receptivity. Elevated cAMP levels in pC1b and c reduce EHP and reinstate their responsiveness to male courtship cues, promoting re-mating with faster sperm ejection. This study establishes MIES as a genetically tractable model of sexual plasticity with a conserved neural mechanism.

Over 350 species of Stathmopodidae have been reported worldwide, but due to their morphological similarities, there are many difficulties in species identification. To address these issues, various methods including larval, behavioral ecology, molecular techniques, and others have been utilized. In this study, we compared the resistance to pressure based on wing venation, which has not been extensively covered before, to further elucidate the differences between species. Type species, and one species from the genus reported in Korea, this study utilized Fusion 360 to create 3D models and visually represented resistance under the same pressure with colors. Colors derived from simulation results are extracted for trend analysis using PCA (Principal Component Analysis), and differences between groups formed through K-means clustering are analyzed.

Bombyx mandarina (Lepidoptera: Bombycidae), the presumed ancestor of the domesticated silkworm B. mori, has long been a subject of study to illustrate the geographic relationships in connection with origin of B. mori. We sequenced 100 mitochondrial genomes of B. mandarina collected from South Korea and Japan and these were combined with public data. Phylogenetic and population genetic analyses showed that all individuals collected in South Korea, except one individual from Inje, formed a strong group together with northern China and some individuals of southern China. This group was placed as the sister group to B. mori strains, suggesting that this group could have been served as an immediate progenitor for B. mori. For further robust inference more analysis is underway.

Xenorhabdus와 Photorhabdus 속은 각각 곤충병원성 선충인 Steinernema와 Heterorhabditis에 공생하는 공생세 균이다. 감염성 선충의 유충은 공생세균을 표적 곤충의 혈강에 전달하고, 여기서 세균이 증식하여 숙주 선충의 발달을 돕는다. 이러한 선충과 세균 복합체의 성공적 공생관계는 세균의 이차대사산물을 통한 숙주의 면역억제 에 달려져 있다고 알려져 있다. 본 연구에서는 서로 다른 살충력을 보이는 6종의 Xenorhabdus를 확보하고 이러한 차이가 세균의 성장속도와 NRPS (Non ribosomal peptide synthease)에 의해 생성되는 세균의 이차대사산물 발현에 서 기원한다는 것을 확인하였다. 서로 다른 균주들은 콩명나방 (Tenebrio molitor)에 대한 살충력에 차이를 가지고 있었다. 이러한 세균들은 TSB 배지에서는 세균 성장 속도에 차이가 존재하지 않았지만 콩명나방 혈강 내에서는 세균의 성장 속도에 차이가 존재하는 것으로 나타났다. 또한 각 세균의 이차대사산물 추출물을 통한 곤충의 면역 억제 실험 결과 PLA2 활성 억제, 세포독성 능력들이 살충력과 상관관계가 있는 것으로 나타났다. 이러한 이차대 사산물의 경우 많은 물질이NRPS (Non ribosomal peptide synthease)에 의해 생성되므로 각 세균 별 NRPS의 유전자 발현을 보았을 때 흥미롭게도 살충력이 더 높은 스트레인의 세균이 일부 NRPS 유전자의 발현이 더 높은 것으로 나타났다. NRPS에 의해 합성되는 물질을 포함한 세균의 이차대사산물의 차이를 서로 비교하기 위하여 이차대사 산물 추출액을 GC-MS/MS를 이용하여 분석하였다. 본 연구를 통해 곤충병원세균에 살충력의 기원이 NRPS를 통해 합성되는 이차대사산물에 있다는 것을 확인하였으며 이를 이용한 다양한 NRPS 유래 물질 연구는 신규 살충 물질 개발에 들어가는 비용과 시간을 획기적으로 줄일 수 있을 것으로 기대된다.

담배가루이는 전세계의 온대 및 아열대 지방에 넓게 분포하고 있으며, 한국에서는 시설재배작물의 주요 해충 이다. 1998년 충북 친천군 장미재배지에서 처음 확인되었으며, 이후 전국적으로 확산된 것으로 추정된다. 담배가 루이는 고추, 토마토, 오이 등 300종이 넘는 넓은 기주범위를 가지며, 식물체를 흡즙하여 작물의 생산성을 저하시 키고 토마토황화잎말림바이러스(tomato yellow leaf curl virus, TYLCV) 등 100여종이 넘는 바이러스를 매개한다. 담배가루이는 주로 살충제를 이용한 방제가 이루어진다. 하지만 살충제를 이용한 방제법은 살충제 저항성 개체 를 발생시킨다. 살충제 저항성 개체가 발생하게 되면 방제 효율이 급감하여 농가에 추가적인 경제적 피해를 야기 한다. 본 연구는 국내 지역별 담배가루이를 대상으로 약제별 살충제 저항성의 발생 현황을 조사하여, 지역별 효과적인 약제를 탐색하고 향후 방제 전략 수립에 기여하고자 한다. 담배가루이는 전국 15지역(파주, 양평, 화성, 양구, 횡성, 평창, 당진, 천안, 공주, 예천, 구미, 사천, 남원, 나주, 고흥)에서 채집되었다. 살충제는 작용기작 별 사용량이 많은 8종을 선정하였으며, 엽침지법을 사용하여 살충률을 확인하였다. 곤충생장조절제(insect growth regulators, IGR) 피리프록시펜계 약제는 알을 대상으로, 그 외 7개 약제는 2령약충을 대상으로 살충률을 확인하였 다. 모든 지역에서 높은 살충력을 보인 약제는 아버멕틴과 밀베마이신계, 스피노신계, METI살충제, 디아마이드 계 약제이다. 특히 아버멕틴과 밀베마이신계 약제는 살충제 권장사용농도(10ppm)보다 낮은 8.9ppm이하의 LC90 값을 보여 감수성으로 추정되며, 예외적으로 천안 지역의 25.6ppm으로 상대적으로 높은 LC90값을 보였다. 낮은 살충력을 보인 약제는 네오니코티노이드계, 설폭시민계, 피리프록시펜계, 테트론산 및 테트람산 유도체 약제이 다 특히 네오니코티노이드계 약제는 모든 지역에서 살충제 권장사용농도(50ppm)보다 높은 715ppm이상의 LC90 값을 보여, 모든 지역에서 살충제 저항성이 발생한 것으로 추정된다. 실험결과를 통해 살충제 별 살충력의 차이와 지역별 살충제 저항성을 검정하였다. 연구결과를 통해 지역별/약제별 저항성관리 및 대응전략을 수립하여 농업 생산성을 향상시키는 것에 도움이 되고자 한다.

Climate change has led to increased insect pests and pest distribution changes. Traditionally, chemical control using synthetic pesticides has been the main method for pest management, but the emergence of pesticide-resistant pests has become a problem. There is a need to develop new pest control agents to overcome these issues. Entomopathogenic fungi used in pest management have minimal environmental side effects and possess a mechanism of action distinct from that of synthetic pesticides. However, there is a need for the development of technologies to maximize the insecticidal effects of fungi against pests, and expressing and releasing dsRNA within the fungi can preemptively knock out the activation of the insect’s defense system, thereby enhancing the insecticidal effect. Controlling insect defense genes and using entomopathogenic fungi as bio-carriers forms a new pest management strategy. This approach, described as a “microbial insecticide agents development strategy of cassette concept, ” can versatilely modify genes and microbes. It is expected to overcome the limitations of synthetic pesticides.

In this study, we introduce a novel TiN/Ag embedded TiO2/FTO resistive random-access memory (RRAM) device. This distinctive device was fabricated using an environmentally sustainable, solution-based thin film manufacturing process. Utilizing the peroxo titanium complex (PTC) method, we successfully incorporated Ag precursors into the device architecture, markedly enhancing its performance. This innovative approach effectively mitigates the random filament formation typically observed in RRAM devices, and leverages the seed effect to guide filament growth. As a result, the device demonstrates switching behavior at substantially reduced voltage and current levels, heralding a new era of low-power RRAM operation. The changes occurring within the insulator depending on Ag contents were confirmed by X-ray photoelectron spectroscopy (XPS) analysis. Additionally, we confirmed the correlation between Ag and oxygen vacancies (Vo). The current-voltage (I-V ) curves obtained suggest that as the Ag content increases there is a change in the operating mechanism, from the space charge limited conduction (SCLC) model to ionic conduction mechanism. We propose a new filament model based on changes in filament configuration and the change in conduction mechanisms. Further, we propose a novel filament model that encapsulates this shift in conduction behavior. This model illustrates how introducing Ag alters the filament configuration within the device, leading to a more efficient and controlled resistive switching process.

Ni-CNT nanocomposites were synthesized via the electrical explosion of wire (EEW) in acetone and deionized (DI) water liquid conditions with different CNT compositions. The change in the shape and properties of the Ni-CNT nanopowders were determined based on the type of fluids and CNT compositions. In every case, the Ni nanopowder had a spherical shape and the CNT powder had a tube shape. However, the Ni-CNT nanopowders obtained in DI water exhibited irregular shapes due to the oxidation of Ni. Phase analysis also revealed the existence of nickel oxide when using DI water, as well as some unknown peaks with acetone, which may form due to the metastable phase of Ni. Magnetic properties were investigated using a Vibrating Sample Magnetometer (VSM) for all cases. Nanopowders prepared in DI water conditions had better magnetic properties than those in acetone, as evidenced by the simultaneous formation of super paramagnetic NiO peaks and ferromagnetic Ni peaks. The DI water (Ni:CNT = 1:0.3) sample revealed better magnetic results than the DI water (Ni-CNT = 1:0.5) because it had less CNT contents.