The microstructure and mechanical properties of the heat-affected zone welded using the GTAW process on SDSS material used in offshore structures were analyzed. The chemical composition of the specimen material was analyzed using XRF. The microstructure of the heat-affected zone where the plate was welded was examined by SEM, and the ferrite volume fraction was assessed using the point count method of ASTM E562. A lot of ferrite was formed in the overheated weldment region, and In the weld cap where the cooling rate was fast, ferrite was not converted back to austenite and the microstructure was not uniform. From the ferrite phase fraction, it was shown that it can be applied to the pitting resistance equivalent numbers through changes in mechanical properties according to welding conditions.

In this study, Bacillus velesensis TJS119, isolated from freshwater, demonstrated growth inhibition against insect pathogenic fungi. The culture medium of the B. velezensis TJS119 strain underwent sequential fractionation with n-hexane, chloroform, ethyl acetate, n-butanol, and water. Notably, the n-butanol fraction exhibited significant antifungal activity against Metarhizium anisopliae and Beauveria bassiana. LC/MS analysis of antifungal peaks identified the production of various lipopeptides by B. velezensis TJS119, including two types of iturin A (C14, C15), four types of fengycin A (C14, C15, C16, C17), and two types of fengycin B (C16, C17). The antifungal efficacy of Iturin A and Fengycin against insect pathogenic fungi was further validated using the paper disc diffusion method. These findings underscore the potential of B. velezensis TJS119 as a promising candidate for future research and applications in the realm of agricultural biological controls against fungal diseases.

Protaetia brevitarsis seulensis larvae from industrial insects are traditionally recognized as functional health foods in South Korea. We evaluated the immuno-modulatory effects of feeding beneficial microorganism (Bacillus velezensis TJS119) to P. brevitarsis larvae as a dietary source. In this study, we investigated the immune-enhancing activities of P. brevitarsis larvae hot-water extract (PLW) and PLW after treatment with B. velezensis TJS119 (PLWB) using the RAW 264.7 macrophage cell line. We examined the effects of PLWB on cell proliferation, cytokine production, and nitric oxide production in RAW264.7 cells. PLWB showed no cytotoxicity at concentrations ranging from 7.8 to 1,000 μg/mL in RAW264.7 cells. Treatment with PLWB increased the production of nitric oxide and pro-inflammatory cytokines [tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and interleukin-1β (IL-1β)] at doses of 62.5 to 1,000 μ g/mL in RAW264.7 cells. As a result, PLWB exhibited a stronger immune-enhancing effect compared to PLW. In conclusion, the results of this study offer experimental evidence to support the potential utilization of PLWB as an immunity-enhancing nutraceutical ingredient.

Bacillus velezensis TJS119 was isolated from the freshwater, and antagonistic activity against of pathogenic fungi. Strain TJS119 showed a broad spectrum of antagonistic activities many fungal pathogens, including the green muscardine fungus Metarhizium anisopliae. The whole-genome sequence of B. velzensis TJS119 was analyzed using the illumina platform. The genome comprises a 3,809,913 bp chromosome with a G + C content of 46.43%, 3,834 total genes, 10 rRNA and 73 tRNA genes. The genome contained a total of 8 candidate gene clusters (difficidin, fengycin, bacillaene, macrolactin, bacillibactin, bacilysin, surfactin and butirosin) to synthesize secondary metabolite biosynthesis. Overall, our data will aid future studies of the biocontrol mechanisms of B. velezensis TJS119 and promote its application in insect disease control.

Fruit Flies (Diptera: Tephritidae) are polyphagous, highly invasive pests in which female adults lay eggs under the skin of fruit and larvae damage the fruit. Among them, the Oriental Fruit Fly, Bactrocera dorsalis (Hendel) was first reported in Taiwan and is distributed throughout much of Southeast Asia, including Vietnam, as well as on the African continent and in the Pacific region. In order to prevent the introduction of pests into country, the Animal and Plant Quarantine Agency has designated them as prohibited pests and is conducting surveillance and investigation on their occurrence. The experimental countries were Taiwan and Vietnam, and statistical analysis was conducted based on the number of B. dorsalis caught by setting up traps for about 8 months. Methly eugenol (ME; 4-allyl-1,2-dimethoxy-benzene) is a widely distributed natural plant and is used because it strongly attracts males of B. dorsalis. The experiments aimed to verify the effect of attractant formulations (liquid, solid, wax) and traps (Delta trap, Lynfield trap, Steiner trap) on B. dorsalis.

유기농업자재 제조 원료가 되는 주요 식물인 제충국, 고삼, 데리스, 님 등은 대부분 수입에 의존하고 있는 실정 으로 제품수급, 효용성 및 안전성 등에 빈번한 문제가 발생되고 있다. 이러한 문제점을 해결하기 위하여 국내 자생식물을 추출물 원료로 이용하기 위한 연구를 수행하고 있다. 이중 마트린이 함유되어 살충제로 이용되고 있는 고삼에 흰가루병, 총채벌레, 줄붉은들명나방, 담배거세미나방, 거품벌레류가 발생하여 피해를 주었다. 특 히 줄붉은들명나방(Uresiphita prunipennis)은 7월 하순부터 9월 중순까지 발생하여 엽육을 갉아먹고 엽맥만 남기는 피해를 주었고, 피해주율은 11% 였다. 이를 방제하기 위해 18종의 유기농업자재의 살충효과를 조사한 결과 주성분이 마늘추출물 80%, 데리스추출물 70% 등인 자재 6종이 80% 이상의 살충률을 나타내었다.

Sweet persimmons are valuable commodity in the export market. However, present of insect pest such as Asiacornococcus kaki can cause limit to many export markets. In this study, ethyl formate(EF), as alternative to methyl bromide(MB), was used in scale-up commercial trial(20ft reefer). Application of 50 g/m3 of EF for 6 hours at 5 ℃ showed proven efficacy against all developmental stages of A. kaki without LLDPE-packaging fruits and no phytotoxic damage on sweet persimmons. This study demonstrated that EF fumigation can be effectively control to target A. kaki before packaging with LLDPE-film of fruits.

As global warming and consumer’s preference for tropical/subtropical fruits increase, the number of orchards cultivating tropical/subtropical fruits in Korea is increasing. Accordingly, concerns about the introduction of exotic invasive pests that host tropical fruits. In this study, efficacy of ethyl formate(EF), as alternative to methyl bromide(MB), was evaluated. Commercial trial of EF was conducted in mango post-harvest storage conditions for controlling Scirtothrips dorsalis. Application of 10 g/m3 of EF for 4 hours at 10 ℃ showed proven efficacy on S. dorsalis without any phytotoxic damage on mango fruits in that condition.

2022년 국내 노지 마늘, 대파, 양파, 부추 작물재배지에서 채집한 파총채벌레 지역집단들에 대하여 살충제 저항성을 조사하였다. 제조사 추천약량에서의 살충력은 acrinathrin SC를 제외한 6종 약제들이 안성 등 8개 집단 에서 모두 90%이상을 보였으며, Spinetoram SC와 fluxametamide EC는 추천농도의 100배 희석농도에서도 전 지역 집단에 걸쳐 높은 살충력을 보여주었다. 미리 저항성 진단농도로 코팅한 바이알을 이용한 지역집단의 저항성 검정을 실시한 결과, emamectin benzoate의 저항성이 신안 등 9개 지역집단에서 매우 높았으며, chrantraniliprole은 부산 등 4개 , spinetoram은 의성 등 3개, actamiprid와 chlorfenapyr는 각각 1개의 지역집단에서 저항성이 높게 발달 하고 있는 것을 확인할 수 있었으며, 지역별로는 주요 대파 및 양파 재배지인 안성, 서산, 진도, 신안 지역의 저항성 이 모든 약제에 대하여 전반적으로 높게 나타났다.

2022년 10월부터 2023년 5월까지 친환경 딸기재배 농가에서 점박이응애는 칠레이리애응애와 사막이리응애, 진딧물은 콜레마니진디벌을 대상으로 하는 천적처리구와 유기농자재를 사용하는 관행방제구에서 천적의 해 충 밀도억제 효과를 조사하였다. 천적처리구에서 점박이응애 성충 밀도는 잎당 1.5마리 이하, 알은 4개 이하로 관리되었고, 사막이리응애는 잎당 최대 0.4마리까지 증가하여 점박이응애 밀도억제에 많은 영향을 미친것으로 보인다. 반면, 관행방제구에서 점박이응애 밀도는 천적 방사구에 비하여 오히려 많은 발생량을 보였지만, 3월 9일부터는 사막이리응애의 증가와 유기농자재의 효과로 점박이응애 밀도는 급격하게 감소하였다. 진딧물 천적 처리구에서 진딧물 밀도는 1월부터 발생하였으며 3월 상순에 잎당 0.3마리까지 증가하였으나 이후 감소하였고, 콜레마니진디벌은 진딧물 발생이 많지 않아 3.9마리/㎡(2회) 방사하는 데 그쳤다. 한편, 관행방제구 포장의 진딧 물은 유기농자재의 영향으로 거의 발생하지 않았다.

최근 주요 절화 수입량이 증가하면서 외래 병해충 유입률 또한 증가하고 있다. 농림축산검역본부 병해충정보 시스템(PIS)에 따르면 최근 10년간(2011-2020년) 수입된 절화류에서 검출된 총채벌레목은 총 43종 6,734건이다. 그중 가장 많이 검출된 총채벌레는 Frankliniella occidentalis (2,526건), Thrips tabaci (1,470건)로 전체 검출건수의 59% 이상 차지한다. 본 연구에서는 수입 절화류에서 검출률이 가장 높은 총채벌레 두 종의 미토콘드리아 DNA CO I 유전자를 이용하여 염기변이에 의한 국가별 다양성과 유전적 다양도 분석을 실시하였다. 네덜란드, 중국 등 7개국에서 검출한 Frankliniella occidentalis 184개 개체에서 9가지의 단상형(haplotype)이 관찰되었다. 또한 페루, 네덜란드 등 6개 국가에서 검출된 Thrips tabaci 80개 개체에서는 7가지 단상형이 보였다. 본 연구에서 검출 한 mtDNA내 염기서열 다형성은 총채벌레 집단의 국가적 변이성 추정 및 연관성 분석에 기초자료로 활용할 것으 로 기대한다.

Rotylenchus pini Mamiya, 1968 was reported from rhizospheric soils of Zoysia japonica in Korea. Females and males of the characterized population conform to the original species description from Japan and also to other subsequent species descriptions with variations in a few details in morphometrics including the existence of pharyngeal gland overlap in some specimen. Bayesian analysis of all the three DNA markers consistently grouped R. pini together with Rotylenchus species including R. zhongshanensis, a morphologically close species. Additionally, the newly obtained sequences of R. pini were found to be almost identical to the sequences assigned to Rotylenchus aff. devonensis in GenBank. These Rotylenchus aff. devonensis isolates might be representatives of R. pini populations. The current and previous phylogenetic studies supported by the recorded morphological plasticity within populations of the genus validate the proposed synonymy of Pararotylenchus with Rotylenchus.

The onion thrips, Thrips tabaci, is a serious global pest attacking many agricultural crops such as onion and Welsh onion. The thrips, assumed to originate in the Mediterranean region, has been reported for a long time in South Korea. According to worldwide molecular works, the species composes of three genetic lineages (LI, L2 and T) which related to reproductive mode (arrhenotoky vs. thelotoky). To understand the genetic diversity of T. tabaci in South Korea, we investigated genetic lineage and haplotype composition, using about 80 mitochondrial COI gene sequences (369bp) along with foreign sequences from GenBank and BOLD. The COI gene analysis shows that both of thelotokous L1 and arrhenotokous L2 population distribute in South Korea. Among 97 COI-haplotypes worldwide, only six haplotypes are found and thelotokous H1 dominantly distributes.

최근 기후변화, 국제교역량, 여행객 및 외국 이주민 증가 등으로 고위험 식물병해충의 유입이 증가하고 있으 며, 고위험해충에 대한 국내 유입여부를 상시 조사하여 외래식물해충을 발견하고 발생시 조기 대응하는 전문지 식과 경력을 갖춘 민간 전문가를 활용한 예찰시스템 구축의 필요성이 요구되고 있다. 침입우려 고위험 해충인 오리엔탈과실파리(Bactrocera dorsalis)는 광식성 해충으로 파프리카, 망고, 바나나, 감귤류 등 약 80종의 과실 농작물에 피해를 입히고 있으며, 해당 종의 국내정착 시 큰 경제적 피해를 입을 것으로 예상된다. 2023년 조기 방제 및 선제적 대응과 국내 확산 정착을 방지하기 위해 4개도(강원, 전북, 전남, 경남) 18개 시군 90개소에 유인트 랩(스테이너)을 설치하여 설치장소별 월 1회 정밀조사를 실시하였다. 트랩에 포획된 해충을 수거 후, 동정한 결과 오리엔탈과실파리는 발견되지 않았다.

Fall armyworm Spodoptera frugiperda (Lepidoptera: Noctuidae) is a polyphagous agricultural pest that damages about 80 species of plants. It mainly damages Poaceae and plants used as food resources for humans. Its original habitat is the American continent, but it unintentionally settled in tropical and subtropical Asia, including Africa, India, and Sri Lanka. It occurs every year even in southern China, which is geographically adjacent to the Korean Peninsula, causing damage to crops. In Korea, it was first discovered on Jeju Island in June 2019 and is being discovered every year in Jeju and some inland areas. In 2023, there were a total of 13 discoveries, including those in the Jeju and Jeonbuk regions. Quarantine agency identified the maternal genotypes of all currently discovered individuals using COI and identified differences in genetic traits between individuals using the sex-related Z-chromosome. For comparison with the information on the individuals that invaded the country, 15 individuals from Guangxi and Guangdong provinces in China were collected and secured. Through the analysis of overseas samples, a database has been added to compare genetic information with domestic invasive species, and the reliability of the analysis is expected to increase.

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.