Longhorned tick, Haemaphysalis longicornis (Ixodida: Ixodidae) is one of the vectors of severe fever with thrombocytopenia syndrome virus (SFTSV) in human. The tick occurs in mostly grass fields, and the use of pyrethroid insecticides induced pest resistance and environmental residual toxicity. Particularly the use of chemicals near residential areas where persons live become a big issue, so environmentally safe control agents need to be considered. Here in this work, our interest was given to the selection of highly virulent fungi against H. longicornis. A total of 101 fungal pathogens collected from mountainous areas were assayed by a dipping the nymph stage of ticks into a conidial suspension (1×107conidia/ml). Interestingly among several species, one species showed high virulence and mycosis were observed in 7-15 days. Most of the selected isolates produced a large amount of conidia in Italian millet, rice and millet with thermotolerance at 40-45°C. Based on these results, we selected a couple of isolates with high virulence against H. longicornis and they could be used for the control of the ticks after the set-up of a practical application strategy in fields by optimizing fungal colonization in soil and phyllosphere.

Thrips is one of the serious insect pests in many economic crops, in which general managements rely mainly on chemical insecticides. However, the overuse of chemicals led to the development of insect resistance and environmental residual issues. Therefore, thrips management requires the consideration of alternative strategies which are less harmful to the environment and working on different target points. In this work, we isolated entomopathogenic fungi from soil, and identified them with morphological and molecular biology methods, followed by a preliminary virulence assay against Tenebrio molitor larvae. Selected fungal isolates were adjusted to 1×107 conidia/ml for an indoor virulence assay against thrips adults, and highly virulent isolates were added to a thrip-pathogenic fungal library. Biological characteristics of efficacious isolates were investigated comparing to a previously commercialized fungal isolate. This entomopathogenic fungal library could be used as a valuable resource for developing effective strains to control thrips in agricultural fields.

Entomopathogenic fungi have been known as promising candidates for biological control of insect pests. Recently, researchers consider the fungal thermotolerance in formulations and field applications. In this study, we investigated the production of thermotolerant Isaria javanica and I.fumosorosea conidia through grain-based solid cultures and exposure to light stress. As results, of the ten grain substrates, Italian millet, rice, perilla seed and sesame, rice, sorghum produced highly thermotolerant conidia in the strains. The two strains were exposed to a light stress and showed enhanced thermal stability compared to control, when exposed to 45°C for 2 hours. This work suggests that heatresistant entomopathogenic fungal conidia can be produced by grainbased solid cultures and exposure to light stress.

Whitefly has a broad host range of more than 600 species, and 40 biotypes have been reported worldwide. Among the various ecological types, B and Q are the most problematic. Especially, Biotype Q, which causes serious damage in the green house, mediates more than 40 kinds of viruses, including Tomato yellow leaf cull virus (TYLCV). The development of resistance to whitefly, adverse effects on non-target organisms, and strengthened legal regulations are making chemical control difficult in application. For these reasons, the use of alternative strategies is needed to suppress the Biotype Q whitefly population. Entomopathogenic fungi were investigated and developed to control hard-control insect pest, such as whitefly. These fungi are natural pathogen of their invertebrate host and contribute to the regulation of their host population in the environment. In addition, these agents are typically harmless to humans and non-targeted organisms and do not adversely impact the environment. Therefore, in this study, we screened pathogenic fungi against whitefly using our entomopathogenic fungal library, and virulence tests were conducted with conoidal suspension (1×107conidia/ml) in laboratory conditions. As a result, 10 isolates showed 80-100% mortality at 5 days after treatment. We will analyze the characteristics of these fungal isolates and evaluate their potential as insecticides against whitefly. The selected isolates against the high mortality of whiteflies can be effectively used in integrated pest management programs for whiteflies.

Japanese pine sawyer beetle, Monochamus alternatus Hope (Coleoptera: Cerambycidae) is considered as a serious pest in pine trees. To develop an eco-friendly strategy to manage this forest insect, we collected entomopathogenic fungi from Korean soil and assessed their virulence against the adults of the insect in laboratory conditions. As a result, two isolates with conidial suspension (1.0×107conidia/ml), showed 87% and 90% mortality 12 days after fungal treatment, respectively. We assessed the potential of the fungi-derived destruxin and protease as additives to the fungal isolates, and they showed insecticidal activity via feeding and spraying treatments. Finally, we produced fungal conidia in massive solid cultures and formulated wettable powders, and now studying optimal conditions of oil-based formulation with two isolates. Based on these results, we are evaluating the control efficacy of the fungal agents against M. alternatus in field conditions.

본 연구에서는 국내 유통 중인 농산물 9품목(n = 578)에 대한 납과 카드뮴 함량을 조사하고 이들의 섭취로 인한 위해성을 평가하고자 하였다. 납과 카드뮴의 함량은 마이크로웨이브 분해 후 ICP-MS로 분석하였다. 조사대상 농산물의 납 평균 함량은 각각 보리 0.014 mg/kg, 완두콩 0.010 mg/kg, 강낭콩 0.008 mg/kg, 녹두 0.006 mg/kg, 파인애플 0.008 mg/kg, 살구 0.016 mg/kg, 매실 0.015 mg/kg, 자두 0.021 mg/kg, 대추 0.019 mg/kg이었고, 카드뮴 평균함량은 보리 0.017 mg/kg, 완두콩 0.004 mg/kg, 강낭콩 0.007 mg/kg, 녹두 0.005 mg/kg, 파인애플 0.001 mg/kg, 살구 0.002 mg/kg, 매실 0.002 mg/kg, 자두 0.002 mg/kg, 대추 0.003 mg/kg이었다. 모든 시료의 납, 카드뮴 함량은 EU, CODEX 및 국내 기준보다 낮은 수준이었다. 조사 대상 농산물에 대한 납, 카드뮴의 인체노출량을 산출한 결과, 납은 잠정주간섭취허용량(PTWI, 25 μg/kg b.w./week)의 0.067%, 카드뮴은 월간잠정섭취허용량(PTMI, 25 μg/kg b.w./month)의 0.28%이었다. 이상의 결과는 조사 대상 농산물의 납, 카드뮴 오염도와 이들의 섭취에 의한 위해성이 모두 낮은 수준이라는 것을 보여준다.

Edible biopolymer films were developed from the exopolysaccharides (EPS) extracted from Weissella confusa 113-2. The optimum composition for film formation was determined using the response surface analysis with the explanatory variables of the EPS (0.5-5.5%) and glycerol (0.5-5.5%) concentrations and the response variable of film elastic modulus (EM). The mass ratio of distilled water to solids was set constant (14:1). Tensile strength (TS), percentage elongation at break (%E), EM, water vapor permeability (WVP) of EPS films were evaluated. The glass transition temperatures of the films were also determined by a dynamic mechanical analysis. The optimum mass ratio of EPS to glycerol was 0.754:0.375. The WVP, TS, %E, and EM of the film under the optimal composition were 3.53±0.21 g·mm/kPa·h·m2, 7.03±0.49 MPa, 84.82±12.31%, and 62.03±6.93 MPa, respectively. The glass transition temperature varied from 54 to 83 °C. The EPS film has the potential to be applied to food products as an edible film with physical and barrier properties comparable to other biopolymer edible films.

벼메뚜기의 인공사료 개발을 위하여 일본의 Konno식 먹이를 대조구로 하고, 28개의 배합비율별 인공사료를 제작하여 급이시험을 하였다. 시험결과, Konno식 보다 6주 후 1마리당 체중은 22개 처리에서 높았고 우화성공율은 23개 처리에서 높았다. 폐사율은 부화입식 후 45일까지 Konno식 대비 24개 처리에서 높았다. 1마리당 체중, 우화성공율, 폐사율을 종합해 볼 때 탄수화물원으로는 옥수수 건조잎 분말 또는 통밀가루와 단백질원으로는 2~5%의 탈지대두분 또는 어분의 배합비율이 벼메뚜기의 인공사료로서 가능성이 높았다.

Previously, a partial mitochondrial COI and CytB gene sequences have been used to infer genetic diversity and gene flow of the species. In this study, we additionally collected C. tripartitus from one previous and two new localities, sequenced the COI and CytB genes. Sequence divergence of current samples showed slightly lower values, but nearly equivalent to previous study. Haplotype diversity was still high and nucleotide diversity indicating that Seogwi-dong showed the highest estimates in both gene sequences. Gene flow among populations is high, but a significance difference was detected between Gulupdo and Anmado; and between Gulupdo and Seogwi-dong only in COI sequences (P < 0.05). Considering the high genetic diversity and gene flow in C. tripartitus populations, one of the major issues regarding conservation seems not to be the recovery of genetic diversity as has been suggested before.

Beauveria bassiana (Bb) is a potential biopesticide against western flower thrips. To understand molecular characteristics of two Bb isolates (ERL836 and JEF-007), whole genome sequencing and RNA-seq were performed. The whole genome of Bb ERL836 was sequenced (3,934,801,443 bp) using Pacbio sequencing and 15 contigs were analyzed. To understand the molecular mechanisms of pathogenicity in two Bb genome (before infection and after infection), next generation sequencing (NGS) was analyzed to compare transcriptomes. A result of differentially expressed gene (DEG) showed that 2,689 contigs were up-regulated and 2,619 contigs were down-regulated. Randomly selected five genes were validated to be highly up-regulated. This work can provide an understanding of the interaction between Bb and westetn flower thrips.

Japanese pine sawyer, Monochamus alternatus Hope (Coleoptera: Cerambycidae) in forest is considered as a serious forest pest in pine trees. In this study, we collected entomopathogenic fungi from soil and assessed their virulence against the adults of the inset using a spray method in laboratory condition. Two entomopathogeinc fungi isolates showed high virulence against the adults. In the concentration of 1.0 × 107conidia/ml, the mortality rate of the adults were 53% and 60%. In semi-field condition, one isolate showed a virulence of 60% against the adult. Consequently, we confirmed the possibility of the fungal isolates in controlling the beetles. In near the future, we will investigate several factors which is possibly related to the control of the forest insect pest using entomopathogenic fungi in field conditions, given the importance of fungal formulation and practical application methods.

The hard tick, Haemaphysalis longicornis (Ixodida: Ixodidae) is one of the vectors of severe fever with thrombocytopenia syndrome virus (SFTSV) causing in humans, however little consideration was given to the biological control of the pest. Therefore, this study provides a screening method to select entomopathogenic fungi, having high virulence against H. longicornis. The virulence test was conducted by dipping method with a conidial suspension (1×107 conidia/ml). As a result, cadavers of H. longicornis infected with entomopathogenic fungi were obtained by this method. Based on this results, we selected several isolates having high virulence to H. longicornis. We suggest that, selected isolates in this study can be used for the control of H. longicornis.

Entomopathogenic fungi have been known as promising candidates for biological control of insect pests. Recently, researchers consider the fungal thermotolerance in formulations and field applications. In this study, we investigated the production of thermotolerant Isaria javanica and I.fumosorosea conidia through grain-based solid cultures and exposure to light stress. As results, of the ten grain substrates, Italian millet, rice, perilla seed and sesame, rice, sorghum produced highly thermotolerant conidia in the strains. The two strains were exposed to a light stress and a heat stress. And they showed enhanced thermal stability compared to control, when exposed to 45°C for 2 hours. This work suggests that heat-resistant entomopathogenic fungal conidia can be produced by grain-based solid cultures and exposure to light stress.

Melon thrips, Thrips palmi Karny (Thysanoptera: Thripidae) is a serious insect pest of various crops in the world. The management of this pest mainly have relied on chemical agents. However, the overuse of chemical agents for long times causes insect resistance, and negative effects on environment. Therefore, alternative control methods, such as biological control, that are less harmful to the environment and have different mode of action are needed to control this pest. In this study, we isolated entomopathogenic fungi from Korean soil, and characterized them via morphological and molecular identifications and pathogenicity check against Tenebrio molitor larvae. The isolated fungi were subjected to virulence assay against T. Palmi with a conidial suspension of 1×107 conidia/ml in laboratory conditions. This entomopathogenic fungi library would be a good resource to select effective strains for the control of T. palmi in fields.

Entomopathogenic fungi play an important natural role in regulating their insect host populations, and their ecology was also associated with plant and soil. These microorganisms have been living by reacting to insect, plant and environmental factor. The advanced bioinformatics technology such as next-generation sequencing and RNA sequencing has revolutionized in understanding of entomopathogenic fungi. Recently studies provided a lot of information on evolutionary relationships and virulence-related characteristics. We are starting to know where these microorganisms from is, and how they live in nature. The bioinformatics technology will give us further our understanding of the natural roles of these fungi in nature.

The entomopathogneic fungal colonization has become an interesting issue in ecological pest management. Plant-orientedfungi induce plant growth promotion and act as natural control agents against insect pest. Herein this work, we evaluatedthe ability of fungal colonization on bark, branches and leaves of pine tree (Pinus densiflora) to select optimal candidatesfor controlling Japanese pine sawyer (Monochamus alternatus), which is the pine wilt disease vector in Korea. As a result,some Beauveria and Metarhizium isolates could colonize on the substrates of P. densiflora and showed pathogenicity againstM. alternatus. This result suggests that the selected entomopathogenic fungi are possibly candidates for long-term managementof M. alternatus in pine tree forest.

Japanese pine sawyer, Monochamus alternatus HOPE (Coleoptera: Cerambycidae) are considered as important pine forestinsect pests in several countries which transmits the pine wood nematode, Bursaphelenchus xylophylus. In this study, wetried to control Japanese pine sawyer using entomopathogenic fungi to prevent the spread of pine wilt disease in Korea.Several entomopathogenic fungi were exposed to the adults of Japanese pine sawyer and mycosis was observed in themembranous cuticles after 6 days. In particular, two isolates showed high virulence against the adults. The selected 2isolates were sprayed to the adults at 1×105, 1×106 and 1×107 conidia/ml. In the concentration of 1×107 conidia/ml, thesurvival rates of insects were 40% and 47%, respectively. Based on these results, the possibility of controlling the Japanesepine sawyer was confirmed.

Chemical pesticides have been used for persimmon pest control, however the overuse caused insect resistance andenvironmental toxicity. Herein this work, we investigated the biological potential of eco-friendly organic pesticides (biologicals)and entomopathogenic fungi in controlling persimmon pests, Stathmopoda masinisaa and Riptortus pedetris. A botanicalmixture of Chinese scholar tree, goosefoot and subtripinnata extract, Bacillus thuringesis NT0423 and one isolate of Beauveriabassiana showed high insecticidal activity against the pests in laboratory conditions. The selected botanical extract andmicroorganism were combined with a chemical pesticide (buprofezin+dinotefuran WP) and were assessed their controlefficacy in persimmon fields. Compared to the three times of chemical spray, the combination of more than one timeof chemical spray and the selected biologicals controlled the persimmon pests with an acceptable levels. Consequentlyone time of biological spray can be integrated to the spray program where only chemicals are strongly considered.

Many entomopathogenic fungal isolates received interests for controlling insect pests. But very few numbers of isolatesreached agricultural fields as commercial products. In this study, we investigated the feasibility of grain substrates forconidial production, focusing on conidial productivity and thermotolerance. Next to efficiently use the produced conidiafor spray application, conidia need to be separated from the grain substrates. Isaria javanica and I. fumosorosea conidiawere solid-cultured on ten kinds of cereal grains. Solid-cultured grains were packed in a screen bag and immersed inwater with a variety of surfactants at 100 ppm, such as Silwet, CO-2.5, CO-12, LE-7, PE-61, TDE-3, Tween 20 or Tween80. High levels of conidial release were observed on LE-7, TDE-3 and Tween80 treatments. This work suggests thatthe screen bag can be used to separated conidia from the cultured grains with the help of surfactants.

A genus of entomopathogenic Beaveria bassiana has been widely used in pest management, however little studies havebeen given to its virulence-related genes. To identify the roles of virulence genes, AtMT-induced random mutants weregenerated and followed by localization study with TAIL-PCR. Two genes, Complex I intermediated-associated protein30 (CIP30) and Autophagy protein 22 (Atg22), were predicted as virulence-related genes in B.bassiana JEF-007. To validatethe a possible relationship between two genes and fungal virulence, hpRNAi was performed. A hpRNAi plasmid wasconstructed as a model system to knock down of egfp gene in egfp-expressing B. bassiana transformant. A Real-TimePCR showed the knock down of egfp gene expression via hpRNAi. The CIP30 and Atg22 genes in B. bassiana willbe validated by the established RNAi technique. This work can be a strong platform for the functional genetics in B.bassiana.