• Korean journal of applied entomology
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• v.46 no.1 s.145
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• pp.165-168
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• 2007

This experiment was conducted to investigate population dynamics of white grubs and its damages in sweet potato fields. There were three species of white grubs that fed on the roots of sweet potato in Honam area. Among them, Holofrichia parallela was a major insect pest. Damage rate of sweet potato by white grubs were about 2 to 40% differed with regions. In some region where it was severe the damage rate of sweet potato was about 80% or more. H. parallela overwintered as a late 3rd instar larvae in soil from late October to late-June, and the survival rate of them was 92%. The occurrence pattern of H. parallela larvae varied in different seasons. In sweet potato field, H. parallela larvae populations started being observed during late-July to mid.-August. The damage by the grub began to occur late-August in field and lasted to the harvest time.

• Journal of Microbiology and Biotechnology
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• v.19 no.10
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• pp.1223-1229
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• 2009

To construct a new recombinant strain of Bacillus velezensis that has antifungal and insecticidal activity via the expression of the insecticidal Bacillus thuringiensis crystal protein, a B. thuringiensis expression vector (pHT1K-1Ac) was generated that contained the B. thuringiensis cry1Ac gene under the control of its endogenous promoter in a minimal E. coli-B. thuringiensis shuttle vector (pHT1K). This vector was introduced into a B. velezensis isolate that showed high antifungal activities against several plant diseases, including rice blast (Magnaporthe grisea), rice sheath blight (Rhizotonia solani), tomato gray mold (Botrytis cinerea), tomato late blight (Phytophthora infestans), and wheat leaf rust (Puccinia recondita), by electroporation. The recombinant B. velezensis strain was confirmed by PCR using cry1Ac-specific primers. Additionally, the recombinant strain produced a protein approximately 130 kDa in size and parasporal inclusion bodies similar to B. thuringiensis. The in vivo antifungal activity assay demonstrated that the activity of the recombinant B. velezensis strain was maintained at the same level as that of wild-type B. velezensis. Furthermore, it exhibited high insecticidal activity against a lepidopteran pest, Plutella xylostella, although its activity was lower than that of a recombinant B. thuringiensis strain, whereas wild-type B. velezensis strain did not show any insecticidal activity. These results suggest that this recombinant B. velezensis strain can be used to control harmful insect pests and fungal diseases simultaneously in one crop.

• Korean journal of applied entomology
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• v.49 no.4
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• pp.385-391
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• 2010

This study reports the results of natural enemy application against four insect pests on greenhouse sweet pepper in winter cropping system. Orius laevigatus ($3.3/m^2$) was released at two different times (Nov. 2005 & Feb. 2006) to control Frankliniella occidentalis, western flower thrips (WFT). Throughout the cropping season, the lowest level recorded of WFT was less than 2.0 individuals per yellow sticky trap. Amblyseius swirskii ($232.3/m^2$) was released four times (Nov. 2007 ~ Aug. 2008) to control Bemisia tabaci, tobacco whitefly (TWF). Until July 2008, TWF population had been suppressed lower than 6.6/trap. Phytoseiulus persimilis ($44.5/m^2$) was released seven times (Apr. 2008 ~ Aug. 2008) to control Tetranychus kanzawai, tea red spider mite (TRSM). As a result, TRSM population was suppressed lower than 1.7/1eaf. To control aphids, Aphidius colemani ($9.5/m^2$) was released seven times (Oct. 2004 ~ Jan. 2005), with the transplantation of banker plants ($5.5pot/660m^2$). As a whole, aphid's population has been successfully reduced to less than 2.0/leaf.

• Korean Journal of Environmental Agriculture
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• v.28 no.3
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• pp.301-309
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• 2009

The use of bioactive materials derived from microorganisms and plants has played a role in pest management in environmentally-friendly agriculture (EFA) system. In Korea, a number of agricultural agents for the control of insect pests have been registered officially as biopesticides and marketed widely. However, most of the biopesticides has a limitation in the resource availability of bioactive materials, which has been one of main problems related to the commercialization of agricultural agents. Plant materials and microbial metabolites are the best sources as starting components to commercialize natural-occurring agricultural agents for pest management. The lack of modernized system for the standardization and quality control of the starting materials, however, has also received as a main problem related to the commercialization of agricultural agents. Considered that EFA business has kept growing bigger and bigger with global economic status, the commercialization of agricultural agents is necessary to meet the required number of agricultural agents officially available in EFA. This study describes the status and future prospects of pest control agents in EFA. A number of main issues hindered in the commercialization of agricultural agents are discussed in order to present a promising approach to successful commercialization.

• Mycobiology
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• v.48 no.4
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• pp.245-251
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• 2020

During a survey of putative fungal pathogens infecting oak trees in the Gangwon Province of the Republic of Korea, a fungus resembling a Ceratocystis sp. was repeatedly isolated from natural wounds on Quercus variabilis. Morphological comparisons and DNA sequence comparisons based on partial β-tubulin and TEF-1α gene regions showed that the fungus resided in a distinct lineage. This novel Ceratocystis species is described here as C. quercicola sp. nov. This is the first novel species of Ceratocystis to be reported from Korea. A pathogenicity test showed that it can cause lesions on inoculated trees but that it had a very low level of aggressiveness. The discovery of this fungus suggests that additional taxa residing in Ceratocystis are likely to be discovered in Korea in the future.

• Journal of Apiculture
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• v.34 no.2
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• pp.141-147
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• 2019

Pollinators play important roles for crop production as well as maintenance of wild plants' reproduction. Pollinator dependency in Korean agriculture have increased, but the degradation of habitat quality pose significant threats to pollination in agroecosystem. Provisioning flower habitat is one of the major activities to increase pollinator abundance and richness. We tested the effect of flower habitat supplementation on the pollinator, pest and natural enemy abundance in pepper field. Results showed that Hymenopteran pollinators were more abundant in the pepper plots close to the flower habitat. Among natural enemies, the similar pattern from pollinators was observed to parasitoids in the family of Eulophidae, but not to those of Ichneumonidae. There were no statistically significant differences of insect pests like aphids and thrips, as well as pepper production among plots in the pepper field. Even limited spatial scale, this study showed supplementing the flowering plant habitat to the agricultural landscape could conserve and boost pollinators and natural enemies, and possibly resulting better fruit production by pollination service.

• Korean Journal of Organic Agriculture
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• v.25 no.4
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• pp.737-747
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• 2017

This experiment was carried out to determine the optimal concentration of agricultural organic materials using sulfur and oil for the insect pest control in pepper and cherry tomato cultivation. The control value of aphids and Oriental tobacco budworm (OTB) was examined one day after spraying with sulfur preparation (SP) (0.33~0.17%), oil preparations (OP) (2.00~0.33%), SP+OP, OP+ginkgo leaf extracts (GLE), SP+OP+GLE on the "Super Manidaa"pepper. The aphid control in pepper was complete by applications of SP+OP (0.25+1.00%) in the early growth stage and the control value was above 98.1% by the application of OP+GLE (1.00+1.00 %), SP+OP+GLE (0.25+1.0+1%), SP+OP+GLE (0.25+1.0+0.5%) in the middle to late growth stage while showing 0% in the control treatment. The OTB was completely controlled by the 3 times application with the high concentration of SP+OP (0.25+1.00%) in pepper cultivation. This result indicates that the oil and the sulfur preparations should be applied at low concentration before insect pests do not appeared, and then sprayed at the high concentration after they appear at pepper plant. The greenhouse whitefly in 'Minichal' tomatoes was completely controlled by three times application of SP (0.25~0.33), OP (1.0~2.00%). and all the treatment of SP+OP. However, continuous control with intervals of 1~3 days was considered favorable in the tomato plant. By the periodical control with agricultural organic materials using sulfur and oil, the greenhouse whitefly, which is a high-temperature insect pest, several moths of OTB did not occur at all. In conclusion, SP+OP (0.17%+0.33%) treatment was the most economical combination to control the aphid, OTB, and greenhouse whitefly in pepper and tomato cultivation when considering operating cost. In addition, we recommend that SP should not be sprayed on the plant shoots during the day time from July to August because of high temperature.

• Korean journal of applied entomology
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• v.57 no.4
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• pp.361-372
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• 2018

Migratory insect pest populations migrate from the southern China to Korea through jet streams. In Korea, 5 major migratory insect species are important, i.e. Nilaparvata lugens, Sogatella furcifera, Laodelphax striatellus, Cnaphalocrocis medinalis and Mythimma separate, which are damages to the major crops, rice. This study was conducted from late July 2016 to early September 2016 and from July 2017 to August 2017 in rice paddy of Jeolla-province. C. medinalis and M. separata collected using pheromone traps, while N. lugens, S. furcifera and L. striatellus collected using 3 methods (visual surveys, sweeping surveys, sticky traps). SADIE (Spatial Analysis by Distance IndicEs) among geostatistics was used to analyze migratory insect pests. SADIE was used to analyze spatial distribution and index of aggregation $I_a$, index of clustering $V_i$, $V_j$ were used to investigate the spatial distribution. Also, the clustering indices were mapped as red-blue plot. C. medinalis and M. separata showed different distribution based on SADIE spatial aggregation analysis and red-blue plot analysis. Initial spatial distributions of L. striatellus and other planthoppers were differed for sampling location and time.

• Journal of Life Science
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• v.22 no.12
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• pp.1614-1620
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• 2012

Transgenic rice plants with increased resistance to rice brown planthopper (Nilaparvata lugens St${\aa}$l) were generated by particle bombardment-mediated transformation of plants with a gene encoding snowdrop lectin (Galanthus nivalis agglutinin; GNA) under control of the rice Rubisco small subunit (rbcS) promoter.. A large number of transgenic rice plants containing the GNA gene were generated. The integration, expression, and inheritance of this gene in the $R_1$ and $R_2$ generations were demonstrated by Southern and western blot analyses. The plants contained one to five copies of the transgene. The GNA protein comprised approximately 0.01-2.0% of total soluble protein in the $R_1$ and $R_2$ transgenic plants. Insect bioassays and feeding studies showed that the GNA protein expressed in the $R_2$ transgenic rice plants reduced the survival of brown planthoppers. The introduction of GNA into rice plants therefore can help to control insect pests.

• International Journal of Industrial Entomology and Biomaterials
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• v.18 no.2
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• pp.105-112
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• 2009

The greenhouse whitefly, Trialeurodes vaporariorum (Westwood) and the sweet potato whitefly, Bemisia tabaci (Gennadius) are serious insect pests that have a wide host range including cucumber, tomato, and pepper. In this study, we tested larvicidal efficacy of several on-the-market environment-friendly agricultural materials (EFAM) to select the effective products after the target pests were stabilized in indoor rearing condition. The developmental periods of two whiteflies are as follows: in the case of T. vaporariorum, egg duration is 9.6 days and nymph is 18.9 days, and in the case of B. tabaci, egg duration is 7.4 days and nymph is 15.2 days under $25^{\circ}C$ with relative humidity (RH) of $60{\pm}5%$ and a photoperiod of 16 L:8D. The total period of T. vaporariorum was 5 days longer than B. tabaci. Among 22 EFAMs six products showed more than 60% of insecticide efficacy against T. vaporariorum BTV B, BTV D, BTV G, BTV L, BTV M, and BTV S. On the other hand, seven EFAM products showed over 60% of insecticide efficacy against B. tabaci BTV D, BTV G, BTV K, BTV L, BTV M, BTV N, and BTV U. In the case of Spodptera litura previously, 16 EFAMs were tested against $2^{nd}$ instar S. litura, and six EFAMs were found to have more than 90% efficacy. Test of these six EFAMs against entire larval stages were performed in this study. Although some of these products showed still more than 90% of insecticidal efficacy against up to $3^{rd}$ instar larvae, the efficacy of these EFAMs sharply decreased as ages increase, resulting in less than 60% of efficacy of the products at most. This result indicates the difficulty to control S. litura with the on-the-market EFAMs alone under economic injury level. Collectively, it is required to find more EFAMs, and find alternative method, and combined way of controlling to control those insect pests tested in this study.