• Weed & Turfgrass Science
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• v.4 no.1
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• pp.58-64
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• 2015

The black cutworm, Agrotis ipsilon (Hufnagel) is a major insect pest of economic crops including turfgrasses on golf courses. The entomopathogenic nematode, Steinernema carpocapsae GSN1 strain (ScG), a Korean isolate, is an effective biological control agent for soil dwelling and greenhouse insect pests in Korea. In addition, ScG is commercially produced in Korea. We conducted laboratory, greenhouse, and field trials to evaluate efficacy of ScG against black cutworms in turfgrasses. A rate of 63 infective juveniles (Ijs) per larva killed >90% of $3^{rd}$ instars feeding in cups of artificial diet within 3 days. In greenhouse trials against cutworms feeding in pots of turfgrass, efficacy of ScG was higher against $4^{th}$ instars than against $2^{nd}$ instars (90.0 vs 81.2% mortality, respectively, at $2,000Ijs\;pot^{-1}$) in perennial ryegrass, and higher against $3^{rd}$ instars in creeping bentgrass, Agrostis palustris than in zoysiagrass, Zoysia japonica (96.7 vs 52.5% mortality at $100,000Ijs\;m^{-2}$) in pot. The corrected mortality of $4^{th}$ instar was 79.9% at the rate of $100,000Ijs\;m^{-2}$ in the creeping bentgrass in the field. So ScG could be used as biological control agent against black cutworm in turfgrass of golf courses.

• Korean journal of applied entomology
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• v.41 no.3
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• pp.217-223
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• 2002

The chestnut brown chafer, Adoretus tenuimaculatus Waterhouse, is serious insect pests in golf courses. Adults feed on the leaves of latifoliate trees but larvae feed on roots of turfgrases such as bentgrass, Agrostis spp. Damage of A. tenuimaculatus larvae was observed at the Jinju golf club which showed damage symptom on perennial ryegrass, Lolium perenne in tees and fairways in July, 2000. Damaged turf by A. tenuimaculatus larvae became yellowish and wilted. Symptom of laval damage of A. tenuimaculatus was similar to summer depression in warm season turfgrasses but not recovered by irrigation when Korean isolates of entomopathogenic nematodes were evaluated for the control of A. tenuimaculatus larvae in laboratory and field as a possible biological control agent. The nematodes used were Heterorhabditis bacteriophora Jeju strain, Hererorhabditis sp. Gyeongsan strain, Steinernema carpocapsae Pocheon strain, S.glaseri Dongrea strain, and S.longicaudum Nonsan strain. In the laboratory test H.bacreriophora Jeju strain and Heterorhabditis sp. Gyeongsan strain were highly effective for 3rd instars with 95% mortality. In the field test reduction rates of A.tenuimaculatus larvae were higher by ranging from 28 to 57% by H. bacteriophora Jeju strain, Heterorhabditis sp. Gyeongsan strain, and S.carpocapsae Pocheon strain compared to 7% by natural cause.

• Korean journal of applied entomology
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• v.63 no.1
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• pp.13-23
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• 2024

Vespa velutina nigrithorax du Buysson, 1905 is the invaded species in Korea since 2003. Since its importance as the honey bee pest, beekeepers use insecticides to kill the adult and immature hornets. However, its legality and effectiveness has not been confirmed. This study investigated the susceptibility of insecticides commonly used to control hornets by beekeepers in Korea. Eight insecticides were tested on adult worker and larvae by topical or oral treatment. Adults showed more than 70% mortalities from Clothianidin, Dinotefuran, and Carbosulfan treatment within 30 minutes. Bifenthrin and Cartap hydrochloride showed relatively low toxicity. The median lethal dose (LD₅₀) for Clothianidin, Dinotefuran, and Carbosulfan was 0.29, 0.65, and 2.21 ㎍/bee, respectively. In larval feeding test where 5^th instar larvae were fed 3 times every 24 hours, the mortality began after second treatments. After 3rd treatments (72 h), all insecticides showed mortality more than 70%. The LD₅₀ values of Clothianidin, Dinotefuran, and Carbosulfan to V. velutina were approximately 10 to 100 times higher than those to honey bee, Apis mellifera. This study provides the basic information of those chemical toxicities to Vespa hornet and honey bees.

• Applied Biological Chemistry
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• v.35 no.5
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• pp.361-366
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• 1992

The antagonistic bacteria, showing distinguished effect against Fusarium oxysporum and Rhizoctonia solani were isolated from the rhizosphares of horticultural plants and identified as Bacillus subtilis. The strains were studied for their chracteristics of biochemistry, physiology, antagonistic effect against plant pathogenic fungi, and growth promoting effect on horticultural plants. The Bacillus thuringiensis(BT) HD-1 toxin gene was introduced into these B. subtilis. The BT toxin genes on chromosome of the bacteria were identified by southern blotting, but its proteins were not detected by SDS-PAGE. These transformed bacteria showed growth promoting effect and showed also insecticidal and antagonistic effects against Bombix mori and fungi F. oxysporum and R. solani but not against nematode Bursaphelenchus xylophilus.

• Korean journal of applied entomology
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• v.48 no.3
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• pp.335-345
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• 2009

Effect of four nematicidal herbal extracts (Daphne genkwa, Eugenia caryophyllata, Quisqualis indica and Zingiber officinale) and 3 acricidal herbal extracts (Pharbitis nil, Xanthium strumarium, and Desmodium caudatum) on entomopathobenic nematodes [Steinernema carpocapsae Pocheon strain (ScP) and Heterorhabditis sp. Gyeongsan strain (HG)], silkworm (Bombyx mori), and ground beetles (Synuchus sp.) were investigated in the laboratory and field. D. genkwa was highly toxic to SCP and HG (100% mortality) at the concentration of 5,000 ppm in X-plate. All the infective juveniles of HG were dead after 3 days by E. caryophyllata and Q. indica. The mortality of ScP and HG was below 10% by D. genkwa, D. caudatum, E. caryophyllata, Q. indica and Z. officinale at the concentration of 1,000 ppm two days after treatment while mortality of HG was 62.8% by D. genkwa at the concentration of 1,000 ppm in X-plate. However, 1,000 ppm had not effect on nematode survival and pathogenicity of ScP in sand column. On the contrary, E. caryophyllata had effect on pathogenicity of HG. Mean number of dead Galleria mellonella larva of HG was 0.5 in E. caryophyllata treatment. Q. indica did not effect silkworm reared on mulberry leaves at the treatment of 1,000 ppm in 10 days after treatment. However, there were 20.0 and 100% mortalities in the treatment of D. genkwa 3 and 10 days after treatment, respectively. The weight of silkworm was low in D. genkwa and did not pupate. The weight of pupa and cocoon were not different in E. caryophyllata, P. nil, Q. indica, X. strumarium and Z. officinale. D. genkwa, E. caryophyllata, P. nil, Q. indica and Z. officinale had no effect on ground beetles, Synuchus sp. in forest soil.

• Asian Journal of Turfgrass Science
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• v.17 no.1
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• pp.35-44
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• 2003

Popillia quqdriguttata is a serious insect pest in Korean golf courses. The adult feeds on leaves of latifoliate trees and herbaceous plants while the larva feeds on roots of turfgrass. Thus, control of p. quadriguttata adults was tried with registered insecticides in golf courses in Korea. The insecticides used in the experiments were carbaryl + phosalone WP, chlorpyrifos + diflubenzuron WP, chlorpyrifos-methyl EC, deltamethrin EC, etofenprox WP, etofenprox + diazinon WP, etofenprox + tebufenozide EC, fenitrothion EC, imidacloprid SC, pyraclofos WP, and tralomethrin EC. Mortalities of P. quadriguttata were over 95% in carbaryl + phosalone WP, chlorpyrifos + diflubenzuron WP, etofenprox + diazinon WP, and fenitrothion EC at petri dish and in greenhouse. In the field test, corrected mortality of P. quadriguttata was 95.2% and 80.9% in carbaryl 40% +phosalone 20% WP and fenitrothion 50% EC, respectively. Spreading agent enhanced toxic effect of used insecticides to p. quadriguttata adults except carbaryl + phosalon 20% EC. p. quadriguttata adult was firstly observed to feed on leaves of Canna generalis at the Yongwon golf club in Jinhae, Gyeongnam and Prunus ameriaca var. ansu and p. salicina at the Anyang Honest golf club in Gunpo, Cyeonggi. Therefure, host plants off quadriguftata became 29 species of 26 genera in 19 families. Zoysia matreila at the fairway and roughs of Anyang Benest golf club was damaged by p. quadriguttata larvae in Octomber, 2002 and not recovered in April, 2003. Damaged turfgrass became yellowish and wilted and that retarded recovering in the following spring.

• Journal of Mushroom
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• v.12 no.4
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• pp.357-362
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• 2014

Pathogenicity of Steinernema carpocapsae GSN1 strain was evaluated against Morophagoides moriutii larvae. In Petridish tests, insect mortality by the nematode was dose dependent, which increased with dose from 5 to 160 infective juveniles(IJs)/larva. Pathogenicity against fourth-instar larvae was higher than the rate of corresponding second- and third-instar larvae, showing 100% insect mortality with the dose of 40 IJs/$4^{th}$ instar larva and 80 IJs/$2^{nd}$ or $3^{rd}$ instar larvae. Lethal concentration values at 50% ($LC_{50}$) of S. carpocapsae GSN1 strain were 4.2 IJs/$2^{nd}$ instar larva; 8.5 IJs/$3^{rd}$ instar larva; and 2.3 IJs/$4^{th}$ instar larva, respectively. The number of nematodes established in M. moriutii larvae after infection increased in the increment of dose and insect developmental stage. The highest number of nematodes was harvested from fourth instar larvae of M. moriutii at a dose of 160 IJs per larva, showing 22.5 nematodes per insect larva. Nematode reproductive capacity was related to insect developmental stage, showing 6,335 IJs/$2^{nd}$ instar larva, 21,660 IJs/$3^{rd}$ instar larvae, and 88,700 IJs/$4^{th}$ instar larvae.

• Microbiology and Biotechnology Letters
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• v.13 no.1
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• pp.51-57
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• 1985

Delta-endotoxin in Bacillus thuringiensis var. finitimus, HD-1, HD-9 and HD-73 strains were isolated by NaBr, CsCl and Renografin density gradients. The purity of the toxin was about 98%. The purified o-endotoxin was analyzed by SDS-PAGE, electron microscopic observation and bioassay. According to SDS-PAGE, the molecular weight of subunits of the o-endotoxin were about 66,000 and 130,000 daltons. The shapes of the crystal toxin observed by TEM except finitimus strain were bipyramidal. When the purified endotoxin was bioassayed against tobacco horn worm, the entomocidal activities ($1{\mu}g/ml$) of HD-1 and HD-73 strains were, respectively, 60% and 100% at nine days after treated. The molecular weights of the plasmids isolated from B. thuringiensis were various from 0.5 to 120 Kb. The numbers of plasmids in HD-1, HD-9 and HD-73 strains were 12, 3 and 11, respectively, but B. thuringiensis var. finitimus strain had no plasmid.

• The Korean Journal of Pesticide Science
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• v.2 no.1
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• pp.91-96
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• 1998

For the expression of the cry11Aa gene highly toxic to dipteran insects, we constructed two cyanobacteria-Escherichia coli(E. coli) shuttle vectors, pCYASK5-l and pCYASK5-2. These vectors were transformed into E. coli and selected with kanamycin. The expression of the cry11Aa gene in E. coli was characterized by SDS-polyacrylamide gel electrophoresis and Western blot analysis. Two E. coli transformants harboring pCYASK5-1 and pCYASK5-2 expressed the cry11Aa gene in size of 72 kDa and 64 kDa, respectively and showed over 89% mortality against Culex pipiens larvae.

• Korean journal of applied entomology
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• v.40 no.1
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• pp.51-58
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• 2001

Entomopathogenic fungus, Paecilomyces japonicus, has been commercially used as medicinal purpose . The silkworm, Bombyx mori, as an optimal host for the fungi, has been selected and used for the production of the fungal fruit bodies. In current method, newly molted fifth instal larvae should be exposed to the adverse stress environment of high temperature (3$0^{\circ}C$), high relative humidity ( 90%), and starvation for 24h for better fungal inoculation to the host insects. In this study, an alternative method using chemical agent, dexamethasone (DEX: an eicosanoid biosynthesis inhibitor), was tried to get the immunodepressive effect on the larvae to elevate the inoculation rate of the fungi to the silkworm without any harsh rearing environment. DEX (100$\mu\textrm{g}$) showed significantly synergistic effect on the hemocyte lethality of the fungus, and was effective to decrease cellular immune responses measured by the number of hemocyte microaggregation and phenoloxidase activity of the fifth instar larvae in response to the fungal injection. A detergent of 0.05% Triton-X was effective to increase the in- oculation rate of the fungi to the larvae and used in all fungal spraying solutions. Without any environ- mental stress treatment, only DEX (100$\mu\textrm{g}$) injection to the fifth instar larvae followed by the fungal spray was effective to get the inoculation rate equivalent to the current fungal spray method requiring harsh rearing environment. These results suggest that the inoculation of P. japonicus can be elevated by the help of DEX and that the silkworms use eicosanoids to elicit cellular immune response against fungal pathogen.