• Korean journal of applied entomology
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• 제38권3호
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• pp.255-260
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• 1999

Pathogenicity and multiplication of entomopathogenic nematode, Steinernema carpocapsae Weiser, ere analyzed in two insect hosts, Spodoptera exiga (Hubner) and Sp. litura(Fabricius). The estimated ${LC}^{50}s$(lethal concentration of the infective juveniles to kill 50% of the host insect population) were not different between tow insect species or among their developmental stages on the filter paper assay, thought the actual numbers of the infected nematodes were varied among them. The significant variation, however occurred in nematode multiplication between tow inset hosts. Temperature also gave sosignificatn effect on nematode multiplication rate that it took 6 days after infection at $25^{\circ}C$, but did 12 days at $20^{\circ}C$ to show the maximal nematode population peak($\approx$500,000 infective juveniles(IJ) in a 5th instar larva of Sp. litura and $\approx$-100,000 IJ in a 5th instar larva of Sp. exigua).

• Korean Journal of Environmental Agriculture
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• 제29권3호
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• pp.300-303
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• 2010

Laboratory trial on the control effect of Beauveria bassiana against Paratlanticus ussuriensis was carried out with fungi collected from South Korea, China and Peru. All B. bassiana species from collected at each site had a strong fungicidal activity against P. ussuriensis. The Abbott's formula was the highest showing 100% mortality and the others also showed over 60% mortality. It took 3 to 6 days until katydid attained to death after inoculation with all B. bassiana treatments. From this trial, B. bassiana fungus was found to have some effects as pathogenicity of entomopathogenic activity against P. ussuriensis. So B. bassiana could be considered as one of the environment-friendly and effective pesticides for the control of P. ussuriensis.

• Journal of Microbiology and Biotechnology
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• 제18권12호
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• pp.1915-1918
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• 2008

An entomopathogenic fungus was isolated from an infected aphid. The isolate conformed most closely to Lecanicillium attenuatum CBS 402.78 (AJ292434) based on the internal transcribed spacer (ITS) region of its 18S rDNA, and thus was designated L. attenuatum CNU-23. Laboratory and field evaluations of CNU-23 blastospores were carried out for the control of green peach aphids. The laboratory evaluations of CNU-23 revealed an aphid mortality of about 80% with an estimated $LT_{50}$ of 3.72 days after the application of CNU-23 at $1{\times}10^6$ blastospores/ml. Meanwhile, the field evaluations of CNU-23 performed on greenhouse pepper plants during the rainy season showed an aphid mortality ranging from 72% to 97%. Significant sporulation was observed in the aphids treated with CNU-23. Therefore, the results suggest that L. attenuatum CNU-23 can be used as a biocontrol agent for green peach aphids on greenhouse pepper plants.

• International Journal of Industrial Entomology and Biomaterials
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• 제22권1호
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• pp.25-28
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• 2011

The virulence against the two-spotted spider mite, Tetranychus urticae Koch, was evaluated with entomopathogenic fungus Paecilomyces lilacinus (Thom) Samson HY-4 which is isolated from coleopteran insect and registered to Korean and US patents. Virulence tests were conducted with conidial suspensions ($1.5{\times}10^6conidia/ml$) of P. lilacinus HY-4 against T. urticae adults and positive results were recorded in laboratory conditions. The spraying device was also developed for the efficient and exact evaluation of treatment. The developed spraying device was named as SD-tower sprayer and its efficacy of spraying conidia was evaluated. The accumulated mortality caused by P. lilacinus HY-4 using SD-tower spray was about 73% at 6 days after inoculation. This suggest that the isolate P. lilacinus HY-4 may be considered as promising for a new approach to prevent adult infestations by T. urticae.

• The Korean Journal of Mycology
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• 제24권1호통권76호
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• pp.49-55
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• 1996

This study was conducted to find out antifungal activities of entomopathogenic fungus, Metarhizium anisopliae, against phytopathogenic fungi, Fusarium oxysporum, Botrytis cinerea and Alternaria solani. M. anisopliae was confirmed its antagonistic effect through mycelial inhibition zone of phytopathogenic fungi by culture filtrate of the antagonist. The filtrate (30%: v/v) inhibited the conidial germination of B. cinerea and F. oxysporum to 21.5% (control: 88.2%) and 53.0% (control: 78.6%), respectively and delayed the start of spore germination about 8hours. Microscopic observations proved that the addition of 10% culture filtrate of M. anisopliae restricted the growth of phytopathogenic fungus, F. oxysporum, to the formation of chlamydospore. From these results, we concluded that an addition effect of the filtrate from M. anisopliae on culturing F. oxysporum was fungistatic.

• Journal of Microbiology
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• 제45권5호
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• pp.422-430
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• 2007

Clonostachys rosea (syn. Gliocladium roseum) is a well-known biocontrol agent and widely distributed around the world. In this study, an endochitinase gene Crchi1 was isolated from the mycoparasitic fungus C. rosea using the DNA walking strategy. The Crchi1 ORF is 1,746 bp long and interrupted by three introns. The cloned gene Crchi1 encodes 426 amino acid residues and shares a high degree of similarity with other chitinases from entomopathogenic and mycoparasitic fungi. Several putative binding sites for transcriptional regulation of Crchi1 in response to carbon (5'-SYGGRG-3') and nitrogen (5'-GATA-3') were identified in the upstream of Crchi1. Expression of Crchi1 gene in different carbon sources was analyzed using real-time PCR (RT-PCR). We found that the Crchi1 expression was suppressed by glucose but strongly stimulated by chitin or solubilized components of the cell wall from Rhizoctonia solani. Phylogenetic analysis of chitinases from entomopathogenic and mycoparasitic fungi suggests that these chitinases have probably evolved from a common ancestor.

• Applied Biological Chemistry
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• 제39권6호
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• pp.449-454
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• 1996

We investigated the optimal condition for the production of extracellular pretense(a cuticle-degrading pretense) from entomopathogenic fungus Beauveria bassiana(ATCC7159) in liquid medium by adding of gelatin, bovine serum albumin(BSA), casein and polypeptone. The optimal induction medium for production of extracellular pretenses is composed of 0.5% polypeptone, trace elements and 50 mM potassium phosphate(pH 6.0). In this condition, the production of extracellular pretenses increased rapidly after the 24hrs, peaking at the third day and there was little inductive effect in culture broth more than pH 7.0. The pretenses were inhibited by phenyl methyl sulfonyl fluoride(PMSF). High activity of pretense was showed both range of pH 8.5 and 11.5 and also detected by three different portions of slice gel derived from non-denaturing isoelectricfocusing gel. At least three different extracellular pretenses are produced in optimal production medium when polypeptone is used as the sole carbon and nitrogen source.

• Journal of Microbiology and Biotechnology
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• 제24권1호
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• pp.1-7
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• 2014

The possibility of using hyphomycete fungi as suitable biocontrol agents against greenhouse whitefly has led to the isolation of various insect pathogenic fungi. Among them is Beauveria bassiana, one of the most studied entomopathogenic fungi. The objective of this study was to use B. bassiana M130 as an insecticidal agent against the greenhouse whitefly. M130 isolated from infected insects is known to be a biocontrol agent against greenhouse whitefly. Phylogenetic classification of M130 was determined according to its morphological features and 18S rRNA sequence analysis. M130 was identified as B. bassiana M130 and showed chitinase (342.28 units/ml) and protease (461.70 units/ml) activities, which were involved in the invasion of the host through the outer cuticle layer, thus killing them. The insecticidal activity was 55.2% in petri-dish test, 84.6% in pot test, and 45.3% in field test. The results of this study indicate that B. bassiana has potential as a biological agent for the control of greenhouse whitefly to replace chemical pesticides.

• Journal of Sericultural and Entomological Science
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• 제46권1호
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• pp.18-22
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• 2004

For the purpose of accumulating the research outcomes on Cordyceps and retrieving them efficiently, this study was carried out to identify and standardize the key factors in cultivating Paecilomyces tenuipes and classifying characteristics of Cordyceps. The key factors in cultivating Paecilomyces tenuipes are divided into three major sections according to its stage: silkworm rearing period, cultivation period, and preservation period. Silkworm rearing and cultivation sections are divided into three sub-sections: temperature, humidity, and duration. There are other factors including rearing tools, equipment etc. The key factors in classifying characteristics of Cordyceps are divided into 14 items, 41 divisions on the basis of its general features and its taxonomic features. 14 items contain general article, host, perithecium, conidia, etc. 41 divisions are partitioned by its size and color. The classification system of Kobayasi (1940) or of Shimizu (1994) was adopted for the key factors of Cordyceps species and their anarmorphs.

• Asian Journal of Turfgrass Science
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• 제18권4호
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• pp.193-200
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• 2004

Environmentally sound control of fall webworm, Hyphanria cunea (Drury) with entomopathogenic nematode, Sreinernema carpocapsae Pocheon strain was evaluated in the laboratory and pot. Pathogenicity of 5. carpocapsae Pocheon strain was different depending on larval stage, i.e., mortality of the 2nd instar and the $3\~4th$ instar was $100\%$ with >20 infective juveniles (Ijs)/larva in 3 days, but the 5th instar was $34\%$ with (Ijs)/larva in 3 days. Pathogenicity of 5. carpocapsae Pocheon strain was higher with increasing nematode concentration. Mortality of Hyphanria cunea larva by 5. carpocapsae Pocheon strain was not significantly different (more than $70\%$) between nematode concentration on treated trees (Malus alba and Platanus orientalis) and in pot.