• Landscaping Tree
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• s.128
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• pp.30-36
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• 2012

• Korean Journal Plant Pathology
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• v.3 no.1
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• pp.28-34
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• 1987

• Korean journal of applied entomology
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• v.29 no.3
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• pp.184-189
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• 1990

A nuclear polyhedrosis virus (NPV) of the tobacco cutworm, Spodoptera litura would be a promisible agent for the control of the insect. To develop a viral insecticide using S. litura NPV, effect of spray on soybean leaves, temperature, storage, an sunlight on the pathogenicity of the virus were studies as follows: Median lethal concentration ($LC_{50}$) of the virus sprayed on the leaves against the third and the fifth instar larvae were $1.301\times10^{4 PIBS}/ml$ and $1.087\times10^{5 PIBS}/ml$, respectively. On the concentration of $1.0\times10^{5 PIBS}/ml$, median lethal times ($LT_{50}$) were 7.3 days for the 3rd and 8.9 days for the 5th instar larvae. Stability of S. litura NPV was quickly decreased at the higher temperate than $60^{\circ}C$ and at the longer exposure to the higher temperature. Storage of the virus at $-20^{\circ}C$ was kept higher pathogenicity than $4^{\circ}C$ and $25^{\circ}C$. Viral activity was maintained more than 10 days in the sprayed-under leaves, but decreased at 3 day after spray in th sprayed-on the leaf surface when exposed the virus to sunlight.

• Korean journal of applied entomology
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• v.35 no.1
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• pp.80-84
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• 1996

Infectivity of entomopathogenic nematodes and fungus was evaluated against fly larvae in the laboratory and outhouses. Mortalities of Muscina stabulans larvae were 96.7f 2.8% in Steinernema glaseri Dongrae strain, 90.0+0.0% in S. carpocapsae All strain, 86.7f 2.7% in Heterorhabditis bacteriophora Hamyang strain, and 70.0+9.4% in S. carpocapsae Pocheon strain on the filter paper. When 260, 000 nem\ulcornertodes were sprayed into the outhouses, H. bacterwphora Hamyang strain killed 100%, S. glaseri Dongrae strain killed 76.9+3.9%, and S. carpocapsae Pocheon strain killed 58.5+6.1% of maggots. When 130, 000 nematodes and 7.0X lo9 cfu of entomopathogenic fungus, Beauveria brongniartii were sprayed alone or combined into outhouses, mortalities of maggots were 73.6+0.1% in B. brongniartii alone, 77.8+3.9% in S. carpocapsae Pocheon strain plus B. brongniartii, and 77.7f 5.1% in H. bacteriophora Hamyang strain plus B. brongniartii. Entomopathogenic nematodes and fungus were potential biological control agents in this study.

• Journal of Sericultural and Entomological Science
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• v.33 no.2
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• pp.75-81
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• 1991

The study has been carried out to acquire some basic informations about Bacillus thuringiensis for developing the microbial pesticide. Pathogenicity tests on three of B.thuringiensis var. aizawai, kurstaki, and dendrolimus were determined in two species of insects, H. cunea and B. moris. The pathogencity in varieties of B. thuringiensis against H. cunea and B. mori was depended on instar age of tested larvae. Bacillus thuringiensis var. dendrolimus, kurstaki, aizawai are arranged in order of pathogenicity against H. cunea and B. mori. In result Bacillus thuringiensis var. kurstaki was shown the most stable toxicity with respect to each instar of tested larvae.

• Korean Journal of Microbiology
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• v.9 no.2
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• pp.61-68
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• 1971

Borrelina virus was inoculated into Hyphantrea cunea DRURY in the labolatory and in the field. The pathogenecity of Borrelina virus upon Bompyx mori L. and Dendrolinus spectabilis BUTLER, too, was examined with following results. 1) $10^8$/ml, $10^7$/ ml, $10^6$/ml concentration of nuclear-polyhedrosis virus was inoculated into the larvae of H.cunea at various ages. The corrected mortality of the larvae were 97.4%, 95.2%, 94.7% in the 3rd instar, and 88.6%, 73.6%, 62.5% in the 6th instar, respectively, with three different concentration of NPV. 2) The symptom of disease of the larvae appeared on 4days after inoculation and most of the larvae were dead within 18 days. 3) The youngest larvae treated with the highest concentration of NPV showed the highest mortality. With older larvae and lower concentriton treated, it appeared that the time needed for death grew longer, marking slower death curve. 4) When we sprayed NPV of $10^6$/ml concentration to H. cunea in the field, the mortality was 94.8% in the first year, 84.6% in the second year and 78.3% in third year. By this, we could admit the continuous effects of the pathogens for several years. 5) About the larvae of B. mori of 3rd and 5th instar and D.spectabilis of 3rd instar inoculated with $10^8$/ml concentration of inoclum, we could not see any pathogenic effects.

• Korean Journal of Microbiology
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• v.9 no.2
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• pp.69-73
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• 1971

On June in 1970 the authors discovered a pathogenecity, cytoplasmic polyhedrosis virus, of the Smithia virus in the larvae of Liparis dispay L. appeared on quercus forest in Chung-Neung district and had carried out a experiment to detect the pathogenecity of Smithia virus through the inoculation of it into the larvase, such as Liparis dispay L. Hyphantrea cunea DRURY, and Dendrolinus spectabilis BUTLER. The results obtained were as follows ; 1) Death rate of L.dispay and D.spectabilis treated by 10$^{6}$ /ml cytoplasmic polyhedrosis virus of Smithis virus were 88.0% and 85.5% respectively, when the larvaes of these insects are big enough. But there were none of pathogenecity in case of Hyphantrea cunea DRURY. 20 Dead larvae caused by the injection of Smithia virus had begum to find out about on 10 days after inoculation. Miximum death rate of L. didpay and D. spectabilis appeared on 20-25days nad on 25-30days, respectively, after the incoulation. 3) In the cytoplasm of Mid-gut cylindrical cells of both of these insects, polyhedrosis, such s hexagonal (0.5-2.0-6.0 micron) were found out and in these insects, polyhedrosis, such as hexaginal (0.5-2.0-6.0 mivton) were found out and in case of D.spectabilis were a few polyhedrosis, such as tetragonal, trianglar polyhedrosis. 4) Diluted concentration of `0$^{6}$ /ml cytoplasmic polyhedrosis virus of Smithia virus were spread out in the field conditions. The corrected mortality was confirmed as about 87.8%.

• Korean journal of applied entomology
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• v.29 no.4
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• pp.252-256
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• 1990

Viral insecticides were formulated with Spodoptera litura nuclear polyhedrosis virus and different U.V. protectants based on white carbon, molasses, and white carbon and molasses mixture to use as microbial control agents. Effect of rainfall on the attachment of formulated viruses to leaves was no different between the treated and the non-treated experiment. Persistence of the formulations was lated 5 days on the surface-sprayed leaves and 12 days on the under-sprayed leaves which was showing 60% mortality. Total mortality of the viral insecticides was more than 97% with no differences among them. Field evaluation of three viral insecticides in soybean field was very successful then carried out in Chinju, a southern part of Korea. Mortality by the formulation in the field during 14 days was more than 93%, but the formulations contained molasses showed phytotoxicity on soybean leaves. Spray effect of the viral insecticides was begun to appear from 7 days later than that of chemical insecticide.

• Journal of Sericultural and Entomological Science
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• v.34 no.1
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• pp.41-48
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• 1992

Dissolution and degradation of the parasporal crystal proteins produced from B. thuringiensis var. kurstaki, B. thuringiensis var. dendrolimus and B. thuringiensis var. aizawai were investigated. SDS-polyacrylamide gel electrophoresis analysis showed that the crystals contained major protein with molecular weight of approximately 134 kDa for B. thuringiensis var. aizawai 143 kDa for B. thuringiensis var. kurstaki and 149 kDa for B. thuringiensis var. dendrolimus, respectively. Crystals of three other strains were incubated alkali solutions at various pH or gut juice of Silkwarm Bombyx mori, Fall webworm Hyphantria cunea, and Common Cabbage worm Pieris rapae. When crystals of these strains were solubilized by alkali solutions, no major differences among strains B. thuringiensis could be detected. Among the strains studied, crystal protins (130-66 kDa) consist of protease resistant polypeptides in the 45-66 kDa size range when treated with gut juice of three insect species.

• Korean journal of applied entomology
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• v.34 no.3
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• pp.218-223
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• 1995

A nuclear polyhedrosis virus isolated from the oriental tobacco budworm larvae, Helicoverpa assulta (Guenee) was characterized by electron microscopy, SDS-PAGE, restriction endonuclease analysis and cross infectivity. The shape of a polyhedron was $1.0\mu\textrm{m}$ in average with icosahdral outline, and the virus particle was $65nm\times300nm$ in average with rod-shape. The nuclear polyhedrosis virus was contained a single nucleocapsid within a viral envelope embedded in a polyhedron. The polyhedral protein was composed of a single polypeptide with a M.W. of 31 Kd. The genome size of the virus by restriction endonuclease analysis was about 120 Kb. Among several nuclear polyhedrosis viruses, the nuclear polyhedrosis virus from Helicoverpa assulta (HaNPV) and Autographa california nuclear polyhedrosis virus (AcNPV) were infected the oriental tobacco budworm larvae.