• The Korean Journal of Soil Zoology
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• v.1 no.1
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• pp.28-36
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• 1996

A survey for entomopathogenic nematodes was conducted throughout the nine provinvrd and within three city limits during the summer of 1990 and 1991. Six of the nine provinces and one of the three cities were positive for entomopathogenic nematodes. Out of the total 499 soil samples, 23(4.6%) were positive for entomopathogenic nematodes with 19(3.8%) containing Steinernema and 4(0.8%) containing Heterorhabditis. Heterorhabditis bacteriopora and three distinct groups of Steinernema species were idintified. One groups was indentified as S. carpocapsae, another S. glaseri and the other S. monticola based on cross breeding studies. Positive sample sites in each habitat includes 15 of the 415(3.6%) from forests including regrowth areas with shrubs, 1 of the 27(3.7%) from turfgrass including golf courses and parks, 3 of the 24(12.5%) from agricultural fields, 2 of the 16(12.5%) along riparian areas, and of the 17(11.8%) near the seashore. We advocate that more surveys be conducted for entomopathogenic nematodes before commercial sources of nematodes are widely applied which may obscure the naturally-occurring nematodes. A key to Steinernema is provided for the identification.

• Journal of Sericultural and Entomological Science
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• v.45 no.2
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• pp.103-107
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• 2003

Entomopathogenic nematodes were isolated through the investigation in soils collected from cultivated and non-cultivated fields using silkworms (Bombyx mori) and Galleria mellonella trap. The detectable rate of entomopathogenic nematodes of silkworms trap was higher than the G. mellonella trap. This study indicates the detection of entomopathogenic nematodes from soils that silkworms are sensitive superior to the G. mellonella to entomopathogenic nematodes. The steinernema, rhabditidae, and diplogatroidae strains successfully cultured on the silkworms host as well as on artificial media. Reproductivity in the living silkworm larva and pupa was 1.5 to 3.5${\times}$ 10$\^$5/ nematodes per host However, G. mellonella could be multiplied less than 5${\times}$l0$\^$5/ nematodes. The dried pupa of the silkworm following mositurize was cultured 0.5 to 2${\times}$10$\^$5/) nematodes per host. The culture methods of the steinernema, rhabditidae, and diplogatroidae strains, using silkworm powder, extracted chicken intestine, and food waste fertilizer could be applicative, but rate of reproduction was low.

• Proceedings of the Korea Society of Environmental Biology Conference
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• 2003.11a
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• pp.81-85
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• 2003

In round numbers the 100 strains of entomopathogenic nematodes were isolated through the investigation of cultivated including the ginseng forming cultivated and forest soil samples by silkworm trap. The 28 strains of nematodes were selected among the isolated entomopathogenic nematodes that were confirmed the pathogenicity against Holotrichia morosa, Hoiotrichia diomphalia and Ectinus sericeus, the pest of korean ginseng and silkworm. Pathogenicity of the 2025, 2027, 2028, 2034, 2039 and 2057 strains was excellent. Selected entomopathogenic nematodes are classified of two species by morphologiacl and molecular studies, which were Sterinernma carpocapsae sp. and Diplogaster lethier sp.. Diagnostic characters include body length, lateral field pattern, tail shape and so on. The DNA sequences of the ITS region of rDNA shows similar to S. carpocapsae and .D. lethier. Isolated entomopathogenic nematodes were demonstrates that are quite within the realms of possibility for biological control agents of the pests of Korean Ginseng.

• Biotechnology and Bioprocess Engineering:BBE
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• v.6 no.2
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• pp.139-143
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• 2001

The efficacies of several entomopathogenic nematodes of Steinernema and Heterorhabditis spp. were examined against tobacco cutworm, Spodoptera litura Fabricius. H. bacteriophora HY showed 100% mortality after 20 h against 2nd instar of tobacco cutworm. In the case of 3-4th instar, S. carpocapsae PC, H. bacteriophora HY and S. monticola CR showed 100% mortality after 47 h. In the case of 5-6th instar, S. carpocapsae PC proved more effective than the others. Generally, the number of nematodes harvested as their size decreased. Also, the highest number of nematodes was obtained in the 5-6th instar of S. litura by H. bacteriophora HY, showing about $1.3{\times}10^6$ nematodes per larva. In vitro cultured S. carpocapsae PC showed 100% mortality after 73 h against 5-6th instar tobacco cutworm, indicating that nematodes produced in vitro can be potentially used for the biological control of S. litura instead of nematodes in vivo.

• Asian Journal of Turfgrass Science
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• v.13 no.4
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• pp.213-222
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• 1999

The toxic effects of four pesticides on the entomopathogenic nematodes. Heterorhabditis bacteriophora NC strain, Steinernema glaseri NC and Dongrae strain were tested by checking the mortality of infective juveniles(Ijs) in aqueous solution of pesticide. Mortality of Ijs was influenced by pesticide and concentration and soaking time. The herbicide alachlor and insecticide fenitrothion were toxic to Ijc of three entomopathogenic nematodes. But, the fungicides mepronil and tolclofos-methyl were nontoxic to Ijs. Tolclofos-methyl showed significantly very week toxicity at 28 days after soaking for S. glaseri NC strain. H. bacteriophora NC strain was more highly sensitive to high temperature condition then were the other nematodes.

• The Korean Journal of Ecology
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• v.22 no.5
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• pp.255-263
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• 1999

Entomopathogenic nematodes were isolated through the investigation of soil samples from various biotopes in south Korea, the efficiency of isolation for highly pathogenic nematodes to silkworms (Bombyx mori) was as high as 28 %. Twenty-eight strains of nematodes, selected among 100 samples by silkworms were confirmed the pathogenicity, multiplicity, and tolerance against various condition of preservation. Pathogenicity of the nematode isolates to agricultural and environmental pests such as Calliphora vomitoria, Pseufaletia separata, Palomena angulosa, and Melolontha incana were high. Mortality was varied from 20 to 100% by the pest insects and nematode strains. The high detectablity of entomopathogenic nematodes resulted from the methods of collection for soil samples within 10 cm depth after eliminating dried soil surface and the use of silkworm trap. High population of entomopathogenic nematodes represented the strong activity and broad action radius in the environment. Most of the nematode isolates were successfully cultured on the silkworm host as well as on artificial media, and proved their potential for the use of biological control agent.

• KSBB Journal
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• v.17 no.3
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• pp.271-275
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• 2002

Fatty Acid contents of entomopathogenic nematodes(EPNs) were examined by various types of nematodes and culture methods. Seven different types EPNs cultured by in vivo did not contain same fatty acid contents, but similar compositions. It was also found that Steinernema carpocapsae among EPNs cultured by in vivo and in vitro contained not only different fatty acid contents, but also revealed distinctive motilities in a soil. The addition of olive oil in the in vitro culture medium resulted in similar fatty acid contents of S. carpocapsae to in vivo and greatly improved the pathogenicity of nematodes compared to that of soy oil in the medium.

• KSBB Journal
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• v.30 no.3
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• pp.132-139
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• 2015

In order to use the symbiotic bacteria from ethomophatogenic nematodes as a biological control agent for agriculture, the cultural condition for maintaining phase I and antifungal activity was investigated. Symbiotic bacteria (SB) 1 stain from nematodes were selected from the three strains isolated from entomopathogenic nematodes. The growth of the SB 1 strain in NB, TSB, TY and YS medium was higher than that of the SB 2 and SB 3 strain. The packed cell volume of the SB 1 strain was reduced in NB medium which showed radical pH change. Phase I of the SB 1 strain was maintained in TSB medium after being stored for 2 weeks at $4^{\circ}C$. Culture broth with the SB 1 strain in TSB medium for 6 days and 7 days showed antifungal activities against Rhizoctonia solani KACC 40142, Botrytis cinerea Pers. KACC 40854, and Botrytis cinerea Pers. KACC 41008. Culture broth with the SB 1 strain in TSB medium containing 100 mM L-proline for 5 days showed antifungal activities against Rhizoctonia solani KACC 40142, and Botrytis cinerea Pers. KACC 40854.

• The Korean Journal of Soil Zoology
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• v.1 no.2
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• pp.81-88
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• 1996

Entomopathogenic nematodes, Steinernema carpocapsae, was able to invade and kill the several lepidopteran pests including the beet armyworm, Spodeptera exigua Hubner, which was the most effective target host. The beet armyworms treated with the effective nematode concentrations were died within 48 hrs. The lethal effect of the nematode was varied among the developmental stages of the host. The fifth instar larvae of the beet armyworm was more vulnerable to the nematode than the third instar larvae. Pupae was, however, refractory to the nematode. All three bioessays (topical application, filter paper test, and soil treatment) showed the positive correlation between the number of the treated nematodes and the mortality of the host. Topical application was the most effective and fast-acting method so that it gave the lethal effect 2 days earlier than did filter paper test at the same number of the treated nematodes. Soil treatment required higher number of the nematodes to get the effective lethality than did filter paper test. The fifth instar larvae of the beet armyworm expressed the specific hemolymph proteins of 5 to 10 kDa in response to nematode infection.

• Korean journal of applied entomology
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• v.30 no.1
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• pp.50-53
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• 1991

The entomopathogenic nematodes, Steinernema carpocapsae and Heterorhabditis bacteriophoTa, were laboratory tested for the control of rice stem borer Chilo suppressalis. When 8 cm long of two rice stems infected by rice stem borers were treated with S. carpocapsae by spray application to the concentrations of 250, 500, 1,000, or 2,000 nematodes/ml, 68.6 $\pm$ 10.0-94.9 $\pm$ 2.6 % control was obtained. When 8 cm long of rice stems infected by rice stem borers were treated with H. bacteriophoTa by spray application to the concentrations of 100, 200, 400, or 800 nematodes/ ml, 91.4 $\pm$ 0.7-100 % control was obtained. On the other hand, when 8 cm long of three rice stems were treated with H. bacteriophora by dipping application to the concentrations of 100 or 200 nematodes/ml, 46.2 $\pm$ 4.7-63.1 $\pm$ 4.7 % control was obtained. Because the moist habitat of rice stems were favorable to nematode survival and searching abilities, entomopathogenic nematode, were confirmed to be a potential biological control agents against rice stem borers.