• 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.

• The Korean Journal of Mycology
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• v.30 no.1
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• pp.44-49
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• 2002

The study was conducted to isolate and identify insecticidal bacteria for biological control of larvae of mushroom fly, Lycoriella mali, which is one of serious pests to oyster mushrooms during its cultivation period. Among eight bacteria isolated from the soil in the oyster mushroom beds and the dead body of L. mali, two bacteria, Bti-D and Bti-U showed more toxicity with mortality rate than other six-bacteria isolates. The two bacteria showed more toxicity in three instar of the period of development of the mushroom fly than in other instar. Symptoms of the larvae of L. mali infected by the two bacteria developed as follows: at the early infection, the front middle gut changed color to light brown, the middle gut to brown, whole body to black brown, and eventually, the fly died. For the identification of these isolates, cultural and biochemical characteristics by Bergey's manual and Biolog system, cell morphology by TEM, endospore and endotoxin by phase-contrast microscope, and test using 33H antisera were examined. According to the results, these two isolates, Bti-D and Bti-U were identified as Bacillus thuringiensis subsp. israelensis respectively.

• 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.

• The Korean Journal of Pesticide Science
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• v.10 no.4
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• pp.335-343
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• 2006

Five strains of Korean entomopathogenic nematodes(EPN), steinernematids and heterorhabditids(Steinernama carpocapsae GSN1, Steinernema sp. GSNUS-10, Steinernama sp. GSNUS-14, Heterorhabditis bacteriophora Hamyang, Heterorhabditis sp. GSNUH-1) were evaluated and tried in petri dish, pot, and vegetable greenhouses for environmentally friendly control of beet armyworm, Spodoptera exigua. $LC_{50}$ values of five EPN strains against beet armyworm was different depending on nematode strain and beet armyworm instar. $LC_{50}$ value of Steinernema carpocapse GSN1(GSN1) was 3.8-5.1 infective juveniles(Ijs) in 2nd to 4th instars of beet armyworm. Pathogenicity of five EPN strains against beet armyworm different in nematode strain, concentration, application times, and vegetable species in pot and greenhouse. Steinernema spp. was more effective than Heterorhabditis spp. against beet armyworm. Two or three times of applications of EPN were found to be effective regardless of nematode strain and concentration in pot and greenhouse. ENP showed different reactions on vegetable species. Efficacy of EPN was higher on Chinese cabbage than that on cabbage and kale. GSN1 was one of the most effective nematodes and 100,000 infective juveniles per $m^2$(720,000 Ijs/$7.2m^2=1{\times}10^9$Ijs/ha) resulted in higher mortality in greenhouse.

• 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.

• The Korean Journal of Pesticide Science
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• v.12 no.3
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• pp.249-255
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• 2008

The comparative toxicity of recommended rates of three acaricides, fluacrypyrim, cyflumetofen and spiromesifen to the predatory mite, Neoseiulus womersleyi and its prey, Tetranychus urticae was bioassayed in the laboratory. Fluacrypyrim and cyflumetofen were much less toxic to adult females of N. womersleyi than to those of T. urticae. Adult female predators treated with these two acaricides produced $88{\sim}93%$ as many eggs as did control females. Fluacrypyrim and cyflumetofen did not affect the hatch of N. womersleyi eggs or the development of surviving immature predators, and $92{\sim}96%$ of immature predators reached adulthood. Spiromesifen at its treated concentration did not significantly affect the survival and reproduction of adult female predators but caused 100% mortality in larvae of N. womersleyi. Adult female predators survived on a diet of spider mites treated with fluacrypyrim and cyflumetofen, and their fecundity was not significantly affected. Moreover, immature predators developed normally on prey treated with these two acaricides. The results indicate that fluacrypyrim and cyflumetofen are promising candidates for use in integrated mite management programs where N womersleyi is the major natural enemy.

• Journal of the Korea Organic Resources Recycling Association
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• v.12 no.4
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• pp.105-111
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• 2004

When the clitellate tiger worms(Eisenia fetida) were fed with paper mill sludge, sewage sludge of agricultural-urban area and sewage sludge of agricultural area, number of cocoons produced by individual clitellate earthworm for 104 days were 11.8, 8.6 and 3.5, respectively. However, clitellate earthworms that had been fed with sewage sludge of agricultural-urban area for 52 days or fed with sewage sludge of agricultural area for 95 days could not produce cocoons, whereas the earthworms that were fed with paper mill sludge kept producing cocoons through the investigating period. The hatchability of cocoons produced by the clitellate tiger worms(Eisenia fetida) fed with sewage sludge of agricultural-urban region, sewage sludge of agricultural region and paper mill sludge were 42.8%, 38.3% and 39.2%, respectively. And hatching periods of cocoons were 33.8~36.0 days, which were not affected by the kinds of sludges. However, the cocoons produced by clitellate earthworms which had been fed with sewage sludge for about 1.5 months could not hatch at all. Death rates of second generation hatched from cocoons produced by tiger worms(Eisenia fetida) which had been fed with the sewage sludge from agricultural-urban region and the sewage sludge from agricultural region reached to 100% and 90% at 60 days after hatching, respectively, whereas death rate of second generation fed with paper mill sludge reached to 16%.

• The Korean Journal of Pesticide Science
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• v.17 no.1
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• pp.27-32
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• 2013

Damage of tea bagworms, Eumeta minuscula was observed for the first time from grape leaves of grape (varieties: Cambell Early and M.B.A.) from a vinery at Gumho-up, Gyeongsan, Gyeongbuk on 31 August, 2012. Activity of insecticides [Bacillus thuringiensis var. kurstaki (serotype IIIa, IIIb) WP, chlorantraniliprole 5% GP, methoxyfenozide 21% SC, spinetoram 5% GP, and spinosad 10% GP] was tested on fourth instar larvae of Eumeta minuscula in laboratory. Mortality of 4th instar of Eumeta minuscula was higher when treated with spinosad 10% WG (88.7%) and spinetoram 5% WG (67.7%) sprayed with field recommended concentration using a home sprayer in laboratory. Mortality decreased as the concentration decreased, however leaf damage rate was significantly different between the one-fourth rate and the control. Spinetoram 5% WG and spinosad 10% WG showed 63.7 and 55.7% respectively mortality of fourth instar Eumeta minuscula in field. Though these two insecticides could be used for the control of bagworms on grape, a more effective insecticide needs to be found.

• The Korean Journal of Pesticide Science
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• v.13 no.1
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• pp.54-61
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• 2009

EPN-resistant diamondback moth were tested the developmental characteristics, longevity, fecundity and synergistic effect with synergists when treated with the bistrifluron, an inhibitor of chitin synthesis. Inhibition rate of egg hatch was below at the recommended concentration (50 ppm) to the EPN-resistant strain than EPN-non selected strain, however, mortality within 24hr after hatching was showed as 50-60%. They did not show the difference between two strains. Mortality of larval instars were showed effective to two strains with no difference. Inhibition rate of emergence did not show any effect when treated with pupae. Moreover, they did not affect to the longevity and fecundity. When bistrifluron was treated at 50 ppm to the adult, however, longevity and fecundity was decreased with no difference between two strains. Bistrifluron to the EPN-resistant strain showed synergistic effect as high as 137.7 and 73.1 folds with synergist such as PBO (microsomal oxidase inhibitor) and polyoxin B (chitin synthetase inhibitor), respectively.