• Korean journal of applied entomology
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• v.28 no.3
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• pp.146-153
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• 1989

These studies were conducted to investigate development of chemical resistance in two-spotted spider mite (Tetranychus urticae Koch) trough single selection for a given period of time with five acaricides including carbophenothion and ethion of organo-phosphate compound, dicofol of organo-chlorine compound, cyhexatin of organo-tin compound, biphenthrin of synthetic pyrethroid compound; and to examine cross-resistance among the acaricides to the selected populations. The development of chemical resistance of two-spotted spider mite was greatly varied under single selection of the each five acaricides. The carbophenothion- and the ethion-populations at the 22nd and the 24th selected generations showed 156- and 64.1-fold resistant levels, respectively, as compared with the susceptible population. However, the dicofol population at the 28th selected generation exhibited 39.7-fold resistant level, and the biphenthrin population at the 24th selected generation revealed 25.2-fold resistant level, while the cyhexatin population at the 20th selected generation showed 13-fold resistant level. The carbophenothion-selected population showed high cross-resistance to ethion, and low cross-resistance to dicofol and biphenthrin. The ethion-selected population revealed also high cross-resistance to carbophenothion. The dicofol-or the biphenthrin-selected populations, however, exhibited moderate cross-resistance to carbophenothion and ethion. Meantime, the cyhexatin-selected population showed high cross-resistance to ethion and carbophenothion.

• Journal of the Korean Society of Tobacco Science
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• v.19 no.2
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• pp.107-116
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• 1997

Karyotype of apterous green peach aphid (Myzus persicae SuIBer) populations occurring in tobacco fields and their resistance to insecticides were investigated. All of the 16 clones collected from tobacco fields had same chromosome number of 2n=12. Among them, 5 clones had the normal karyotype, regardless of color morph, but chromosomal translnations between #1 and #3 autosomal chromosomes were noted in the other 11 clones. All of the aphid clones were highly resistant tolambda cyhalothrin, a pyrethroid pesticide, having over 20 times higher concentrations of LD90 than recommended concentration (10ppm) for the aphid. However, their resistance to acephate, demeton 5-methyl and pirimicarh varied depending on the clones, among which green-colored clones were generally more resistant to the pesticides than red-colored ones. No association was found between the insecticide resistance and the karyotype of the aphid in this experiment.

• Korean journal of applied entomology
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• v.30 no.4
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• pp.291-293
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• 1991

Inter-regional difference in median lethal concentration of Bacillus thuringiensis diamondback moth was disclosed to be high. Pyungchang strain showed at most 41 times resistance compared to KN-IA strain of which $LC_{50}$ value was 5.5 ppm. and Oksan strain Showed 11 times resistance. The JMC strain, susceptible to pyrethroids, also showed 12 times resistance against B.T., suggesting difference in resistance mechanism between pyrethroid and B.t.

• Journal of Life Science
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• v.10 no.2
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• pp.164-168
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• 2000

To understand the biological characteristics of Corythucha ciliata occurring in Korea, developmental periods and its susceptibility to several insecticides were examined under growth chamber condition at $25^{\circ}C$. It took 11.1 day from egg to hatch. And duration of each stage up to the 5th nymph after hatching was 4.0, 2.1, 2.0, 2.9, and 4.0 days, respectively. Total duration from egg to adult was 26.1 days, preoviposition period was 12.2 days, and average number of eggs laid by a female was 83.0. Sex ratio of female was 51.6% and lifespan of female adult was 43.2% days. LC50 value of deltamethrin and esfenvalerate were 0.8 and 0.9 ppm, respectively. Insecticidal effects were better in pyrethroids than organophosphates and carbamates.

• Proceedings of the Korean Society of Toxicology Conference
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• 2002.11b
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• pp.166-166
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• 2002

In the present study, estrogenic or antiestrogenic activity of cypermethrin, a pyrethroid insecticide was investigated. We used immature rat uterotrophic assay, estrogen-responsive calbindin-D9k (CaBP-9k) gene expression assay and luciferase reporter gene assay for measure of estrogenic potential of cypermethrin.(omitted)

• Proceedings of the PSK Conference
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• 2001.10a
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• pp.178.2-178.2
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• 2001

• Journal of Life Science
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• v.28 no.4
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• pp.483-487
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• 2018

Cypermethrin, a commonly used domestic and agricultural pyrethroid pesticide, is widely considered detrimental to the environment and to many organisms because of its residual property and toxicity. Cellulophaga lytica DAU203, isolated from coastal sediment, was chosen because it degrade cypermethrin. Cellulophaga lytica DAU203 effectively degraded cypermethrin, as the utilized carbon source and substrate, in a mineral salt medium. Effective factors, such as carbon source, nitrogen source, initial pH, and temperature, for cypermethtin biological degradation by Cellulophaga lytica DAU203 were analyzed by one factor at a time method. Temperature ($22{\sim}42^{\circ}C$), initial pH (5~9), and yeast extract concentration (0.1~2.5%[w/v]) were selected as the three most important factors. There were optimized at $33.4^{\circ}C$, pH 7.7, and 2.4%(w/v) by response surface methodology, respectively. The Box- Behnken design consisting of 46 experimental runs with three replicates was used to optimize the independent variables which significantly influenced the cypermethrin biological degradation. This model for cypermethrin degradation by Cellulophaga lytica DAU203 is highly significant (p<0.05). Under the optimized condition, Cellulophaga lytica DAU203 degraded approximately 83.7 % of the cypermethrin within 5 days. These results suggest that Cellulophaga lytica DAU203 may be useful for the biological degradation of cypermethrin in cypermethrin-contaminated environments.

• Korean journal of applied entomology
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• v.52 no.1
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• pp.35-43
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• 2013

All tested Korean populations of the diamondback moth, Plutella xylostella, are known to be resistant especially against pyrethroid insecticides by mutation in its molecular target, para-sodium channel. Moreover, P. xylostella is able to develop resistance against most commercial insecticides. This study was performed to develop an efficient control technique against P. xylostella by a combined treatment of an endoparasitoid wasp, Cotesia plutellae, and a microbial insecticide, Bacillus thuringiensis. To investigate any parasitism preference of C. plutellae against susceptible and resistant P. xylostella, five different populations of P. xylostella were compared in insecticide susceptibilities and parasitism by C. plutellae. These five P. xylostella populations showed a significant variation against three commercial insecticides including pyrethroid, organophosphate, neonicotinoid, and insect growth regulator. However, there were no significant differences among five P. xylostella populations in their parasitic rates by C. plutellae. Moreover, parasitized larvae of P. xylostella showed significantly higher susceptibility to B. thuringiensis. As an immunosuppressive agent, viral ankyrin genes (vankyrins) encoded in C. plutellae were transiently expressed in nonparasitized larvae. Expression of vankyrins significantly enhanced the efficacy of B. thuringiensis against the third instar larvae of P. xylostella. Thus an immunosuppression induced by C. plutellae enhanced the insecticidal efficacy of B. thuringiensis. These results suggest that a combined treatment of C. plutellae and B. thuringiensis may effectively control the insecticide-resistant populations of P. xylostella.

• Korean Journal of Environmental Biology
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• v.22 no.4
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• pp.501-506
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• 2004

In organic agriculture, choose of effective and cheap bio-pesticide is very important. The authors developed an insecticidal extract from neem cake, waste of neem oil from kernel, and applied as a bio-pesticide. Bio-pesticide neem cake extracts experiment on cabbage pest was carried out at Wonju Agricultural Technology and Extension Center from 11 March to 30 May 2003. There were six treatments with three replications, using completely randomized design. Treatments involved three and six sprays of synthetic pyrethroid pesticide cypermethrin 10 EC at the dilution rate of 2.2 mL $L^{-1}$ of distilled water and four, five and six sprays of bio-pesticide neem at the dilution rate of 13.3 mL $L^{-1}$ of distilled water, and untreated control. For each treatment, designated sprayings were done at 7 days interval. Pre-spray data showed that the plants in all the experimental plots were already infested with aphid (Aphis gossypii), and diamondback moth (Pluetella xylostella). The results indicated that all neem pesticide treatments were more effective in insecticidal activity than the untreated control and the chemical treatments in controlling aphids and diamondback moth. Among the three neem treatments, there were no significant differences between them.

• Environmental Analysis Health and Toxicology
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• v.7 no.1_2
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• pp.17-34
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• 1992

The object of this study is to investigate the toxicity of S-biol (d-allethron-d-transchrysanthemate) and the mode of action between other synthetic pyrethroid insecticides and S-biol in rats. Rats were treated daily with S-biol (25 mg/kg, 50 mg/kg, 100mg/kg) by oral administration for 5 weeks. The experimental results were summerized as follows: Biochemical parameters such as LDH and Glucose in serum were much more increased in control groups. No significant hematological change excepts for MCHC in rats treated with S-biol 100 mg/kg were observed in all groups compared to control groups. In animals treated with S-biol for 4∼5 weeks, the levels of cytochrome P-450 in the liver were significantly increased. In renal microsomal fractions, however, no significant changes of cytochrome P-450 contents were observed. The activitis of ATPase in groups treated with S-biol (50 mg/kg, 100 mg/kg) were decreased compared to those in other groups. TBA values and activities of glucose-6-phosphatase in the liver were increased a little in the groups treated with S-biol (100 mg/kg) for 5 weeks. The activities of cholinesterase in hepatic and serum were not significantly changed in all groups but slightly decreased in animals treated with high dose of S-biol (100 mg/kg). The activities of carboxylesterase in serum and in the liver were slightly increased but not significantly changed.