• Korean journal of applied entomology
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• v.29 no.3
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• pp.194-200
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• 1990

The diamondback moth (Plutella xylostella L.) was selected over 24 generations with fenvalerate. The resulting resistant strain was tested to study development of insecticide resistance and cross resistance to some insecticides in the laboratory. Insecticide resistance of diamondback moth at the 24th generation devleoped 66.2 fold compared to the parent strain for fenvalerate. The fenvalerate selected strain exhibited 145 fold, a high level of cross resistance to deltamethrin, and also showed 17.4-45.0 fold cross resistance to alphamethrin, cypermethrin, fenvalerate, permethrin, and tetramethrin in the pyrethroid insecticides. The fenvalerate selected strain showed 2.5-4.3 fold, low cross resistance to diazinon, dichlorvos, EPN, BPMC, cabaryl, and methomyl. However, it did not show cross resistance to acephate, fenitrothion, phenthoate, and carbofuran.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1998.11a
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• pp.108-113
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• 1998

Egasyn is accessory protein of ${\beta}$-glucuronidase(${\beta}$-G) in the liver microsomes. Liver microsomal ${\beta}$-G is stabilized within the luminal site of the microsomal vesicles by complexation with egasyn which is one of carboxylesterase isozymes. We investigated the effects of organophosphorus compounds(OPs) such as insecticides on the dissociation of egasyn-${\beta}$-glucuronidase(EG) complex. The EG complex was easily dissociated by administration of OPs, i.e., Fenitrothion, EPN, Phenthionate, and bis-p-nitrophenyl phosphate(BNPP), and resulting ${\beta}$-G dissociated was released into blood, leading to the rapid and transient increase of plasma ${\beta}$-G level with a concomitant decrease of liver microsomal ${\beta}$-G level. In a case of phenthionate treatment, less increase in plasma ${\beta}$-G level was observed, as compared with those of other OPs. This may be explained by a fact that phenthionate was easily hydrolyzed by carboxylesterase. Similarly, carbamate insecticides such as Carbaryl caused rapid increase of plasma ${\beta}$-G level. In contrast, no significant increase of plasma ${\beta}$-G level was observed when pyrethroid insecticides were administered to rats. This is due to a fact that pyrethroids such as Phenthrin and Allethrin were easily hydrolyzed by A-esterase as well as carboxylesterase. On the other hand, addition of OPs to the incubation mixture containing liver microsomes caused the release of ${\beta}$-G from microsomes to the medium. From these in vivo and in vitro data, it is concluded that increase of the plasma ${\beta}$-G level after OPs administration is much more sensitive biomarker than cholinesterase inhibition to acute intoxication of OPs and carbamates.

• Korean journal of applied entomology
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• v.30 no.1
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• pp.1-9
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• 1991

Cross-resistance and inheritance of resistance in laboratory-selected strains of the brown planthopper to various types of the insecticides were investigated. The fenobucarb-selected ($R_{f}$), carbofuran-selected($R_{c}$), and diazinon-selected($R_{d}$) strains were 50.3, 49.2 and 5.8 times less sensitive to the corresponding insecticides than th susceptible strain. both $R_{f}$ and $R_{c}$ strains were highly resistant to the other carbamate insecticides, and moderately resistant to cypermethrin and deltamethrin, but nearly not resistant to fenvalerate and the organophosphorus insecticides except malathion and phenthate. Moderate resistance to malathion and phenthoate in the $R_{f}$ and $R_{c}$ strains was obtained at the rate of 13.0-12.0 and 8.5-7.5 times, respectively. The $R_{d}$ strain showed low levels of resistance to the carbamate, organophosphorus and pyrethroid insecticides, but negatively correlated cross-resistance to fenvalerate. Resistance of the brown planthopper to all the test insecticides was inherited by partially dominant autosomal factor(s).

• The Korean Journal of Pesticide Science
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• v.11 no.2
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• pp.87-94
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• 2007

Pyrethroid insecticide have widely been used for agricultural sector and residential environments. To assess the exposure of insecticide which is absorbed through skin the analysis of urinary metabolite is essential. At present, the urinary 3-PBA was analyzed using liquid-phase extraction. But LPE have many limitations, such as long pre-treatment time and low recovery. So, this study was conducted to determine the optimum conditions for analysing 3-PBA in urine using solid phase extraction. Furthermore, this study intend to investigate the relation of concentrations of pyrethroid, deltamethrin in air and 3-PBA in urine. The optimum condition for hydrolysis was found to be done with hydrochloric acid for one hour. The recovery rates of 3-PBA were $84.6%{\pm}1.2%$, $54.8{\pm}0.9%$, $99.8{\pm}1.2%$ with XAD-2, XAD-7, XAD-16 using as the aborbents and acetone as eluents respectively. But acetonitrle and methanol gave low recovery rate and methyl cellosolve could not elute the compound. The amount of acetone for elution were 6mL, 9mL, 3mL for XAD-2, XAD-7, XAD-16 as absorbents respectively. The non-absorbed rates was $0.8{\pm}0.5%$, and $0.7{\pm}0.3%$ under XAD-16, mesh size 140-200, amount of resin 1.4g and the flow rate of eluent was 0.1mL/min. In the concentration process, we obtained 11 times higher concentration of material. The amounts of urinary 3-PBA were. The LODs of 3-PBA and deltamethrin were 0.004 mg/L, 0.038 mg/L, respectively. The further research of minute monitoring which include spray pattern, environmental condition is needed And more research about the relation between total pyrethroid exposure and urinary various metabolite are also necessary.

• 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.

• 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 PSK Conference
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• 2001.10a
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• pp.178.2-178.2
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• 2001

• Korean journal of applied entomology
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• v.40 no.4
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• pp.327-335
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• 2001

In order to establish a whitefly control system using conventional groups of insecticide(carbamate, organophosphorus and pyrethroid insecticides), three alternative application methods were designed on the medium growth stage of cucumber. To discriminate the effectiveness of these sequences observed were the residual activity of insecticides, frequency of insecticide applications, residue of insecticides in cucumber leaves, development of insecticide resistance in whitefly, and yield of fruits. Spraying furathiocarb, a carbamate insecticide, was very effective in reducing the frequency of application for the control of white flies. The effectiveness of furathiocarb was enhanced by the potentiation process to carbofuran, the long residual activity, and the lower development rate of insecticide resistance. Methion, an organophosphorus insecticide, did not show resistance development after successive use but resulted in short residual activity. However, other organophosphates, profenofos and phenthoate, lost their activity by the resistance development. Decreasing activity was common to pyrethroids, deltamethrin and zetacypermethrin due to resistance. From these results it could be drawn a conclusion that furathiocarb, a carbamate insecticide, was the most desirable among conventional insecticide groups for the management of greenhouse whitefly population on the cucumber. To prevent an outbreak of the insect pest by various cause, it was recommended to choose acetamiprid, a nicotinoid, which showed very good control efficacy to the resistance insects to conventional insecticides.

• Korean journal of applied entomology
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• v.26 no.2 s.71
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• pp.83-88
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• 1987

Differences in susceptibility of several organophosphate, carbamate and pyrethroid insecticides to three species of aphids were determined by leaf-dipping and spray methods. The insects tested were the apterous adults of the green peach aphid (Myzus persicae), cotton aphid (Aphis gossypii) and soybean aphid (Aphis glycines). The comparison of $LC_{50}$ levels was indicated as follows; (1) The susceptibility to insecticides tested were greatly varied with the test methods. (2) The leaf dipping method is more recommendable than the spray method for insecticide screening with aphids. It was easier, more accurate and less variable than the latter. (3) The susceptibility to insecticides was greatly varied between the aphid species. Soybean aphid was more susceptible to the insecticides than green peach aphid and cotton aphid. Exceptionally, pirimicarb was not effective on the cotton aphid.

• The Korean Journal of Pesticide Science
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• v.9 no.4
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• pp.380-390
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• 2005

This study was carried out for looking into the status of susceptibility of vinyl house insect pests to insecticides. The Thrips (Thrips palmi and Frankliniela occidentalis), Mites (Tetranychus urticae), Aphids (Aphis gossypii) and Whitefly (Trialeurodes vaporariorum) were captured at various areas where the host crop was being cultivated and the susceptibility level of each pest insect was investigated. The susceptibility of each pest insect varied by insect species and areas where they were caught. The tested insecticides showed good control effect to palm thrips in 2000, but in 2003 showed decrease of effect to them. Western flower thrips showed low susceptibility to neonicotinoids, imidacloprid and thiamethoxam, but high to chlorfenapyr, spinosad, emamectinbenzoate and fipronil. Antibiotic insecticides, abamectin and milbemectin, and chlorfenapyr were very effective on mite control and dicofol still had good effectiveness to it despite of long year use. No aphid species showed resistance to pyrethroid and carbamate insecticides. Relatively new insecticides such as imidacloprid, spinosad, pymetrozine were effective to whitefly, but not were organophosphates, carbamates and pyrethroids.