• Proceedings of the Korean Society of Toxicology Conference
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• 2001.05a
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• pp.122-122
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• 2001

Flupyrazofos is a new type of pyrazole organophosporus insecticide, which has a high activity against the diamond-back moth (Plutella xylostella). The potential of this agent to induce developmental toxicity was investigated in the Sprague-Dawley rat.(omitted)

• 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.

• Journal of Microbiology and Biotechnology
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• v.17 no.6
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• pp.1002-1009
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• 2007

A rapid, convenient homogeneous competitive enzyme immunoassay for estimating the amount of fenthion is described. The assay utilizes glucose-6-phosphate dehydrogenase-hapten conjugates that are inhibited in solution by antibodies obtained from bovine serum albumin-hapten conjugates. In order to investigate the effects of bridging group recognition on the sensitivity of dose response characteristics, the bridging groups of varying alkyl chain length were attached at the phosphate position of fenthion. Among the antibodies used, the one obtained from the use of hapten (fenthion analog) with the same bridging group structure that was used in preparing the enzyme-fenthion conjugates showed maximum inhibition (up to 51.8%) in the absence of fenthion. In the presence of fenthion, the activity of the enzyme-hapten conjugate is regained in an amount proportional to the fenthion concentration. Under the optimized condition, the $ED_{50}$ value for fenthion was $0.809{\mu}g/ml$. The assay developed in this study is a rapid effective screening method for fenthion prior to precise analysis.

• Food Science and Biotechnology
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• v.15 no.6
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• pp.990-992
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• 2006

In a previous study, we obtained polyclonal antibodies against the organophosphorus insecticide fenitrothion and developed an enzyme-linked immunosorbent assay (ELISA) for this pesticide. Using these antibodies and an enzyme tracer, a direct competitive ELISA method specific for fenitrothion using a dipstick format was developed. Dipstick ELISA using antibodies to fenitrothion immobilized on an Immunodyne membrane allowed the quick visual detection of fenitrothion at concentrations above $10\;{\mu}g/L$. The $IC_{50}$ value of dipstick ELISA using reflectance detection was $27\;{\mu}g/L$ with a detection limit of $2\;{\mu}g/L$. The recovery of fenitrothion from spiked lettuce and rice samples using the dipstick ELISA ranged from 87-107%.

• The Korean Journal of Pesticide Science
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• v.5 no.1
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• pp.30-35
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• 2001

Diamondback moth (Plutella xylostella L.) recently became a single worst insect which is not controlled effectively by organophosphorus and carbamate insecticides in Kangwon alpine croplands. The objective of this study was to determine if diamondback moth has developed a resistance to organophosphorus and carbamate insecticides. Resistance of diamondback moth, collected at Keichon, Jangpyong Taebaek, Chunchon, and Hongchon, was determined by the concentration required to kill fifty percent of population, $LC_{50}$. Their response of resistance varied to insecticides and locations: Taebaek populations were 35 and 70 times more resistant to chlorpyrifos and fenitrothion, respectively, than susceptible(S) population. Hongchon populations were 94 and 254 times more resistant to chlorpyrifos and fenitrothion, respectively, than S population. In addition, Chunchon populations were 37 and 19 times more resistant to profenofos and benfuracarb, respectively, than S population. However, the field populations did not differ in resistance to diazinon, phenthoate, flupyrazofos, carbofuran, and furathiocarb. This study show that field populations of diamondback moth found in Kangwon alpine vegetable croplands have developed a resistance and/or multiple resistance to some insecticides, implying that farmers are losing organophosphorus and carbamate insecticide options for selective control in vegetable crops.

• Journal of Preventive Medicine and Public Health
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• v.23 no.2 s.30
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• pp.194-200
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• 1990

The paraoxonase (E. C. 3.1.1.2) is a major enzyme to detoxicate the organophosphorus and carbamate which are the most widely used as the agricultural spraying insecticides. To investgate the distributions of plasma paraoxonase activity and the factors affecting the enzyme activity, the plasmas of 945 Korean rural population were analysed with the modified Krisch's direct sphectrphotometry method. Three indices of the enzyme activity - basal activity, stimulated activity (by NaCl), % stimulation - were obtained from the analysis. Three indicies suggested unimodal distributions, so we couldn't identify the low activity group risk group to organophosphorus & carbamate insecticides poisoning. There is no significant relation between 3 actvity indicies and sex, age, or history of insecticide use (p>0.05). The basal activity and the stimulated activity have significant relationship and high coefficient of determination with the activities of their parents ($r^2$=0.30, 0.24 ; p<0.05), but the % stimulation does not ($r^2$=0.02 ; p<0.05). These results suggest that the activity of paraoxonase is determined mainly by the genetic factor.

• Korean Journal of Environmental Agriculture
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• v.6 no.2
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• pp.77-83
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• 1987

Present study was carried out to elucidate the effect of phorate (0,0-dietyl S-ethylthiomethyl phosphorodithioate), an organophosphorus insecticide on the acetylcholinesterase(AChE) and cholinesterase(ChE) activity in the chicken brain and plasma. The inhibitory effect of phorate and its metabolites on AChE and ChE activity was also increased in the order of phorate (p=S,S)$(p=S,SO_2)<phoratoxon$ (p=O,S)$(P=O,SO_2)$. Acute oral $LD_{50}$ of phorate was 1.02mg/kg. After oral administration of phorate, the activity of plasma ChE was inhibited more rapidly then that of brain AChE, whereas recovery of plasma ChE activity was more rapid than that of brain AChE activity.

• Korean journal of applied entomology
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• v.26 no.3 s.72
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• pp.165-170
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• 1987

This experiment was carried out to evaluate the difference in the biochemical characteristic of the brown planthoppers of the insecticide risistant, susceptible strains and their hybrid progenies. Activity of the esterase isozyme separated by electrophoresis method was remarkably high in the resistant strain as compared with the susceptible strain. Esterase activity between the insecticide-treated strains and the non-insecticide strains was not degraded in the resistant strain and the $F_1$, but remarkably degraded in the susceptible strain. The increase of esterase activity was associated with the development of resistance, and that was inherited with a dominant gene.

• Korean Journal of Microbiology
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• v.35 no.1
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• pp.61-64
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• 1999

Organophosphorus inseclicide phosphamidon-degrading bacteria were isolated from agricultural soils and identified using Biolog microtiter assay. All Gram-positive degrading bacterial strains belong to genus Bacillus and many Gram-negative bacteria were rare soil species. Among them fast growing strains on phosphamidon-containing minimal medium were sclected and their biodegrading capability wcre measured. YD-17 which was identified as Capnocytophaga gingivalis showed the highest biodegradation rate. It could incrcase the removal of phosphamidon up to 52%. During the biodegradation continuous increase of amount of cell protein was observed, which indicated that phosphamidon was utilized as a carbon source for phosphamidon-degrading bacteria.

• Environmental Analysis Health and Toxicology
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• v.24 no.3
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• pp.231-240
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• 2009

We explored collective behaviors of indicator species to elucidate the effect of the chemical stress. After the treatments of an insecticide, diazinon, at low concentrations (1.0 and 10.0 ${\mu}g/L$), spatial dispersion patterns of Daphnia magna were checked in a test chamber. The I-index was used to characterize the movement data before (0~1 h) and after (1~2 h) the treatments in laboratory conditions. The slopes of the frequency distribution of I-index in semi-log scale decreased significantly, and the test populations appeared to be more dispersed with a lower degree of aggregation after the treatments. The index was feasible in indicating decrease in the ability of the specimens to keep desirable distances with neighbor individuals under chemical stress and showed a possibility of monitoring presence of toxic chemicals in environment through group behavior measurement.