• The Korean Journal of Pesticide Science
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• v.11 no.3
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• pp.179-185
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• 2007

Esterase isozymes were investigated from digestive juice of M. saltuarius adults after pesticide treatment. Twelve esterase isozymes were separated on 12% native-PAGE gel and stained with three different substrates(${\alpha}$-naphthyl acetate, ${\beta}$-naphthyl acetate, and ${\alpha}$-naphthyl butyrate). Interestingly, the isozyme of Est1(${\alpha}$-naphthyl acetate) was strongly inhibited by the carbofuran and methomyl. The Est1 activity was completely inhibited by the chlorpyrifos and partially inhibited by methidation about 70 %. In addition, eserine suppressed esterase isozyme activities of Est1 about 70% and isozyme activities of Est2, Est3, and Est4 were weakly inhibited. ${\alpha}$-pinene did not suppressed esterase isozyme activities but activities of esterases were very weakly inhibited in camphor and bornyl acetate.

• Korean Journal of Environmental Agriculture
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• v.24 no.3
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• pp.289-294
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• 2005

The toxic effects of 12 commercially available insecticides on the earthworm, Eisenia fetida (Savigny), were evaluated using artificial soil, surface sprayed soil, immersion, and contact filter tests. The risk to earthworm was assessed by the TER (toxic exposure ratio) value, which was calculated by the formula, TER=NOEC/PEC (predicted environmental concentration). TER was 3 for methomyl SL, 20 for carbaryl WP, 20 for phosphamidon SL, 30 for imidacloprid WP, and 60 for dichlorvos EC the in artificial soil test. At recommended, the earthworm mortality to methomyl SL reached 50% in the surface sprayed soil test, 72% in the immersion test, 30% in the contact filter paper test, whereas that to imidacloprid WP reached 56, 32, and 100 respectively. As a result of the four methods, methomyl SL and imidacloprid WP would be toxic insecticides to earthworm.

• 월간산업보건
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• s.103
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• pp.28-29
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• 1996

• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.1
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• pp.17-19
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• 2003

The purpose of this study was to evaluate the effect of pesticides on insect pest control of Rhophalosiphum nymphaeae, growth characteristies and dry root yield from the cultivated after early maturing rice cropping. All pesticides treated had no effect on the growh period, flowering rate of Alisma plantago. The major pesticides were methomyl-Lf, 24.1 %, imidacloprid-Wp, 10%, carbosulfan-Wp, 20%, and methomyl-Wp, 45%. Dry yield of root were increased largely with imidacloprid-Wp, 10% (10g/20$\ell$), pesticide than the other pesticides and control. All pesticides were had no injury with recommended concentration. On the other hand all pesticides were slightly harmful in the double dosage level for the Alisma plantago.

• The Korean Journal of Pesticide Science
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• v.12 no.4
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• pp.382-390
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• 2008

This study was performed to evaluate the acute toxicity and residual toxicity of the 69 kinds of agrochemicals (41 insecticides, 18 fungicides, and 10 acaricides) against honeybee, Apis mellifera and bumblebee, Bombus terrestris. According to the IOBC standard, the toxicity showed below 30% was classified as non-toxic. Among 41 insecticides, five insecticides (acetamiprid, chlorfenapyr, thiacloprid, milbemectin, and buprofezin+amitraz) against the honeybee; eight insecticides (methomyl, thiodicarb, acetamiprid, chlorfenapyr, thiacloprid, abamectin, spino sad, buprofezin+amitraz) against the bumblebee did not show any toxic effect. Therefore, it thought to being safe. Other 18 fungicides and 10 acaricides were safe against the honeybee and bumblebee. In residual toxicity against the honeybee, eight insecticides (dichlorvos, methomyl, imidachlorprid, emamectin benzoate, spinosad, cartap hydrochloride, chlorfenapyr, and endosulfan) among 41 insecticides tested were safe at three days after treatment; however, sixteen insecticides (dimethoate, fenitrothion, fenthion, methidathion, phenthoate, pyraclofos, fenpropathrin, clothianidin, dinotefuran, thiamethoxam, abamectin, acetamiprid+ethofenprox, acetamiprid+indoxacarb, bifenthrin+imidacloprid, ethofenprox+phenthoate, imidacloprid+methiocarb) still remain high toxicity at eleven days after treatment. Against the bumblebee, residual toxicity showed as safe in seven insecticides (dimethoate, methidation, a-cypermethion, ethofenprox, indoxcarb, chlorpyrifos+a-cypennethrin, esfenvalerate+fenitrochion) at three days after treatment; however, eight insecticides (fenitrothion, pyraclofos, clothianidin, fipronil, acetamiprid+ethofenprox, chlorpyrifos+bifenthrin, ethofenprox+phenthoate, imidacloprid+methiocarb) still showed high toxicity at seven days after treatment. From above results, it will be useful information to select insecticides being safe and effective against the honeybee and bumblebee.

• Korean journal of applied entomology
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• v.38 no.1
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• pp.53-57
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• 1999

Simple diagnostic kits for monitoring insecticide susceptibility of beet armyworm, Spodoptera exigua (Hiibner) were developed and applied to the field populations. The operation of the kits was based on the correlations between enzyme activities of esterase (EST) and acetylcholinesterase (AChE) and the insecticide susceptibilities. Four different kinds of diagnostic kits (ED, EM, AD, and AM) were designed and classified by diagnostic enzymes (E for esterases and A for acetylcholinesterase) and inhibitors (D for dichlorvos and M for monocrotophos). Diagnostic inhibitor concentrations were 1 mM for ED, 10 mM for EM, 100 mM for AD, and 100 mM for AM. Resistant larvae which were not inhibited by the diagnostic amounts of insecticides developed positive staining (red color), but susceptible~ s howed negative (no color). An insect was used for both EST and AChE diagnostic kits, but different in their samples: hemolymph for EST and the head for AChE. These four diagnostic kits were applied to 1 1 different populations which showed variations of insecticide susceptibilities. Four kits were different in the capability discriminating the insecticide susceptibilites according to insecticides: ED to bifenthrin, AD to methomyl, and ED and AM to chlorpyrifos-methyl. These diagnostic devices can be used for insecticide-resistance management program for this insect pest. It also provide a technical guide to insect pest management for farmers, directors, and researchers.

• The Korean Journal of Pesticide Science
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• v.8 no.3
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• pp.184-188
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• 2004

The residue analysis of the insecticide thiodicarb in sweet persimmon was analyzed with a gas chromatograph equipped with nitrogen phosphorus detector(NPD) to evaluate efficacy of analysis method and safety of thiodicarb in persimmon. Minimum detectable amount of methomyl oxime, hydrolysate of thiodicarb, was 0.2 ng and detection limit of thiodicarb was 0.05 ppm. The mean recoveries evaluated from untreated samples spiked at 0.5 ppm and 2.5 ppm were $93.9{\pm}3.9$ and $92.8{\pm}2.0%$, respectively. When thiodicarb was sprayed onto the sweet persimmon two times until 40 and 30 days before harvest, three times until 40, 30 and 21 days before harvest, and four times until 40, 30, 21 and 14 days before harvesting, the mean residual amount in sweet persimmon were $1.50{\pm}0.04$, $1.86{\pm}0.04$ and $2.11{\pm}0.12$ ppm, respectively. It would be safe when thiodicarb 40% WP is treated four times 14 days before harvesting to control fruit moth in sweet persimmon.

• The Korean Journal of Pesticide Science
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• v.15 no.3
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• pp.329-334
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• 2011

Insecticidal activity of 31 registered insecticides was tested against Metcalfa pruinosa adults. All experiments were conducted at the recommended concentration (ppm) of each insecticide. Among them, 16 insecticides from organophosphates (dichlorvos, fenitrothion, fenthion, methidathion, phenthoate), carbamates (methomyl), pyrethroids (${\alpha}$-cypemethrin, deltamethrin, fenpropathrin, ${\gamma}$-cyhalothrin), neonicotinoids (acetamiprid, clothianidin, dinotefuran, imidacloprid, thiamethoxam), and other (endosulfan) showed 100% mortality by spraying on the body of M. pruinosa adults. Dichlorvos, fenitrothion, fenthion, methidathion, phenthoate and endosulfan showed 100% mortality by plant-dipping method. The residual effect was showed 100% mortality in four insecticides (fenitrothion, fenthion, methidathion, phenthoate) at one day after treatment, and three insecticides (fenitrothion, methidathion, phenthoate) were showed the mortality of 90% at three days after treatment.

• The Korean Journal of Pesticide Science
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• v.13 no.4
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• pp.216-222
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• 2009

The present study aims to monitor pesticide residues in cut flowers collected from the farms and markets. Cut flowers used in this study included rose, lily and chrysanthemum collected from June to September, 2008. Samples were collected once from farms in Hwasung, Goyang (Gyeonggi-do), Inje (Gangwon-do) and thrice from wholesale market in Namdaemunm, Yangjae and Gangnam (Seoul). Total of 24 pesticides (12 fungicides, 11 pesticides and 1 acaricide) were detected from samples collected from farm and total of 64 pesticides (25 fungicides, 36 pesticides, 1 acaricide and 2 fungicides) were detected from samples collected from wholesale market. The highest detection frequency of pesticide from farm was for carbaryl (15%) and for boscalid, fluacrypyrin, fluquinconazole, methomyl, pyraclostrobin, trifloxystrohin (10%), with overall detection of $0.1-36.99\;mg\;kg^{-1}$. While the highest detection frequency of pesticides from wholesale market was for carbaryl, fluquinoconazole and kresoxim-methyl (18.52%), methomyl (16.6%), and methiocarb and thiacloprid (12.96%) with overall detection amount of $0.1-56.2\;mg\;kg^{-1}$. Higher amount of pesticides were detected in leaves than in flowers. Among the pesticides detected, detection frequency of unregistered pesticides for rose, chrysanthemum and lily was 55%, 60% and 63% collected from farms and 47%, 60% and 89% collected from markets, respectively. These pesticides require registration and further monitoring in floricultural crops.

• Korean Journal of Environmental Agriculture
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• v.34 no.4
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• pp.274-281
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• 2015

BACKGROUND: A lasting release of low levels of persistence chemicals including pesticides and pharmaceuticals into river has a bad influence on aquatic ecosystems and humans. The present study monitored pesticide residues in the Yeongsan and Seomjin river basins and their tributaries as a fundamental study for water quality standard of pesticides.METHODS AND RESULTS: Nine pesticides(aldicarb, carbaryl, carbofuran, chlorpyrifos, 2,4-D, MCPA, methomyl, metolachlor, and molinate) were determined from water samples using SPE-Oasis HLB(pH 2) and LC/MS/MS. Validation of the method was conducted through matrix-matched internal calibration curve, method detection limit(MDL), limit of quantification(LOQ), accuracy, precision, and recovery. MDLs of all pesticides satisfied the GV/10 values. Linearity(r²) was 0.9965- 0.9999, and a percentage of accuracy, precision, and recovery was 89.4-113.6%, 3.1-14.0%, and 90.8-106.2%, respectively. All pesticides exclusive of aldicarb were determined in the river samples, and there was a connection between the positive monitoring results and agricultural use of the pesticides.CONCLUSION: Monitoring outcomes of the present study implied that pesticides were a possible non-point pollutant source in the Yeongsan and Seomjin river basins and tributaries. Therefore, it is required to produce and accumulate more monitoring results on pesticides in river waters to set water quality standards, finally to preserve aquatic ecosystems.