• Mass Spectrometry Letters
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• v.9 no.4
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• pp.100-104
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• 2018

As a part of efforts to establish the positive list system (PLS) in South Korea, a method to determine residual emamectin benzoate (EB) in various aquatic products using QuEChERS-EDTA and LC-MRM was developed. The developed method was validated in the aspects of specificity, linearity (correlation coefficient of at least 0.996), sensitivity (the limit of detection and the lower limit of quantitation ${\leq}5ng/g$), recovery (the recovery range of 87.4 and 96.2), and precision (the relative standard deviation of recovery between 0.9 and 13.5). Additionally, the validated method was successfully applied for monitoring EB contamination in eel, halibut, and shrimp collected from local food markets. To our knowledge, the present method is the first one to determine residual EB in various aquatic products at the level satisfying the PLS and could contribute to the establishment of the PLS in South Korea.

• Korean journal of applied entomology
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• v.51 no.2
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• pp.153-156
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• 2012

Surveys were conducted on the occurrence of nematodes in the root systems of 1-3-year old Cymbidium hybida Swartz cultivated for export in Korea. The most frequently detected plant-parasitic nematode was Ditylenchus sp. with 4.7, 43.7, and 49.7/200 cc growth medium in 1, 2, and 3 year-old cymbidiums, respectively. And the densities of non-parasitic nematodes, dorylaimids, were 35.3, 70.5, and 155.8/200 cc growth medium in 1, 2, and 3-year-old cymbidiums, respectively. Three-year-old cymbidiums collected from Siheung, Ansan, and Gimpo had low densities of Aphelenchus sp. and Aphelenchoides sp. with under 40 individuals/pot, and the dorylaimid densities were 56-824/pot. To evaluate the effects of nematicides on Ditylenchus sp. in cymbidium, Emamectin benzoate EC, Fosthiazate SL, and Cadusafos CS were tested at two farms in Ansan and Gimpo. Emamectin benzoate EC showed control effects of 75.7 and 89.5%, whereas Fosthiazate SL and Cadusafos CS showed 27.2 and 65.3% and 30.1 and 90.5% control effects in the tests.

• The Korean Journal of Pesticide Science
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• v.16 no.4
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• pp.350-356
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• 2012

Performance of proficiency testing and the validation of analytical method was included a scheme of quality assurance in analytical chemistry laboratory to monitor a laboratory's performance abilities and produce consistently reliable data. This study was assessed the applicability of proficiency testing scheme proposed for analytical laboratories of pesticide product in domestic. The validation of analytical methods, stability and homogeneity for formulated pesticide products (emulsifiable concentrate) of emamectin benzoate and lufenuron was confirmed for the proficiency testing. The z-score of 33 participation laboratories for emamectin benzoate were that the numbers of outlier were 2 laboratories (6.0%), z-score outside the range from -3 to 3 designated "unaccptable" were 2 laboratories and z-score in the ranges -2 to -3 and 2 to 3 designated "questionable" were 3 laboratories (9.0%). Three laboratories (9.0%) showed the z-score designated "questionable" for lufenuron. The additional proficiency testing for various product types will be needed to establish the scheme of quality control.

• Korean journal of applied entomology
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• v.44 no.2
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• pp.151-156
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• 2005

The development of resistance to bifenazate (resistance ratio of egg=40.3 folds) was found in population of the twospotted spider mite, Tetranychus urticae, collected from rose greenhouses in Chilgok, Gyeongbuk Province in December 2000. This population was selected for 4 years with bifenazate treatment (over 150 times), and showed 248.8 folds increase in resistance as compared to susceptible (S) strain. Inheritance of bifenazate resistant strain (R) and cross resistance of this strain to 9 acaricides were investigated. There were differences of susceptibility in the bifenazate concentration-mortality relationships in F1 progenies obtained from reciprocal cross with the S and R strain $(R{\times}S,\;S{\times}R)$. Degrees of dominance were 0.48 and 0.94 in adult females and eggs of $R{\times}S$ and -0.85 and -0.17 in adult females and eggs of $S{\times}R$, respectively. Inheritance type in the F1 progeny of $R{\times}S$ was incomplete dominant, and F1 progeny of $S{\times}R$ was incomplete recessive. These results suggest that inheritance of bifenazate resistance is controlled by a complete dominance. The R strain exhibited cross resistance to acequinocyl and fenpyroximate in adult females, and amitraz, emamectin benzoate, fenpyroximate, milbemectin, pyridaben and spirodiclofen in eggs. However they showed negatively correlated cross-resistance to emamectin benzoate and milbemectin in adult females, and abamectin in eggs.

• Korean Journal of Environmental Biology
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• v.35 no.4
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• pp.557-565
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• 2017

For our survey of insecticidal resistance of Palm thrips (Thrips palmi Karny), we established the discriminating time (DT) and concentration (DC) of nine insecticides, and we conducted a bioassay about seven local populations via leaf-dipping methods. The discriminating times of the recommended concentration (RC) were 24 h at emamectin benzoate EC and spinetoram SC, 48 h at chlorfenapyr EC, 72 h at spinosad SC, cyantraniliprole EC, acetamiprid WP, dinotefuran WG, imidacloprid WP and thiacloprid SC after treatment. The DC estimated the concentration which showed the difference within the mortalities of these local populations. The DCs were emamectin benzoate EC $0.013mg\;L^{-1}$ (RC, $10.8mg\;L^{-1}$), spinetoram SC $0.125mg\;L^{-1}$ (RC, $25.0mg\;L^{-1}$), chlorfenapyr EC $0.25mg\;L^{-1}$ (RC, $50.0mg\;L^{-1}$), spinosad SC $0.083mg\;L^{-1}$ (RC, $50.0mg\;L^{-1}$) and cyantraniliprole EC $5.0mg\;L^{-1}$ (RC, $50.0mg\;L^{-1}$), and DCs of neonicotinoids were their RCs, that is, acetamiprid WP (RC, $40.0mg\;L^{-1}$), dinotefuran WG (RC, $20.0mg\;L^{-1}$), imidacloprid WP(RC, $50.0mg\;L^{-1}$) and thiacloprid SC (RC, $50.0mg\;L^{-1}$). From our investigation into the resistance of the local populations with DT and DC application, the neonicotinoid insecticides have shown a high resistant level for all the local populations, and the other insecticides have demonstrated low or non-resistance. In the use of neonicotinoid insecticides to control Palm thrips, one must take caution. As a result, the establishment of DT and DC in the single dose bioassay method was helpful for surveying the insecticide response dynamics and the development of an insecticide resistance management strategy.

• The Korean Journal of Mycology
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• v.46 no.3
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• pp.271-280
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• 2018

The ectomycorrhizal basidiomycete Tricholoma is one of mushroom groups that cannot be cultivated artificially. To use this mushroom as applicable resource for food production, it is necessary to obtain information about their mycelial growth properties in various environmental conditions. This study investigated the mycelial growth of four domestic isolates of Tricholoma species (T. bakamatsutake, T. fulvocastaneum, T. matsutake, T. terreum) at different physical and chemical conditions. The optimal physical conditions for their mycelia growth were found to be a temperature range of $20{\sim}25^{\circ}C$ and a pH range of 4.0~7.0 in dark condition. The growth of T. matsutake was retarded at high temperature ($30^{\circ}C$). Tests to determine the chemical factors that affected mycelial growth showed that the four Tricholoma spp. grew 1% saline. T. matsutake grew in up to 2% saline. In the presence of various heavy metals (50 ppm) and pesticides (suppliers' recommended concentration), mycelial growth was inhibited the most by cadmium and emamectin benzoate, respectively. However, all the four Tricholoma spp. grew with $Cu^+$. The growth of T. matsutake was not inhibited by abamectin, acetamiprid, and thiacloprid. Extracellular enzyme activities of amylase and ${\beta}$-glucosidase were detected only in T. bakamatsutake and T. fulvocastaneum. The results of the present study allowed us to determine suitable or harmful environmental conditions for the mycelial cultivation of the Tricholoma spp.

• Korean journal of applied entomology
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• v.52 no.3
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• pp.161-169
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• 2013

From the results achieved by the evaluation of toxicities to an aphid predator, Aphidoletes aphidimyza Rondani eggs with 47 pesticides used for cucumber farming, 22 pesticides including emamectin benzoate showed low toxicity. 12 pesticides with flonicamid among 22 pesticides tested on eggs showed low toxicity (mortality, 0~2.7%) to A. aphidimyza lavae and indoxacarb + teflubenzuron and chlorantraniliprole showed toxicity of 35.4% and 64.6%, respectively. 14 pesticides including indoxacarb + teflubenzuron and chlorantraniliprole demontrating low toxicity against A. aphidimyza lavae showed low toxicity to A. aphidimyza pupae and adults as well.

• Korean journal of applied entomology
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• v.61 no.2
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• pp.299-305
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• 2022

We investigated the occurrence and damage information of 9 species (7 families) of insect pests in two places of rucola (Eruca sativa Mill.) cultivated houses in Gyeonggi Province from 2019 to 2021, and selected five insecticides that could efficiently control the beet armyworm, Spodoptera exigua. Five insecticides (spineram SC, fluxametamide EC, chlorantraniliprole WG, cyantraniliprole DC, and emamectin benzoate EC) showed high control effects over 95% against 3^rd instar larvae of S. exigua at the two places of rucola cultivation, and there was no phytotoxicity at double dose of concentration.

• The Plant Pathology Journal
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• v.39 no.1
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• pp.75-87
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• 2023

The pine wood nematode (PWN), Bursaphelenchus xylophilus is a well-known devastating pathogen of economic importance in the Republic of Korea and other countries. In the Republic of Korea, trunk injection of nematicides is the preferred method of control. In this study, the efficacy of 16 locally produced formulations of emamectin benzoate against the PWN are compared through determining their sublethal toxicities and reproduction inhibition potentials. Nematodes were treated with varying concentrations of the tested chemicals in multi-well culture plates, and rates of paralysis and mortality were determined after 24 h. Reproduction inhibition potential was tested by inoculating pre-treated nematodes onto Botrytis cinerea, and in pine twig cuttings. Despite the uniformity in the concentration of the active ingredient, efficacy was contrastingly different among formulations. The formulations evidently conformed to three distinct groups based on similarities in sublethal activity (group 1: LC₉₅ of 0.00768-0.01443 mg/ ml; group 2: LC₉₅ of 0.03202-0.07236 mg/ml, and group 3: LC₉₅ of as high as 0.30643-0.40811 mg/ml). Nematode paralysis generally occurred at the application dose of 0.0134-0.1075 ㎍/ml, and there were significant differences in nematode paralysis rates among the products. Nematode reproduction was only evident at lower doses both on B. cinerea and pine twigs, albeit the variations among formulations. Group 1 formulations significantly reduced nematode reproduction even at a lower dose of 0.001075 ㎍/ml. The variations in efficacy might be attributed to differences in inert ingredients. Therefore, there is need to analyze the potential antagonistic effects of the large number of additives used in formulations.

• The Korean Journal of Pesticide Science
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• v.17 no.3
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• pp.185-192
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• 2013

This study was performed to evaluate the spray toxicity and leaf residual toxicity of 52 kinds of insecticides registered for strawberry against adult honeybee Apis mellifera. According to the IOBC standard, the acute toxicity by spraying showed below 30% was classified as non-toxic. Among tested insecticides, 32 insecticides (flonicamid, lufenuron, novaluron, three kinds of acetamiprid, thiacloprid, milbemectin, acequinocyl, TBI-1, two kinds of chlorfenapyr, chlorfluazuron, cyenopyrafen, cyfumetofen, etoxazole, fenpyroximate, flubendiamide, flufenoxuron, hexythiazox, metaflumizone, two kinds of methoxyfenozide, DBB-2032, pyridalyl, spiromesifen, tebufenpyrad, teflubenzuron, acetamiprid + methoxyfenozide, acrinathrin + spiromesifen, bifenazate + spiromesifen, cyenopyrafen + flufenoxuron) did not show any toxic effect, it is thought to be safe. And the others (20 insecticides) showed higher toxicity to honeybee. Insecticides which showed acute toxicity higher than 90% was selected and tested the residual toxicity. All insecticides except emamectin benzoate EC, and indoxacarb SC showed 100% mortality at one day after treatment (DAT). However, the toxicities of emamectin benzoate, indoxacarb SC, and abamectin did not show until 3, 7, 14 DAT, respectively. Nine insecticides such as indoxacarb WP, thiamethoxam WG, abamectin + chlorantraniliprole SC, acetamiprid + etofenprox WP, acetamiprid + indoxacarb WP, bifenthrin + clothianidin SC, bifenthrin + imidacloprid WP, bifenazate + pyridaben SC, chlorfenapyr + clothianidin SC showed over 90% residual toxicity until 31 Day. In pouring treatment, thiamethoxam WG showed 76.9% mortality at 28 DAT and 50.0% mortality at 31 DAT. After 35 days, thiamethoxam WG showed no effect to honeybee. Bifenthrin + clothianidin SC and tefluthrin + thiamethoxam GR showed 57.1 and 80.0% mortality at 24 DAT, respectively. In spraying treatment, thiamethoxam WG and bifenthrin+clothianidin SC showed very high residual toxicity with 100% mortality in thirty-five DAT. After spraying treatment with thiamethoxam WG, bifenthrin+clothianidin SC, bifenthrin + imidacloprid WP, thiamethoxam WG showed 100% residual toxicity until 21 DAT and there was no activity after 28 DAT. Bifenthrin+clothianidin SC and bifenthrin+imidacloprid WP showed very high residual toxicity until 49 DAT.