• Korean journal of applied entomology
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• v.43 no.2
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• pp.175-180
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• 2004

This study was conducted to determine the effect of sublethal concentrations ($LC_{10}$ and $LC_{30}$) of insecticides on pupal duration, emergence, adult longevity and oviposition of tobacco cutworm, Spodoptera litura Fabricius, when 3rd instar larva of tobacco cutworm was treated with insecticides of chlorpyrifos, ethofenprox, chlorfenapyr-bifenthrin and hexaflumuron-chlorpyrifos . Pupal duration of female and male were 6.9 days and 8.0 days at untreatment, and were 7.2 to 7.6 days and 8.3 to 8.6 days at insecticide treatment, respectively. Thus pupal duration at the insecticide treatment was slightly longer than that at the untreatment, and that of the males was slightly longer than that of the females even though significant difference between sublethal concentrations and among insecticides was not observed. Percent mergence was 88％ at untreatment and ranged from 79％ to 95％, in particular which showed above 91％ treated with chlorfenapyr-bifenthrin and ethofenprox, at insecticide treatment. Adult longevity was 7.7 days and 7.9 days for female and male at untreatment respectively, and 7.1 to 8.4 days for female and 7.7 days to 9.0 days for male at treatment. There was a significant difference between insecticides and sublethal concentrations of insecticides except showed the longest adult longevity at hexaflumuron-chlolfyrifos treatment. Total number of eggs laid were less at treatment (778-948) than that (1,010) at untreatment regardless of sublethal concentrations of insecticides. Accordingly the pupal duration and oviposition of tobacco cutworm were affected at the insecticide treatment of sublethal concentration.

• The Korean Journal of Pesticide Science
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• v.15 no.2
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• pp.140-148
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• 2011

The official analytical method of residue pesticides in herbal medicines by KFDA cannot be applied to all of the pesticides and herbal medicines because of various active materials in herbal medicines and various physicochemical properties of pesticides. Moreover, liquid-liquid partition uses harmful solvents such as methylene chloride and is consuming a lot of time and effort. In order to improve the problems, we have studied for the availability of the analytical method applying the macroporous diatomaceous earth (MDE) column instead of liquid-liquid partition to simultaneously analyze five pesticides in two dried herbal medicines. The results showed that the recovery rates of acetamiprid and azoxystrobin in Astragalus root by GC/ECD ranged from 89.6 to 94.1%, from 86.8 to 94.4%, respectively, and those of bifenthrin, chlorfenapyr, chlorpyrifos in Cnidii Rhizoma by GC/MS ranged from 83.6 to 88.4%, from 77.4 to 83.8%, from 82.6 to 84.3%, respectively. Also, the coefficients of variation (CV) for triplication ranged from 0.5 to 1.7%. The results satisfied the criteria of residue pesticide analysis, setting 70~120% for the recovery rate and below 10% for the coefficient of variation. The improved methods are safer to residue pesticide analysts, faster and less laborious than the KFDA official method.

• 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.

• Journal of Food Hygiene and Safety
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• v.34 no.5
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• pp.421-430
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• 2019

In this study, 195 pesticide residues in fruit samples (n=150) at local markets in Chungcheongnam-do Chungnam, Korea were monitored using a multi-residue method combined with GC-MS/MS and LCMS/MS. Among 150 fruit samples, 40 types of pesticides were detected in 63 samples and the detection rate was 42.0%. However, the amounts were below the maximum residue limit (MRL). Detection rates for pesticides in each thpe of fruit were as follows ; citrus fruits (55.2%), pome fruits (41.3%), berries (38.7%) and stone fruits (36.0%). Although the sample size was small (n=2), pesticide residues were not detected in tropical fruits. Occurrences of detection of pesticide residues in apple showed the highest level, and mainly, insecticides were detected most frequently. The most commonly detected pesticides residues were bifenthrin (21), pyraclostrobin (17), novaluron (13), boscalid (10), chlorfenapyr (9), trifloxystrobin (9), furathiocarb (9), acetamiprid (8) and chlorpyrifos (8). Five types of residual pesticides (bifenthrin, chlorfenapyr, deltamethrin, fenpropathrin and fenvalerate) were detected in quince, and out of these five, fenpropathrin exceeded the MRL based on the Positive List System (PLS). These results suggested that pesticide residues in fruit samples should be continuously monitored, although residue levels in 63 other fruit samples were evaluated as being within a safe level.

• Korean journal of applied entomology
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• v.61 no.1
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• pp.267-274
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• 2022

Portable and vehicle thermal fogs were tested using etofenprox, bifenthrin, and deltamethrin diluted with diesel oil, kerosene, and water against domestic vector mosquitoes, Aedes albopictus, Anopheles sinensis s.l., Culex pipiens, and Culex tritaeniorhynchus. The female mosquitoes were confined in small cages suspended on poles at progressively greater distances from the fog release point at an open field. The average mortality rates of four vector mosquitoes to the three insecticides were 52.0% and 64.0% at a portable thermal fogs diluted with diesel oil and water within a 10 m distance, respectively. A vehicle thermal fog had a mean mortality of 34.8% of the females to the insecticides diluted with diesel oil within 50 m. The mortality rates were not significantly different among all the tested distances. At a dilution solvent test, the mortality of the females to the insecticides diluted with kerosene was 1.9 times higher than that of diesel oil.

• Korean journal of applied entomology
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• v.53 no.4
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• pp.457-460
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• 2014

Toxicity of several insecticides was tested against the brown marmorated stink bug, Halyomorpha halys (Hemiptera: Pentatomidae), and adult Gymnosoma rotundatum (Diptera: Tachinidae) in a sweet persimmon orchard. H. halys was captured using black light traps and G. rotundatum adults were collected using sticky traps lured with an aggregation pheromone, methyl-(E,E,Z)-2,4,6-decatrienoate of Plautia stali. Five insecticides, namely, bifenthrin 2 WP, buprofenzine+dinotefuran (20+15) WP, clothianidin 8 SC, dinotefuran 10 WP, and thiamethoxam 10 WP, were moderately toxic to G. rotundatum, resulting in 55.3% to 74.3% mortality. Bifenthrin 2 WP caused 93.1% mortality at 72 h within cages as a residual toxicity, and others caused varied mortalities.

• Weed & Turfgrass Science
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• v.5 no.1
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• pp.35-41
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• 2016

Earthworm cast is a harmful factor which reduces the uniformity of management of turfgrass and play quality in golf courses and playground. This research was conducted to carry out the efficacy of some pesticide (bifenthrin GR + clothianidin GR, ethoprophos GR, imidacloprid SC, picoxystrobin WG, thiophanate-methyl WP) and tee tree (Camellia oliefera) extracts against reducing earthworm cast in golf courses. All tested materials were acted reducing earthworm cast, thiophanate-methyl among them showed the highest effect reducing earthworm casts in golf courses. Tea tree extracts was occurred similar efficacy among tested chemical pesticides. However, pellet type byproduct of tea seed extract and liquid formulation of tea tree extract were better than granule formulation of them. Byproduct of tea seed and tea tree extract can be used for alternative biological management material for reducing earthworm cast in heavily casting occurrence area.

• Korean Journal of Environmental Agriculture
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• v.16 no.4
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• pp.373-381
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• 1997

In order to investigate the drift of pesticides sprayed on Chinese cabbage, 7 pesticides chlorpyrifos, EPN, pirimiphos-methyl, phenthoate, tetradifon, dicofol and bifenthrin were applied in two sets of field tests. The pesticide residues were quantified bar multiple-residue analysis, in which the recovery rate was 78${\sim}$92% and standard deviation was ${\pm}0.683{\sim}52%$. It was found that most of the tested pesticides were spread by drift to neighbouring area and brought about the contamination of the unsprayed crops. The extent of drift varied depending upon the pesticide, distance and wind direction. The mean residue levels on unsprayed crops were 0.66% at 3 meter distance, 0.10% at 6 m distance and 0.05% at 9 m distance from the applied area and the maximum level was 1.83% of the residue on sprayed crops.

• The Korean Journal of Pesticide Science
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• v.4 no.3
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• pp.75-81
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• 2000

These studies were carried out to investigate the toxicities of 38 registered insecticides to the sweetpotato whitefly (Trialeurodes vaporariorum). Insecticide activities were evaluated by testing systemic action and residual effect in the laboratory, and control efficacy in the greenhouse. All experiments were tested at the recommended concentration(ppm) of each insecticides. Insect growth regulators (IGRs), only pyriproxyfen showed over 90% of ovicidal effect. The insecticides that showed over 90% of larvicidal activity oil 3rd nymphal instars were abamectin, acetamiprid, chlorpyrifos-methyl, imidacloprid, pyripoxyfen, and acetamiprid+ethofenprox. Insecticides with 100% adulticidal activity were abamectin, acephate, acetamiprid, benfurcarb, bifenthrin, furathiocarb, endosulfan, fenitrothion, imidacloprid, phenthoate, pymetrozine, acetamiprid + ethofenprox, ethofenprox + diazinon, furathiocarb + difluberlzuron, and triazamate+${\alpha}$-cypermethrin. Abamectin, acetamiprid, imidacloprid, pyriproxyfen, and acetamiprid + ethofenpox showed both residual effect and systemic activity. In tile control efficacy test on B. tabaci, 90% control values were obtained at 11th day after treatment of the insecticides including abamectin, acetamiprid, imidacloprid, pyripoxyfen and acetamiprid + ethofenprox. These results indicate that abamectin, acetamiprid, imidacloprid, pyriproxyfen and acetamiprid + ethofenprox can be used for tile control of B. tabaci in field.

• Korean journal of applied entomology
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• v.60 no.2
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• pp.229-234
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• 2021

This study investigated spray patterns and coverage generated by three types of commercial nozzles for spraying pesticides with Unmanned Aerial Vehicles (UAVs) using a multi-copter. Flufenoxuron+metaflumizone SC and bifenthrin EC were sprayed. The falling particles of the spraying agent were measured using WSP (Water and oil Sensitive Paper) and the coverage was determined. The results showed that the uniformity of falling particles was different according to the difference in wind strength, and there was no difference for different formulations. The injection amount for each nozzle was found to be different from the official information provided by the manufacturers. These results could be used to establish guidelines for the control of UAVs and pesticide registration testing.