• Korean journal of applied entomology
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• v.19 no.2 s.43
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• pp.79-83
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• 1980

The toxicities of some soil insecticides were evaluated in terms of the tolerance to various larval-ins tars of the common cutworm (Agrotis fucosa Butler) using topical application method in the laboratory. $LD_{50}$ values(ug/larva) were determined by the probit analysis and the tolerance-values were obtained with '$LD_{50}$ values for from 2nd-to 6th-instars/$LD_{50}$ values for first-instars.' The relative toxicities of the insecticides were 31so compared with the $LD_{50}$ values for the instars. The degree of tolerance was greatly increased as the larval instar advanced; the ranges of tolerance between the first-and 6th-instar larvae to the insecticides phoxim (Volaton), diazinon, chlorpyrifos (Dursban), carbofuran (Curaterr) and Mocap were 251.6, 126.6, 97.5, 44.3, and 18.7 times, respectively. The average relative toxicities of the insecticides for the instars indicated that the toxicity of phoxim was the greatest and following carbofuran, chlorpyrifos, Mocap and diazinon.

• 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.46 no.3
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• pp.415-423
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• 2007

For the development of integrated pest management system by harmonizing biological and chemical control, some experiments were carried out to select low toxic pesticides and to evaluate residual toxicity to natural enemies. Leaf dipping method and body dipping method were set up for evaluating toxicity to minute pirate bug, Orius strigicollis adult. We had tested 52 kinds of pesticides (33 insecticides, 19 fungicides) commonly used to control greenhouse insects, mites, and disease pests to natural enemies at the recommended concentration. Fourteen insecticides by body dipping method, 12 insecticides by leaf dipping method and 19 fungicides were selected as low toxic pesticides to O. strigicollis adult. After insecticide spraying at recommending dose on the sweet pepper plant, we examined residual effect of insecticides by introducing natural enemies on different days. Safety interval for introduction of O. strigicollis adult was established according to residual toxicity of pesticides. Safety insecticides at one day after treatment were pyraclofos, methomyl, thiodicarb, esfenvalerate bifenthrin, alpha-cypermethrin, etofenprox, fenvalerate, imidacloprid, acetamiprid, abamectin, emamectin benzoate, spinosad, indoxacarb. However, residual toxicity of nee-nicotinoids last up to 21 days to O. strigicollis adults.

• 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.

• Korean journal of applied entomology
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• v.3
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• pp.41-44
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• 1964

1. This experiment was planned to compare the effectiveness of Diazinon granular and gammadol dust with the low toxic organophosphorus insecticides applied on the water-surface for the control of the rice stem borer, Chilo suppressalis Walker, in the 2 nd generation and to determine the proper timing of those insecticidal applications at Suwon, Korea, in 1964. 2. The hatching larvae from the eggs were inoculated on the rice plants in pots and insecticides were applied on the water-surface of pots at a given day intervals. The dose of insecticides used per pot was calculated from the 120g. as a actual ingredient per 10 a. The number of living larvae was observed at the 20 days later from the inoculation (as shown in Table 1.). 3. As shown in Table 2 and 3, there was highly significance between the chemicals and L.S.D. was 24.22. The best effectiveness was Diazinon granular and 2nd was gamma-dol dust. The organophosphorus emulsion concentrations used in this experiment were less effective than two other insecticides. Although there were some suspicious results according to the day intervals inoculated, the order of effectiveness was Diazinon>gamma-dol>Sumithion>EM>EPN> Cidial as the total moan. 4, As shown in Table 2 and 3, there was no significance between the timing of insecticidal applications, but, m the whole, Diazinon granular was most effective at a given day intervals in this experiment and gamma-dol also was effective at the day Plot inoculated. The proper timing of EPN, EM, and Cidial seemed to be at e day plot inoculated and that of Sumithion at the day plot before inoculation.

• 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.

• The Korean Journal of Pesticide Science
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• v.5 no.2
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• pp.62-66
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• 2001

The thirteen commercial insecticides to Lycoriella mali were investigated on their insecticidal activities and mycelial growth of two Letinula edodes strains. For the adults, insecticides showing over 95% insecticidal activity were chlorpyrifos-methyl, fenthion, fenitrothion, benfuracarb, furathiocarb and deltamethrin. For tile larvae, diflubenzuron and cyromazine showed over 90% insecticidal activity. Fenthion, benfuracarb, furathiocarb, deltamethrin, diflubenzuron and cyromazine did not affect the mycelial growth of L. edodes strain, in Imhyup 1 variety. And deltamethrin, diflubenzuron and cyromazine did not affect that in Sanlim-5. Insecticides showing over 80% residual effect for 14 days were benfuracarb to the adults and diflubenzuron and cyromazine to the larvae. Control effect of furathiocarb, fenthion, benfuracarb, deltamethrin, diflubenzuron and cyromazine against larvae of Lycoriella mali showed 90% ten days after application under sawdust cultivation. Among them, benfuracarb, fenthion and furathiocarb revealed excellent control effect against adults. These results indicate that benfuracarb, fenthion, and furathiocarb can be used for the control of Lycoriella mali in the field. However, further studies are needed on the effect of insecticides treatment oil fruit-body yield and chemical residue in the mushroom tissues.

• Korean journal of applied entomology
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• v.60 no.4
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• pp.431-448
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• 2021

We decided the efficient application timings of organo-synthetic insecticides for controlling the first generation larvae of O. furnacalis through investigations of insect stage-specific densities, damage aspects in maize, and effects of insecticides. A waxy maize cultivar, Ilmichal, was cultivated from April 20 (sowing) to July 26 (harvest, dough stage of maize) in Suwon, 2016. The maximum and 50% cumulative catch dates of the overwintering generation adults in the sex pheromone trapping were May 29 and May 31, respectively. Most of the first generation larvae finished their occurrence till the early reproductive stage of maize. The first generation larvae fed on leaves inside the whorl leaves before tassel and stem development of maize, sequentially moved to tassel and stem, and then moved finally to stem and ear parts. In the results of insecticide applications at different dates, the 9-11 leaf stage (June 10~17) and the 6-7 leaf stage (June 3) of maize were the most efficient application timings for direct spray of Etofenprox EC to maize, and for application of Carbofuran granules onto soil surface, respectively, which resulted in suppression of tunnelling damages. The timings for the two insecticides were 12-19 days and 5 days after the adult maximum catch date, respectively. Those timings after the 50% cumulative adult catch date were advanced 2 days.

• Korean journal of applied entomology
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• v.58 no.3
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• pp.251-258
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• 2019

A series of studies were conducted to monitor the seasonal occurrences of onion thrips (Thrips tabaci) and allium leafminers (Acrolepiopsis sapporensis) in northern-type garlic fields, and to evaluate their susceptibility to insecticides. The results showed that the T. tabaci population density increased from mid- March to mid-June, that of A. sapporensis began to increase in mid-March and peaked twice by early July. Also, using recommended concentrations, the insecticidal activities of nine insecticides against these two pests were evaluated. Under laboratory conditions, clothianidin SC, chlorfenapyr EC, dimethoate EC, imidacloprid WP, and cyantraniliprole + thiamethoxam WG insecticidal activities against T. tabaci were all 100%, as well as. those of cyantraniliprole EC, pyridalyl EW, spinetoram SG and abamectin + chlorantraniliprole SC against A. sapporensis. Insecticides, with high insecticidal activities, were evaluated on the two pests under laboratory conditions, and the results showed that all the insecticides exhibited strong insecticidal activities, and the mortality of two pests was >90%.

• Korean journal of applied entomology
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• v.63 no.1
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• pp.53-61
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• 2024

The susceptibility of Aphis gossypii populations collected from three fields (WJ, CC, and GS) was evaluated to three insecticides (afidopyropen, chlorfenapyr and cyantraniliprole) and three binary mixtures. Three field populations showed resistance ratios of over 100 to all insecticides. The Combination Index (CI), %M_(synergism), Co-Toxicity Coefficient (CTC), Wadley Ratio (WR), Synergism Ratio (SR) and Abbott Ratio (AR) were used to evaluate combined effect of the insecticides. Afidopyropen + chlorfenapyr (CI ≤ 0.16; %M_(synergism) ≥ 94; CTC ≥ 764.5; WR ≥ 6.4; SR ≥ 6.9 and AR ≥ 1.1) showed a synergism in all filed populations. WJ and CC populations showed a synergism in all binary mixtures of insecticides, but GS population showed an antagonism for chlorfenapyr + cyantraniliprole (CI, 1.63; %M_(synergism), 30; CTC, 64.0; WR, 0.6 and AR, 0.54) and afidopyropen + cyantraniliprole (CI, 6.7; %M_(synergism), 1; CTC, 19.8; WR, 0.2 and AR ≤ 0.55). All mixtures (afidopyropen + chlorfenapyr, chlorfenapyr + cyantraniliprole and afidopyropen + cyantraniliprole) showed a control value of over 99% after 21 days of treatment in the field. This study highlights that binary mixtures of three insecticides serve as an effective control strategy for A. gossypii.