• The Korean Journal of Pesticide Science
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• v.3 no.2
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• pp.69-73
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• 1999

The insecticidal activities and residues of chlorfenapyr [4-bromo-2-(4-chlorophenyl)-1-ethoxymethyl-5-trifluorornethyl pyrrole-3-carbonitrile] against Thrips palmi was evaluated under laboratory and vinyl house conditions. Effectiveness of chlorfenapyr against T. palmi on red pepper leaves was lasted for 9 days at a concentration of 50 ppm but there was no significant differences between emulsifiable concentration and wettable granule under laboratory conditions. In vinyl house, high toxicity was investigated at 6 hours after application of chlorfenapyr in a concentration of 50 and 100 ppm and insecticidal effect was maintained for 11days after 2 times weekly application in cucumber. Control effect was above 97% against T. palmi larva and larva+adults after 2 times weekly application in vinyl house.

• Korean Journal of Plant Resources
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• v.33 no.6
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• pp.615-623
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• 2020

Brassica rapa is one of the most valuable vegetable crops worldwide. Cultivated varieties of B. rapa exhibit diverse developmental and morphological appearances, which includes important vegetables, oilseeds, and fodder crops. In this study, various phenotypes of recombinant inbred lines (RILs) of B. rapa were investigated, including their responses to five different pathogenic Botrytis cinerea isolates, responses to aphid and thrips during flowering stages, days to flowering, and plant heights. Responses of 113 RILs to five different B. cinerea isolates showed variations, suggesting that genetic factors controlling resistance or tolerance against each isolate were dependent on isolate/genotype pairs. Correlation analysis was performed to understand the nature of genetic factors and the relationship among these phenotypes. Although high levels of correlation were not detected between phenotypes assessed in this study, statistically significant correlation was detected for several combinations. Significant positive correlations were found for different B. cinerea isolates, supporting that certain levels of commonality could exist in genetic components controlling resistance against different B. cinerea isolates. Based on correlation analysis using numbers of insects counted on plants, it was speculated that genetic factors responsible for aphid tolerance or repellence might be also involved in the response against thrips. Relationship between vegetative growth and tolerance against B. cinereal or insects is rather more complicated. However, it was observed that shorter plants appeared to have a certain level of tolerance or repellence against both aphids and thrips. Data presented in this study could be used to assist further genetic studies and breeding efforts to obtain Botritis and insect resistance for B. rapa.

• Korean journal of applied entomology
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• v.59 no.4
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• pp.407-408
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• 2020

We studied the efficacy of the 'Natural Enemy in First (NEF)' technology in controlling thrips and aphids in tomato greenhouses, relative to the natural enemy and conventional chemical treatments. This technology combined the use of natural enemies of the pests (parasites/predators) with their food sources/habitats, and the treatment commenced at the time of planting. The 'NEF' technology, for the control of thrips, had an efficacy 32% higher than the natural enemy treatment, and 82% higher than the conventional chemical treatment. The average population density of aphids after the treatment was not significantly different among all treatments.

• Korean journal of applied entomology
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• v.61 no.4
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• pp.633-638
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• 2022

Banker plants are non-crop plants that can be used to maintain natural enemies of crop pests. Orius laevigatus (Fieber) (Heteroptera: Anthocoridae) is an important natural predator used to control pest insects, such as thrips, in horticultural crops. The development of suitable banker plants is necessary to maintain O. laevigatus populations within agricultural areas and to effectively improve thrips control. The oviposition rate of O. laevigatus was compared when reared on various flowering plants, such as sedum, rose moss, and chrysanthemum; oviposition rate was highest on the yellow-flowered chrysanthemum variety than on any other plant. This study provides important information for the practical application of banker plants to improve the efficiency of O. laevigatus in agricultural areas.

• Korean journal of applied entomology
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• v.63 no.1
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• pp.73-74
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• 2024

To control western flower thrips (Frankliniella occidentalis), a significant pest of peppers, the control effects of eco-friendly agricultural materials were tested when treated alone and in combination. The control effects of yellow sticky roll traps installed on the stem, predatory natural enemy (Hypoaspis miles) inoculated on the stem, and plant extracts (50% custard apple seed oil + 10% cinnamon extract) sprayed on the foliage were 45.3%, 36.6%, and 50.2%, respectively, when treated individually. Meanwhile, when three eco-friendly agricultural materials were comprehensively applied, the control effect was maintained between 62.4% and 80.9% compared to untreated conditions during the pepper harvesting season. These methods can be utilized for the eco-friendly control of western flower thrips in pepper greenhouses.

• Korean journal of applied entomology
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• v.57 no.3
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• pp.221-231
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• 2018

The susceptibility of the western flower thrips, Frankliniella occidentalis and garden thrips, Frankliniella intonsa was evaluated using 51 commercial insecticides. 15 kinds of insecticides which showed more than 90% mortality against both thrips, F. occidentalis and F. intonsa was selected. Many active ingredients were misused and abused in commercial mixture formulation insecticides. Since the F. intonsa was more susceptible than F. occidentalis, it was considered that both thrips can be controlled by insecticides that showed insecticidal activity on the F. occidentalis. Lethal time ($LT_{50}$ and $LT_{95}$), systemic toxicity and residual toxicity of selected insecticides were compared. Both chlorpyrifos WP and chlorpyrifos + diflubenzuron WP revealed the fastest toxicity within 2 h ($LT_{95}$), while spinetoram WG revealed the slowest toxicity as 62.3 h ($LT_{95}$). Chlorfenapyr SC showed toxicity at foliar and drenching application while spinetoram WG was toxic only in foliar application. Chlorfenapyr SC showed residual effect at 3, 5, 7, 10, 15 days after treatment and both benfuracarb WG and chlorpyrifos WP showed residual effect at 3 days after treatment. As a result of treatment of selected insecticides for field population of F. occidentalis, the population collected from horticultural crops showed lower susceptibility than the population collected from vegetable crops.

• Korean journal of applied entomology
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• v.43 no.2
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• pp.103-109
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• 2004

Seasonal occurrence of Japanese gall-forming thrips, Ponticulothrips diospyrosi Haga et Okajima, and its damage pattern on leaves and fruits were studied at sweet persimmon orchards in Gimhae (orchard A, B) and Changwon, Gyeongnam. Korea in 2002 and 2003. Monitoring adults by yellow sticky traps and inspecting each developmental stage in damaged rolled-leaves revealed that the overwintered adults moved to sweet persimmon orchard from late April to late May, and oviposited inside the rolled leaves. Adults developed from the eggs showed peak occurrence of the first generation adults in early to mid June. Inspection of rolled leaves indicated that the peak occurrences of eggs, nymphs, and pupae of the first generation took place in early to mid May, late May to early June, and early June, respectively. Each developmental stage showed the second small peaks in the late season. Results suggest that most thrips live a single generation per year, but a small portion may develop to the second generation in persimmon orchards. The percent of damaged leaves was highest in Changwon orchard at 9.7％ in early June. Percentage of damaged fruits increased from 0.84％ in early June to 30.2％ in early September in Gimhae B orchard. It was found that the closer the persimmon trees were to the edge of the orchard, the worse damaged the leaves were. Appropriate timing for incorporation of control measures were discussed in relation to the seasonal occurrence of adults.

• Horticultural Science & Technology
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• v.16 no.3
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• pp.370-373
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• 1998

Fumigation by combination of methyl bromide/phosphide ($MB/PH_3$) was much more effective in disinfestating the rose insect pests (Aphis gossypii, Tetranychus urticae, and Frankliniella occidentalis) than that by individual MB or $PH_3$. Fumigation for 2 hours in the chamber using ;$MB/PH_3$ at the concentration of $10/3g{\cdot}m^{-3}$ brought about 91.3% and 100% mortality in aphids and thrips, respectively. Fumigation for 3 hrs using ;$MB/PH_3$ at the concentration of 5/3 or $7/3g{\cdot}m^{-3}$ showed over 96% mortalities in mites and thrips as well as no phytotoxicity symptoms, e.g. tip burn or bent neck, in cut roses, while mortalities of mites and thrips were not influenced by increasing $CO_2$ concerntration from 0.03% to 10% or decreasing $O_2$ concentration up to 15% in fumigation chamber.

• Korean journal of applied entomology
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• v.56 no.3
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• pp.309-314
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• 2017

Sampling plan using yellow sticky traps for the major strawberry flying pests - western flower thrips Frankliniella occidentalis adults, cotton aphid Aphis gossypii alate and greenhouse whitefly Trialeurodes vaporarium adults was developed to determine the initial occurrence time. The analyzed trap data were obtained from three commercial strawberry greenhouses for the whole growing season (September to May of the following year) during 2013 to 2017 in Jeju province. Three flying pests showed the aggregated distribution patterns resulted from commonly used regression techniques - Taylor's power law and Iwao's patchiness regression. Taylor's power law was better description of mean-variance relationship of the western flower thrips and the cotton aphid than Iwao's patchiness regression, otherwise greenhouse whitefly was better described by Iwao's patchiness regression. There were highly significant correlated among mean density per trap, maximum density and proportion of traps with more than 10 individuals. To estimate 4.0 heads of mean density per trap, the minimum number of traps were required 13 traps for western flower thrips, 11 traps for cotton aphid and 10 traps for greenhouse whitefly. The sequential sampling plans at the fixed precision level 0.25 were developed using parameters of Taylor's power law for western flower thrips and cotton aphid, and of Iwao's patchiness regression for greenhouse whitefly.

• Korean journal of applied entomology
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• v.50 no.4
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• pp.289-293
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• 2011

This study was conducted to develop economic injury level (EIL) of onion thrips, Thrips tabaci, on welsh onion (Allium fistulosum L. var) in the early transplanting stage. The changes of welsh onion biomass, yield loss, and T. tabaci density were investigated according to the inoculation periods of T. tabaci. In the early transplanting stage of welsh onion, the yield loss (%) increased with increasing inoculation periods: 17.0, 53.3, 38.4, and 80.8% yield loss in 5, 10, 15, and 20 d inoculation periods, respectively. The relationship between Cumulative Insect Days (CID) of T. tabaci and yield loss (%) of welsh onion was well described by a nonlinear logistic equation. Using the estimated equation, EIL of T. tabaci on welsh onion was estimated to 30 CID per plant based on the yield loss 12% (an empirical gain threshold 5% + marketable rate 93% of welsh onion). ET was calculated to 24 CID, which corresponds to 80% of EIL. Until a more defined EIL-model is developed, the present results should be useful for T. tabaci management in early growth stage of welsh onion. The effect of T. tabaci attack on the yield of welsh onion in late growing season (120 days after transplanting) was also examined. The yield of welsh onion increased at a low population density of T. tabaci and decreased at higher densities, showing a typical over-compensatory response.