• Korean journal of applied entomology
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• v.31 no.4
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• pp.360-365
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• 1992

Leaf feeding insect species of welsh onion and shallot were surveyed, and their species abundances were analyzed by fitness test for lognomal disstribution. A total of 13 and 6 species were identified on welsh onion and shallot, respectively. The dominant species on welsh onion were Thrips tabacid, Acrolepiopsis sapporensis, Spodoptera exigua, and Liriomyza chinensis. Thrips tabacid was also identified as the major species on the shallot. The community dominance was high in welsh onion and shallot observed on 12 October, Suwon. The species abundance patterns of the two communities were well described by lognormal distribution(P> 0.50).

• Korean journal of applied entomology
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• v.45 no.1 s.142
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• pp.59-66
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• 2006

The damaged area by and the distribution of Japanese gall forming thrips, Ponticulothrips diospyrosi Haga et Okajima (Thysanoptera: Phlaeothripidae) in Korea were surveyed based on the answers of persimmon growers to questionnaire. Seasonal occurrence of each developmental stage was estimated by monitoring the individuals in damaged leaves, and effect of trap site and side of sticky board were studied by yellow sticky traps at three sweet persimmon orchards in Gimhae and Jinju (orchards A and B), Gyeongnam province, Korea in 2005. P. diospyrosi gave damage to astringent persimmon as well as sweet one. The damaged area of persimmon orchard has sharply increased since 2000, reaching 446 ha nationwide; Gyeongnam province was most severely damaged, followed by Gyeongbuk and Jeonnam provinces. Most of the farmers answered that they sprayed insecticides and removed the damaged leaves to control P. diospyrosi. The overwintered adults were observed in the damaged-rolled leaves from mid May and the 1st generation adults from early-mid June. No thrips were observed in the damaged leaves after mid July. Yellow sticky trap data showed that peak adults catch of the overwintered generation was mid May, and that of the 1st generation was mid-late June in Gimhae and late June in Jinju. Sticky traps set at orchard-pine forest border caught significantly more number of the 1st generation adults than those at the orchard center, even though timing of peak catches was not different between the two sites. There was a tendency of more catches on the side of sticky trap facing pine forest than the other side facing orchard center, even though the catches on both sides showed no statistical difference.

• Journal of Apiculture
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• v.34 no.2
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• pp.141-147
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• 2019

Pollinators play important roles for crop production as well as maintenance of wild plants' reproduction. Pollinator dependency in Korean agriculture have increased, but the degradation of habitat quality pose significant threats to pollination in agroecosystem. Provisioning flower habitat is one of the major activities to increase pollinator abundance and richness. We tested the effect of flower habitat supplementation on the pollinator, pest and natural enemy abundance in pepper field. Results showed that Hymenopteran pollinators were more abundant in the pepper plots close to the flower habitat. Among natural enemies, the similar pattern from pollinators was observed to parasitoids in the family of Eulophidae, but not to those of Ichneumonidae. There were no statistically significant differences of insect pests like aphids and thrips, as well as pepper production among plots in the pepper field. Even limited spatial scale, this study showed supplementing the flowering plant habitat to the agricultural landscape could conserve and boost pollinators and natural enemies, and possibly resulting better fruit production by pollination service.

• Korean journal of applied entomology
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• v.51 no.1
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• pp.1-7
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• 2012

Silver-grey or dark brown scaring, or dark brown discolored damages caused by the yellow tea thrip, $Scirtothrips$ $dorsalis$ Hood (Thysanoptera: Thripidae) have occurred on citrus fruits cultivated in the open field in east-south area orchards of Jeju Island since 2007. The weekly population of yellow tea thrips adults caught with a yellow sticky trap increased gradually from early May and peaked in late August, 2009. In 2010 and 2011, the most population was in early October. The yellow tea thrips of some species usually dominated from July in open citrus fields, and seven generations, at least, had occurred from May to late October 2009 by a yellow sticky trap survey. In 2009, $S.$ $dorsalis$ larva were observed from July and with peaks from late August to mid September and early October on citrus fruits. The damage symptoms appeared in the mid September. In 2011, the population peaks were in early July and late September, and the symptoms increased continually from mid July to late October. The symptoms were silver-scars or initial dark discolorations and then gradually changed to dark-brown discolorations or dark-brown scars. The percent of damaged fruits were 0.9%, 0.4%, 0.8% and 2.7% in 2008, 2009, 2010 and 2011, respectively, by survey in 64 typical orchards in Jeju Island. We are the first to report symptoms of the yellow tea thrip ($Scirtothrips$ $dotsalis$) on citrus fruits.

• Korean journal of applied entomology
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• v.52 no.4
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• pp.415-425
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• 2013

The yellow tea thrips, Scirtothrips dorsalis (Thysanoptera: Thripidae), has been regarded as a minor pest on citrus on Jeju Island. However, the damage of yellow tea thrips has gradually increased since 2007. This study was conducted to develop a forecasting model for generation peak time of S. dorsalis by using degree-days. Simple linear regression analysis was applied to determine the relationship between the generation number (x, dependent variable) and degree-days (y, independent variable). As a result, two regression models were established: citrus-based model (y = 310.9x + 69.0, $r^2$=0.99) and green tea-based model (y = 285.7x + 84.1, $r^2$=0.99). The models was fitted by independent data sets obtained from 2013 and evaluated using the technique of RSS (residual sum of square) and ${\chi}^2$-test. The green tea based-model showed a good fitting ability. The discrepancy between model outputs and actual data, and the practical application of models were discussed.

• The Korean Journal of Pesticide Science
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• v.17 no.4
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• pp.440-447
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• 2013

F. occidentalis (WFT, western flower thrips) is a major pest in artificial chrysanthemum houses. Nnumber of WFT attracted to yellow sticky trap was highest at trap plant and lowest at 15 and 20m places away from trap plant. Number of WFT attracted to yellow stick trap when trap plant was placed in chrysanthemum house 30 days after planting (resident WFT) was 4.4~7.7 times more than at 5 and 10 m places away from trap plant and when trap plant was placed in chrysanthemum house immediately after planting (resident WFT) was 5.7~9.4 times more at 5 and 10 m places away from trap plant. Number of WFT between the place trap plant located and unlocated was undifferent when cultured chrysanthemum formed flower. In case of the plot that trap plant and natural enemy was used simultaneously, number of WFT was highter then chemicals plot. In case of the plot that trap plant and chamicals (chemicals was sprayed on trap plant only) WFT was controlled in trap plant place only but density of WFT on 5m and 10m places away from trap plant was increased. Therefore, WFT could be controlled effectively by use of trap plant (flowering yellow chrysanthemum) and natural enemy simultaneously.

• Korean journal of applied entomology
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• v.56 no.2
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• pp.179-186
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• 2017

This study was conducted to monitor the insecticidal susceptibility of western flower thrip, Frankliniella occidentalis, which damage horticultural crops in the Gyeonggi area. Bioassays were conducted under laboratory and greenhouse conditions by using the recommended concentrations of commercial insecticides being used for the control of thrips. Neonicotinoid insecticides, especially acetamiprid (8%) soluble powder (SP), clothianidin (8%) SC, imidacloprid (10%) wettable powder (WP) and thiacloprid (10%) water dispersible granule (WG) were not toxic to F. occidentalis collected from horticultural crops. However, F. occidentalis collected from vegetable greenhouses was extremely susceptible to acetamiprid + spinetoram (6 + 4%) suspension concentration (SC), clothianidin + spinetoram (6 + 4%) SC and methoxyfenozide + spinetoram (6 + 4%) SC, which resulted in over 90% control of thrips. In the greenhouse test, spinetoram (5%) WG, which caused 100% F. occidentalis mortality in the laboratory test, showed 87.4, 88.0, and 98.3% control at 3, 6, and 9 days after treatment, respectively, while imidacloprid (10%) WP showed below 44% control. From the results of this study, spinosin insecticides, such as more than over 4 and 10% of spinetoram and spinosad, and pyrrole insecticide, such as 5% chlorfenapyr, are recommended for the effective control of F. occidentalis.

• Horticultural Science & Technology
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• v.16 no.3
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• pp.374-376
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• 1998

Effects of traditional fumigation (methyl bromide; MB) and combined fumigation (methyl bromide/phosphide; $MB/PH_3$) on the disinfestation, and phytotoxicity and longevity of cut flowers (lily and rose) were investigated. Combined fumigation with low concentrations of $7/3g/m^3\;(MB/PH_3$) at $10^{\circ}C$ immediately after transportation from harvested place was found to be much more effective in disinfestation of aphid, mite, and thrips than fumigation with $MB\;48g/m^3$ only at $20^{\circ}C$ after simulated transportation for 2 days. Quality and longevity of cut flowers measured after fumigation were better in flowers treated by combined fumigation ($7/3g/m^3,\;MB/PH_3$) at $10^{\circ}C$ for 2.5-3 hrs, irrespective of pretreatment with pulsing solution immediately after transporation, even though phytotoxicity varied with cut flowers fumigated. On the other hand, fumigation with $MB\;48g/m^3$ only at $20^{\circ}C$ after simulated transportation for 2 days showed tendency of enhanced insect disinfestation, but caused phytotoxicity to both lily and rose, regardless of pretreatment and moreover, reduced the longevity of the cut flowers.

• Korean journal of applied entomology
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• v.58 no.4
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• pp.341-345
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• 2019

Ethyl formate (EF) is a rapid kill, environmentally safe, and low mammalian toxicity fumigant, registered to disinfest quarantine insect pests from imported agricultural products. A new concept for controlling insect pests of agricultural crops was tested in a fumigation chamber with EF. Control efficacy of and phyto-toxicity due to EF fumigation were evaluated against four pests (Thrips palmi, Bemisia tabaci, Myzus persicae, and Tetranychus urticae) and on seedlings of four fruit vegetables (FVs; yellow melon, cucumber, tomato, and pepper). Ethyl formate fumigation at a dose of 1.5 g m^-3 for 12 h produced >93.3% mortality in T. palmi, B. tabaci, and M. persicae. However, T. urticae was tolerant to fumigation, showing only 20% mortality at 2.0 g m^-3. In terms of concentration × time (CT) products, at least 8.9 g·h m^-3 CT at 20 ± 1.5℃ was needed to achieve > 90% mortality against the three susceptible insect pests. Fumigation at 1.5 g m^-3 for 12 h caused no phyto-toxicity to any of the four FV seedlings. Ethyl formate application, as a new disinfestation method in greenhouses, could be an alternative to reduce the use of conventional insecticides. However, further studies are needed to determine the efficacy of this method at different pest developmental stages and in different greenhouse environments. Additionally, research is needed to elucidate the phyto-toxicity of EF application at different growing stages of a wide variety of crops.

• Korean journal of applied entomology
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• v.42 no.1
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• pp.35-41
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• 2003

Anthocorid bugs (Orius spp.) are known as polyphagous predators preying on thrips, aphids, mites, eggs of small insects and whiteflies. This study was conducted to investigate the nym-phal development, survival rate, longevity of Orius sauteri adult and oviposition, when nymphs of western flower thrips (Frankliniella occidentalis) and cotton aphid (Aphis gossypii), and eggs of two-spotted spider mite (Tetranychus uritcae) were fed as diets. Nymphal development of female/male O. sauferi fed with F. occidentalis, A. gossypii and T urticae took 12.2/12.8, 13.0/l3.2, and 17.9/17.8 days at 27$^{\circ}C$, respectively, Survival rates during nymphal development were 96.4, 78.4, 73.8%, longevity of female/male adults were 55.9/51.0, 30.2/30.8, and 25.8/25.1 days, and daily oviposition were 5.6, 4.1, and 1.9 eggs, respectively. Oviposition of O. sauteri fed with F. occidentalis usually began 3-4 days after emergence at 27$^{\circ}C$, and reached at its peak of 7-8 eggs female day 20-40 days after emergence.