• Title/Summary/Keyword: indoor to outdoor ratio

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Ecological Characteristics of Cotesia glomerata L. (Hymenoptera: Braconidae) and Its Parasitism Rates for Diamondback Moth (Plutella xylostella L.) in a Kimchi Cabbage Field in The Korean Highland Area (배추나비고치벌(Cotesia glomerata L.)의 생태적 특성 및 고랭지 배추밭에서 배추좀나방(Plutella xylostella L.)에 대한 기생률)

  • Kwon, Min;Kim, Juil;Hong, Eunju;Lee, Yeonggyu
    • Korean journal of applied entomology
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    • v.58 no.4
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    • pp.355-362
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    • 2019
  • Cotesia glomerata L., an internal parasitoid wasp, attacks the larvae of both the cabbage white butterfly (Artogeia rapae L.) and the diamondback moth (Plutella xylostella L.). It can be utilized as a natural biological enemy to control these two insect pests in the summer cabbage fields of the Korean highland areas. The developmental response and sex ratio of C. glomerata to various temperatures and its longevity were examined in the laboratory. The egg-to-larva and pupa stages of C. glomerata were 12.1 ± 2.1 and 6.4 ± 1.8 days, respectively, at 20℃, The developmental threshold for egg-to-larva and pupa stages were 7.7 and 8.5℃, respectively. The sex ratios of C. glomerata when reared under various temperatures were 61.0 ± 4.5% at 15℃, 44.2 ± 1.0% at 20℃, and 39.0 ± 2.3% at 25℃, and the incidence of females increased as the temperature decreased. The longevity of C. glomerata when fed a 10% sugar solution was 20.4 ± 0.2 days, while in adults without any feed, the longevity was 3.6 ± 0.1 days. Indoor reared C. glomerata adults were released into cabbage fields from 2007 to 2018, in early August of each year, and the outdoor parasitism rates were surveyed. The parasitism rates were found to increase gradually as the year passed (Y = 0.2696X + 2.8633, R2 = 0.3994). The highest parasitism rate was observed in 2013 at 7.6%, and the lowest was in 2018 at 6.5 %. These results could be used as basic information for biological control of kimchi cabbage pests at highland fields.

The Extrapolations to Reduce the Need for Pesticide Residues Trials on Continuous Harvesting Leafy Vegetables (농약 잔류 시험을 위한 연속수확 엽채소류의 외삽)

  • Son, Kyeong-Ae;Im, Geon-Jae;Hong, Su-Myeong;Kim, Chan Sub;Gil, Geun-Hwan;Jin, Yong-Duk;Kim, Jinba;Ihm, Yang Bin;Ko, Hyeon Seok;Kim, Jang Eok
    • The Korean Journal of Pesticide Science
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    • v.17 no.4
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    • pp.293-301
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    • 2013
  • This study was carried out to investigate the pesticide residue pattern among different leafy vegetables applied with foliar spraying under greenhouse and to check extrapolating from some residue trial data to other minor crops. Leafy vegetables used in this study were: Mustard greens (Brassica juncea L.), Kale (Brassica oleracea L.), Dacheongchae (a kind of pak-choi (Brassica rapa subsp. chinensis L.)), Leaf broccoli (Brassica oleracea var alboglabra), Perilla leaf (Perilla frutescens (L.) Britton var. Frutescens), Leaf lettuce (Lactuca sativa L.), Swiss chard (Beta vulgaris L. subsp. vulgaris) and Red leaf chicory (Cichorium intybus L. var. foliosum Hegi). These are cultivated all year under indoor or outdoor and cut the leaf from plant continuously during harvest time. The amounts of pesticide deposit in/on the continuous harvesting leafy vegetables were affected by the ratios of leaf area to weight. Ratio of perilla leaf was the largest among crops as 58 $cm^2/g$. The residue levels of 7 pesticides in/on perilla leaf were the highest than those of other crops through the statistical analysis from zero day to fifth day after last application. The representative crop in 8 crops was perilla leaf selected based on the amounts of daily consumption and the high residues. This study suggest that the continuous harvesting leafy greens should be separated from the one time harvesting leafy vegetables for the pesticide recommendations because of different harvesting habits and pre-harvest intervals.