• Title/Summary/Keyword: 가해양상

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Species, Damage and Population Density of Pseudococcidae Injuring Pear Fruits (배를 가해하는 가루깍지벌레류와 가해양상 및 밀도변동)

  • 박종대;홍경희
    • Korean journal of applied entomology
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    • v.31 no.2
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    • pp.133-138
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    • 1992
  • This study investigated species, damage to fruits and population density of Pseudococcidae on pear in Naju, Chonnam province from 1990 to 1991. Three species, Planococcus kraunhiae, Pseudococcus comstocki and Crisicoccus matsumotoi, were identified. Of them P. kraunhiae was most abundant as 80.6%. Rate of fruit damages was greatest in var. Poongsoo as 39.7% but locations of field did not affect the rates. Degree of damages on Singo(late var.), Poongsoo (midseason var.) and Haengsoo(early var.) was 21.2, 18.2 and 13.3%, respectively. Population density of scales within paper bag of fruits began to increase from mid-June and showed the first at mid-July, the second at mid-August and third peak at early October. Rate of fruit damages was 48% at the first peak and 50.6% at 7 days after the second peak. Density increased from early October again but migration was not active presumably because of cold weather.

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조경수의 병해충 - 최근 문제가 되고 있는 외래돌발해충

  • Go, Sang-Hyeon
    • Landscaping Tree
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    • s.147
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    • pp.38-42
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    • 2015
  • 최근 기후변화 개방화로 산림과 농경지 모두가 서식처인 외래종 꽃매미, 미국선녀벌레, 갈색날개매미충 등의 새로운 해충이 돌발적으로 발생하여 그 피해가 심각해지고 있다. 이 해충들은 흡즙성의 가해양상을 보이며 알로 월동하고 생활사가 유사하며 기주범위가 상당히 넓다는 공통적인 특징을 지니고 있다. 꽃매미의 유입 정착사례에서 보듯이 최근의 기후변화가 발생과 관련되어 있어 앞으로 수목과 농작물 모두에 피해가 우려되고 있는 실정이다. 특히 최근 온화한 겨울 기온과 봄철 이상기온으로 인해 알로 월동하는 해충들의 월동치사율이 감소하고 발생시기가 빨라질 것으로 예측되는 상황에서 이들 문제 해충의 생태 및 방제법에 대하여 간단히 소개하고자 한다.

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Autoregressive Cross-lagged Effects Between the Experience of Bullying and Victimization: Multigroup Analysis by Gender (학교폭력 가해경험과 피해경험의 종단관계 검증: 자기회귀교차지연 모형을 통한 성별 간 다집단 분석)

  • Jisu Park;Yoonsun Han
    • Korean Journal of Culture and Social Issue
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    • v.24 no.1
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    • pp.1-27
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    • 2018
  • The purpose of this study was to identify the persistent and dynamic association between bullying and victimization. Gender differences in patterns of school bullying was hypothesized based on the literature. Analysis were based on waves 3-6 of the Korea Children and Youth Panel Survey, a nationally representative data of primary and secondary school students in South Korea (N = 1,881). Autoregressive cross-lagged model was employed to identify the reciprocal association between bullying and victimization in longitudinal data. As hypothesized, regardless of gender, lagged effects were statistically significant between each time points such that current bullying caused future bullying and current victimization led to future victimization. However, there was no cross-lagged effects of current victimization on future bullying nor current perpetration on future victimization for both male and female youth. Findings from this study may have implications for designing policies against school bulling. Not only is short-term intervention for handling immediate psycho-social maladjustment important, but so are long-term plans that prevent youth from falling into continued perpetration and victimization in the system of school bullying.

Occurrence of Lycoriella mali (Diptera: Sciaridae) in Mushroom House (버섯재배사에서 긴수염버섯파리, Lycoriella mali의 발생양상)

  • Lee, Heung-Su;Kim, Hyeong-Hwan;Park, Chung-Gyoo;Shin, Hyun-Yul
    • The Korean Journal of Mycology
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    • v.27 no.6 s.93
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    • pp.420-423
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    • 1999
  • A Sciarid fly, Lycoriella mali was a serious pest in commercial production of the cultivated mushroom, Pleurotus ostreatus. It was found in light trap and compost samples taken from mushroom houses during all growing seasons. The fly population 'was increased with the development of mushroom growth, the larvae occurred about 30 days after spawn inoculation in compost. The highest population was developed spring cultivation season (March to June) and decreased during summer season (August to September). The larvae feed on mycellium and compost; injury to the growing mushroom mycellium and the subsequent consumption of the primordia; they entered and tunneld sporospore stem and infect pinhead formation which would be resulted in decrease of mushroom yield.

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Occurrence, Injury aspects and Effect of insecticide applications of Liriomyza trifolii Burgess on Tomato Cultivated in Plastic house (토마토에서 아메리카잎굴파리의 발생, 가해양상 및 살충제처리 효과)

  • Park, Jong-Dae;Uhm, Ki-Baik;Yoo, Jae-Gi;Kim, Sang-Chul
    • The Korean Journal of Pesticide Science
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    • v.4 no.2
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    • pp.50-55
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    • 2000
  • Occurrence, Injury aspects and control effect of some chemicals were investigated on tomato in plastic house from 1997 to 1998. Adults trapped by yellow sticky trap and sweeping net were increased from late May abruptly. Survey of population densities by yellow sticky trap was more clear than sweeping net. Damaged leaves were found out all the year round in continuous cropping fields and rate of damaged leaves was below 20% in early April and increased gradually up to 80% level after late May. Otherwise, damaged leaves were appeared from 6 weeks after transplanting in first growing field and then damaged leaves was 80% level in spring culture. In autumn culture, rate of damaged leaves was maintained 80% level from transplanting to harvesting date regardless of cultivation years. Number of adults was trapped from late May and peak was late June but mature larva was $6{\sim}8$ individuals in spring culture. In autumn culture, adult and larval densities was maintained high for 3 weeks after transplanting but begun to decrease from 4 weeks(early September). Chlorfenapyr EC, cyromazine WP and abamectin EC could suppress larval populations of Liriomyza trifolii effectively.

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