• Title/Summary/Keyword: egg laid scar

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Ecological Characteristics of Mulberry Longicorn Beetle, Apriona germari Hope, at the Hibernation Stage in Mulberry Fields (뽕밭에서 월동하는 뽕나무하늘소(Apriona germari Hope)의 생태적 특성)

  • 윤형주;박인균;마영일;이상범;양성열
    • Korean journal of applied entomology
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    • v.36 no.1
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    • pp.67-72
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    • 1997
  • To study the ecological characteristics of the mulberry longicorn beetle, Apriona germari Hope, Mulberry branches with egg-laid scar were regionally collected from ten mulberry fields during the hibernation. It showed that its distribution was highest in Kyunggi province with 3.05% and lowest in Kyungnam province with 0.28%. The number of the egg-laid scar per branch was single with 87.7% of high frequency and its average size was 2.38 L$\times$1.45 W$\times$0.34D cm. The average diameter of scarred branch was 1.7 cm, ranging from 1.3 to 1.9 cm. the shape of egg was long elliptical with width of $2.32\pm$0.33 mm and with length of $6.606.60\pm$0.55 mm. the weight of egg was $16.6\pm$2.94 mg and the color of the just-oviposited egg was milky white, changing into thick brown with time. The weight and length of the just-hatched larva was $16.6\pm$2.4 mg and $6.36\pm$0.66 mm. respectively. Most of the larvae moved downward inside the branch, showing that 94.2% of larvae for outdoor rearing and 87.9% of larvae for indoor rearing moved downward in the branch. As a result, it was found that it hibernated at egg stage with a higher rate than at larval stage by two or three folds in Kyunggi and Kyungbuk province and contrarily at larval stage with higher rate than at egg stage in Chunbuk, Chunnam and Kyungnam provinces. The survival rate for the egg after hibernation was significantly low with 6.6% and contrarily for the larva after hibernation remarkably high with 91.2%. Although the survival rate of the egg in this survey was relatively low, the result indicated that there were two types of hibernation of A. germari in Korea; egg and larval stage.

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Halo Spot Symptom Induced by Oviposition of Frankliniella occidentalis on Grape Fruits: Molecular Diagnosis by a Species-specific DNA Amplification and Microscopic Characterization of the Symptom (꽃노랑총채벌레 산란에 의한 포도 과피 달무리 반점: 종 특이적 분자진단법을 이용한 종동정과 반점 증상의 형태적 특징)

  • Ahn, Seung-Joon;Cho, Myoung Rae;Park, Cheol Hong;Kang, Taek Jun;Kim, Hyung Hwan;Kim, Dong-Hwan;Yang, Chang Yeol
    • Korean journal of applied entomology
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    • v.53 no.3
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    • pp.281-286
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    • 2014
  • In grape vineyards, whitish spots in a cloud shape have been often observed on the fruit surface recently. However, the cause of the halo spot symptom was unknown, hindering countermeasures to be properly designed for the control. A small hole in the middle of the formless halo spot remained as a scar formed by oviposition of the thrips. It became later a suberized scab, which is separated from the epidermal cells on the surface either to be retained on or to be detached from it as time proceeds. Such a symptom is distinguished from the feeding damages caused by thrips or true bugs occurring on the grape fruits. With DNA extracted from the egg-shell found in the hole, molecular diagnosis by amplifying an ITS2 region with universal primers and subsequently digesting the PCR product by an restriction enzyme (RsaI) revealed that the egg was laid by Frankliniella occidentalis. In addition, a mitochondrial COI sequence confirmed that the halo spot symptom was formed by its oviposition. This study provides accurate information on the peculiar damage symptom caused by oviposition of F. occidentalis that could be useful in the control strategies for this pest in vineyards.