• Title/Summary/Keyword: Forest insect pests

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Occurrence of Sporendocladia bactrospora on Quercus variabilis in Korea

  • Lee, Dong-Hyeon;Seo, Sang-Tae;Lee, Sang-Hyun;Lee, Seung Kyu;Lee, Sun Keun
    • The Korean Journal of Mycology
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    • v.45 no.4
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    • pp.394-398
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    • 2017
  • A survey to assess the diversity of wound-associated Ophiostomatales and Microascales, the so-called ophiostomatoid fungi, on Korean native trees, was undertaken in 2017. Wounds were artificially created, and a fungus resembling a species of Sporendocladia was consistently isolated from the exposed cambium and inner bark of artificially induced wounds on Quercus variabilis. Morphological examination and DNA sequence comparisons based on the internal transcribed spacer (ITS) and 5.8S regions of the rDNA confirmed the identity of the fungus as Sporendocladia bactrospora. This is the first report on S. bactrospora occurring on Q. variabilis in Korea.

Tree-crown Defoliation caused by Outbreak of Forest Insect Pests in Korea during 2020 (2020년 산림해충 대발생에 의한 산림의 식엽 피해)

  • Jung, Jong-Kook;Nam, Youngwoo;Kim, Dongsoo;Lee, Sang-Hyun;Lim, Jong-Hwan;Choi, Won Il;Kim, Eun-Sook
    • Korean journal of applied entomology
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    • v.59 no.4
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    • pp.409-410
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    • 2020
  • This report describes the damage caused by gypsy moths (Lymantria dispar) and stick bugs (Ramulus mikado) to forests and host plants in 2020. Severe tree-crown defoliation was found in central parts of Korea, especially Gangwon (1,638 ha), Gyeonggi (1,134 ha), Chungbuk (726 ha) and Seoul (476 ha). Stick bug outbreaks occurred in hilly areas, such as Mt. Bongsan, located between Seoul and Goyang.

Changes in Forest Disturbance Patterns from 1976 to 2005 in South Korea

  • Park, Pil Sun;Lee, Kyu Hwa;Jung, Mun Ho;Shin, Hanna;Jang, Woongsoon;Bae, Kikang;Lee, Jongkoo;Lee, Don Koo
    • Journal of Korean Society of Forest Science
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    • v.98 no.5
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    • pp.593-601
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    • 2009
  • Forest disturbances including forest fire, insect pests and diseases, landslides, and forest conversion from 1976 to 2005 were investigated to trace the changes of major forest disturbance agents and their characteristics over time in accordance with changes in natural and social environment in South Korea. While the damaged area by insect pests and diseases continuously decreased for the past 30 years, damaged areas by forest fire and landslide were fluctuating through years. The interval of large forest fires has become shorter with increased tree volume. The precipitation between January and April were significantly correlated with large fire occurrences as Pearson's correlation coefficient -0.400 (P=0.029). The composition of major insect pests and diseases damaging Korean forests has been changed continuously, and become more diversified. While damages by pine caterpillar (Dendrolimus spectabilis) and pine needle gall midge (Thecodiplosis japonensis) decreased, damage by introduced pests has been more serious recently. The change of precipitation pattern that brought more localized heavy rain or powerful typhoon resulted in the recent increase in landslide areas. The major land uses to induce forest conversion have been changed, reflecting the changes in industrial structure in South Korea as agriculture and mining in 1970s, mining and golf ranges classified in pasture in 1980s, and road and housing construction in 1990s and 2000s. Changes in forest disturbance patterns in South Korea show that a country's industrial development is jointly working with global warming on forest stand dynamics. Altering energy structure and land use pattern induced by industrial development accumulates forest volume and reforms microenvironments on forest floor, interacting with climate change, inducing shorter interval of large forest fire and changes in major species composition of forest insect pests and diseases.

Difference of Developmental Time, Survival Rate and Sex Ratio of Dichocrocis punctiferalis (Lepidoptera: Pyralidae) on Three Hosts

  • Choi, Kwang Sik;Han, Kyung Sik;Park, Il Kwan;Hong, Jeong Im;Kim, Chul Soo;Chung, Yeong Jin;Shin, Sang Chul
    • Journal of Korean Society of Forest Science
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    • v.95 no.2
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    • pp.174-176
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    • 2006
  • The experiments were conducted by supplying hosts with natural food(chestnut, peach, Quince). The developmental difference of peach pyralid moth, Dichocrocis punctiferalis was examined in the laboratory under three different natural food regime. The periods of egg, larva and pupa were $6.01{\pm}0.07$, $12.23{\pm}0.03$ and $13.32{\pm}0.01$ days on the chestnut fruit, $6.21{\pm}0.01$, $18.69{\pm}0.02$ and $13.38{\pm}0.03$ days on the peach fruit and $7.02{\pm}0.04$, $22.62{\pm}0.04$ and $13.44{\pm}0.14$ days on the quince fruit, respectively. The growth of D. punctiferalis larva was better chestnut fruit than other tested fruits. The rates(%) of hatching, pupation and emergence were 94.0, 57.0 and 63.3 on the chestnut fruit, 89.2, 77.8 and 85.7 on the peach fruit and 79.6, 52.6 and 70.7 on the quince fruit, respectively. The survival rate(%) of D. punctiferalis from hatching to emergence were 31.0 on the chestnut fruit, 4.8 on the peach fruit and 14.3 on the quince fruit, respectively. The sex ratio (female: male) of all pupae obtained on the tested natural food fruits were 52.7 : 47.3. The sex ratio of D. punctiferalis reared on three difference food fruits were no significantly. It can be used a as the basic research for the study of D. punctiferalis.