• Proceedings of the Korean Society of Applied Entomolohy Conference
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• 2005.05a
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• pp.172-172
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• 2005

• Research in Plant Disease
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• v.20 no.4
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• pp.295-298
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• 2014

Oak wilt caused by Raffaelea quercus-mongolicae was first noticed in South Korea in 2004 and, ever since, its distribution and damage have been increasing. To screen a fungicide effective for oak wilt control by tree injection, laboratory and field experiments were conducted. Ten fungicides and one antibiotic were examined in vivo for their effectiveness in restricting the growth of R. quercus-mongolicae and R. quercivora (Japanese oak wilt pathogen) isolates. To the Korean isolates of R. quercus-mongolicae, chlorothalonil showed the highest fungicidal effects, followed by benomyl and propiconazole. To the Japanese one, propiconazole was highest in the fungicidal effectiveness, followed by benomyl and bitertanol. Propiconazole was selected for field-testing of its control efficacy because it showed good fungicidal effects in vitro and systemic activity. The control efficacy in the field was 87.5% in the first year of injection and 66.7% in the second year, indicating the fungicidal effects last at least over one year.

• Journal of the Korean Wood Science and Technology
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• v.48 no.6
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• pp.820-831
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• 2020

Fumigation treatment is mainly used on dead trees affected by the oak wilt disease to prevent the spread of damage. To verify the possibility of intensive use of the damaged Mongolian Oak wood treated by the fumigation treatment, we performed the compression and bending performance evaluation of the fumigation treated wood. The fumigation was done with Nemasect (Metam-sodium) for about 9 months. The dry longitudinal compressive strength of the fumigation treated oak wilt-diseased wood at the ambient temperature and humidity, and the compressive modulus of elasticity were measured to be 58.87MPa, and 5.66GPa, which were similar to the non-treated wood. The strength performance of mature wood of fumigation treated wood was 16% higher than that of juvenile wood. The compression fracture of the non-treated oak wood showed various shapes, however, most of the fumigation treated wood showed shear-type fracture shape. The bending strength of the fumigate treated wood was measured to be 157.43MPa, which was 8% higher than that of the non-treated wood, and the bending modulus of elasticity was measured to be 16.38GPa, which was 16% lower than that of the non-treated wood. However, it was confirmed that the coefficient of variation for the bending strength performance value of the fumigation treated wood was lower than that of the non-treated wood.

• The Korean Journal of Mycology
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• v.38 no.1
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• pp.62-68
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• 2010

This study was performed to investigate the antagonistic properties of mushroom strains against Korean oak wilt pathogen (Raffaelea quercus-mongolicae) by assessing their predominance on potato dextrose agar plates after pairing culture. Among the total of 158 strains of mushroom tested, thirty-three strains showed no antagonistic activities against the pathogen in both the short term (6~7 days) and long term (27~31 days). Ninety-six strains of tested mushrooms had a weak or no long term antagonistic activity. The antagonistic activities of 29 strains were higher than those of other strains with the levels of $\geq$ R+ and $\geq$ R for short and long term, respectively. We found that these strains with antagonistic activities against R. quercus-mongolicae belong to the species of mushrooms living on different host plants such as conifers, oaks and other broad-leaved trees. In order to use the trees damaged by Korean oak wilt as a resource(bed-log) for cultivating mushrooms, seven strains of antagonist 29 strains were selected as follows; Laetiporus sulphureus KFRI 654, Laetiporus miniatus KFRI 914, Lentinula edodes KFRI 269 and 764, Pycnoporus coccineus KFRI 588, Schizophyllum commune KFRI 832 and Trametes versicolor KFRI 100.

• Korean journal of applied entomology
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• v.47 no.2
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• pp.127-131
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• 2008

Ambrosia beetle, Platypus koryoensis, is a vector of oak wilt disease caused by Raffaelea sp. in Korea. The degree of damage by oak wilt disease was dependent on the density of the beetles in the oak trunk, a relationship between the degree of damage by oak wilt disease and the density of beetle on the basis of the number of entry hole was studied. Entry hole distribution within tree trunk was analyzed by the nearest neighbor method. Thirty four oak trees (Quercus mongolica) located in survey area were selected and then degree of damage, the number of attack hole/$623cm^2$ in upper (50cm from the surface) and lower (surface) trunk and the nearest neighbor distance between the holes were measured. The number of hole and the nearest neighbor distance in upper and lower part were positively correlated with each other. As the degree of damage was severer, the number of the holes increased, whereas the nearest neighbor distance decreased. The distribution pattern of the hole was changed from clumped one to uniform as the severity of damage increased. These results suggested that Platypus koryoensis attacked the oak tree in concentrative manner at initial stage of attack but at final stage, it distributed uniformly to reduce intraspecific competition between the beetles.

• Journal of the Korean Wood Science and Technology
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• v.48 no.6
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• pp.807-819
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• 2020

The aim of this study was to investigate the anatomical characteristics of Quercus mongolica infested by oak wilt disease. To analysis the anatomical characteristics of the wood specimens infested by the oak wilt, the anatomical structures of an infected wood, a dead wood, and sound wood were observed at 10-year-old intervals from 10 to 50 annual rings using both an optical and a scanning electron microscope. The fiber length was measured in units of 5 annual rings from the pith, and the diameter of the vessel element and the ratio of the vessel including the tyloses were measured for each 10 annual ring. In the cross section, on the infected and dead wood specimens, mycelium was also observed with the tyloses in the vessel. There was no signification difference between the wood specimens in the fiber length and the vessel diameter of the vessel element. The fiber length was not difference after 20-30 annual rings which is a part of juvenile wood. The average of the vessel ratio including tyloses in the infected wood was the highest. Especially, the ratio of tyloses was the highest 40-50 annual rings in the infected wood and the dead wood. Therefore, the large difference between the infested wood by oak wilt and the sound wood was the ratio of tyloses. This result can be used as a basic data to utilize the infested wood.

• Research in Plant Disease
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• v.17 no.2
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• pp.136-141
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• 2011

In other previous in vitro tests, the hyphal growth of Raffaelea quercivorus was inhibited by the treatments of various concentration of nano-silver. In this field tests, treatment of different concentrations of nano-silver to oak trees in Cheolwon and Hongcheon sites showed the inhibition effects against wilt disease caused by Raffaelea quercivorus. However, nano-silver-treated oak tree in Chuncheon site showed mild wilt symptoms with no phytotoxicity. Scanning electron microscope (SEM) observation confirmed that the spore and hypha of Raffaelea sp. inside the vessels were damaged by nano-silver. This result indicates the application of nanosilver is effective for control of Raffaelea quercivorus in the field.

• Korean Journal of Remote Sensing
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• v.33 no.5_3
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• pp.879-888
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• 2017

This study is a preliminary research conducted in Buhansan mountain National Park to develop a management system to predict and control oak wilt disease by indicating spatial factors which affect diffusion of the disease. After analysing altitude factor during the estimation of spatial analysis of damaged area, it is indicated that damaged trees are mainly distributed at altitude of 200-500 m and number decreased drastically over the altitude of 500 m. The result showed that 92% of total damaged trees are on slope between 20~40 degrees and the number decreased drastically on slope steeper than 40 degrees. It is indicated that damaged area is mainly distributed on southern aspect. It is estimated by using CART that slope factor affected the diffusion of disease mostly but aspect factor did not. Surface temperature and altitude showed similar effect.By simulating possible diffusion scenario, it is estimated that the disease could spread to DO-BONG Mt., northeast of Bukhansan mountain.

• Korean journal of applied entomology
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• v.49 no.2
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• pp.145-149
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• 2010

Differences in the number of Platypus koryoensis (Murayama) (Coleoptera: Platypodidae) trapped in different trap types, colors and positions on the trunk were evaluated to develop a monitoring trap for Platypus koryoensis, a known vector of Korean oak wilt disease. The experiments were conducted in an oak forest located in Gwangtan-myeon, Paju-si, Gyeonggi-do, Korea using two types of trap: sticky trap and multi-funnel trap. Trapping efficiency of the two trap types was not significantly different. Trapping efficiency of the sticky trap was not affected by four trap colors: yellow, black, white and transparent. The number of beetle caught was higher in the traps facing the upper slope than the lower slope regardress of trap type. Our results showed that both traps type are useful for monitoring Platypus koryoensis.

• Journal of the Korean Institute of Landscape Architecture
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• v.50 no.2
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• pp.41-63
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• 2022

The purpose of this study is to secure objective and precise data through ecosystem monitoring, to reveal ecological characteristics through comparison and analysis with past survey data, and to accumulate basic data for diagnosing the current situation and predicting changes in the ecosystem. The target site is the 'Quercus mongolica forest on the Buksa-myeon of Namsan', which was designated as an Ecological Landscape Conservation Area (ELCA) of Seoul in July 2006. The research contents are analysis of soil environment change (1986~2016), change of actual vegetation (1978~2016), and change of plant community structure (1994~2016). A total of 8 fixed surveys (400~1,200m²) were established in 1994 and 2000. Analysis items are importance value, species and population, and Shannon's species diversity. The soil environment of Namsan is acidic (pH 4.40 in 2016), which is expected to have a negative impact on tree growth and vegetation structure due to its low capacity for exchangeable cations. Quercus mongolica forest in Namsan is mainly distributed on the northern slopes. The actual vegetation area changed from 49.4% in 1978 → 80.7% in 1986 → 82.4% in 2000 → 88.3% in 2005 → 88.3% in 2009 → 70.3% in 2016. In 2016, the forest decreased by 18% compared to 2009. While there was increased growth of Quercus mongolica in the tree layer from 2009 to 2016, the overall decline in vegetation area was due to logging and fumigation management following the spread of oak wilt in 2012. As for the changes in the plant community structure, Quercus mongolica of the tree layer was damaged by oak wilt, and the potential vegetation that can form the next generation was ambiguous. In the subtree layer, the force of urbanization tree species such as Styrax japonicus, Sorbus alnifolia, and Acer palmatum. was maintained or increased. In the shrub layer, the number of trees and species increased significantly due to the open tree crown, and accordingly, the species diversity of Shannon for woody plants also increased. In Quercus mongolica forest of Namsan, various ecological changes are occurring due to the effects of urban environments such as air pollution and acid rain, the limitation of Quercus mongolica pure forest due to oak wilt, and the introduction of exotic species, thus, it is necessary to establish a management plan through continuous monitoring.