A Study on the Investigation of the Presence of Potential Infected Tree in the PREVENTION of Pine Wilt Disease

Purpose: The methods of preventing and controlling pine wilt disease(PWD), currently used in Korea, include fumigation, incineration, and fragmentation of the infected tree, which shows exterior discoloration. However, there are potential infected trees that have a healthy appearance but is already running out of resin, which serves as a breeding ground for Monochamus alternatus, aka Japanese pine sawyer. Method: Therefore, in order to confirm the presence of potential infected trees in the affected area, the dam-age was divided into five grades, and potential infected trees were investigated through the process. Accordingly, the time sequential examination of the reduced pine resin and the coniferous discoloration in a total of 1,057 pine trees of kinds(Pines, Japanese black pines, Korean pines, Pinus rigida) was conducted to investigate the ex-istence of the potential infected trees in the 2 district of extreme damage in this study and among them 176 trees(16.7%) were selected as the potential infected trees. Results: The results of this study showed that there were usually 4 to 5 percent of potential infected trees right after the removal of infected trees and that the percentage gradually increased over time. In addition, 26 diagnos-tic kits and 29 microscopic examination of 32 samples confirmed Bursaphelenchus xylophilusas in the target trees. Conclusion: Therefore, it is considered necessary to concentrate on checking the expansion of the pine wilt by preventing the attracted egg laying of the vectors by searching the potential infected trees through the relatively easy-to-perform extraction of pine resin from the healthy trees in external appearance around the damaged with-ered trees. The cross-checking of the results of the diagnosis kit and microscopic examination confirmed the pres-ence of Monochamus alternatus in the potential infected trees with the 25 samples.