Ensemble evaluation of the spatial distribution of pine wilt disease mediated by insect vectors in South Korea

Pine wilt disease (PWD), caused by Bursaphelenchus xylophilus, a pine wilt nematode (PWN), is one of the most serious forest diseases of the genus Pinus and a nationwide concern in South Korea. It is spread by vectors of the sawyer beetles, genus of long-horned beetles, and it rapidly kills the host plant, resulting in economic and ecological losses. Therefore, developing an early monitoring system using spatial evaluation to minimize PWD dispersion is necessary. In this study, we predicted the distribution of PWD and of its insect vectors using a spatial ensemble model with MaxEnt and CLIMEX. High-risk areas were mostly concentrated around low-altitude and current occurrence areas. The risk of PWD under future climatic change scenarios is significantly reduced. However, PWD is expected to be distributed in most of South Korea by insect vectors, suggesting a continuous damage from PWD without an appropriate control strategy of its insect vectors. This study provides fundamental data for efficiently establishing a monitoring strategy under limited resources by proposing areas to focus in advance.