PWD wilt pines were first diagnosed in Busan, Korea in 1988
(Fig. 1). Because of strict control efforts in the early period of infection, numbers of PWD wilt pines declined abruptly from 345 in
1988 to 20 in 1990 (Korea Forest Service, unpublished). As public
interest in PWD became weakened, however, the number of
PWD wilt pines began to increase in Busan. In 1997, PWD wilt pines
were found in pine forests bordering the junction of the Namhae
and Guma highways in Haman, which is located 55 km from the
first infection site in Busan (Fig. 1). In the next year, there were
PWD wilt pines in 5 ha of pine forests bordering main roads within
downtown in Jinju. The PWD epidemics had spread over 50% of the
districts of Gyongnam Province by 2002, and through all districts by
2007.