Natural disturbances, such as forest fires, windstorms and defoliating insects, can also create favourable conditions for the breeding of pine shoot beetles which may lead to shoot damage in the surrounding pine forests (Nilsson 1974a; Ehnstr??m et al., 1995, L??ngstr??m et al. 1997 2001, Annila and Heikkila 1999, Cedervind et al. 2003, in Martikainen et al. 2005).