All forests are home to a wide range of insect pests. Various bark beetles, pine weevils, pine shoot beetles, hymenoptera and many other insects are all part of the natural forest life, but in excessive numbers they can endanger the health of the entire forest. Pests can target both weak and perfectly healthy trees. Therefore, diverse forests with a varied tree population can withstand the damages caused by insects better than groves consisting of a single tree species. The objective of Finland’s ‘Insect Act’ is to prevent damage caused by insects and fungi. For example, coniferous tree piles must be transported from the sides of forest roads and from intermediate storages within a certain period of time. This prevents the overpopulation of various pests.