Bark beetles are important components of the natural dynamics of coniferous forests. In Europe, the European spruce bark beetle (Ips typographus) in particular has the potential to cause extensive infestations and thus can act as an ecological disturbance. After disturbances such as windthrow or drought, this beetle can increase its population density to such an extent that it is able to successfully colonize vigorous trees. The further development of mass infestations of living trees mainly depends on temperature and the susceptibility of the host trees. From an ecological viewpoint, bark beetles contribute to the natural dynamics of forest ecosystems and create valuable new habitats for many organisms. Socio-economically, however, bark beetle outbreaks often lead to extensive damage.