Stock Photo - 11 September 2019, Saxony-Anhalt, Wernigerode: Hikers walk in the Harz National Park through a piece of forest with dead spruces. The coniferous trees are a victim of the bark beetle. In warm weather with little rain the bark beetle can spread strongly. The larvae nest under the bark, causing diseased and weakened trees to die. In the core area of the national park, the pest is not fought but the forest is largely left to its own devices. This should not interrupt the natural cycle of nature because the bark beetle dies in the dead wood by itself, but the forest grows again with healthy and young trees. Photo: Klaus-Dietmar Gabbert/dpa-Zentralbild/ZB. - Wernigerode/Saxony-Anhalt/Germany