Bark beetle

Again and again along the Rothaarsteig you will see areas of forest that are completely dead. The trees there have strange patterns on their trunks. These patterns were caused by bark beetles. They live everywhere in the forests and only attack diseased trees. However, if there are a lot of trees of the same species in an area and they become diseased at the same time, the bark beetle can multiply very quickly and very strongly. Forest areas with only one tree species are called monocultures. Along the Rothaarsteig, there are many such areas with spruce trees. The bark beetle has spread very strongly here in recent years because it had very good conditions to live in. After storms and due to extreme heat, many trees here became diseased.

How does the bark beetle get into the trees? An adult beetle bores into the tree from the outside. It does this very easily in diseased trees that are too weak to produce sticky resin. The resin would have stopped the beetle.

The bark beetles then reproduce under the bark. The layer underneath is called bast and is the food for the larvae of the beetles. They eat the many branched channels in the bast that you can see on the infested trees. Gradually they destroy the bast, through which the tree also transports water and nutrients from its roots to its corms. The tree then dies. At the same time, thousands of new beetles hatch from the tree and infest the neighboring trees.