The bark beetle is multiplying again in large numbers in many places in Bavaria. The cool and wet spring did not bring relief as hoped, said Andreas Hahn, responsible for forest protection at the State Institute for Forestry and Forestry (LWF) in Freising. “It’s at least as tense as in previous years.” The first beetle generation of the year is now swarming out to drill into the bark of new trees and lay numerous eggs. “The warmer, the faster they develop,” explained Hahn.
Franconia and parts of Lower Bavaria are particularly affected, as the LWF bark beetle monitoring shows. This is based on the assessment of the situation in the individual forest districts and the data that the LWF experts collect on bark beetle traps and laid out breeding trees. Forest owners can use this to determine how often they should inspect their trees.
But even the South could not feel safe, said Hahn. At two thirds of the locations, a striking number of bark beetles of the type beetle were trapped. These are beetles from last year that have survived the winter. According to the expert, these have been able to lay eggs twice since May – 80 to 150 pieces per female. And their offspring are now laying eggs again – an exponential growth, explained Hahn.
According to Hahn, the bark beetle benefits from global warming. There used to be an average of 1.5 beetle generations per year. Now it’s two or three, he said. At the same time, the trees suffered from the drought and were less able to withstand a bark beetle infestation. This can be observed in particular in the Franconian Forest in north-eastern Franconia, where there are many spruce trees. Large numbers of infested trees had to be felled there last year.