Erfurt (dpa/th) – According to the state forestry service in Thuringia, the bark beetle species book printer has started its swarm flight. Nationwide, bark beetle traps, which are used to control the occurrence of the pests, showed strong flight movements of the beetle, Thüringenforst announced on Wednesday in Erfurt. Around 11,000 book printers were currently caught in a bark beetle trap in the forestry office in Saalfeld-Rudolstadt. But also in western, central and southern Thuringia, forest experts would have counted 5,000 to 10,000 beetles per trap per week.

It was said that forest owners who had spruce in their stocks had to start looking for fresh infestation immediately. Because the swarming flight of the bark beetle, which rarely goes more than a kilometer, serves to infest new spruce trees after wintering, in order to start breeding there. In addition, forest owners should check spruce wood from February that has not yet been processed for fresh bark beetle infestation.

The forest owners now have a window of about five weeks to take countermeasures, it said. During this period, the development of the first brood of the year was completed and the first hatched young beetles of the year would then in turn flock to multiply.

A female bark beetle can produce up to 150,000 offspring over the course of a year. “This enormous reproductive power makes the book printer so dangerous,” explained Thüringenforst board member Volker Gebhardt. It is all the more important to use the first infestation phase to render as many bookworm larvae and pupae harmless as possible.