Last year, the fir bark drill destroyed over half a million cubic meters of forest in Sörmland. Now it is important to get the traps up before the heat starts in earnest and the spruce bark starts to swarm. The fir bark drills are attracted to the traps with the help of a pheromone.
- The traps must smell better than the forest, says Monica Pettersson.
How the mild winter has affected the forest and the spruce bark is unclear.
- The research on it is not certain. It may have disadvantaged the spruce bark. At the same time, the vitality of the spruce, however strong the neighbor, is an important factor. The Christmas tree may also have been a little worse when it did not get its "winter rest", says Monica Pettersson.