New bark beetle species in Bavaria

So far, introduced bark beetle species have not been an issue of major concern for forest and forest nature conservation. However, according to investigations on the species Gnathotrichus materiarius Fitch, Cyclorhipidion bodoanus Rtt., Xyleborus alni Niisima, Xyleborus germanus Blandf. and Taphrorychus villifrons Duf., these species may become a substantial threat to indigenous tree species. Their ecological impact cannot be totally assessed. At the moment, and based on our data, we consider Xyleborus germanus and Cyclorhipidion bodoanus to be the most dangerous species. In the deciduous forests of northern Bavaria, they are already the dominant bark-beetle species, penetrating increasingly into open landscape stands. The impact of these two introduced bark beetles on the autochthonous fauna and flora must be urgently investigated and pheromones for these species extricated for monitoring.