About the Bronze Birch Borer
The bronze birch borer is a wood boring beetle, common across the northern half of the United States, which attacks all birch species. The adult is a copper/bronze colored slender beetle. The larva, which does the damage, is unseen, feeding on the vascular tissue under the bark. The bronze birch borer typically attacks trees which are already stressed or in decline. A birch infested with bronze birch borer will start showing dieback in the crown which will increase in severity as the infestation continues, often leading to the death of the tree. In the later stages of infestation, the trunk will show D-shaped, rust stained exit holes and may also have swollen extrusions under the bark where the tree tried to grow over larval galleries.
Host Trees for Bronze Birch Borer
Birchese: White, Water, Paper, Yellow, Whitebarked, Himalayan, Gray, Sweet