Bronze Birch Borer

The bronze birch borer is a wood boring beetle from North America. In its native range, outbreaks of the beetle can cause widespread mortality in birch forests and damage to ornamental and urban trees. 

This pest is not known to have spread outside its native range but poses a threat as it could be introduced through movement of wood packaging, wood products and live plant materials. European birch species are known to be particularly susceptible to damage by the beetle. 

Bronze birch borer causes damage to host trees during its larval phase. The larvae feed and tunnel in the inner bark of the tree, damaging the tree’s ability to move and access water and essential nutrients. As a result, a heavy infestation can be fatal. This pest is difficult to detect as much of its life is spent inside the tree. Signs and symptoms include yellowing foliage, leaf loss, and swellings or bumps on the branches or stems, along with the exudation of rust-coloured sap and D-shaped exit holes in the outer bark.  

For more information on Bronze birch borer, see the resources below.