Ornamental birch trees are susceptible to attacks from these borers. White-barked birch are more susceptible than others. An early sign of bronze birch borer damage is a yellowing and thinning of foliage in the upper crown of the tree. These symptoms are most evident in hot, dry weather. We can help diagnose the presence of these borers and recommend a course of treatment, including the application of a safe, effective pesticide. Keep your birch trees healthy. Contact Tree Care at: 815-965-5757.