Bronze birch borer
Agrilus anxius

• Raised lumps or ridges can be seen on the trunk and branches
• D-shaped exit holes can eventually be observed on the trunk
  and branches
• S-shaped galleries can be seen under the bark
• Foliage at top of the canopy first becomes sparse
• Eventually twigs and then branches dieback starting at the
  top of the canopy and progressively working its way down
• Preferred hosts are European white birch and whitebarked Himalayan birch; paper birch, gray birch are also attacked; river birch is rarely infested
• More information on Bronze birch borer