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Extension > Garden > Diagnose a problem > What's wrong with my plant? > Deciduous Trees > Birch > Raised ridges on trunk and branches

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Birch > Trunk/Branches > Raised ridges on trunk and branches

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  • Image: Bronze birch borer 1
  • Image: Bronze birch borer 2
  • Image: Bronze birch borer 3

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...

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