Leaves Larger Branches or Trunk	BIRCH - Betula spp. AFFECTING LEAVES: CONDITION CAUSE Leaves with tan-colored, blotchy mines Birch leafminer (Fenusa pusilla) or Aphids (several, species unknown) AFFECTING TRUNK AND LARGER BRANCHES: CONDITION CAUSE Tunneling, raised, papery bark, or dieback Bronze birch borer (Agrilus anxius Gory) Areas of dead bark With discoloration and small pimple-like fruiting bodies (pycnidia) Cytospora canker (Valsa spp., Leucostoma spp.)
Missoula County Extension Office; Missoula, Montana 59808 - Updated for 2006