Why Are My Birch Trees Dying?
Birch trees are dying in cities throughout the Pacific Northwest. Due to increasingly hotter and drier summers, Birch trees, like many other trees in our community are stressed and weakened, leaving them susceptible to attack.
Bronze Birch Borer
Bronze birch borer (Agrilus anxius Gory) is a native wood-boring insect, but populations of the insect are intensifying because of the abundance of vulnerable, stressed birch trees in our communities.
Photo by John .A. Davidson
Photo by USDA Forest Service – Coeur d’Alene Field Office
Photo by David G. Nielsen, The Ohio State University
Signs and Symptoms
- D-shaped exit holes
- Bleeds on the bark
- Serpentine ridges (insect activity beneath bark)
- Thinned foliage, branch dieback, or total loss of canopy
Resources
Dive deeper
Get Involved
Forest Health Watch – Birch Tree Health Watch, iNaturalist
Participate in monitoring birch tree dieback by sharing observations on iNaturalist.
