Cryphonectria parasitica

Chesnut blight

Lethal canker on main stem. Image: Linda Haugen, USDA Forest Service, Bugwood.org

  • Caused by Cryphonectria parasitica
  • Enters through wounds in the bark and grows underneath it causing a canker
  • Cankers are not easily seen on older thick barked trees until they crack open, exposing the buff-coloured inner bark and orange fungal fruiting structures.
  • Eventually girdles and kills the branch above the infection point
  • Branch loss stimulates the tree to sprout from below the infection point or from the collar region
  • Can kill the tree if the trunk is girdled by a large canker or several cankers growing together
  • The first signs of infection are often wilting, yellowing and death of leaves and shoots. Yellow-brown to orange cankers on young smooth barked trees or branches may also be early signs of infection
  • The fungus is spread by animals that come into contact with the cankers and in the air after rain
  • Chestnut blight occurs in Japan, China, Korea, USA, Canada, Italy and throughout Europe and infects chestnut, oak, red maple, shagbark hickory and eucalypts

High priority pest of: Chestnuts

Scientific name: Cryphonectria parasitica
EPPRD Category: 2
Life Form: Fungus

Pest Documents

FS: fact sheet

CP: contingency plan

DP: diagnostic protocol