ZonePlant

Disease on crop

fungal

Thousand Cankers Disease on black walnut

Geosmithia morbida (vectored by Pityophthorus juglandis)

Fatal disease of black walnut caused by a fungus vectored by the walnut twig beetle. Spreading eastward from the western US, devastating native black walnut stands.

Disease
Thousand Cankers Disease
Pathogen type
Fungal
Crop
Black Walnut
Scientific name
Geosmithia morbida (vectored by Pityophthorus juglandis)

Thousand Cankers Disease on black walnut

Detailed guidance for this section is being prepared. Check back soon.

Symptoms on black walnut

  • Yellowing and thinning canopy
  • Tiny pinhole beetle entry points on branches
  • Coalescing dark cankers under bark when scratched
  • Branch dieback progressing to whole-tree death over 3-5 years

IPM controls

  • No effective treatment once symptomatic; prompt removal and burning of infected trees
  • Avoid moving black walnut firewood across regions (the primary spread vector)
  • Maintain tree vigor (drought-stressed trees are more susceptible)
  • Report suspected cases to state forestry departments

Other crops affected by thousand cankers disease

Related