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Thousand Cankers Black Walnut Disease

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Thousand cankers disease -
Scientific Name:
Geosmithia morbida (Kolařík et al. 2011)
Common Name:
Thousand cankers black walnut disease (TCD)
Thousand Cankers Disease - Walnut twig galleries and cankers in branch of hybrid walnut; associated with walnut trig beetle Ned Tisserat, Colorado State University
Native To:
Disease was first detected in the Western U.S.; the disease vector, the walnut twig beetle, is native to the southwestern U.S. and Mexico (Utley et al. 2013)
Date of U.S. Introduction:
First observed in the 1990s, but not recognized until 2008 (Utley et al. 2013)
Means of Introduction:
Unknown, but possibly through the transportation of logs and firewood (Randolph et al. 2013)
Fungal disease of walnut trees (Juglans spp.), particularly the black walnut (Juglans nigra), that is usually lethal within a few years; disease is transmitted by the walnut twig beetle, Pityophthorus juglandis (Tisserat et al. 2009)
Current U.S. Distribution:
Widespread throughout the Western U.S.; first detected in the Eastern U.S. in Aug 2010



Selected Resources

The section below contains selected highly relevant resources for this species, organized by source. To view all related content for this species, click on "View all resources for species" in the top left of this page.


European and Mediterranean Plant Protection Organization.
Nature Conservancy. Don't Move Firewood.
Ontario's Invading Species Awareness Program (Canada).
North Central Integrated Pest Management Center.
See also: Pest Alerts for more resources

North American Plant Protection Organization.

Thousand Cankers Disease.

Federal Government

USDA. FS. Northeastern Area State and Private Forestry.

USDA. Animal and Plant Health Inspection Service.
USDA. FS. National Forest Health Monitoring.

State and Local Government

Wisconsin Department of Natural Resources.

Missouri Department of Conservation.
See also: For more information about Invasive Tree Pests (insects and diseases) that are not native to Missouri

Minnesota Department of Agriculture.

Kansas Department of Agriculture.
Thousand Cankers poses a serious threat to the health of black walnut trees. The Kansas Department of Agriculture, Kansas Forest Service and K-State Research and Extension need your help to help stop the introduction, and to limit the spread, of this disease in Kansas. We are deeply concerned that if it reaches the native range of black walnuts in central and eastern Kansas, we may lose this tree in our urban and native forests.

Indiana Department of Natural Resources. Entomology and Plant Pathology.

Tennessee Department of Agriculture.
Thousand Cankers Disease (TCD) poses a serious problem to the health of the black walnut tree. Tennessee Department of Agriculture officials urge area residents and visitors to help prevent the spread of TCD:
  • Don't transport firewood, even within Tennessee.
  • Don't buy or move firewood from outside the state.
  • Watch for signs of infestation in your walnut trees.
If you suspect your walnut tree could be infected with TCD, refer to the TCD Symptoms Checklist to alert state plant and forestry officials, or call TDA's Consumer and Industry Services Division at 1-800-628-2631.


Kansas State University. Kansas Forest Service.
Ohio State University. Extension.
Colorado State University. Department of Bioagricultural Sciences and Pest Management.
University of California. Statewide Integrated Pest Management Program.
University of Florida. Institute of Food and Agricultural Sciences.
Utah State University. Cooperative Extension.
See also: Landscape Ornamental Insects for more fact sheets