Thousand Cankers Black Walnut Disease | National Invasive Species Information Center

Scientific Name

Geosmithia morbida (Kolařík et al. 2011)

Common Name

Thousand cankers black walnut disease (TCD)

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)

Impact

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

Thousand Cankers Disease

Credit

Walnut twig galleries and cankers in branch of hybrid walnut; associated with walnut trig beetle Ned Tisserat, Colorado State University

Source

Invasive.org.

Find more images

Distribution / Maps / Survey Status

Early Detection & Distribution Mapping System (EDDMapS) - Thousand Cankers Disease
- University of Georgia. Center for Invasive Species and Ecosystem Health.
- Provides state, county, point and GIS data. Maps can be downloaded and shared.

Videos

YouTube - Outsmart Invasive Species Project: Thousand Cankers Disease ID
- Google. YouTube; University of Massachusetts - Amherst.
YouTube - Tree Diseases (includes Thousands Cankers)
- Google. YouTube; University of Tennessee Extension (Knoxville County).

All Resources

View and Filter All Thousand Cankers Black Walnut Disease Resources

Selected Resources

The section below contains highly relevant resources for this species, organized by source.

Partnership

EPPO Global Database - Geosmithia morbida
- European and Mediterranean Plant Protection Organization.
Gallery of Pests - Thousand Canker Disease
- Nature Conservancy. Don't Move Firewood.
Invaders Factsheet: Thousand Cankers Disease
- Ontario's Invading Species Awareness Program (Canada).
Southern Forest Health - Thousand Cankers Disease
- USDA. Forest Service; Southern Regional Extension Forestry. Forest Health Program.
- Includes species related publications, webinars and other resources.
Thousand Cankers Disease
- Thousand Cankers Disease.

Federal Government

Plant Pest and Disease Program: Plant Disease - Thousand Cankers Disease
- USDA. Animal and Plant Health Inspection Service.

State and Local Government

Thousand Cankers Disease - 2010 Georgia Update [PDF, 889 KB]
- Sep 2010
- Georgia Forestry Commission.
- See also: Forest Health - Diseases for more resources
Invasive Tree Pests - Thousand Cankers Disease
- Missouri Department of Conservation.
- See also: For more information about Invasive Tree Pests (insects and diseases) that are not native to Missouri
Plant Diseases - Thousand Cankers Disease of Walnut
- Minnesota Department of Agriculture.
Plant Protection and Weed Control - Thousand Cankers Disease of Walnut
- 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.
Regulatory & Scientific Information: Thousand Cankers Disease
- Indiana Department of Natural Resources. Entomology and Plant Pathology.
Walnut Twig Beetle and Thousand Cankers Disease
- Maryland Department of Agriculture.
- Thousand cankers disease (TCD) is a disease complex native to the western United States and primarily affects black walnut, Juglans nigra. This disease is the result of the combined activity of a fungus, Geosmithia morbida, and the walnut twig beetle WTB), Pityophthorus juglandis. On January 12, 2015, the the Maryland Secretary of Agriculture issued a quarantine order to minimize the risk of moving infested material out of the limited action area in Cecil County, and to provide confidence in Maryland walnut products moving into neighboring states from non quarantined areas. The 2015 quarantine order has been updated to include all of Baltimore City and part of Baltimore County [PDF, 1.2 MB]. The new quarantine [PDF, 1.0 MB] was signed on May 1, 2019 by the Maryland Secretary of Agriculture.

Academic

Thousand Cankers Disease: A Threat to Black Walnut in Florida
- Feb 2013
- University of Florida. Institute of Food and Agricultural Sciences.
Utah Pests Fact Sheet - Thousand Cankers Disease of Walnut [PDF, 1.44 MB]
- Aug 2011
- Utah State University Extension; Utah Plant Pest Diagnostic Laboratory.
- See also: Landscape Ornamental Insects for more fact sheets
Thousand Cankers Disease of Black Walnut: A New Pest May Threaten Texas Walnut Trees [PDF, 1.46 MB]
- Feb 2010
- Texas A&M University. Texas Forest Service.
Emerging Threats: Thousand Cankers Disease of Walnut
- Kansas State University. Kansas Forest Service.
Pacific Northwest Plant Disease Management Handbook - Thousand Cankers Disease (Black Walnut Decline)
- Oregon State University. Extension Service.
Thousand Cankers Disease
- Ohio State University. Extension.
Thousand Cankers Disease and the Walnut Twig Beetle in California
- University of California. Statewide Integrated Pest Management Program.

Professional

Black Walnut Mortality in Colorado Caused by the Walnut Twig Beetle and Thousand Cankers Disease
- Aug 2009
- Plant Management Network. Plant Health Progress.
Insects and Diseases - Thousand Cankers Disease
- Walnut Council.

Citations

Kolařík, M., E. Freeland, C. Utley, and N. Tisserat. 2011. Geosmithia morbida sp. nov., a new phytopathogenic species living in symbiosis with the walnut twig beetle (Pityophthorus juglandis) on Juglans in USA. Mycologia 103(2):325-332.
Randolph, K.C., A.K. Rose, C.M. Oswalt, and M.J. Brown. 2013. Status of black walnut (Juglans nigra L.) in the eastern United States in light of the discovery of thousand cankers disease. Castanea 78(1):2-14.
Tisserat, N., W. Cranshaw, D. Leatherman, C. Utley, and K. Alexander. 2009. Black walnut mortality in Colorado caused by the walnut twig beetle and thousand cankers disease. Plant Health Progress.
Utley, C., T. Nguyen, T. Roubtsova, M. Coggeshall, T.M. Ford, L.J. Grauke, A.D. Graves, C.A. Leslie, J. McKenna, K. Woeste, M.A. Yaghmour, W. Cranshaw, S.J. Seybold, R.M. Bostock, and N. Tisserat. 2013. Susceptibility of walnut and hickory species to Geosmithia morbida. Plant Disease 97(5):601-607.