 |
 |
 |
 |
 |
 |
 |
Thousand Cankers Disease |
|
 |
|
Background
In May 2008, walnut mortality observed in Colorado as early as 2003 was attributed to numerous cankers developing in association with insect galleries. The new disease complex is referred to as “thousand cankers disease” (TCD) and is considered to be native to the United States.
TCD results from the combined activity of Geosmithia morbida fungus and the walnut twig beetle (WTB, Pityophthorus juglandis). The WTB has expanded both its geographical and host range over the past two decades, and, coupled with Geosmithia morbida, walnut mortality has occurred in California, Oregon, Washington, Idaho, Utah, Arizona, New Mexico, and Colorado. In July 2010, TCD was first reported east of the 100th meridian in Knoxville, Tennessee. This raised concerns that large native populations of black walnut in the eastern United States may suffer severe decline and mortality. Therefore, surveys were conducted in various states in 2011, and TCD was found in Pennsylvania and Virginia.
Black walnut is a significant economic, social and environmental resource, and appears to be highly susceptible to TCD. Black walnuts exhibit little to no resistance to the pathogen and its vector.
News and Information
- Thousand Cankers Disease Information
- US Forest Service Thousand Cankers Disease Pest Alert
- US Forest Service Thousand Cankers Disease web page
- USDA-APHIS-PPQ Pathway Assessment: Geosmithia sp. and Pityophthorus juglandis Blackman movement from the western into the eastern United States
- Q&A about TCD from Colorado State University
Plans
- Thousand Cankers Disease Survey Guidelines for 2012 (PDF; 3.37 Mb)
- 2012 PPQ Activities for TCD (PDF; 17 Kb)
- National Response Framework for Thousand Cankers Disease (TCD) on Walnut
Regulations
There is no federal regulation in place for TCD; however, several states have set up exterior quarantines. This includes, but may not be limited to, Illinois, Indiana, Kansas, Michigan, Minnesota, Missouri, North Carolina, Nebraska, Ohio, Oklahoma, Pennsylvania, Virginia, and Wisconsin. For further information about a specific quarantine, please contact the State Department of Agriculture.
Contact:
Julie Spaulding
National Program Manager
Telephone: (301)851-2184
E-mail: Julie.S.Spaulding@aphis.usda.gov
