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U.S. Forest Service
Caring for the land and serving people

United States Department of Agriculture

Mapping & Reporting

Thousand Cankers Disease Survey Maps

Thousand Cankers Disease (TCD ) results from the combined activity of a fungus, Geosmithia morbida, and the walnut twig beetle (WTB), Pityophthorus juglandis. TCD was originally described from scattered locations throughout western states. Now it appears that walnut twig beetle (WTB) and, by association, TCD, is present wherever susceptible walnut species grow in the west. In July 2010, TCD was reported in Knoxville, Tennessee, causing dieback on black walnut. The Tennessee infestation is believed to be at least 10 years old. This was the first report east of the 100th meridian, raising concerns that large native populations of black walnut in the eastern United States may suffer severe decline and mortality. We do not know the true distribution of this insect/disease association across the United States. While TCD has caused dieback and mortality across various climatic zones and among several walnut species, the extent of risk and impact to black walnut within its native range is still unknown.

Black walnut is a significant economic, social and environmental resource, and appears to be highly susceptible to TCD. Laboratory and field research with G. morbida have shown that all walnuts and butternut show significant amounts of dead bark tissue in response to controlled inoculations of the pathogen. The survival of butternut is already seriously threatened by butternut canker. The only other known host for WTB and G. morbida is wingnut (Pterocarya spp.)

How are the Thousand Cankers Disease Survey Maps going to be used?

Since 2012, United States Department of Agriculture: Forest Service (FS) and Plant Protection and Quarantine (PPQ) have funded eastern and central states to establish a WTB trap network. Survey information supports early detection of new outbreaks and helps us define the range of WTB and the level of risk to the walnut resource from TCD.

The aggregation pheromone lure can be used to detect an incipient population of WTB, or, in areas where TCD or WTB has been recently discovered, to delimit a known population. Once identified, State Plant Regulatory Officials may decide to impose quarantines on the movement of walnut material from infested counties to prevent the human assisted spread of the disease complex.

Walnut twig beetle survey map results example

Thousand Cankers Disease Survey Information
Survey Guidelines PDF
Instructions to obtain Thousand cankers disease survey guidelines for 2019 Adobe Acrobat File
WTB Trap Survey Map Results PDF
2018 WTB Trap Survey Results Adobe Acrobat File
2017 WTB Trap Survey Results Adobe Acrobat File
2016 WTB Trap Survey Results Adobe Acrobat File
2015 WTB Trap Survey Results Adobe Acrobat File
2014 WTB Trap Survey Results Adobe Acrobat File
2013 WTB Trap Survey Results Adobe Acrobat File
Thousand cankers disease survey forms by state xlsx
Arkansas Microsoft Excel File
Delaware Microsoft Excel File
Georgia Microsoft Excel File
Illinois Microsoft Excel File
Indiana Microsoft Excel File
Iowa Microsoft Excel File
Kansas Microsoft Excel File
Kentucky Microsoft Excel File
Maryland Microsoft Excel File
Michigan Microsoft Excel File
Minnesota Microsoft Excel File
Missouri Microsoft Excel File
New Jersey Microsoft Excel File
New York Microsoft Excel File
North Carolina Microsoft Excel File
Ohio Microsoft Excel File
Pennsylvania Microsoft Excel File
South Carolina Microsoft Excel File
Tennessee Microsoft Excel File
Virginia Microsoft Excel File
West Virginia Microsoft Excel File
Wisconsin Microsoft Excel File
Additional Information

Contact Information

Paul Merten
Region 8 Entomologist

Noel Schneeberger
Northeastern Area Forest Health Program Leader