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National and State Maps of TCD

National and State Maps

TCD Information

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 (Pityophthorus juglandis).

Fungal spores are carried and introduced into the tree by adult beetles during gallery construction. Subsequent canker development in the inner bark disrupts the flow of nutrients throughout the tree. Widespread mortality of black walnut since 2001 in Colorado led to the recogniction and description of the disease. TCD has since been confirmed in several western states (PDF, Pennsylvania Department of Agriculture) and also been found in black walnut's native range in the states of Tennessee, Virginia, and Pennsylvania.

Identifying black walnut

Identifying Thousand Cankers Disease

Identifying other common black walnut issues

Latest News

Walnut Twig Beetle Detected in Indiana - Apr. 09, 2015

MD implements TCD quarantine in Cecil County - Jan. 12, 2015

PA expands TCD quarantine to include Lancaster County. - Nov. 03, 2014

TCD fungus found on S. pallidus weevil in Indiana. Walnut twig beetle not yet detected. - Jun. 19, 2014

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