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Thousand Cankers Disease - Black Walnut Disease
Thousand cankers disease (TCD) is a recently recognized disease of certain walnuts (Juglans spp.). The disease results from the combined activity of the walnut twig beetle (Pityophthorus juglandis) and a canker producing fungus in the genus Geosmithia (proposed name Geosmithia morbida). Until July 2010 the disease was only known to the western United States where over the past decade it has been involved in several large scale die-offs of walnut, particularly black walnut, Juglans nigra.