Thousand cankers disease (TCD) is a fatal disease of black walnut (Juglans nigra), and most recently, butternut (Juglans cinerea). The disease complex involves a fungus that is carried to trees by the walnut twig beetle, causing numerous cankers on branches and killing trees 5 to 6 years after infection. The disease complex is widespread in the western U.S., and has recently been identified in Tennessee, Pennsylvania, and Virginia.