Chapter 8 - Assessment and etiology of thousand cankers disease within the native range of black walnut (Juglans nigra)This article is part of a larger document. View the larger document here.
Thousand cankers disease (TCD) is caused by a fungus (Geosmithia morbida) vectored by the walnut twig beetle (WTB), Pityophthorus juglandis (Coleoptera: Curculionidae: Scolytinae). This pest complex was first described in Colorado where it has caused the widespread death of eastern black walnut (Juglans nigra) along the Front Range and throughout the Western United States (Tisserat and others 2009). In August 2010, TCD was found in Knoxville, TN—the first discovery of the disease within the native range of black walnut (Grant and others 2011). Since that time, six other States in the Midwest and East have detected the beetle or pathogen on black walnut trees: Virginia, Pennsylvania, North Carolina, Maryland, Ohio, and Indiana (Juzwik and others 2015, Seybold and others 2012).