Incidence and distribution of walnut twig beetle, Pityophthorus juglandis, and thousand cankers disease on black walnut in Tennessee

In 2010, thousand cankers disease (TCD) was documented in Tennessee, representing the first confirmation of this disease in the native range of black walnut and the first known incidence of TCD east of Colorado. Tennessee Department of Agriculture personnel conducted limited surveys in 2010 and more extensive surveys in 2011 to determine the extent of TCD in counties in eastern Tennessee. Personnel at the University of Tennessee processed the samples of symptomatic black walnuts for signs/symptoms of the causative agents, walnut twig beetle, Pityophthorus juglandis, and the fungal pathogen Geosmithia morbida. This poster will summarize the incidence and distribution of TCD and its associated organisms, as well as associated tree decline and/or morality, in Tennessee. An update on regulated counties (quarantined and buffer counties) also will be presented. Research is underway to further assess the incidence and impact of TCD on black walnut in Tennessee.