First Report of Geosmithia morbida on Ambrosia Beetles Emerged From Thousand Cankers-diseased Juglans nigra in Ohio

Abstract

Eastern black walnut (Juglans nigra) is a highly-valued species for timber and nut production in the eastern United States. Thousand cankers disease (TCD), caused by the interaction of the walnut twig beetle (Pityophthorus juglandis) and the canker fungus Geosmithia morbida (Tisserat et al. 2009), was first found in the eastern United States in 2010 and is a threat to the health of black walnut in its native range. The recent detection of G. morbida on a weevil species (Stenomimus pallidus) (Juzwik et al. 2015) led to an effort to determine the extent to which beetles other than P. juglandis acquire the fungus on their bodies from TCD-symptomatic trees.