Thousand Cankers Disease of Walnut

Geosmithia morbida is a species of anamorphic fungus in the Bionectriaceae family that, together with the activity of the walnut twig beetle, causes thousand cankers disease in species of walnut trees (Juglans spp.). It was described as new to science in 2010 from specimens collected in the southern United States. The fungus, transmitted by the walnut twig beetle, Pityophthorus juglandis, is known from the western USA from California to Colorado. The cankers resulting from infection restrict...