No. 16/September 10, 2010
Thousand Cankers Disease
Thousand cankers disease, Geosmithia sp., and its vector, walnut twig beetle has been found in black walnut, Juglans nigra, for several years from the Rocky Mountains on west. In August, it was found in the Knoxville, Tennessee area.
Walnut Twig Beetle
Many cankers of thousand cankers disease on black walnut contain tunnels of walnut twig beetle, Pityophthorus juglandis, on their surface. The walnut twig beetle is a bark beetle, Family Scolytidae, that is very tiny, only about one and one-half millimeters long (one-twentieth of an inch long).
Yellow-bellied sapsuckers attack Illinois trees during both spring and fall migrations through the state. These woodpeckers typically fly south through Illinois from about mid-September through October, and they fly back north in the spring from early April through mid-May.