Thousand cankers of walnut is an insect vectored disease that kills black walnut trees. So far the disease has been reported in western states and not in Iowa or other parts of the native range of black walnut. However, like other tree disease and insect pests this one is easily spread by human transport of wood materials. Pass the word along about this emerging disease problem and keep an eye on your walnut trees.
For more information please see the ISU Yard & Garden Column.
Thousand cankers are caused by Geosmithia sp. fungi.