Fact Sheets And Publications

Thousand Cankers Disease of Walnut

Thousand cankers disease (TCD) of walnut has been detected in Maryland and Pennsylvania, so a detection is possible in Delaware this season. The disease caused by a fungus and carried by the very small walnut twig beetle may be fatal to mature walnut trees in our area. The disease was originally found in the southwestern U.S., where it was not problematic. After occurrences in Colorado resulting in the loss of many trees, the disease spread to Tennessee, Virginia, Pennsylvania, and Maryland. It now occurs in 16 states. A quarantine has not been enacted in Delaware. However, it is recommended that wood and firewood not be moved across state lines into Delaware. Movement of wood may allow for transport of the insects and fungi involved in a number of diseases on trees and shrubs.

Suspect samples of walnut tree branches should be submitted to your local county Cooperative Extension office or to Delaware Dept. of Agriculture. Look for this disease beginning in late May or early June.

Check the website below for information on Thousand cankers disease:  http://www.thousandcankers.com/