Thousand Canker Disease of Black Walnut and Walnut Twig Beetle

The title sounds like something straight out of SCI-FI, but it is a deadly disease.  I was asked by Whitney Cranshaw, Professor of Entomology, Colorado State University if I would mention it in one of my blogs.  The subject came up in one of our Master Gardener Courses and how important it is to disseminate the word on this serious disease.

In the past decade there has been an increasingly number of Black Walnut (Juglans nigra) falling prey to the Thousand Canker Disease.  The Walnut Twig Beetle, though native to North America, is ususally connected with the Arizona walnut tree.  The Walnut Twig Beetle, though not harmful to the Arizona walnut tree, is exceedingly harmful to the black walnut trees in the eastern half of the United States.  An infestation of the Walnut Twig Beetle in the East, where the tree is native, would be a tremendous blow to the lumber and black walnut nut industry.