New Threat to Ohio's Black Walnut Discovered

Posted on: July 30, 2013
Tags: Pests
New Threat to Ohio's Black Walnut Discovered

Sorry that I have to break into our current series but important information has come to light. Walnut Twig Beetles have been found in Butler County. You may be saying 'What are Walnut Twig Beetles?'. Well, they are beetles that are found to cause Black Walnut Disease. This disease was first found in Colorado in 2003 and has since spread all around the United States including Pennsylvania, North Carolina, and Tennessee. Black Walnut Disease is a disease found in Black Walnuts but it has also been found in the Arizona Walnut, the English Walnut, and the California Walnut.

You may be wondering what the symptoms of Black Walnut Disease are. The Walnut Twig Beetles go into the bark of Black Walnuts and other Walnut trees and kill a localized area in the phloem. The phloem is the living tissue in a tree that carries organic nutrients to all areas of the tree. These areas that are killed over lap from many strikes, as many as 35 insects per square inch. This leads to the thinning of branches and yellowing of leaves at the top of the tree. The only part that is very noticeable from the surface of the tree is small entry points from the beetles and small, star shaped cracks.

The disease can be detected by inspections but can easily be missed if the cuts are made too deep. There is no known spray for the tree that has been found of be effective once the tree is infested. There are some options to repel the beetles from the tree such as insecticides and injections into the tree. If your Black Walnut has been infested by the Walnut Twig Beetle, it will most likely die within 3 years time but spraying insecticides can help to keep the deadly insects away from your tree.

If you are looking for someone to help you with the prevention of this beetle, Arborx Tree Specialists can help. We do spray trees with insecticides and inject the trees to prevent them from getting the beetles under their bark. Our certified arborist can identify and if necessary, treat your tree to protect them from pests and diseases. Our team regularly attends classes to help keep us current on all issues that could effect your tree's health. You can call us at 513-759-8733 or E-mail at You can also like us on Facebook and get all of our blogs every week.