Walnut Pest Spreads In Ohio

The incurable thousand cankers disease carried by the walnut twig beetle poses a great threat to one of the state's most valuable lumber products.

Published on: Jun 19, 2013

The Ohio Department of Agriculture recently announced more detections of the walnut twig beetle in Butler County in southwest Ohio. The insect carries a fungus that causes deadly, incurable thousand cankers disease in walnut trees, although at this point the disease itself hasn't been found in the county.

The beetles were found in traps set by department officials near walnut trees in Butler County, officials said. Beetles were found in nine of 26 traps. This is the second time walnut twig beetles have been detected in Butler County. In late 2012 the beetles were found in traps set by Ohio Department of Natural Resources Division of Forestry officials near a wood processing business. ODA officials have quarantined walnut products that have the potential to spread the pest from leaving the site of discovery, according to the agency.

Adult walnut twig beetles measure less than 2 millimeters long. (Photo courtesy Colorado State University/Whitney Cranshaw.)
Adult walnut twig beetles measure less than 2 millimeters long. (Photo courtesy Colorado State University/Whitney Cranshaw.)

The following experts in Ohio State University's College of Food, Agricultural, and Environmental Sciences can offer insight on the fungus and its implications:

The walnut twig beetle is currently in 12 other states. It was first identified in Colorado around 2000 and has become widespread in the West. It was first found in Ohio at a single location in Butler County in late 2012. It so far hasn't been detected in any other county in the state. The state's native walnut trees are of major economic value and the eastern Oak-Hickory forests contain numerous walnut trees. ODA has now added Butler County to a list of national TCD quarantine areas.

OSU Extension offers a free fact sheet on thousand cankers disease. There is also a free wallet-size TCD identification card. Details on how to get it can be found here.

The team also recently released a free smartphone app that allows users to report the walnut twig beetle and other invasive species to researchers. Details, including download instructions, are here, here and here.