Skip to Main Content

Thousand Cankers Disease Detected in Cecil County

MDA LogoANNAPOLIS, MD (January 13, 2015) – The Maryland Department of Agriculture (MDA) today enacted a quarantine, effective immediately, that makes it illegal for anyone to move any walnut material and hardwood firewood out of a 21 square mile area in the northeast corner of Cecil County. The area quarantined is bounded by the Pennsylvania and Delaware state lines, I-95 and MD Route 213. Non-compliance with the quarantine order could result in criminal or civil penalties.

Thousand cankers disease (TCD) is a disease complex native to the western United States that primarily affects black walnut, Juglans nigra. This disease is the result of the combined activity of a fungus, Geosmithia morbida, and the walnut twig beetle (WTB), Pityophthorus juglandis.

The quarantine is designed to prevent the spread of thousand cankers disease, which was discovered in the Fair Hill Natural Resource Management Area where surveillance traps were set to detect the walnut twig beetle. This is the only detection of the disease in the state. The trap site where the beetle was discovered has tested positive for the walnut twig beetle for the past two years. The fungus was detected in 2014 in trap logs set by MDA at the site where the beetles were detected. MDA’s Forest Pest Management and Plant Protection sections along with the Maryland Department of Natural Resources and University of Maryland Extension have been working to survey for walnut twig beetles and slow the spread of thousand cankers disease, for which there is no known cure, since 2011.

“MDA believes the Fair Hill site is an isolated infestation,” said Agriculture Secretary Buddy Hance. “The quarantine prohibits the movement of potentially infested material out of the area, and helps to reassure neighboring states that Maryland walnut products do not carry the disease.”

The quarantine restricts the movement out of the quarantined area of all walnut material without a certificate of inspection for this pest, including nursery stock, budwood, scionwood, green lumber and firewood. It also covers other walnut material that is living, dead, cut or fallen, including stumps, roots, branches, mulch and composted and uncomposted chips. Due to the difficulty in distinguishing between species of hardwood firewood, all hardwood firewood is considered quarantined.

Nuts, processed lumber and finished wood products without bark are exempt from the quarantine

Impact of Thousand Cankers Disease

Walnut trees become diseased when walnut twig beetles, which carry the fungus, tunnel beneath the bark of walnut trees, causing small cankers to form. The beetles, dark brown and about the size to a poppy seed, are extremely difficult to detect. As more beetles attack the tree, the cankers increase, slowly starving the tree of nutrients and killing it within 10 years of initial infestation.

Early symptoms of the disease are yellowing of leaves and foliage-thinning of the upper crown of the tree. As the disease progresses, larger limbs die followed by the trunk.

Black walnut trees produce high-valued lumber used in woodworking and furniture-making. The nuts of the trees are consumed by humans and wildlife. Black walnut trees are important in riparian forest buffers which are planted to provide better fish habitat, cleaner streams and a healthier watershed for the Chesapeake Bay.

Since many species of wood-boring insects, including the walnut twig beetle and emerald ash borer, can be spread through transport of infested firewood and logs, campers and homeowners are encouraged to use only locally harvested firewood, burn all of it on-site and not carry it to new locations.

People who suspect they have seen thousand cankers disease or walnut twig beetles should contact their local county extension office or call 410-841-5870 Visit for more details.

# # #

Contact Information

If you have any questions, need additional information or would like to arrange an interview, please contact:

Jason Schellhardt
Director of Communications
Telephone: 410-841-5888

Megan Guilfoyle
Public Information Officer
Telephone: 410-841-5889