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Thousand Cankers Disease Quarantine Spreads To Lancaster County, Pa.

Thousand Cankers Disease Quarantine Spreads To Lancaster County, Pa.

Expanded Thousand Cankers Disease quarantine restricts hardwood and wood product movement in a fifth Southeast Pennsylvania county.

Following detection of Thousand Cankers Disease in Lancaster County, Pennsylvania Department of Agriculture has imposed an immediate quarantine to restrict movement of wood and wood products in the county. Lancaster joins Chester, Delaware, Montgomery and Philadelphia counties, which were quarantined in August 2014, and Bucks County, which was quarantined in 2011.

The quarantine restricts movement of all walnut material and hardwood firewood from the six counties plus other states known to have the disease. That includes neighboring Maryland, North Carolina, Ohio, and Virginia.

GREATLY MAGNIFIED: Tell-tale signs of the brown beetle are grooves under the bark and wood dust surrounding bore holes.

"Thousand Cankers Disease poses a significant threat to our billion dollar hardwoods industry, as Pennsylvania walnut is considered the best in the world," says State Ag Secretary George Greig "Transporting wood is the easiest way to spread the species that can devastate our forests."

What to watch for
The disease is introduced to a tree when Walnut Twig Beetles, which carry the fungus, tunnel beneath the bark of walnut trees, causing small cankers to form. The beetles are dark brown, similar in size to a poppy seed, and are extremely difficult to detect.

As more beetles attack the tree, the number of cankers increases, slowly starving the tree of nutrients and causing it to die within 10 years of initial infestation. Early disease symptoms are yellowing of leaves and foliage-thinning of the upper crown. As the disease progresses, larger limbs die followed by the trunk.

ON LINCOLN'S HEAD: This gives you an idea of how small Walnut Twig beetles, the carrier of Thousand Cankers Disease, are.

The quarantine restricts movement of all walnut material including nursery stock, budwood, scionwood, green lumber and firewood. It also covers other walnut material 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. However, nuts, processed lumber and finished wood products without bark are exempt.

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.

There's no known cure. An informational session will be held on Monday, Nov.10, at 1 the Lancaster County Extension Office 1383 Arcadia Road, Lancaster.

If you suspect you've seen Thousand Cankers Disease or walnut twig beetles, contact your county Cooperative Extension office or call the ag department's hotline at 1-866-253-7189. Visit and search "Thousand Cankers." 

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