Thousand Cankers Disease has been found in a Bucks County Black Walnut tree, causing the Pennsylvania Department of Agriculture to bar moving all walnut material including nursery stock, green lumber and firewood from the county. The only exceptions are nuts, processed lumber and finished wood products with no bark. The property owner found the infected tree in Plumstead Township, adding to the diseases that could harm the state’s hardwood industry. Thousand Cankers Disease is caused by Walnut Twig Beetles, no larger than a poppy seed, that tunnel under the bark and leave a fungus that causes the trees to develop small cankers, or ulcer-like sores. They slowly starve the trees to death, and there is no known cure.