Landowners across Northern Virginia and Northwest Virginia are seeing damage to the bark of ash trees, and many are calling the Virginia Department of Forestry asking what is wrong. Bark on these trees is being stripped off by woodpeckers hunting for Emerald Ash Borer larvae – a process called “blonding.”
Emerald Ash Borers (EAB) are wood-boring beetles with a metallic green body that are feeding on the layer of the tree just under bark that moves life-sustaining sugar, water and nutrients throughout the ash tree.
“A single EAB larva has little effect on an ash tree,” said Lori Chamberlin, VDOF’s forest health manager. “But the feeding of thousands of EAB larvae will kill the tree. So, the blonding process isn’t killing the ash trees per se, but the thousands of EAB larvae that are attracting the woodpeckers are.”
In a forest setting, there isn’t an effective treatment for EAB; the ash trees are, unfortunately, going to be killed by EAB. A forest landowner can perform salvage logging or enjoy the wildlife habitat that is created by the standing dead trees. In a landscape setting, however, ash trees can be treated with systemic insecticides through either a stem injection or a root soak. The treatment process can be expensive and has to be repeated either every year or every other year.
“One of the biggest problems with trying to treat ash trees is that it’s best to begin the treatment before the tree shows signs of infestation,” Chamberlin said. “Unfortunately, most ash trees are infested with EAB before anyone knows the beetles are present. At some point – typically when a tree has lost half of its crown, the tree reaches the tipping point where the damage is so severe that it’s too late to save it. It’s now time to remove and destroy the tree, and plan tree replacement with alternative species. Never move infested wood as that’s the quickest way to spread EAB,” she said.