An invasive insect first found in Fairfax County in 2003 has spread across Virginia, threatening the state’s ash trees.
The emerald ash borer has been found in four more counties, the Virginia Department of Agriculture and Consumer Services announced last week. Alleghany, Bath, Fauquier and Page counties become the latest of the 21 counties and seven cities in Virginia where the emerald ash borer has been detected since 2003.
Emerald ash borer larvae burrow under the bark of a tree and cut off a tree’s water circulation, gradually killing it.
The beetle, native to Asia, has spread quickly from its first appearance in Michigan in 2002 to other states, including Virginia. The insect has killed millions of ash trees across the U.S. and Canada, according to the Virginia Department of Agriculture and Consumer Services.
In the decade the emerald ash borer has spread throughout Virginia, it has taken firm hold in Fairfax County.
“We consider Fairfax County completely infested,” said Adria Bordas, a natural resources extension agent for Virginia Cooperative Extension’s Fairfax office. “If you’re in our county, it’s very likely your tree is infested.”
Individual ash trees can be saved with pesticide treatment. If homeowners have an ash tree they want to protect, Bordas advises them to contact an arborist and begin treatment immediately.
“We really want to stress professional treatment for this,” Bordas said. “The products available to the homeowner are not as effective as the products available to the professional, and the emerald ash borer is very aggressive.”
Terry Lasher, a senior area forester at the Virginia Department of Forestry’s Northern Virginia office, said people can wait to look for outward signs a tree is infested: dying branches; branches sprouting near the base of the tree; cracking and peeling bark.
“Still, typically by the time you notice any outward signs, you’ll already have had an infestation for a year or two or even longer,” Lasher said. “And then it’s too late to save the tree.”
While individual ash trees can be protected if an infestation is caught in time, there is no large-scale effort to stop the insect’s destructive path. Ash trees make up about two percent of Virginia’s forests, but protecting large swaths of trees is not practically or economically feasible, Lasher said.
The state of Virginia is under a federal quarantine, prohibiting the movement of ash logs, ash nursery stock and all firewood out of the state as these could harbor the beetle and facilitate its movement from state to state.
Even within state lines, residents should try to buy firewood close to their home or campsite to limit the emerald ash borer’s spread, said Adam Downing, a natural resources extension agent with Virginia Cooperative Extension’s Northern Region office.
“There’s a lot of movement lately to buy local, so think of it like that,” Downing said. “It may seem weird to think about, buying firewood local, but it will help reduce the free insect hitchhikers that can be carried by the wood.”