PLAINFIELD — An invasive green beetle responsible for the destruction of tens of millions of ash trees in the U.S. and Canada has arrived in the heart of the Upper Valley, where officials predict it will continue to kill trees and wreak havoc on local forests.
The emerald ash borer was recently documented in Plainfield, according to Sullivan County Forester Dode Gladders.
Infestations are already active in Croydon and New London, he added, meaning it’s likely the beetle is now present throughout much of the Upper Valley.
“I think if you looked really hard in Cornish, you’d find it in Cornish. You look really hard in Enfield, I bet you’d find it in Enfield,” Gladders said Monday morning.
Discovering the emerald ash borer, which kills its host trees by girdling them beneath their bark, usually takes three to four years before traps or woodpeckers unveil their presence to foresters, he said. By that time, it’s often too late to stop the beetle.
“We know we can’t really stop emerald ash borer,” Gladders said. “It’s just a matter of time before it sort of does its thing across the whole state.”
The emerald ash borer, which is native to Asia, likely arrived in the U.S. through wood packing materials, according to the U.S. Department of Agriculture. Its spread through 30 states was then facilitated by the movement of firewood.
The beetle was first spotted in Concord in 2013. Since then, it’s expanded so there are now infestations from the Massachusetts border up through the northern Lakes Region.
In Vermont, pockets of emerald ash borer dot the state. And locally, an infestation was discovered two years ago near where Washington, Orange and Caledonia counties intersect.
But the Plainfield finding puts the invasive insect in the core of the Upper Valley, including, most likely, in Lebanon itself.
A large swath of Croydon into Grantham is considered a “generally infested area,” as is a circle hovering over part of Plainfield, Lebanon and Enfield, according to maps produced by the New Hampshire Department of Natural and Cultural Resources.
Similarly, a high-risk area where the beetle’s presence is considered slightly less likely extends across the Connecticut River into Hartford.
Anywhere within the 10-mile radius of a confirmed siting of an emerald ash borer “there’s a high risk that the insect is present,” said Ginger Nickerson, forest pest education coordinator at the University of Vermont Extension program.
“I don’t believe that there’s actually been a confirmed sighting of either the pest or an infested tree (in Hartford),” she added.
Still, municipalities are readying a response.
“This is sort of the scenario that we’ve been expecting,” Brad Goedkoop, Hartford’s tree warden, said in a phone interview. “It’s time to think about protecting the trees that we want to protect and making a move on that.”
Hartford developed a plan and conducted an inventory of its ash trees in preparation for the emerald ash borer several years ago.
Many of the trees along roadsides, public lands and right-of-ways will have to be cut down before they become hazardous, Goedkoop said.
“There will be a lot that have to come down because it won’t be possible to save them,” he said.
However, there are about 60 trees, including several in Veterans Park on Railroad Row, the town hopes to treat with insecticide.
The treatment costs about $150 per tree and needs to be performed semi-annually, Goedkoop said.
Officials also are calling on landowners to make tough decisions to either save their trees through costly treatments or prepare to see them die. Gladders said foresters and loggers typically selectively harvest a forest every 15 years.
“I think that foresters are kind of assuming in Sullivan County that if you go in this year to do a harvest, any ash trees that you leave behind probably won’t be there the next time you go in,” he said.
Landowners are also being asked to follow best management practices, which include only moving ash logs after Sept. 1 and only within a five-mile area.
Tim Camerato can be reached at tcamerato@vnews.com or 603-727-3223.