In February, the presence of the invasive emerald ash borer pest was confirmed in northern Orange County, about an hour’s drive southwest of Stowe.
This is the first emerald ash borer infestation discovered in Vermont. Forestry crews have been dispatched to the area to determine the extent of the infestation, which some believe is fairly large and may be measured in square miles.
Native to China and eastern Asia, the emerald ash borer was first discovered in the Detroit area in 2002. The borer is now known to be established in 32 states and three Canadian provinces, where it has destroyed tens of millions of ash trees to date.
The beetle measures one-half inch and is metallic green in color. Emerald ash borer larvae tunnel through the wood beneath the bark, killing the ash tree by cutting off the flow of nutrients. Healthy ash trees typically die within one to four years of showing their first sign or symptom of infestation.
All species of ash trees are susceptible; however, about 1 percent of ash trees survive infestation.
What threat does the emerald ash borer pose to Vermont and to Stowe?
Since the majority of ash trees infested with emerald ash borer will die, the borer poses a threat to both Vermont’s economy and ecology. It spreads quickly, is difficult to detect, and eradication is not expected.
About 5 percent of Vermont’s trees are ash, and they are a valuable tree from many perspectives. Ash trees grow straight and tall, encouraging their neighbors to do the same, helping to create better saw logs. Ash trees are highly valued for construction and cabinetry. Ash trees are also important ecologically, being commonly found in forested wetlands.
Given the high proportion of montane/higher-elevation forests in Stowe, the percentage of ash is probably less than the statewide average, yet is still a significant component of our local forests.
The primary concern in our area will probably be street and yard trees, where ash trees are commonly used. Dead trees may become a hazard and a liability, thus impacting Vermont municipalities and private homeowners.
In 2016, in partnership with the Vermont Urban and Community Forestry Program, the Stowe town government completed an inventory of street trees in Stowe village. The study found that nearly 50 percent of street trees in the village are ash.
However, Tom Jackman, Stowe planning director, points out that many of these trees are outside of the public right-of-way and located on private land, therefore outside the purview of the town.
“The town is well positioned to deal with the emerald ash borer issue,” Jackman said. “We plan on finishing our Emerald Ash Borer Preparedness Plan this year, and we are planning on replacing all of the trees on Main Street next year as part of the sidewalk project, many of which are ashes.”
Statewide, officials are currently focusing on quantifying the area affected, identifying any additional infestations, and slowing the spread.
“I think the key right now for everyone is we want to slow its spread,” said Michael Snyder, commissioner of the Vermont Department of Forest, Parks and Recreation and a Stowe resident. “We want to buy some time, in particular, so that science and management have a chance to help. There’s work right now going on into natural predators — parasites, for example — that might help defend us against these insects.”
• What should you do with ash trees on your property?
Don’t panic and don’t follow advice to cut all of your ash trees right now. Scientists point out that the 1 percent survival rate shows there is some resistance within the population, which supports the recommendation not to cut all the ash trees. There is still time to learn and to act when the time is right.
Rick Dyer, Lamoille County forester with the Vermont Department of Forest, Parks and Recreation, explains there are still many unknowns, and urges folks to take a cautious approach.
“We aren’t sure when the (emerald ash borer) arrived in the state, and we don’t yet know how far it has spread. We can’t say at this point when it might arrive in Stowe,” Dyer said. “Regardless, people should stay vigilant, talk to their foresters, and think about options before taking action.”
If your land is enrolled in current use, you will need to work with your forester to revise your forest management plan before changing your management significantly.
There are prophylactic insecticidal treatments available, but they need to be reapplied every three to four years. These treatments are recommended only if there is an active infestation within 30 miles of your location, and only on certain high-value trees.
Insecticides have an environmental cost, so it’s not a recommended option for treating large areas.
For information about what to do with your ash trees, contact your county forester. The Lamoille County forester, Rick Dyer, can be reached at 802-888-5733, ext. 406, or [email protected]
• Where can I learn more and what can I do to help?
Visit the Vermont Invasives website at vtinvasives.org/eab for more information on emerald ash borer identification, signs and symptoms, and biology.
Look for signs and symptoms of the emerald ash borer (visit vtinvasives.org/eab for a slideshow of images). Report suspicious findings on vtinvasives.org.
Visit firewood.vt.gov for more information on how the movement of firewood can spread invasive insects like the emerald ash borer.
Don’t inadvertently move invasive pests. Buy your firewood where you burn it and encourage others to do the same. Don’t move firewood!