Emerald ash borers will soon be back for the 2019 season. The invasive species, which was first found in early 2018 in Vermont, has already spread to eight counties across the state.
Officials have extended the period during which ash can be moved from infected areas before the beetles emerge.
The “non-flight” period before the beetles emerge from affected trees has been extended to June 1 to better reflect local conditions and insect biology. After that time, moving ash debris, logs and firewood can quickly spread the destructive insect, according to officials.
Though the invasive species has been moving across the United States for almost 20 years, it didn’t reach Vermont until February 2018. The insects could only move about a mile or two a year on their own six legs, but the transportation of firewood has been a major cause in the species’ spread.
Mike Parisio, a forest health specialist with the Department of Forests, Parks and Recreation, said about 5% of Vermont trees are ash — but they aren’t spread evenly across the state. He said in some areas, the devastation will be a lot worse than in others.
Champlain Valley will be particularly impacted, Parisio said, though the infected areas include parts of Bennington, Caledonia, Chittenden, Franklin, Grand Isle, Orange, Washington and Windham counties.
Though officials are working to slow the beetles’ spread, infected trees have about a 99 percent mortality rate. Pariso said this is because ash trees have no “co-evolution” history with emerald ash borers, leaving the species totally susceptible. In Northeast Asia where the beetles originate, he said the trees have a higher level of resistance.
The larvae kill ash trees by tunneling under the bark and interrupting their vascular system.
Pariso said this is an epidemic that will affect a lot of Vermonters directly because about 80 percent of the state is privately owned land. He said the problem is also very urban and suburban — not just limited to the state’s forests. And with trees likely dying faster than they can be removed, Pariso said he expects real health and safety concerns.
“The emerald ash borer doesn’t discriminate where it kills,” he said.
