Emerald ash borer, a voracious tree-killing insect that has destroyed millions of trees throughout North America, has been found in Stark County, in Northeast Ohio. In this story, Alison Matas from the Canton Repository interviews Jeff Wernet from Davey’s Canton office about the insect.
Posted June 11, 2013
Stark County’s ash trees are under attack.
Emerald ash borers — beetles of Asian origin that decimate ash trees — have been considered an imminent threat for the region for years.
Now, a decade after the state began battling a borer infestation, the beetles have arrived in Stark County. While homeowners and cities have some options when it comes to combatting the bugs, experts can’t say for certain what their spread means for the future of the approximately 3.8 billion ash trees in the state.
“It’s impossible to stop, really,” said Jeff Wernet, with Davey Tree.
WHAT’S A BORER?
The borer is a metallic-green insect about a half-inch in length that tunnels into an ash tree, interfering with the tree’s pathways for receiving nutrients and water.
“It’s basically cutting off the circulation of the tree,” said Cotton Randall, special projects administrator for the Ohio Department of Natural Resources Division of Forestry.
The beetle is active from mid-May to September, and its larvae spend the remaining months growing beneath tree bark. Once a tree becomes infested, it dies within three to five years, according to the Ohio Department of Agriculture.
“It’s a pretty quick mover,” said Brett Gates, spokesman for the department.
BORERS IN STARK COUNTY
As of January 2013, Stark County was not considered to be housing emerald ash borers, according to an infestation map from the state Department of Agriculture. But Gates said within the past few days there’s been confirmation the beetles are now wiping out trees in Stark County.
On Monday, Wernet pointed out serpentine tunnels running up the trunk of a tall, dead ash tree in the front yard of a home on Middlebury Circle SW in Perry Township. Wernet said he saw some evidence of the borers last fall, but they “showed up like a tidal wave” this season.
Spotting an infestation before a tree is dead can be difficult because much of the damage occurs beneath the surface. Sometimes, the trees have increased woodpecker activity, experience canopy-thinning and display D-shaped holes where the beetles emerge from the bark, Wernet said.
HOW THEY SPREAD
Emerald ash borers can fly, but they’re spread mostly when people transfer wood products, such as firewood. They’ve also been found at rest stops after they apparently attached to the backs of cars, Randall said.
Ohio used to be under quarantine to mitigate the spread of emerald ash borers, but the quarantine was lifted because the beetle is entrenched in most of the state — though the Agriculture Department is still asking residents to be cautious when moving firewood.
Emerald ash borers don’t pose a major danger to humans — the biggest threat is that weakened trees present a safety hazard — but experts agreed the cost of removing dead trees from yards inflicts a financial burden.
Wernet said ash trees can be pretreated to ward off emerald ash borers and that the method is fairly effective. But once the beetles take hold, trees don’t really stand a chance.
Consequently, those with ash trees have few choices for trying to salvage their trees. Homeowners who have an ash tree might consider treating it with insecticide. But for cities with lots of ash trees — or people with forests in their backyards — the cost of treating multiple trees is probably too high, Randall said. Instead, some cities have started tree replacement programs and are swapping ash trees for a different species.
FUTURE OF ASH TREES
Researchers are working to breed resistant trees after finding some Asian species of the tree can withstand the bug. There are also efforts to collect seeds in case the trees need to be replanted after a rash of destruction from the beetles. But ultimately, Randall said, he is not sure what will happen to Ohio’s ash trees.
Gates said emerald ash borers aren’t a problem the state will ever be rid of.
“It’s something we just have to manage as best as we can,” he said.