By Ed Runyan
Much like Dutch elm disease, which wiped out most of Ohio’s elm trees in the 1960s and 1970s, the emerald ash borer will kill most of Ohio’s ash trees in the coming years, authorities say.
It has been moving east from Detroit, following busy highways since 2002 and was identified officially in Trumbull County in the spring, said Alan Siewert, an urban forester with the Middlefield office of the Ohio Department of Natural Resources.
The bug was identified about two years ago in two Mahoning County locations, both near the Ohio Turnpike — on the north side of the turnpike between US Route 224 and Western Reserve Road in Boardman Township and beside the turnpike just southwest of New Middletown in Springfield Township.
The borer travels on vehicles and is dislodged from vehicles at rest-stops and in vehicle accidents, Siewert said. Because of the Ohio and Pennsylvania turnpikes, the infestation has traveled nearly as far east as Pittsburgh.
“It will be a great loss for the urban forest,” Siewert said of ash trees, of which there are several varieties in Ohio. “It’s as catastrophic as the loss of the American Elm.”
Siewert said he doesn’t have an estimate for what percentage of Ohio trees are ash — but says 5 percent to 10 percent of its street trees are ash.
It was a top choice for Ohio street trees because it is “tough” and has a long life. Some commercially available chemical treatments can be used to protect a tree from the bug, but they are too expensive for widespread use, Siewert said.
Siewert first observed emerald ash borer along U.S. Route 422 in Southington Township last April while assisting his daughter after her car slipped off the road near the Trumbull-Portage county line. Lab results confirmed the infestation.
Siewert returned to that area recently to peel the bark off of several ash trees to reveal the larvae under the bark and to point out the distinctive “D” shaped exit hole an adult beetle makes as it leaves the tree.
“This is the end point,” Siewert said of a dead ash tree along US Route 422. “At this point, it’s really standing firewood.”
The tree, one of several like it in the area, was leafless. With part of the bark removed, one could see the curvy, zig-zagging trails the larvae had made as they fed themselves. The trails were extensive, circling the entire bottom of the tree.
Because emerald ash borer has been destroying that particular tree for three to five years, Siewert said it’s likely that the infestation has reached farther south and east into Trumbull County by now.
The infestation can be hard to identify because it starts high in the tree where most people can’t see anything, Siewert said.
There also are diseases and weather conditions that kill ash trees, Siewert said, so it would be wrong to assume that all dying ash trees are being attacked by the bug, Siewert said.
There also are two other types of ash borer that feed on weak ash trees but don’t kill them. The red-headed ash borer and clear-winged ash borer also make trails in ash trees, but the bug waste they leave behind is usually “kicked out” of the tree rather than left inside like the Emerald Ash Borer, Siewert said.
Don Augusta of Route 422 is one Southington resident who has noticed a lot of dead and dying ash trees on his property in recent years. But Augusta said he didn’t know what was causing it.
Siewert pointed out ash trees with the borer near Augusta’s property, but said photographs taken by The Vindicator of dead ash trees farther back from the road on Augusta’s property didn’t indicate the presence of EAB even though the trees had bug trails under the bark.
“I’m concerned because I’m a nature guy, and my ash trees are dying,” Augusta said.
Siewert compared the steady march of the emerald ash borer east and south through Ohio to a tidal wave whose crest is just west of Cleveland in the Elyria area and its leading edge is a line south from Mentor to just west of Akron.
The emerald ash borer infestations in Trumbull and Mahoning counties are “ripples,” Siewert said.
The borer is the most destructive tree disease or infestation in Ohio right now, Siewert said, with the problem likely to kill nearly every ash tree in Trumbull County by the end of this decade.