Posted: 12:05 a.m. Monday, July 1, 2013

Options limited for dealing with emerald ash borer

By Kevin O'Donnell

Staff Writer

Cities and citizens’ options for dealing with the “wild fire” of the emerald ash borer that has engulfed the Miami Valley, are limited: treat them or take them out.

The ash borer, whose larvae eat phloem tissue of ash trees, can be killed with insecticide but because they must be applied annually to beat back the beetle, some cities find treatment cost prohibitive compared to removing the ash.

“Some companies are saying they can get two or three years out of a treatment, but that gets pretty expensive,” said Larry Early of the Miamisburg Parks Department.

Success rates for treatment vary depending on product and how well users follow the directions, according to Ohio State entomology professor Joe Boggs. “You might hear people say ‘treatments aren’t effective.’ That’s simply not true,” said Boggs, who recommends calculating tree benefits before taking action.

Of the 600 ashes treated by Emamectin benzoate injection, TREE-age, in Five Rivers MetroParks, almost all have avoided the beetle’s bite, Director of Conservation David Nolin said. On the other hand, Springboro began treating with TREE-age later in the season and saw only two of 20 ashes survive, said Assistant Public Works Officer Vince Murphy.

“It was a matter of detection, we were more worried about getting trees taken down for reasons of public safety. So we treated the ones in public property later and didn’t know where they were in the infection process,” said John Brown, a certified arborist with Springboro Parks.

Injections that cover a tree for two years usually require the expertise of a certified arborist, Boggs said.

Cities are recommended to take inventory of trees to identify which need treatment or removal. Since 2006, Kettering Parks have treated several hundred ashes with Safari, a dinotefuran bark spray. Matt Byrd, parks supervisor in Kettering, said an annual treatment costs between $25 and $30 per tree with the city’s in-house crew, as opposed to the thousand dollar price tag of removing a tree. Those prices can vary wildly for homeowners depending on tree size and location.

Horticultural resources provide comparisons of treatment methods and timing, but the best option depends on the situation and level of expertise with tree care. If visible signs of damage appear, the borer has probably already killed the tree, which must be removed.

Bayer’s Imidacloprid insecticide is most common for homeowners, but incorrect or late application is a deal breaker. If the soil is too wet or too dry or if mulch covers the roots by the trunk, then the tree won’t soak up the chemical that kills EAB.

Knowing proper plant diagnosis can help catch EAB in the linear phase before treatment becomes ineffective. By the time dead limbs and bore holes appear on the tree, it’s probably too late to save, according to Jason Muchmore, manager at Davey Tree.

In hiring tree contractors, Jim Breniger, Dayton manager of street maintenance, suggests homeowners get a bonded and insured company with ISA certified arborists for consultation.

He said ashes should be removed or treated before they show deadwood, which usually indicates irreparable trunk damage.

“A lot of citizens are still in denial. If they have some green in that tree they think it’s still alive,” said Breniger.


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