Miami Valley styles
Cold weather arrives
'Tis the Season Festival
Protecting ash trees from borer may take insecticide or a foreign wasp
Some areas have set up yards to chip infested trees and are configuring power plants to burn the wood.
Saturday, July 14, 2007
What can you do when your ash trees are at risk from the emerald ash borer?
Experts suggest that you can dose the trees with insecticide, perhaps attack the borer with Chinese wasps or just let nature and the borer take their course and use your freshly cut wood for the fireplace or to make furniture.
Extras
Photos
In Detroit, where the borer first made its appearance, yards were set up to chip infested trees. The chips powered cogeneration power plants.
In Chicago, power plants are being configured to burn the wood. There's been talk of building a plant to make tool handles.
"People need to prepare for the wood that is available," said Mike Prouty, field representative for the USDA Forest Service, in St. Paul, Minn. "There's a lot of ash in urban areas."
Just how much ash is out there is debatable. Dan Balser, forest health specialist with the Ohio Division of Forestry, estimates there are 3.5 billion to 5 billion ash in Ohio, including seedlings. Trees an inch or larger in diameter probably number 254 million.
The trees include white ash, common on upland ground; green and black ash, found in swamps and near streams; blue ash on limestone soils and pumpkin ash found in wetlands.
All are susceptible to the borer, which kills all trees within three to five years of infestation.
Ornamental trees can be protected by homeowners, said Dan Herms, professor of entomology at Ohio State University and a member of the Ohio Department of Agriculture's borer task force.
If there's a special tree that someone wants protected, it would be a good idea to start soon. Herms is recommending products containing imidacloprid, such as Bayer Advanced Tree & Shrub Insect Control.
It's a root soak homeowners can pour at the base of a tree. It should be used in the first year an insect starts attacking, Herms said.
The city of Oakwood this month treated more than 100 ash trees in parks, on boulevards and in the business district with an imidacloprid insecticide. It's hoped the treatment will last two years, said Carol Collins, director of Leisure Services. Trees between sidewalks and curbs in the city have not been treated, she noted. They're in the city right of way and the city trims them, but homeowners are otherwise required to take care of those trees, she said.
An inventory found more than 400 ash in the city. "Some homeowners have already taken care of it," Collins said. "The city will work with homeowners to guide them in the right direction."
A more permanent solution is being proposed that involves releasing a tiny, stingless parasitic wasp that is native to China, just like the borer.
Leah Bauer, a USDA research entomologist based in Lansing, Mich., who has been working with the wasp for the past five years, has thousands of the wasps ready and waiting, she said.
Federal officials are evaluating public comments on the proposed release, said Sharon Lucik, USDA spokeswoman. Michigan, where the borer has hit hardest, would be the only state where the wasps would be released initially. An environmental assessment by wasp researchers showed they could survive in Michigan's climate and kill up to 75 percent of the borers.
Female wasps find their way to ash trees by smell and use antennae to listen for borer larvae feeding beneath tree bark. The wasp then drills through the bark and into the larvae, laying its eggs. When the wasp eggs hatch, they feed on the borer larvae and kill it.
The greatest risk, said Herms, is that the Chinese wasps could harm native wood borers, which are an important part of the ecological cycle. But the potential loss of North America's ash trees outweighs the risks of a release, he said.
"It's probably worth trying," Herms said. "It's impossible to predict how effective it will be. It won't stop the borer, but whether it slows it down remains to be seen."
Contact this reporter at (937) 225-7407 or sbennish@DaytonDailyNews.com.
