By Megan Hopps
SUN PRESS Newspapers
Emerald Ash Borer (EAB) is an exotic beetle that was first discovered in southeastern Michigan in the summer of 2002.
The adult beetles nibble on ash foliage, but cause little damage. The larvae, however, feed on the inner bark of ash trees, disrupting the tree’s ability to transport water and nutrients to the branches and leaves.
“It affects all white, green and black ash trees,” said Minnesota DNR’s Forestry and Invasive Species Program Coordinator, Susan Burks. “And some blue ash as well.”
Ash Borer really became a problem in Minnesota in 2009 when it was discovered in Ramsey, Hennepin and Houston counties. Later that year, these counties were quarantined by the U.S. Department of Agriculture Animal and Plant Health Inspection Service.
“It’s not here yet,” said City of Champlin’s Tree and Weed Inspector, Craig Wissink. “But that doesn’t mean we’re not concerned.”
The city is currently in the process of setting up an Emerald Ash Borer Management Plan in case the little buggers do shack up in Champlin’s ash trees. “We are still doing evaluations and formulating a plan,” said Wissink.
Some cities are making plans to slowly cut out the ash trees and replace them with other species. But Wissink says that’s not what Champlin plans to do. “Right now, we are leaving our trees as is,” said Wissink.
And for good reason. Most cities tree make up is anywhere from 30 to 60 percent ash trees. “Minnesota has more ash trees than any state in the county,” said Burks.
A total of 998 million ash trees in fact. And there’s no telling how the beetle could change Minnesota’s ecosystem if it’s not contained. “If we lose the ash trees, we’ll lose the ground cover,” Burks said.
And what it does to the environment is only one potential problem. “This can be a huge infrastructure problem as well,” said Burks. “Once EAB starts to take over the tree it becomes very brittle. This can be a safety concern, the trees become hazardous.”
A major culprit in spreading EAB and other insect pests is firewood. Larvae and pupae can hide beneath the bark and escape as adult beetles after being transported many miles. Many of the places where it was found are parks and campgrounds. People carried EAB with them when they brought infested firewood on a picnic or camping trip.
“The best way to prevent it from spreading is not to move raw wood materials,” said Burks. And that means burning wood in the same city its purchased. “Outreach, education and regulation are our main priorities right now,” explains Burks. “Larger industries are easier to monitor than private ones.”
A number of insecticides, some of which can be applied as a soil drench or injectable are available for protecting individual trees. These are only good for trees with a 20 inch diameter trunk. Some can be used to pre-treat the trees before an infestation occurs.
“Right now the DNR is looking at what ash they have and where it’s located,” said Burks. “Then comes the tricky part. They need to look at our budget remove infested trees, pre-treat healthy ones and replant when necessary.”
And the DNR along with the county and the cities of Dayton and Champlin need their residents help. By never moving firewood, burning it where it was purchased and knowing the signs of an infested ash tree, residents can help stop the spread of the Emerald Ash Borer.
Ash trees tend to have “tight” bark with a distinct pattern of diamond shaped ridges. Its leaves are compound and composed of anywhere between five and 11 leaves. If the tree has been infested with EAB it will show signs of dieback at the tops of the canopy and sprouts will begin to grow at the bottom of the trunk. The bark may split to expose S-shaped galleries and small, D-shaped holes in the bark of the tree.
To learn more about Emerald Ash Borer and how to protect your neighborhood from an infestation visit the U.S.D.A.’s website at stopthebeetle.info.
Contact Megan Hopps at [email protected]