Don’t treat ash trees despite the presence of EAB in Wisconsin
Source: Jeffrey Hahn, entomologist, U of M Extension
Contact: Catherine Dehdashti, U of M Extenison, (612) 625-0237
Don’t treat ash trees despite the presence of EAB in Wisconsin
ST. PAUL, Minn. (8/25/2008)
With the recent news that emerald ash borer was discovered next door in Wisconsin, there is a greater sense of urgency to take some kind of action to protect Minnesota’s ash trees. A natural reaction to this potential threat is to have insecticide treatments applied to your ash trees now before it’s “too late.” But is that really the best thing to do?
“The answer is an emphatic no!” says Jeff Hahn, University of Minnesota Extension entomologist. “Emerald ash borer has not yet been found in Minnesota, so chemically treating trees to protect them makes little sense.”
“University experts throughout the emerald ash borer-infested states do not advise insecticide treatments without a confirmed infestation within 12 to 15 miles,” Hahn added.
Current insecticide treatments for emerald ash borer require a yearly application to the tree via stem injection or soil application. No one knows when emerald ash borer will be found in Minnesota, and more particularly no one knows when emerald ash borer will be found in the part of the state where you live. If you begin preventative treatments for emerald ash borer without the presence of a verified infestation of this pest, you are risking years of unnecessary applications and expense.
It is true that emerald ash borer has gone undiscovered for five or more years in many infested areas. When emerald ash borer is discovered in Minnesota, we may find that it has been here that long, too. However, emerald ash borer does not kill every tree in an area overnight. “The fight against emerald ash borer will play out over many years, even after it is found in Minnesota,” says Hahn. “There will be time to react once emerald ash borer is actually found here.”
So what can you do in the meantime to help in the fight against emerald ash borer?
Hahn says that one of the most important ways you can help is by not moving firewood even within Minnesota. “Hitchhiking” in loads of firewood is the primary way emerald ash borer moves into previously uninfested areas. Always buy firewood locally from reputable, professional vendors. When camping, try to buy your firewood on site. Don’t bring firewood home with you—either burn it or leave it at the site.
Be on the watch for ash trees that are dying for unknown causes. You can go to the Minnesota Department of Agriculture website for information on how to recognize emerald ash borer, and distinguish it from look-a-likes (not all green insects are emerald ash borers). The website also explains how to recognize the symptoms of emerald ash borer-infested trees and how to report possible cases.