By David Steinkraus
Journal Times | Posted: Monday, August 4, 2008 12:00 am
Experts kept saying that it was probably just a matter of time, and the time arrived on Monday when state officials announced that the emerald ash borer has been found in Wisconsin.
The site is a private woodlot near the village of Newburg in Ozaukee County, said a press release from the state Department of Agriculture, Trade and Consumer Protection. But the infestation didn't stop there. Patti Nagai, horticulture educator with the University of Wisconsin-Extension in Racine County, said a tour on Monday included several trees in the village which were also infested by the borer.
Where the insects came from no one knows, but perhaps that can be determined as specialists continue their investigations, said Jane Larson, a spokeswoman for DATCP. Given the fact that the trees in the woodlot were dead, the insects may have been in the area for some years.
So far the state has imposed a quarantine to restrict the movement of firewood, ash trees from nurseries, or any other wood which could spread the borer. There are also 64 trees that will be taken down this fall, Larson said. Further actions will depend on the results of the state's investigation as well as findings from the ash borer traps blanketing southeastern Wisconsin.
Before its presence in Wisconsin was disclosed, the nearest known borer infestation had been in Algonquin, Ill., about 20 miles from the Wisconsin state line. Since it was found in the Detroit area in 2002, the borer has killed millions of ash trees in the United States and Canada.
Borer control
The future for ash trees isn't dim, however. Several years' worth of information show some insecticides can fight borers and help preserve a tree, said Chris Williamson, associate professor of entomology at the University of Wisconsin-Madison. For several years he has studied emerald ash borer infestations in Chicagoland.
"At low population density, in other words the early years of infestation, this pest is nearly impossible to detect, and that is the biggest problem," Williamson said.
All the chemicals available now are to be used on trees already infested, sometimes by a property owner, sometimes by a trained applicator, he said, and they can do well on trees that have 40 percent or more of their canopies intact. ("As long as you follow - always, always follow - the label directions the risk is pretty low.") But chemicals aren't recommended unless a tree is within 10 to 12 miles of the site of an infestation.
Chemical use wouldn't be appropriate now in Racine
County, Nagai said. They will have an effect on the environment, and there's a question of cost. Application may be prohibitively expensive except to preserve one particularly nice tree.
At this time, people should look at their trees and know what they have, she said. Some trees are in natural decline; some are under attack by native borers. "Or they have a mountain ash, which is not an ash at all, and it's not subject to this particular insect."
It's also important to learn about the bug, she said. "We've had people bring in hornets and all sorts of insects they think were emerald ash borer."
Extension staff can help people identify trees or insects from specimens or pictures brought to the Extension office at the county's Ives Grove office complex, 14200 Washington Ave., in Sturtevant.
But of first importance, Nagai said, is that if people suspect they have seen an emerald ash borer then the state wants to know about it.
Where to get help
If you think you know of a tree infected with the emerald ash borer, you can call the state hot line at (800) 462-2803.
You can also find information from the state government's ash borer Web site at http://www.emeraldashborer.wi.gov or from one put together by scientists at the University of Wisconsion-Madison at http://www.entomology.wisc.edu/emeraldashborer which includes information on insecticides and has comparison pictures of the borer and other insects which may be confused with it.