Contact: Jane H. Larson (608) 224-5005 Cell (608) 212-3094
MADISON–State and university plant specialists are telling Wisconsin homeowners who are concerned about the recent find of an ash boring tree pest in Illinois, that applying pesticides to ash trees is not necessary at this time.
“First of all, we have not identified emerald ash borer in Wisconsin,” emphasized Bob Dahl, Department of Agriculture, Trade and Consumer Protection plant regulation section chief. “Hiring a company to apply pesticides to your ash trees isn’t necessary right now and it might be a potential waste of money.”
According to information from Michigan State University, trees located more than two miles from an infestation don’t need pesticide applications for EAB. Pesticide treatments are only recommended for trees within a quarantine area around a known infestation.
“The extent of the infestation in Illinois hasn’t been determined and the current area that is being checked is about 40 miles from Wisconsin’s southern border,” Dahl said.
Should the ash boring beetle be identified in Wisconsin, then each homeowner near an infestation would need to make a decision based on the cost of the treatment versus the value of the tree, the health of the tree and if they are within a quarantine area.
“Pesticide applications to ash trees can be costly and they must be done every year. Also, if the tree is in poor overall health, pesticides may not be effective or worthwhile,” said Dr. Chris Williamson, Turfgrass and Ornamental Specialist, Department of Entomology, University of Wisconsin-Madison. “Also, if you are in an area where state officials decide to remove all ash trees, those treatments will go to waste.”
Although EAB will attack healthy trees, they may not die as quickly as a tree that is stressed from other factors including other insect pests, disease, drought, or environmental stress. Thus, maintaining the overall health of your trees is important.
“If EAB is found in Wisconsin and you are in an EAB quarantined area, based on research results from Michigan, insecticide treatments appear to be more effective on healthier trees,” Williamson said.
According to Williamson, should you choose to treat your ash trees, you have two options: 1) hire a licensed pesticide applicator such as an arborist, landscape specialist, or tree and shrub expert or 2) do-it-yourself.
“For the do-it-yourselfers there is a consumer treatment option available that can be purchased at garden centers or big-box stores, called Bayer Advanced Tree & Shrub Insect Control(tm),” Williamson said. “Be sure to read and carefully follow all label instructions before using the product.”
There are other steps to prevent and limit EAB in Wisconsin. Follow the Department of Natural Resources’ current ban on bringing out of state firewood into state parks or DNR-managed property. Your firewood will be confiscated and you may be violating federal and state laws if the wood originated from an area infested with EAB. If you are going camping, buy local firewood near your camping site.
If you are planning some home landscaping, select non-ash trees to add diversity and variety to the trees around your home.
“Learn the signs and symptoms of EAB so if your trees become infested, you can contact authorities as soon as possible,” Dahl said.
For more information on EAB, visit http://www.entomology.wisc.edu/emeraldashborer. The web site has identification information for EAB and ash trees, symptoms to watch for and EAB look-alikes. If you suspect you might have EAB, contact the EAB hotline at 1-800-462-2803.
