Emerald ash borer (EAB) is a destructive insect that has killed millions of ash trees in Michigan, Indiana, Illinois, Ohio, and Ontario, Canada, since it was first discovered in the U.S. in the early 2000s. Since then, EAB has spread into Wisconsin and Minnesota and has been confirmed in St. Paul, Minneapolis, and Houston County in southeast Minnesota. EAB attacks all species of ash trees and causes tree death in two to three years.
Currently, there is no known cure or widespread prevention for this destructive insect. A high-valued landscape tree can be protected by various insecticide treatments. Forestry staff is watching for ash trees displaying symptoms of emerald ash borer.