Welcome to the UW-Madison Emerald Ash Borer Information Page
The Emerald Ash Borer (Agrilus planipennis) was discovered in Michigan in June 2002. It is a species of metallic wood boring beetle (Buprestidae) that attacks ash (Fraxinus), usually killing trees in one-three years, when beetle populations are high. When beetle populations are low (i.e., a new infestation) it can take 5 or more years for trees to die.
This beetle has been found in at least 19 states and two Canadian Provinces (map). The majority of the known infestations occur in a band from the Detroit and Cleveland area west to the greater Chicago area. All counties in the lower peninsula of Michigan and Ohio are under some form of quarantine as well as much of northern Illinois and Indiana. Isolated infestations of EAB have now been found in Connecticut, Illinois, Indiana, Iowa, Kansas, Kentucky, Maryland, Massachusetts, Michigan, Minnesota, Missouri, New Hampshire, New York, Ohio, Pennsylvania, Tennessee, Virginia, West Virginia, and Wisconsin. This insect was found in southeast Wisconsin in July of 2008, southwest Wisconsin in April of 2009, and was detected in Brown County (Green Bay area) in July 2009. Currently, 15 Wisconsin counties have been quarantines for EAB: Rock, Walworth, Kenosha, Racine, Milwaukee, Waukesha, Washington, Ozaukee, Sheboygan, Fond du Lac, and Brown in the eastern part of the state, and La Crosse, Vernon, Crawford and Trempealeau counties along the Mississippi River. A list of municipalities with known EAB infestations can be found here. So far in 2013, EAB has been confirmed in five new cities, towns, and villages in southern Wisconsin. For the most recent information on the current EAB quarantines in Wisconsin, visit the WIsconsin DATCP EAB website.
Why the Concern?
Emerald Ash Borer (EAB) is an aggressive wood borer that attacks and kills all species of ash. Ash wood is used in making flooring, baseball bats, tool handles, and cabinets. It is estimated that there are well over 700 million ash trees in Wisconsin. Although stressed trees are always more prone to borer attack, evidence from Michigan suggests that healthy, well maintained trees are also attacked and killed by this beetle.
The main defense in Wisconsin is to identify and destroy infestations before they can become widespread. The most likely source of problems is infested firewood that has been brought into the state from infested areas. For this reason, the Department of Natural Resouces is conducting a statewide survey of state forests and parks, specifically looking for signs of this insect. The insect can also be transported in infested nursery stock. The Wisconsin Department of Agriculture, Trade and Consumer Protection will be conducting a statewide survey of nurseries, searching for signs of this insect. The Wisconsin Department of Agriculture, Trade and Consumer Protection also conducts trapping efforts using prism traps.