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 33 states and 4 Canadian Provinces (map). The Federal EAB quarantine covers much of the eastern US, with scattered detections in South Dakota, Nebraska, Kansas, Oklahoma, Texas, and Colorado. EAB was first 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. Since then, infestations have been discovered throughout the southern half of Wisconsin and several of the Northern counties.
Previously, the emerald ash borer quarantine in Wisconsin was determined on a county-by-county basis. However, as of March 30, 2018, the entire state has been placed under quarantine. An interactive map showing Wisconsin municipalities with known EAB infestations can be found here. For additional details of the 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 typically more prone to borer attack, the Emerald Ash Borer can attack and kill both healthy and stressed trees.
The main defense in Wisconsin is to identify infestations before they can become widespread. THis will allow local municipalities and other groups time to prepare and take appropriate actions. 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 Resources 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.