By Paul Cigan, DNR Forest Health Specialist, Hayward, Paul.Cigan@wisconsin.gov or 715-416-4920.
Emerald ash borer (EAB) has been discovered for the first time in Barron County, in the town of Lakeland. Dead and dying green ash were observed and larval specimens were subsequently lab-confirmed. Most of the green ash across a 20-acre area are either dead or dying from EAB attack.
This marks the 61st county of the state’s 72 to have an EAB discovery since first detected in 2008. To see where EAB has been found in Wisconsin or to report new municipal/township level detections, please visit the interactive Wisconsin EAB detections map.
Of Wisconsin’s ash species, green ash is highly vulnerable to EAB and supports the highest EAB densities, with a typical size tree at this site — 15 inches DBH — supporting the development of over 1,500 EAB adults. Estimates from a recent study in Michigan showed that a 40-acre green ash-dominated stand produced over a million adult EAB, with only about 2% green ash survival.
This detection serves as a reminder that EAB will continue to spread throughout the state’s north and is almost certainly more widespread than our maps and survey efforts can show. For that reason, it’s good practice to always keep management options for ash forests in mind when working with landowners and drafting timber management plans and sales. For more details on management options, check out the EAB Silviculture Guidelines. For more info on all things EAB in Wisconsin, refer to our new EAB webpage.