Emerald ash borer found in Esko

Thomson Township is the latest Carlton County area to learn it is now home to the emerald ash borer, an invasive forest pest known for its devastating impact on ash trees.

Jonathan Osthus, technical assistance coordinator with the Minnesota Department of Agriculture, informed the township that the MDA had located an infested ash tree at 16 E. Highway 61 in Esko. The area already falls within what is considered a “generally infested” area, which means any ash tree not currently being treated has a high likelihood of already being impacted by EAB, whether showing symptoms or not.

Anyone with ash trees they prefer to not lose should begin insecticide treatment, Osthus advised, provided the tree looks healthy with no more than 30 percent canopy decline. Trees should not be removed during late spring or summer when EAB is actively flying. Residents are asked to avoid moving firewood from one location to another, and use only locally sourced firewood.

The MDA has links and a host of EAB information on its website, http://www.mda.state.mn.us/eab.

EAB was discovered in Minnesota in 2009 and Duluth in 2015. Osthus found the first infested tree in Cloquet in April 2022. Fond du Lac officials announced the discovery of infested trees in June 2024.