The Minnesota Department of Agriculture (MDA) has confirmed the presence of emerald ash borer (EAB) in Mille Lacs and Benton Counties for the first time. There are now 44 counties in the state, including Mille Lacs and Benton, with EAB.

Tree care professionals in both counties noticed trees with signs of an EAB infestation and made reports to the MDA. The Mille Lacs County infestation was discovered in Milaca along a set of powerlines. The Benton County infestation was found in a neighborhood in St. Cloud.

EAB was first discovered in Minnesota in 2009. The insect larvae kill ash trees by tunneling under the bark and feeding on the part of the tree that moves nutrients up and down the trunk. The trees show several signs of infestation. Woodpeckers like to feed on EAB larvae, and woodpecker holes may indicate the presence of emerald ash borer. Also, EAB tunneling can cause the bark to split open, revealing characteristic S-shaped galleries underneath.

Because this is the first time EAB has been identified in Mille Lacs and Benton Counties, the MDA is enacting an emergency quarantine which limits the movement of firewood and ash material out of the area. The quarantine area for Mille Lacs County will be the southern portion of the county south of Co. Rd. 11, from Benton to the Isanti County border. All of Benton County will be under the EAB quarantine.

The MDA issues quarantines for all areas known to have EAB to reduce the risk of further spreading the tree-killing insect.

A virtual informational meeting for residents and tree care professionals in Mille Lacs and Benton County will be held on September 28, 2023, from 10 – 11 a.m. Experts from the MDA will give a brief presentation followed by a question-and-answer session.

The public will also have an opportunity to provide input on the proposal to add Mille Lacs and Benton County’s emergency quarantine to the state’s formal quarantine. The MDA is taking comments on the proposed formal quarantine now through October 30, 2023, and recommends adopting the quarantine on November 1, 2023.