March 2, 2023

The Minnesota Department of Agriculture (MDA) has confirmed the presence of emerald ash borer (EAB) in Clay County for the first time. There are now 39 counties in the state, including Clay, with EAB.

A Moorhead city forester found evidence of EAB while pruning trees. The tree had visible woodpecker damage and when the bark was peeled back galleries and insect larvae were present. MDA staff collected the suspected EAB larvae samples. Federal identification confirmed emerald ash borer.

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. Often, the trees show several signs of infestation because of this. 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 Clay County, the MDA is enacting an emergency quarantine of the western portion of the county, from State Highway 9 west to the North Dakota border, which limits the movement of firewood and ash material out of the area.

In addition to this being the first EAB find in Clay County, this is also the first EAB find in northwestern Minnesota. The detection is unfortunate but not unexpected, given the location is near a highly traveled corridor in the state. The public can help limit the spread of this harmful forest pest by not moving firewood and reporting any suspected infestations via the MDA’s Report a Pest service.

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 Clay County will be held on Thursday, March 16, 2023. Experts from the MDA will give a brief presentation followed by a question-and-answer session.

Emerald Ash Borer Virtual Informational Meeting:
Thursday, March 16, 2023
10-11 a.m.
Register here

The public will also have an opportunity to provide input on the proposal to add Clay County’s emergency quarantine to the state’s formal quarantine. The MDA is taking comments on the proposed formal quarantine now through April 14, 2023, and recommends adopting the quarantine on April 17, 2023. The proposed quarantine language can be found at

Comments can be made during the virtual meeting or by contacting:

Kimberly Thielen Cremers
Minnesota Department of Agriculture
625 Robert Street North
St. Paul, MN 55155

There is more EAB information on the MDA website.


Media Contact
Allen Sommerfeld, MDA Communications