Emerald Ash Borer Found in Rock County

Emergency quarantine on wood movement put in place for Rock County

St. Paul, MN: The Minnesota Department of Agriculture (MDA) has confirmed emerald ash borer (EAB) in Rock County for the first time. There are now 51 counties in the state, including Rock, with EAB.

An arborist working in Rock County discovered an EAB infestation near Beaver Creek about 5 miles from the South Dakota border. The arborist reported the infestation via the MDA’s Report A Pest service. EAB larvae was later found, and samples were collected by MDA staff. Federal identification confirmed the samples as 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 Rock County, the MDA is enacting an emergency quarantine of the county. The quarantine limits the movement of firewood and ash material out of the area.

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 Rock County will be held on Wednesday, May 8, 2024, from 10–11 a.m. Experts from the MDA will give a brief presentation followed by a question-and-answer session.

Emerald Ash Borer Virtual Informational Meeting:
May 8, 2024
10–11 a.m.
Register at www.mda.state.mn.us/eab

The public will also have an opportunity to provide input on the proposal to add Rock County’s emergency quarantine to the state’s formal quarantine. The MDA is taking comments on the proposed formal quarantine now through June 10, 2024, and recommends adopting the quarantine on June 12, 2024. The proposed quarantine language can be found at www.mda.state.mn.us/eab.

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
[email protected]

There is more EAB information on the MDA website.

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