Emerald ash borer found in 3 new Minnesota counties, quarantines expanding

(FOX 9) - Emerald ash borer, an insect larvae that kills ash trees by tunneling through them and depriving nutrients, has been confirmed in three new Minnesota counties.

Emerald ash borer confirmed in Minnesota

What we know:

According to the Minnesota Department of Agriculture (MDA), the emerald ash borer was first discovered in Minnesota in 2009.

After being confirmed in Aitkin County for the first time last winter, emerald ash borer has now been confirmed in 54 of 87 counties throughout Minnesota.

An update provided on Friday by the MDA indicates emerald ash borer has now been confirmed in Malmo Township (Aitkin County), Norman Township (Pine county) and the City of Virginia (St. Louis County).

In Aitkin County, their presence was discovered by a county forester at a timber sale site, while residents in both Pine and St. Louis counties self-reported possible infestations that have since been confirmed.

In Pine and St. Louis counties, the infestations were discovered in new areas, leading to an expansion of quarantine areas.

The MDA also says that although no new emerald ash borer confirmations have occurred in Mille Lacs County, its quarantine is also being expanded due to its proximity to Aitkin County.

In April 2024, MDA issued an "emergency quarantine" on wood movement after officials confirmed the presence of emerald ash borer for the first time ever in Rock County, Minnesota.

Minnesota emerald ash borer quarantine

Dig deeper:

The MDA says it will be enacting emergency quarantines in Aitkin County and new areas of Mille Lacs, Pine, and St. Louis counties due to the confirmations.

All of Aitkin County will be quarantined, while expanded quarantine boundaries in Mille Lacs and Pine counties will put each of the counties under full quarantine. A quarantine in St. Louis County will also be expanded further north.

Quarantine efforts limit the movement of firewood and ash material out of the area to help reduce the risk of emerald ash borer in unconfirmed areas.

Fight emerald ash borer in Minnesota

What you can do:

Several treatments are available to kill emerald ash borer, usually involving the use of pesticides.

Systemic insecticides can be injected into a tree trunk, where emerald ash borer move throughout the tree – effectively killing their larvae. 

Soil drench insecticides are applied around the base of a tree, killing newly hatched larvae to stop their spread.

The Minnesota Department of Natural Resources (DNR) has previously announced over $25 million in grants are available for "urban and community forest management."