The invasion of the emerald ash borer is creeping closer to Douglas County.

Last week, the Minnesota Department of Agriculture placed Stearns County under an emergency quarantine after the tree pest was found in the city of Sauk Centre.

City workers there noticed several trees that showed signs of EAB damage and alerted the MDA. Department of Agriculture staff then examined the trees and collected samples of emerald ash borer larvae for confirmation.

Because this is the first time EAB has been identified in Stearns County, the MDA is enacting an emergency quarantine to limit the movement of firewood and ash material out of Stearns County. This will reduce the risk of further spreading the tree-killing insect, according to state ag officials.

A total of 18 Minnesota counties, including Stearns, are now under a full or partial quarantine to prevent the spread of this highly destructive tree pest. Douglas and Todd County are not on the list.

"Given the location of this find, we can be certain that emerald ash borer was brought into Stearns County by someone moving EAB-infested ash," said Mark Abrahamson, director of MDA's Plant Protection Division in a news release. "This highlights the importance of quarantines and the need to limit the movement of firewood and other ash products around the state to protect our ash trees."

The ash borer issue has long been a concern in the Douglas County area because it has an abundance of ash trees that are at risk. Douglas County has one of the highest populations of ash trees in the state - between 15,000 and 50,000, according to the Department of Natural Resources.

The ag department offers these three steps Minnesotans can take to keep EAB from spreading:

• Don't transport firewood. Buy firewood locally, purchase heat-treated certified firewood, and burn it where you buy it.

• Be aware of the quarantine restrictions. If you live in a quarantined county, be aware of the restrictions on movement of products such as ash trees, wood chips, and firewood.

• Watch your ash trees for infestation. If you think your ash tree is infested, go to and use the "Does my tree have Emerald Ash Borer?"guide. Suspect infestations can be reported to MDA's Arrest the Pest line at 1-888-545-6684 or

Emerald ash borer 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 invasive insect was first discovered in Minnesota in 2009 and is now found in 35 states.

Minnesota is highly susceptible to the destruction caused by EAB, said agriculture officials. The state has approximately one billion ash trees, the most of any state in the nation.