Emerald Ash Borer found in Faribault County

This invasive insect from Asia targets ash trees. First detected in the United States in 2002, the Emerald Ash Borer (EAB) is now found in fourteen states centered on the Great Lakes basin. Approximately 130,000 square miles are considered infested, representing 7 percent of the native range of North American ash species. The total value of the annual harvest of ash timber is estimated at $150 million. Many species of ash are riparian, filling important niches in the ecosystem, and ash has been widely planted in urban landscapes. In FY 2010, APHIS anticipates spending $37.2 million to protect the nation’s remaining ash resource from emerald ash borer.

The Minnesota Department of Agriculture (MDA) has confirmed the presence of emerald ash borer (EAB) in Faribault County for the first time. There are now 40 counties in the state, including Faribault, with EAB.

While conducting a visual survey for EAB, MDA staff discovered an infestation of the invasive pest at a rest area off I-90 westbound near the city of Blue Earth. Staff collected larvae and sent them in for confirmation. 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 Faribault County, the MDA is enacting an emergency quarantine of the county, which 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 Faribault County will be held on Thursday, April 13, 2023. Experts from the MDA will give a brief presentation followed by a question-and-answer session.