Mankato-Emerald Ash Borer (EAB), an invasive species, has been confirmed in the City of Mankato for the first time. Infested trees were discovered by the Minnesota Department of Agriculture (MDA) as part of a routine tree survey. View a Minnesota EAB status map.

Residents are encouraged to watch for signs when checking for EAB:

  • Identify ash trees. EAB only feed on ash trees. Ash have branches that come off the trunk directly across from each other, known as opposite branching. On older trees, the bark is in a tight, diamond-shaped pattern. Younger trees have relatively smooth bark.
  • Look for woodpecker damage. Woodpeckers eat EAB larvae and woodpecker holes may indicate the presence of EAB.
  • Check for bark cracks. EAB larvae tunneling under the bark can cause the bark to split open, revealing the S-shaped larval tunnels underneath.
  • Contact a professional. If a tree is believed to be infested with EAB, contact a tree care professional, City of Mankato Natural Resources Specialist Justin Lundborg, or the MDA at [email protected] or leave a voicemail at 888-545-6684.

About EAB
EAB 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. Minnesota is highly susceptible to this invasive insect because it has approximately one billion ash trees, the most of any state in the nation.

How EAB Spreads
The biggest risk of spreading EAB comes from people unknowingly moving firewood or other ash products harboring larvae.

Follow these steps to help reduce the spread of EAB:

  • Don’t transport firewood. Buy firewood locally from approved vendors, and burn it where you buy it.
  • View Blue Earth County EAB quarantine information and be aware of the restrictions on moving products such as ash trees, wood chips and firewood.
  • Watch your ash trees for infestation. If you think your ash tree is infested, visit the MDA EAB Information for Homeowners guide for resources on identifying EAB, how to hire tree care professionals and insecticide options for protecting your ash tree(s).

Find more information and resources on the City’s EAB webpage. For more information contact staff at 311 or 507-387-8600.