What is Emerald Ash Borer?

Emerald Ash Borer (EAB) is an invasive insect that kills ash trees by tunneling under the bark and feeding on the tree. It has killed millions of trees throughout the United States. EAB kills both weak and healthy ash trees. The state of Minnesota is home to nearly a billion ash trees, making the impacts of Emerald Ash Borer significant. Emerald Ash Borer has been detected in neighboring cities since early 2023 and confirmed in Hanover by the Minnesota Department of Agriculture in early October 2024.

 

How do I know if I have Ash trees or if they are infected?

Here's a helpful video from the MN Department of Agriculture to help identify ash trees and potential EAB infestations:

• Be sure you’ve identified an ash tree. This is an important first step since EAB only feeds on ash trees. Ash have opposite branching – meaning branches come off the trunk directly across from each other. On older trees, the bark is in a tight, diamond-shaped pattern. Younger trees have a relatively smooth bark.
• Look for woodpecker damage. Woodpeckers like 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 larval (S-shaped) tunnels underneath.
• Contact a professional. If you feel your ash tree may be infested with EAB, contact a tree care professional or the MDA at reportapest@state.mn.us or 888-545-6684

 

What can I do if I have ash trees in my yard?

Ash trees can be treated with an insecticide to prevent emerald borer infestation but must be repeated every two to three years for the life of the tree. If you do not wish to treat your trees, consider having them removed now. If your ash trees become heavily infested or dead, it will be more expensive to cut down and remove later because the trees become dangerous to cut down.

• Emerald Ash Borer Information for Homeowners | MN Department of Agriculture

• Decision Guide for Managing Ash Trees | Hennepin County Environment and Energy
• Emerald Ash Borer Homeowner Insecticide Guide | MN Department of Agriculture & MN Department of Natural Resources

 

What can I do to help prevent the spread of EAB?

Emerald Ash Borer moves quickly when people move infested ash firewood. A quarantine has been placed in a growing number of counties to help prevent its spread. Firewood and other ash products are regulated by the Minnesota Department of Agriculture.

Three easy steps residents can take to help keep EAB from spreading:

• Don’t transport firewood. Buy firewood locally from approved vendors, and burn it where you buy it.
• Be aware of the quarantine restrictions on movement of products such as ash trees, wood chips, and firewood.
• Monitor your ash trees for infestation. If you think your ash tree is infested, go to https://www.mda.state.mn.us/eab-info-homeowners for resources on identifying EAB, how to hire tree care professionals, and insecticide options for protecting your ash tree.