They may not be from outer space, but emerald ash borers — small, invasive, iridescent green beetles — are attacking and killing ash trees here in Minnesota. All ash trees are susceptible to emerald ash borers (EAB), and Minnesota’s estimated 900 million ash trees are especially vulnerable because we have more ash trees than any other state. Ash trees make up about 15% of the trees in Minnesota communities, but in some cities, ashes account for as much as 25% to 30% of the tree canopy.
Emerald ash borers lay their eggs just inside the bark, and when the eggs hatch, the larvae eat the nutrient layer of the tree, causing it to sicken and eventually die. Check out the Minnesota Department of Agriculture’s video on the lifecycle of the emerald ash borer.
The current EAB infestation in Minnesota affects the Twin Cities area as well as Winona, but the insect spreads quickly, and there are no known native predators to stop emerald ash borers in North America.
It is common for people to unknowingly carry EAB with them by bringing infested firewood on a picnic or camping trip. To prevent further movement, counties are under state and federal quarantines which make it illegal to move any ash wood or products. EAB quarantines are now in effect for the counties of Hennepin, Houston, Ramsey, and Winona.
The most important thing you can do to protect Minnesota from EAB is to avoid moving infested ash wood. Here’s how:
- Buy firewood wherever you are camping instead of bringing it with you.
- Dispose of ash wood properly by observing the county quarantines.
You can help
EAB attacks native ash trees of any size, age, or stage of health. Take a moment to think about how many ash trees are in your yard, neighborhood, community, and woodlands. Then imagine those areas without ash trees. Trees that have been attacked by EAB can die within 2 years. Thus, EAB poses a devastating economic and environmental threat to our state. Help save ash trees or replace removed, infected trees.
- Learn to identify ash trees and EAB.
- Determine whether your tree is infested with EAB. Because larvae are inside the bark, it is often difficult to detect EAB. Visit MDA’s webpage “Does My Tree Have Emerald Ash Borer (EAB)?” to learn more. Contact the Minnesota Department of Agriculture’s program, "Arrest the Pest" if you see signs of EAB.
- When you cut your ash tree down or your tree is removed, replant with a new tree because we all benefit from trees
Benefits of trees
Trees alter our environment by fighting climate change and improving air and water quality.
Trees reduce air pollution and clean our atmosphere. Their leaves filter the air we breathe by removing tiny particles, like dust, and holding them on their surfaces. Trees also absorb greenhouse gases such as carbon dioxide and through photosynthesis convert the gases into oxygen. The oxygen is then released for us to breathe.
Trees help prevent water pollution by reducing stormwater runoff. Stormwater runoff is rainfall that flows over impermeable ground surface. Runoff can pick up pollutants found on paved surfaces and swiftly carry them to our lakes and streams. Trees reduce runoff by decreasing the amount of rainfall that hits the ground. Leaves and branches temporarily hold rain on their surfaces before releasing the water into the atmosphere.
Through shade, properly placed trees provide natural cooling that reduces our summer energy use for cooling houses and buildings. By reducing energy consumption, we also reduce carbon dioxide and other pollution emissions from power plants.