Extension > Garden > Insects > Emerald ash borer
Emerald ash borer
On this page
What you need to know
Emerald ash borer larvae
D-shaped exit hole
Adult emerald ash borer
Since 2002, emerald ash borer (EAB) has killed tens of millions of ash trees. With the largest concentration of ash trees in the country, Minnesota has much to protect. Here is what you need to know:
- Ash trees lack a way to defend against these pests. Unless protected with insecticides, they will be killed when they become infested.
- Look for woodpecker pecks and vertical bark splits on ash. Although this is not definitive for EAB, they are often associated with EAB infested trees.
- Look for 1/8 inch, D-shaped exit holes in trees. These are the result of borers leaving the tree once they have become adults.
- Do not apply insecticides to ash trees out of the known range of emerald ash borer (about 15 miles from confirmed infestations).
- For the most up-to-date information on EAB's location in the state and for EAB and firewood quarantines, visit the Minnesota Department of Agriculture's EAB site.
- Do not transport firewood, even within Minnesota.
- Extension has over 500 volunteers trained as Forest Pest First Detectors. These volunteers can help homeowners determine if their ash trees have been attacked.
- If you think you have found emerald ash borer, go through the steps at Do I have emerald ash borer? (246 K PDF) to try to confirm it.
Learn more about emerald ash borer in Minnesota or see the national emerald ash borer site for more information.
Identification
- Do I have emerald ash borer? (246 K PDF) – University of Minnesota Extension
- ¿Tengo el barrenador verde esmeralda del fresno? (Spanish) (419 K PDF)
- Insects in Minnesota that may be confused with emerald ash borer – University of Minnesota Extension
- Signs and symptoms of emerald ash borer (5 MB PDF) – Michigan State University
- Recognizing insect galleries in ash trees (3 MB PDF) – Minnesota Department of Agriculture
- Ash tree identification (8 MB PDF) – Minnesota Department of Agriculture
- Ash anthracnose or emerald ash borer? – University of Minnesota Extension
Where and when is emerald ash borer?
- Map showing EAB infestations in Minnesota – Minnesota Department of Agriculture
- Map of infestations in the U.S. (950 K PDF) – United States Department of Agriculture
- Degree day accumulation (base 50 degrees F): EAB is expected to start to emerge when the 450 degree day threshold is reached – University of Wisconsin Extension
Management
Urban
- Emerald ash borer cost calculator – Purdue University
- Managing emerald ash borer: decision guide (765 K PDF) – Michigan State University
- EAB management statement (1,021 K PDF) – Coalition for Urban Ash Tree Conservation
- The road to a thoughtful street tree master plan – University of Minnesota Extension
Landowners
- Ash management guidelines for private forest landowners – University of Minnesota Extension
- Other great resources can be found at MyMinnesotaWoods – University of Minnesota Extension
Tree care providers
- How to hire a professional arborist – University of Minnesota Extension
- Tree care company register – Minnesota Department of Agriculture
- Find a local professional forester – University of Minnesota Extension
Insecticides
General
- FAQs regarding potential side effects of systemic insecticides used to control emerald ash borer (307 K PDF) – University of Minnesota Extension
- Insecticide options for protecting ash trees from emerald ash borer (369 K PDF) – University of Minnesota Extension
- Special registration review of EAB insecticides: summary or full article – Minnesota Department of Agriculture
Resident
- Emerald ash borer: Homeowner guide to insecticide selection, use, and environmental protection (885 K PDF) – University of Minnesota Extension, Minnesota Department of Agriculture, and Minnesota Department of Natural Resources
Professional applicator
- Emerald ash borer insecticides: Label guidance for use limits – Minnesota Department of Agriculture
Wood disposal
- Ash tree waste disposal sites within Hennepin-Ramsey-Houston-Winona Counties – Minnesota Department of Agriculture
General
- Recommended trees for Minnesota – University of Minnesota Extension
- Emeral ash borer: what you need to know – Minnesota Department of Natural Resources
Classes
- Forest Pest First Detector program – University of Minnesota Extension
- Self study programs from Purdue Extension – Purdue University
- What you need to know to teach others about EAB (webinar) – University of Minnesota Extension
