Emerald Ash Borer is in Minnesota
On May 14, 2009, emerald ash borer (EAB) was discovered and confirmed in the South Saint Anthony Park neighborhood in St. Paul. EAB is a serious invasive tree pest, and consequently a quarantine has been placed to help slow the spread of EAB to other areas.
NEW: The MDA has enacted an emergency quarantine for Wright County after the discovery of EAB. This emergency quarantine went into effect on September 13, 2018.
Guidelines to Slow the Growth and Spread of Emerald Ash Borer
The MDA, with help from partner agencies, has published a new document on emerald ash borer. This document provides communities and other entities responsible for ash trees in landscaped areas with guidelines to slow the spread of emerald ash borer into areas of Minnesota that are not yet infested. The document includes strategies for communities that have not yet seen EAB, communities where EAB is a recent arrival and those that are heavily infested.
Where is the EAB infestation in Minnesota?
Need a Tree Service?
The MDA recommends using the Tree Care Registry to begin your search for companies. All Tree Care Providers including companies and persons that provide tree care or tree trimming services and/or who remove trees, limbs, branches, brush or shrubs for hire in Minnesota are required by state statute to register with the MDA. If you cannot find a provider on this list they are not registered as a Tree Care Service in Minnesota.
In addition to checking the Tree Care Registry, there are additional steps you can take to ensure that a service provider is properly licensed and insured. Visit the University of Minnesota's My Minnesota Woods for more information on hiring a tree care company.
What is EAB and how does it spread?
EAB is an insect that attacks and kills ash trees. It is spread through transported firewood. The adults are small, iridescent green beetles that live outside of trees during the summer months. The larvae are grub or worm-like and live underneath the bark of ash trees. Trees are killed by the tunneling of the larvae under the tree's bark. Check out this video on the life cycle of EAB.
This video was produced with the collaboration of the faculty and students of Art Institutes International and McNally Smith College of Music, with technical assistance provided by MDA, DNR, University of Minnesota Extension and with funding from USDA.
Mark Abrahamson explains emerald ash borer management strategies and results in this EAB University webinar. The EAB University webinar series is funded by the USDA Forest Service, and produced by Michigan State University, Ohio State University, and Purdue University.
This EAB Visual Inspection Guide was developed by MDA to assist communities in learning how to recognize an EAB infestation. This video was made possible through funding from a U.S. Forest Service grant.
Why should I care about EAB?
What can I do about EAB?
Don't import materials to Minnesota that could harbor EAB such as ash firewood.
- Don't move firewood unless it's MDA Certified firewood (look for the MDA Certified Seal)
- Remember that it is illegal to move all hardwood firewood outside of EAB quarantine areas. See map of emerald ash borer status in Minnesota.
- Become knowledgeable about recognizing EAB and remain vigilant to the condition of your ash trees.
- Stay informed on EAB by signing up to our monthly Plant Pest Insider e-newsletter.
- If you suspect a reportable pest
- Note the exact location
- Take a digital photo if it is possible
- Contact Arrest the Pest
What should I do if my ash tree is in decline?
- Review diagnostic aids for identifying EAB symptoms (PDF: 407 KB / 1 page)
- Look into resources on maintaining tree health
- Consult a local tree expert such as a certified arborist or local extension person
- Always remember to plant a variety of trees and use proper planting techniques.
What are the common myths about EAB?
Myth No. 1. We can’t do anything about EAB anyway; we might as well let it spread.
EAB is a devastating pest; our choices now for ash trees near an outbreak are either treat or remove. Slowing the actual spread of EAB may mean economic viability for cities that are affected. If nothing is done to slow the spread, EAB can kill all area ash trees in a very short time. Slowing the spread means a city can spend $1M a year on ash tree removal for eight years, instead of spending $8M in one year for all the dead trees. Spreading the costs over many years is easier on any city’s budget, and that city’s taxpayers. Another reason is to buy time to let the science catch up: detection methods are improving and more is being learned about EAB weaknesses. Additional research is needed, but it takes time. While it’s unlikely there will be a silver bullet, if scientists can find enough weaknesses in EAB, we may be able to save ash tree species in the U.S.
Myth No. 2. EAB has no impact on human health, it just kills trees.
EAB-killed trees dry out quickly and become hazard trees in less time than after a normal tree death. Hazard trees are trees that can be dangerous because of the possibility of them falling over or large branches breaking off, with a potential to cause personal injury to people. In addition, a recent study by the U.S. Forest Service found that the decrease in tree numbers due to EAB in the Detroit, Michigan area (where EAB started) caused an increase in human mortality related to cardiovascular and respiratory systems.
Minnesota Department of Agriculture considers May 1 – September 30 to be the flight season for emerald ash borer (EAB). This means that EAB adult beetles are emerging from infested wood or trees and flying in search of new hosts during this time. EAB larvae complete their development by pupating into adult beetles in the spring and early summer. However, this process only occurs when temperatures are sufficiently warm and the whole process requires a certain amount of accumulated heat – i.e., development time. Accumulated heat can be measured and tracked by using degree days which are a measure of time spent above a threshold temperature.
For EAB a base temperature of 50° F is used and the following are estimated thresholds for EAB activity:
450 degree days – first EAB adults may begin emerging
900-1100 degree days – peak EAB adult activity
Current base 50° F degree day accumulations for Minnesota are available from US degree-day mapping calculator.
Available material for request in hard copies
Loan materials available for use at events
Info for Residents & Communities
- Ash Tree Identification (PDF: 7.95 MB / 2 pages)
- Firewood Information
- Homeowner Guide to Insecticide Selection, Use, and Environmental Protection
- Six Ways Your Community Can Minimize the Impact of EAB (PDF: 360 KB / 1 page)
- My Minnesota Woods
- Ash Tree Waste Disposal Sites
Info for Tree Care Professionals
- Ash Tree Waste Disposal Sites
- Tree Care Registry
- Reference for Recognizing Insect Galleries in Ash Trees (PDF: 2.95 MB / 8 pages)
- Native borers & look-alikes (PDF)
- Emerald Ash Borer Insecticides: Label Guidance for Use Limits (PDF: 410 KB / 2 pages)
Quarantine & Regulatory Information