Emerald Ash Borer

Encyclopedia Article

The emerald ash borer (EAB), Agrilus planipennis, is an exotic insect pest from Asia. The flattened, creamy white larval stage feeds below the bark and cuts off the living, water and nutrient conducting vessels causing tree death. Adults are small elongated oval beetles that are metallic green in color. This insect colonizes the top of ash trees (Fraxinus species) first, then moves down the tree.

emerald ash borer adult beetle is one-half inch long.

As of February 2014, all 99 counties in Iowa were quarantined by the Iowa Department of Agriculture and Land Stewardship to slow the movement of this destructive pest to non-quarantined areas. EAB has been found in several Iowa counties, as well as in the neighboring states of Illinois, Kansas, Minnesota, Missouri, Nebraska, South Dakota, and Wisconsin.

Initial county EAB detections in North America

Iowa State University Extension and Outreach experts encourage Iowa homeowners to evaluate their ash tree’s health and value in the landscape, and their commitment to years of preventive treatments. If an ash tree is within 15 miles of a known EAB infestation, preventive treatments are suggested for individual trees. The current suggested treatment areas in Iowa is provided in the map below. Check out all of the information (including some in Spanish) about this pest that threatens Iowa’s forests.

New county EAB detections in Iowa and suggested treatment areas.

View one or more of the short video segments about EAB on Emerald Ash Borer Videos YouTube Playlist


Emerald Ash Borer Links

Emerald Ash Borer News Releases

Frequently Asked Questions

Management of Emerald Ash Borer

Ash Identification and Replacement Suggestions

Visual Aids for Emerald Ash Borer Identification

Other Websites

Información del barrenador verde esmeralda en español


Do you live in Iowa and have an insect you would like identified?

The Iowa State University Plant & Insect Diagnostic Clinic will identify your insect, provide information on what it eats, life cycle, and if it is a pest the best ways to manage them.  Please see our website for current forms, fees, and instructions on preserving and mailing insects.   

Contact information for each states diagnostic laboratory for U.S. residents.  If you live outside of Iowa please do not submit a sample without contacting the Plant & Insect Diagnostic Clinic.  

Last Reviewed: 
March, 2021
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