Emerald Ash Borer

Emerald Ash Borer

The emerald ash borer (Agrilus planipennis), commonly referred to as "EAB", is an invasive wood-boring pest of ash trees (Fraxinus spp.). Native to Asia, EAB was first discovered in North America near Detroit, Michigan in 2002. Likely arriving on wood packaging materials, EAB has spread to 35 states since its introduction. Adult beetles are emerald green, one-half inch in length and feed lightly on ash leaves causing little harm. The larvae of this insect feed under the bark of ash trees, creating winding (S-shaped) tunnels that disrupts the movement of water and nutrients. Infested trees usually die within 2-4 years.

Tracking the Spread & Treatment Suggestions

Since its discovery in Iowa in 2010, over two-thirds of Iowa's counties have been confirmed with EAB in one or more locations. Iowa State University specialist consider ash trees within 15 miles of a confirmed EAB location at risk for attack, and preventive treatments are suggested for healthly, vigorous, and valuable trees within the risk zone. Click here for the current map of suggested treatment areas. It may be premature to treat ash trees outside the risk zone. If you live in Iowa and suspect EAB in a county not yet detected, please contact us.

Link - Iowa EAB Confirmed Locations

Link - Emerald Ash Borer Management Options

Quarantines & Regulations

In December 2020, the USDA’s Animal and Plant Health Inspection Service (APHIS) published a final rule to remove the federal domestic EAB quarantine regulations. The final rule became effective January 14, 2021. Due to the deregulation, some states have enacted exterior quarantines for EAB. The exterior quarantines are to restrict the movement of regulated articles to these states. It is important for businesses and individuals to check with the Iowa Department of Agriculture & Land Stewardship (IDALS) for assistance with regulations. Opportunities may exist for a company to move one or more regulated articles (treated or untreated) to a state with an exterior quarantine if the company has a compliance agreement with IDALS and meets mitigation or treatment certification.

Regulated articles include firewood of any hardwood (non-coniferous) species, ash logs, green ash lumber, ash chips/mulch, ash trees, and tree debris of ash (Fraxinis spp.). Questions about quarantines or having a certificate issued for the movement of a regulated article out-of-state can be directed to Mike Kintner by using our Contact us page.


Firewood is a known carrier of injurious insects and disease-causing organisms. The discovery of EAB in Iowa in 2010 is an excellent reminder that firewood movement can quickly spread pests to new areas, unknowingly. Even though firewood can legally move throughout all of Iowa’s 99 counties, in Iowa our motto is Buy Local & Burn Local!

Proper labeling is required for all firewood being offered for sale, sold, or distributed in Iowa. This applies to both packaged and bulk firewood. The aspect of the labeling requirements to include harvest location of wood by county and state is used in part of ongoing efforts to limit the spread of invasive insect pests and diseases.

Link - Iowa Firewood Labeling Requirements

Biological Control of EAB

The non-native EAB has devastated ash trees in many areas since being detected in the U.S. in 2002, and continues to infest new areas. Within its native range in Asia, several species of parasitoid wasps act as predators and play a role in maintaining much lower EAB populations. These specialized wasps attack and ultimately kill the beetles' eggs or larvae (the immature stage). Because of their role of suppressing EAB populations in Asia, four species have been introduced into the U.S. as biological control agents.

Like many other states with EAB, biological control is being implemented as a management tool in Iowa. The Iowa Department of Agriculture & Land Stewardship serves as a cooperator of the USDA EAB Biological Control Program. The parasitoids are produced and supplied by a USDA parasitoid rearing facility in Brighton, Michigan. The approved biocontrol agents (stingless wasps) have been thoroughly evaluated to determine they will not negatively impact other native species of the environment. The biological control of EAB is a long-term management strategy intended to curb the impact for future generations of ash trees.

Link - USDA's EAB Biocontrol Program Questions/Answers