The emerald ash borer (EAB) is a destructive wood-boring beetle that attacks ash trees(Fraxinus spp.). The larvae are the damaging stage of the insect as they feed on the inner bark of ash trees, disrupting the flow of water and nutrients within the tree. The cumulative damage to the vascular system of the tree causes canopy thinning and branch dieback, eventually leading to tree mortality. Infested ash trees usually die within 2-4 years. Native to Asia, EAB was first discovered in the U.S. near Detroit, Michigan in 2002 and has since spread to 37 states. EAB is responsible for widespread ash mortality in Iowa and many other states.

Although EAB has been confirmed in all of Iowa’s 99 counties (as of October 2024), many counties have only isolated areas of an infestation. By limiting the movement of ash wood, people can help slow the spread of this invasive insect. EAB larvae live beneath the bark of firewood and can continue to emerge up to two years after cutting. The adult beetle can fly only short distances on its own. The Iowa Department of Agriculture & Land Stewardship (IDALS) has been tracking and reporting the spread of EAB since it was first discovered in Iowa in 2010. See EAB county detection map.

Ash trees within 15 miles of a known EAB infestation are considered at high risk of attack. Preventative treatments can be used to protect healthy and valuable ash trees within high-risk areas. See a map indicating a 15-mile radius around confirmed EAB detections. Chemical treatment can work for already infected trees, provided the damage is discovered early. For more on management considerations and treatment products, see ISU's publication Emerald Ash Borer Management Options .

The USDA’s Animal Plant Health Inspection Service (APHIS) EAB federal domestic quarantine was eliminated in 2021. Due to the deregulation, some states have state-level exterior quarantines in place to restrict the movement of EAB regulated articles into their state. Regulated articles may include firewood of any hardwood species, ash logs, ash chips/mulch, ash trees, green ash lumber and tree debris of ash. It is important for individuals and businesses to determine if regulations exist prior to the transportation of such articles. Contact IDALS for help in determining regulation status in another state. Opportunities may exist for the movement of EAB regulated articles to a state with regulations through permits, certificates or compliance agreements.

Due to the expansive spread of EAB in Iowa, the transportation of firewood and ash articles are no longer regulated within the state. However, because EAB and other invasive pests insects can unknowingly hitchhike in firewood, people are reminded to use firewood locally sourced from the area where it will be burned to keep EAB and other tree-killing pests from being transported to new areas.