Emerald Ash Borer



EAB is an invasive beetle introduced from Asia. It entered North America from China near Detroit, Michigan, probably on wooden packing crates. It was first detected in Wisconsin in 2008. Since then, we have detected it in 69​​ of Wisconsin’s 72 counties. Currently, the most severe EAB damage is concentrated in the southern half of the state. There are still large areas where we have not yet detected EAB; only about a third of the state's municipalities have confirmed EAB infestations. In these areas, it may not be present yet, or it may be present in such low numbers that damage is not yet apparent.

EAB attacks all species of ash trees, except mountain ash, which are not true ash trees.

Reporting EAB

It is not necessary to report EAB in municipalities where we have already detected it. However, if you live in a county or municipality where we​ have not yet detected it, you should report it. To check your county’s detection status and report if necessary, visit our interactive map​ and type in your address. 

Life Cycle and Damage

Adult EAB beetles are active in late spring and early summer. They lay eggs on the bark, and the larvae, which are flat and worm-like immature beetles, hatch and burrow under the bark. The larvae kill trees by feeding on the wood immediately under the bark. This disrupts the tree’s ability to carry water and nutrients up from the roots and kills the tree from the top down. 


We strongly recommend using DATCP-certified firewood, or that you buy firewood near where you will burn it. This is a best practice to slow the spread of EAB and prevent the introduction of new and potentially harmful forest pests and diseases. It is also important to remember there are restrictions on firewood movement due to spongy moth quarantine regulations. There are also rules for firewood use on state, federal, and Tribal lands in Wisconsin. Read more about moving firewood in Wisocnsin here

Federal Deregulation

In 2021, EAB was deregulated at the national level by the USDA Animal and Plant Health Inspection Service (APHIS), and Wisconsin's EAB quarantine rule was rescinded in 2023. When this regulation changed, some states west of Wisconsin, including Minnesota, took steps to enact exterior quarantines for EAB. The quarantine regulations restrict the movement of ash products such as logs, nursery stock, and/or firewood from Wisconsin to these states. Businesses and individuals should proactively check current plant regulations prior to shipment of any potentially regulated articles. To learn more, visit the State Law & Regulation Summaries - National Plant Board webpage. 

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