Add Rock County to the Emerald Ash Borer list. An adult beetle was found a heavily infested tree in Janesville. That makes 12 counties where the invasive insect has been found: Brown, Crawford, Kenosha, La Crosse, Milwaukee, Ozaukee, Racine, Rock, Vernon, Walworth, Washington, and Waukesha.
Officials also found EAB at another site in Kenosha County at the Richard Bong State Recreation Area, while the county has been under quarantine since 2009; this is the first time the insect has been found on state-owned land.
If landowners suspect a tree may be infected they are asked to contact a certified arborist or tree care professional. Firewood is the main culprit in spreading the pest. More information is available at www.emeraldashborer.wi.gov