
An ash tree next to a walking trail in Oshkosh has been damaged by woodpeckers feeding on emerald ash borer larvae beneath the bark. / Photo Credit: Wisconsin DNR
By Bill McNee, DNR Forest Health Specialist, Oshkosh
Bill.McNee@wisconsin.gov or 920-360-0942
Property owners with healthy, valuable ash trees are encouraged to treat them with insecticide this spring to protect against emerald ash borer (EAB).
The invasive pest is currently the most damaging threat to trees in Wisconsin, killing more than 99% of the ash trees it infests.
Woodpecker damage during the winter is often the first sign that an ash tree is infested. The birds remove pieces of bark while feeding on EAB larvae inside the tree. Insecticide treatment of infested ash trees is more likely to be successful if the trees have low or moderate levels of woodpecker damage.
Continue reading “Protect Valuable Ash Trees Against Emerald Ash Borer”
The purpose of the
Now is the time to sign up to Run for the Trees! Racers can complete their Happy Little (Virtual) 5K anywhere outdoors between April 18-26, 2026. The nine-day window includes Earth Day (April 22) and Arbor Day (April 24). 



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