MADISON, Wis. – The Wisconsin Department of Natural Resources (DNR) encourages property owners to watch for woodpecker damage to their ash trees this winter. …Woodpecker damage, often called “flecking,” happens when birds peck away some of a tree’s bark to access the larvae underneath. Flecking is a common early sign that an ash tree might be infested with emerald ash borer (EAB), an invasive insect. EAB is the most damaging threat to Wisconsin trees, killing more than 99% of the untreated ash trees it infests. …Landowners who spot woodpecker damage in their woodlot ash trees are encouraged to consult a DNR or consulting forester for management advice. Property owners who detect an EAB infestation in its early stages … can take steps to protect their high-value ash trees by treating them with insecticide between mid-April and mid-May. Insecticide treatments are seldom practical or economical for woodlot ash trees.