 They regurgitate on them, then drink the fluids, and acquire defensive chemicals.Larvae are known to feed on some species of alder, ash, birch, blueberry, chestnut, elm, grape, hackberry, hazel, oak, walnut, willow, and many others (Wagner, 2005).No serious injury to trees has been reported for this late-season feeder (Rose & Lindquist, 1982).