Saddled Prominent Caterpillar

The larvae feed on the foliage of a wide range of woody plants, including apple, birch, blueberry, dogwood, hazel, maple, oak, sumac and walnut. The first two instars cling to silken feeding mats on the underside of the leaf. They skeletonize the leaf leaving only a few major veins. Later instars feed on the outside of the leaf consuming all the tissue except major veins. The species overwinters in the pupal stage in a cocoon buried in leaf litter on the ground. - wikipedia