Michigan State University
Size: Up to 1 1/4 - 1 1/2 inches long
Where/When: Feeds on the foliage, buds, blossoms, and fruits of apple. Also found on oak, ash, cherry, elm, and other trees. The larva is active from May until June.
Significance: Damaged fruits have large, sunken, corky wounds at harvest or may fall early from the tree. Damage is restricted to one or two fruit clusters. Damaged fruits may be hollowed out or partially eaten.