On grapes, GWSS treatments also control the variegated leafhopper and western grapeleaf skeletonizer
A: The arborists here think that perhaps you are seeing the damage caused by a leaf roller or oak leaf skeletonizer
(a small moth which attacks birch leaves; Webster's Second)
Particularly in the San Joaquin Valley and the low desert, watch backs of leaves in spring and summer for egg clusters and blue-, black-, and yellow-striped larvae of the grape leaf skeletonizer
9: When bittersweet has golden berries, then oak skeletonizers
are eating the oak leaves.