That is a Viburnum - Viburnum lantana, which has the ungainly common name of Wayfaringtree Viburnum.
I agree that is insect chewing damage. It is extensive enough to worry about whether it is Viburnum Leaf Beetle (VLB) damage. I think your part of PA can be afflicted by this pest.
I would be taking samples to your Cooperative Extension Service to see if you have VLB. That is one destructive insect.