What insects eat elderberry leaves?

One of my elderberry plants was nearly denuded but here's a picture of one that might show the damage better:

I was surprised that the damage was worse lower to the ground rather than up high like Japanese beatles have a habit of doing.

Grasshoppers? That is what those chomps look like to me. Ours gets eaten a bit but that doesn't effect its growth or ability to produce berries. We have a hedge of it and it is maybe more of a wild variety...I'm not sure how it got where it is...It sprouts like crazy from the roots.
I guess, you would see grasshoppers in the daytime though............do you think it's happening over night?

The plants are down by the pond so I don't go down there all that often. We certainly have plenty of grasshoppers around so that's definitely a possibility. I should toss a few grasshoppers to the ducks to see if the ducks eat them. Maybe I just haven't been letting them get down to the pond often enough!