I've got a small Rusty Blackhaw Viburnum and suddenly noticed quite a few of its leaves are gone. It still has about half its leaves (no damage), but the others are completely gone, nothing left, not even the leaf stems. I can't find caterpillars or bugs on it. Any ideas?
what strips viburnum?
I have no idea. If you figure it out, please let us know. I have one I dug up from a small grove at my sister's. It's survived, bloomed, and has set berries. I'd hate to see anything happen to it.
Critters such as deer?
I got to thinking. I had a couple of dill that the swallowtail caterpillars stripped to the stem; then the caterpillars disappeared. (That's why I planted the dill.) This happened over a period of about two weeks. Do you look at your RBV every day? Ajilvsgi's book, "Butterfly Gardening for the South", lists maple-leafed viburnum as a food plant for Henry's Elfin butterfly, but doesn't specify anything about RBV. Of course, grasshoppers will strip plants bare, but you'd have seen those, and it wouldn't just be the RBV. I hope you figure this out.
I thought about deer. While I've never actually seen them in my yard, on occasion I forget to close the back gate to my fence. They've been pretty hungry this year and something even ate the tops off some blooming milkweed outside of my fenced yard. I really don't think that milkweed had caterpillars, so I wondered about deer. No, I don't really look at my viburnum every day. As a matter of fact, I'm really into the butterflies, so if I HAVE TO lose some leaves on my plant, I'd prefer butterfly caterpillars ate them. The good news is that it looks like a few new leaves are starting to come out, so hopefully it will recover!