Hi,
Thanks for your question - and I'm sorry about your highbush cranberry (viburnum)! 

I think you've correctly identified the problem as viburnum leaf beetle, and unfortunately you're not the only one who is seeing significant damage.

This foreign pest has spread west from its first recorded sighting in New York in 1996, and researchers are still learning about how to control it. One suggestion is to remove egg-laying sites on viburnum twigs (put in trash not in compost). You can also try an insecticide.

If plants are severely defoliated they may not survive. Hopefully it won't come to that in your case, but if you did need to consider a replacement viburnum it appears that some varieties may be resistant to the beetle. University of Maryland Extension lists resistant varieties.

Thanks for sharing your question and calling attention to this pest.