Lew,
In what part(s) of the country is this happening?
Lew wrote: "Viburnum species are really getting hit by a insect
pest. It's the worm/larvae that defoliates the plant.
Certain species are very susceptible. I've noticed
that there may be some variability in
prunifolium,however,it's most likely the plant escaped
damage.
I can't remember the name of the insect and the
reference the mentions susceptibility of the viburnum
species."
Lew Ward