1) multiflora is in the lineage of numerous roses. It is my understanding that floribunda's were originally multiflora based.
2) the mites feed on tender new growth
3) If the multiflora is buried and there are no shoots of it around for the mites to inhabit, I don't know how that would make the variety that was selected to plant more susceptible.
Observe, observe, observe
We are fortunate to "see" & appreciate nature in ways others are blind.
