In Mike wrote:
I noticed on three roses in seperate locations damage I've never seen
before. Something has chewed a perfect little ring around the canes
just below new buds. Anyone know what causes this? Another weird thing -
it's just one bud on each rose I've seen. Apparently, this is a
persnickety pest.

I get this too. It's a grub, not sure what kind (rose weevil? rose
borer?).

Anyway, systemic insecticides get rid of them, but in the meantime the
affected blooms are write-offs.