Question
I live in Zone 3-4 in mountains of Colorado.  I have two rose bushes, one a shrub rose the other a Rugosa Hybrid Hansa Rose.  on both, the flower buds shrivel up before opening and I noticed tiny brown pinholes on a couple of the buds.  On both, there are circles chewed in the leaves and some of the leaves are turning first yellow, then brown and dry.  On the Rugosa, the uneaten leaves are faded yellow green instead of bright green when they first budded.

Answer
Your roses are suffering from the Rose Midge. They make a pin hole at base of the flower buds and when the young hatch they feed on the buds and kill them. Any rose insecticide will solve your problem. I would try Orthos Rose Pride insect killer. Just male sure yu also spray all around the base of the rose bushes because the adults will still be in the ground.

More information about the Rose Midge:-
http://oregonstate.edu/dept/nurspest/rose_midge.htm