If flower buds and young shoots are being chewed but no insects visible it may be earwigs. These insects come out at night and can be found in leaf matter under the plant, under bark or under rocks if available. In some cases the insect can be found amongst the petals of the rose flower.
Best control is to trap them. Crumple newspaper into an empty flower-pot, dribble vegetable oil or linseed oil onto the paper, lay pot on its side amongst the plants. They will hide in the paper during the day. Dispose of next day, do over and over again, will reduce their population. More likely found if garden is very dry, so mulch well to retain moisture. Most common in spring and autumn.
Can spray with ‘Confidor’.