The roses should survive just fine, with just canes/stems BUT you should remove the rose hips, as they draw nutrients from the plant. Trim the canes/stems way back, to just above a node (this is where it'll send out new branches). Cut at an angle, so that the rain runs off. Trimming the bushes way back, will ease the stress of nurturing a larger plant. This will give them a better chance to recover, once the beetles are under control.