I was just out in the garden and in the midst of all the aphids on the growing tips were rose slugs. They get right into the tips and you can't pick them out without taking the risk of breaking off the tip so I get them with a toothpick. Either dig them out or stab them. If you see the growing tips chewed off before a bud has had a chance to form it is slugs. I don't spray so the best thing is to check them all every morning. The aphids I flick off or I just leave them alone.