Rose weevils have long beaks with chewing mouthparts at the end. They poke them into rosebuds and munch away, making holes. When the buds unfold, the damaged layers unfurl.
Rose weevils lay eggs in some of the holes they drill in buds. The eggs hatch into wormlike larvae that feed inside the bud and can weaken its attachment to the stem, so many infested buds fall to the ground.
The larvae come out of the buds, burrow into the ground, and spend the winter there. They eventually pupate and emerge the following year, in time to eat more roses.
It reminds me of this poem by William Blake.
The Sick Rose – O Rose thou art sick.
The invisible worm,
That flies in the night
In the howling storms:
Has found out thy bed
Of crimson joy:
And his dark secret love
Does thy life destroy.