Answer: I don't think your plants are diseased but are playing host to either a bud worm or to Japanese beetles. Japanese beetles can be controlled with a neem-based spray or you can try hand picking if the infestation is not too severe. To be honest I have never seen bud worms inside these flowers, but almost anything is possible in the plant and insect world. Since bud worms live inside the flowers about the only effective control would be to cut off and remove those blooms that are affected (look closely at unopened buds for tiny holes). This fall, be very careful to clean up, remove and destroy plant debris to reduce the chance of the pests overwintering in the garden. You might also check with your County Extension to see if they can identify the specific pest and suggest controls.
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