Answer: Butterfly bushes attract butterflies and they are likely to lay eggs which turn into caterpillars. Probably what is feeding on the leaves are the butterfly larvae so I wouldn't use anything to control them - if you did you would kill the next generation of butterflies. Small holes in plant leaves rarely harm the plants and can be made by insects that have fed and already traveled on. Try to capture the culprits and have them identified. Then you can use an insect-specific control. Or you can simply pick them off the plant or hose them off with a strong stream of water. I guess the bottom line is that insects will feed on plant leaves and some insects are beneficial in the garden because they prey on other insects and they transfer pollen so wiping them all out isn't really a good idea. You could kill the beneficials along with the destructive insevcts. I can only suggest identifying the insects you see and then determining whether or not control is the best action. You can take the insects you collect to your local cooperative extension or well staffed nursery for help with their identification and suggested remedies. Good luck with your garden.
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