Hello and thank you for contacting AaE for help.

This is probably the work of the Four-lined plant bug. Their damage only affects the appearance of plants. They do not destroy them unless there is a huge population of them which does happen in some years. The best thing to do is to cut down their host plants during fall clean-up and bury the foliage. Here is a link to the U of MN Extension service article on Four-lined plant bugs where you can learn how to identify them, which plants are host plants and more.