I can't identify these insects based solely on the photo, unfortunately. They do resemble box elder bug nymphs, but there are other insects that they could be. Box elder bugs feed primarily on the developing seeds of box elder trees (Acer negundo) and they are not considered a pest of other ornamental plants. They can feed occasionally on plants that are not box elder, but rarely is this harmful or damaging. There are very similar insects called lesser milkweed bugs (Lygaeus kalmii) that you may see on other plants. Neither of these insects are usually harmful enough to warrant any kind of management. 

You can read more about box elder bugs in this article from MSU Extension: https://www.canr.msu.edu/news/boxelder_bugs_a_real_nuisance_during_spring