I believe you have the four-lined bug. They are very fast and can be killed with direct contact of insecticidal soap. They change to a green and black bug in a few weeks. Try to get them now. They do not kill plants but make them look ugly. I had way too many of them last year so I cut most of my plants back in the late fall and threw the debris in the woods. I have only a few here and there this year. I have learned how to chase them and have become faster than them!

Thanks kimpa! I am heading out with the soap today.

Do a google image search, first. Just to make sure that that's what you've been observing.