Your pests are one of the young growth stages (instars) of the scentless plant bug, Niesthrea louisianica, also commonly referred to as seed bugs because they prefer to feed on the seeds of mallows, including Rose of Sharon and Hardy hibiscus plants. They are generally harmless since mallows produce gazillions of seeds each year and no one tends to want 1,000 new volunteer seedlings each Spring. Also, these bugs are great at controlling the related invasive weed, velvetleaf, as studies show the scentless plant bugs will eat/destroy over 95% the the seeds produced by velvetleaf. If you don't want them on your plants, a simple insecticidal soap spray ought to take care of them.

Thanks, Dawn! I'm getting ready to hard prune my RoS. Last year, they were covered in aphids. Gross. This is a new bug to me. Glad it isn't a pest.

You're welcome.