Thanks everyone. I did a little further checking and found some other pics that looked like these. They were identified as harlequin bug nymphs. There are a number of different kinds of harlequin bugs, but I think they are all in the 'stink bug' family. The tip off for me was the little black things on the eggs. I found a pic with eggs like my pic. The instar green stink bug has black marks, too, but they seem a little different to my eye.
i have a feeling they are not beneficial insects.