I had seen the egg cases of Harlequin Bugs on the internet for a long time and always hoped to find some. Today was my lucky day. A bladderpod plant (Peritoma arborea) was full of adults, nymphs, and egg cases.
The egg cases resemble tiny black and white 'kegs'. The interesting thing is that all the egg case clusters I found were in groups of 12. This seems consistent with other photos online.
Adults are boldly colored and apparently are major pests of plants such as cabbage. I've never seen this species on any plant except for Bladderpod (Peritoma arborea) in southern California.
These things are tiny.