Found on the underside of a Chokecherry leaf at the Fletcher Wildlife Garden. The little black critters are the newly emerged first instar nymphs of a stinkbug. The eggs are lovely (I think). They are like little pots whose tops pop off as the insects emerge. Some stinkbug eggs are like little silver jewel boxes: http://www.pbase.com/laroseforest/image/114761282

The whole mass was probably less than 3mm across.