This tiny pearly white cluster of eggs is on a stinging nettle leaf. The entire cluster measures less than 1/4 inch across. I don't know for sure, but they may be the eggs of a predatory stinkbug (Podisus), for I've seen the adults on this particular stand of nettle many times. At any rate, they are stinkbug eggs of one of the many species we have here. The brownish ones are getting close to hatching.