To most people, the bright, perky robin is the first sign of spring in New England. Not to a bug geek. A tiny, black, cigar-shaped body appeared on my van window this afternoon as I left the bottle redemption place here in Springfield, Vermont. A slow smile spread over my face as I realized that, for all my day-planner scheduling, for all my week-to-week calendar-stuffing, Nature has her own cycle. The true herald of spring has arrived, silently and humbly: the winter stonefly.