The Diapriidae

marginalis at least two-thirds as long as its distance from the basalis; gaster posterior to the petiole long, narrowly fusiform, at least three times as long as wide, strongly laterally compressed at apex and tapering to a fine point. (Propodeal keel sometimes forked)

marginalis at most one-third as long as its distance from the basalis; gaster here nearly always decidedly globose and at most two and a third times longer than wide