Egg.—Conoidal, the base flattened and rounded; marked by 8 or 9 vertical ribs, which near the base are low, but on upper third are considerably elevated, increase gradually in prominence and terminate abruptly around a small flat space at summit; these ribs are thin and their sides are grooved perpendicular to the surface of the egg; color pale green. Duration of this stage from 3 to 4 days in summer, in April and early May 10 days.