Introductory the film presents the external morphology of the adult moth. The newly hatched adults display a characteristic mating behaviour which initiates copulation and egg deposition. Embryonic development lasts about 4 1/2 days (at 23°C). The post-embryonic life includes 5-6 larval instars (altogether 40-45 days), the pupal phase (about 11 days) and relatively short imaginal stage. Larvae live within their food. The last instar larva leaves the food and spins a cocoon, within which the immobilized prepupa enters the pupal molt. During pupal time the development of imaginal traits can externally be traced chiefly by pigmentation processes. Finally the cuticle breaks and the imago leaves the pupal case. After the wings are inflated (by hemolymph), stretched, and hardened, the moth is ready to fly.