The Imperial Moth is a Nearctic moth, whose range extends from Mexico to Canada. The female is larger than the male, and her wings tend to be more yellow. Much of her life is spent as a caterpillar, feeding on coniferous and deciduous plants. She undergoes four moults, with her first within only a few days of hatching. After attaining her fifth instar, she leaves her tree and burrows underground to pupate. At about mid-summer, the fully-formed moth digs her way out before sunrise and begins her search for a mate. She will mate after midnight, and lay her eggs by dusk the next day. As an adult, she does not feed, and will die shortly after.