"Prepupa" is not a separate larval instar, but is an identifiable stage lasting up to 24 hours. The larva attaches its rear abdominal segments to a leaf, which will anchor it as a pupa, and the body becomes stiff and curved. It is motionless unless strongly provoked, and may appear dead.

This prepupal larva was very strongly provoked (another larva tried to eat it) and became active again, although its body remained in the stiff curve. It detached itself from the leaf, awkwardly ran away from its attacker, and hid in a curled-up leaf. I moved it to a separate container, where it formed a prepupa again on Day 12.