Ecdysis and Tanning

Abstract

The period of ecdysis is critical for the insect’s survival. It must successfully shed the old cuticle and survive throughout the period between this process and the completion of tanning. During that time it is extremely vulnerable because its envelope is still soft and fragile. The period between the completion of shedding and that of tanning includes other important steps, particularly the complicated eclosion behavior. This involves the softening of the cuticle, a prerequisite for the expansion that precedes tanning, and requires very precise coordinated regulation that is able to reach all epidermal cells at the appropriate time. Investigations in this field have yielded numerous data and demonstrated the existence of an eclosion neurohormone, a tanning neurohormone called bursicon, and several pupariation factors.