Abstract: The peptides eclosion hormone(EH) and ecdysis-triggering hormone(ETH) trigger ecdysis behaviors and other physiological changes which occur at the end of the molt. EH is synthesized in a discrete set of cerebral neurosecretory cells, and is released into the central nervous system and into the hemolymph in response to the declining ecdysteroid titers. ETH is released from the Inka cells,a component of the segmentally paired epitracheal glands,and acts directly on the CNS to trigger preecdysis and ecdysis behavior. Accumulating evidence suggests that EH is present in all insects and may provide a general hormonal mechanism to regulate ecdysis.

Key words: eclosion hormone, ecdysis, ecdysis-triggering hormone, neuropeptide, neurosecretory cells