|MadSci Network: Biochemistry|
Eclosion hormone is a peptide that is released by either the ventral ganglia or the brain depending on the developmental stage of the insect. When it is released into the hemolypmh it starts a cascade of actions that occur both before and after eclosion. Its presence before eclosion causes plasticization of the wing cuticle and stimulates the release of bursicon, another hormone required for development. In some insects pre-eclosion behavior includes abdominal rotations. Eclosion occurs, the wings begin to spread and further plasticize and then tan. Wing spreading is inhibited until the insect exits the cocoon or the pupal cell. The abdomen begins to contract forcing blood into the wings. Additional bursicon is released assisting in tanning of the wings. Reference: Chapman, R.F. 1982. The Insects. Structure and Function. Harvard University Press, Cambridge, Massachusetts.
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