Hormonal     regulation     of
   metamorphosis.
<P>
<Li> The Corpus cardiacum secretes prothoracicotropic hormone.
<Li> PTTH stimulates the prothoracic gland to produce ecdysone.
<Li> Ecdysone  is released periodically during molting (ecdysis) of the
larva.
<Li> The  Corpus  allatum  secretes juvenile hormone. High levels of JH
signal  leads  to  another  larval  stage,  while low levels of JH
promotes the formation of a pupa and metamorphosis.