Eclosion: When an adult insect emerges from the pupa after metamorphosis, the process is called eclosion, controlled by the hormones produced by neuro-secretory cells in the brain.
The induction of eclosion hormone into the pupa of moth just before the end of the metamorphosis activated the abdominal movements and spreading of wings after emergence.
If the brain is removed, the adult moth emerges, but it lacks the proper coordination in certain activities such as spreading of wings.