an insect is never a pupa & an insect changed from an immature form to an adult form ->  an insect has changed from an immature form to an adult form without being a pupa  metamorphosis is a kind of process & if something undergoes a process without going through a certain stage in that process, then that process was incomplete ->  if something undergoes metamorphosis without going through a certain stage of metamorphosis, then that metamorphosis was incomplete  if something undergoes metamorphosis without going through a certain stage of metamorphosis, then that metamorphosis was incomplete & the pupa stage is a stage in the metamorphosis process of some animals ->  if something undergoes metamorphosis without going through the pupa stage, then that metamorphosis was incomplete  if something undergoes metamorphosis without going through the pupa stage, then that metamorphosis was incomplete & metamorphosis is when an insect changes from an immature form to an adult form ->  incomplete metamorphosis is when an insect reaches the adult stage without being a pupa  an insect has changed from an immature form to an adult form without being a pupa & incomplete metamorphosis is when an insect reaches the adult stage without being a pupa -> the insect has undergone incomplete metamorphosis