On one hand, pupal stage is a time of rest on the other, the most profound changes in the physique of these animals occur during this time.
A caterpillar's body requires very different functions as opposed to its heir, the butterfly.
a large gastrointestinal tract,
but lacks reproductive organs.
The six eyes a caterpillar has on each side
(right picture) are also very different from
the facett eye of the butterfly.
Substantial changes also occur in the transition from caterpillar
to butterfly at the mouth part and locomotion organs. The right picture shows a caterpillar antennae.
These transformations take at least a week for completion.
Many butterflies hibernate in the pupal stage and eclose the next spring.
It is paramount, that all butterflies emerge at the same time, so they can find a mating partner.
This is necessary, because the life span of the butterflies takes a few days in some species.
The eclosing process is dependent on temperature, photo period and light intensity.
With the mating of the new butterfly, the fascinating cycle of metamorphosis starts anew.