Oomurasaki Butterfly

Brown Caterpillar.
Oomurasaki, the Japanese Purple Emperor, is the National butterfly of Japan.

A tiny caterpillar climbs up from the leaf litter where it hibernated over winter.

But the colours that were a perfect camouflage in autumn will soon be dangerously conspicuous, for the caterpillar is climbing back into a changing world.

To survive, the caterpillar must follow suit.
Fat Green Caterpillar.
Responding, like the forest, to the lengthening hours of daylight and the rising temperature, it sheds the skin that looks like a dead leaf and assumes the colours of a spring leaf. The caterpillar mimics the leaves on which it will keep feeding until it undergoes its final transformation into a butterfly of summer.

The caterpillar that emerged from the leaf litter has grown large and plump. Triggered by a combination of the rising temperature and its own internal body clock, it nears the end of one phase of its life and begins to discard a skin it will no longer need.
Moulted mouthparts.
It will never again feed on leaves so it drops the head and mouthparts it no longer needs.

Inside the hardened outer case of the pupa, the body will undergo an amazing transformation, the timing of which is crucial, for when it emerges as a butterfly it favours tree sap which is at its most abundant in summer.
Emerging female butterfly.
After two weeks a butterfly emerges, it's a female.

The males have already appeared and established their territories. She rids herself of excess moisture in her body, then rests for a few hours to let her wings dry. Then she's ready to find a mate in the summer forest.
Male Oomurasaki butterfly.
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