Japan's national butterfly
It was chosen as the national butterfly of Japan in 1957.
A Japanese garden · Butterflies and moths
Great purple emperor
Sasakia charonda
A large, dark butterfly. The male's wings flash violet-blue near the body, and are scattered with white and yellow spots.
- Size
- Wingspan 9 to 11cm
- Look for it
- June to August
- Where
- Broad-leaved woods in Japan, Korea and China
Glides after you on strong wings. Move your pointer and see.
When to look
Great purple emperor
Good to know
Six things about the great purple emperor
The great purple
Its Japanese name, o-murasaki, simply means great purple.
It prefers sap to flowers
It hardly ever visits flowers. It feeds on tree sap, alongside beetles and hornets, and holds its own.
It chases birds
Males guard a treetop and fly out at anything that passes, including small birds.
A caterpillar with horns
The green caterpillar has a pair of horns on its head, and spends the winter among dead leaves at the foot of its tree.
One kind of tree
The caterpillars feed only on hackberry trees.
The real thing
Photos of the great purple emperor
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Photos are from Wikimedia Commons, used under the free licences shown. They have been resized, and cropped where they appear in link previews.
How to spot one
Look at oak trunks where sap is flowing, in July. The wings open and close slowly as it feeds.
How to help
It depends on the old managed woods near villages. Groups across Japan look after woods for it and count it every year.
Keep going
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