Teinopalpus imperialis, the Kaisar-i-Hind, is a rare species of swallowtail butterfly found from Nepal and north east India to north Vietnam. The common name literally means "emperor of India". The Kaisar-i-Hind is much sought after by butterfly collectors for its beauty and rarity. The green iridescence of the wings has been found to be due to three-dimensional photonic structure of the scales and is the subject of much research.

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