Found as catepillars in the flower buds of Gardenia (jasminoides) in Tuen Mun New Town Center Garden, Hong Kong in late spring, 1998.  The eggs are laid on the outside of the bud and the newly hatched larva burrows into the center of the bud.  It eats the inside as the bud develops and finally opens.  The hole the catepillar made is used as a tunnel to allow the catepillar to exit and eat or (sometimes) move to another flower.

Pictured is the male butterfly.  The female is dull dark grey on top, but with larger white patches on the top and bottom of the hindwings near the tails; the tails are also white compared to the male's black.