The Imperial White is a beautiful butterfly from SE Australia, which feeds its caterpillars entirely on Mistletoe plants, especially the Drooping Mistletoe (Amyema pendula). The caterpillars feed communally in the mistletoe, often almost entirely defoliating the plant. When fully grown, they weave a communal web in which they pupate and from which emerge the large white butterflies.
The upper wings are white in the male, grey in the female, with a broad black border. The under wings are quite spectacular, being black, red, yellow and white.