The story
So called as they mimic the appearance of toxic danaid butterflies such as Danaus chrysippus and Danaus plexippus.
Etymology from Wiktionary, CC BY-SA 4.0.
danaid eggfly
Today it means: A common species of nymphalid butterfly, Hypolimnas misippus, of tropical and subtropical Africa, Asia, Australasia, and the Americas. Full definition →