Hypolimnas bolina, the great eggfly, common eggfly, varied eggfly or in New Zealand the blue moon butterfly is a species of nymphalid butterfly found from Madagascar to Asia and Australia.
H. bolina is found in Madagascar in the west, through to South and Southeast Asia, Cambodia, the South Pacific islands (French Polynesia, Tonga, Tuvalu, Samoa and Vanuatu), and occurs in parts of Australia as far south as Victoria during summer and autumn, Japan, and New Zealand. Appearances in New Zealand appear to be linked with favourable winds during April–June migratory periods in Australia, with the butterfly being recorded in 1956, 1971 and 1995. No populations have established locally in New Zealand.
H. bolina is a generally common butterfly across most tropical and sub-tropical habitat types, including wet/dry woodland (such as tropical savanna), rainforest and shrubland. It is a common visitor to suburban back yards and other areas of human disturbance. In the Australian tropics, H. bolina is particularly common along tracks, streambeds, and the corridors formed between remnant gallery forest and cultivated sugar cane fields. Both sexes are invariably found in association with one or more larval hostplant species, especially disturbance species such as Synedrella nodiflora, Sida rhombifolia, and Commelina cyanea.
