The Great Eggfly or Blue Moon is a black bodied butterfly with a wingspan of about 7–81⁄2 cm. The species has a high degree of sexual dimorphism. The male, upperside of the wings are jet black which is offset with 3 pairs of white spots. 2 on the forewing and 1 on the hind. These white spots are suffused with purple. In addition the upperside of the hind wing bears a series of small white dots. Great Eggflies are found in Madagascar in the west through to South and South-East Asia, South Pacific islands (French Polynesia, Tonga, The Great Eggfly is a fairly common butterfly found in lightly wooded country, decidous forests, thick and moist shrub and the greener parts of human habitation. Great Eggflies are known for maternal care with the females guarding leaves where eggs have been laid. Males are also very territorial. The female hovers over a plant to check for ants which will eat her eggs. After selecting a plant which has no ants on it, she lays a single but often 2 - 5 eggs on the undersides of the leaves.
Host plants include Fleuria interrupta, Sida rhombifolia, Elatostemma cuneatum, Portulaca oleracea, Laportea interrupta, Triumfetta pentandra, and Assystasia sp.