Blue Moon (Hypolimnas bolina)
The Blue Moon Butterfly is a species of dark butterflies that are found in 20 different subspecies in several countries. These butterflies are territorial, and the males are found chasing the females during spring/summer, their mating season, which is the best time to watch them. They get their name from the two bright blue circular patches on the male’s wings, resembling the full ‘blue moon’ in the dark sky.
Scientific Classification
- Family: Nymphalidae
- Genus: Hypolimnas
- Common names: Great Eggfly, Common Eggfly
- Scientific Name: Hypolimnas bolina
Description and Identification
Caterpillar
They are black in color with the head and the last segment being orange. The head has two long branched black horns. The entire body is covered with long and branched orangish black spines too.
Pupa
The chrysalis is brownish in color with a hue of grey on the wing region. There are tubercles in the abdominal segments while the entire outer surface is rough. It takes about seven to eight days for the butterfly to emerge. The pupa remains suspended from the host plant from a single point.
Adult Butterfly
Sexual Dimorphism: Distinctly present
Color and Appearance: When the wings are open, the dorsal side of the wings in the male shows a dark jet black coloration with three pairs of white spots bordered by violet iridescence, with two pairs being on the primary wings and one pair on the secondary wings. The hindwings also show a series of small white dots marking the outer border. The females have a brownish black base color and devoid of spots like those of the male. The edges of their wings also display white markings. When the wings are closed, the males show a jet black with intricate white markings arranged in a pattern parallel to the edges, while in the female, the markings are the same as in the male, except that the base color is tan brown in place of black.
Average wingspan: 70 to 85 mm (2.8–3.3 in)
Flight pattern: Slow, yet erratic
Eggs

Pale, glassy green in coloration, having longitudinal ridges all over, except on the head.
Quick Facts |
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Distribution | From Madagascar to Asia, as well as in Australia |
Habitat | lightly wooded deciduous forests, dense and humid scrublands, and the greener areas in human habitats |
Host plants | Primary hosts include Sida rhombifolia, Elatostemma cuneatum, Portulaca oleracea, Laportea interrupta, Triumfetta pentandra, and the Asystasia species |
Adult diet | Flower nectar |
Did You Know?
- The female of the species is a morph mimic of the common Indian crow butterfly.
- Unlike most other butterfly species, the female butterflies are also known for their maternal care, guarding the leaves where they lay the eggs.
- An infection caused by wolbachia bacteria in the caterpillars is known to kill the males exclusively. With this, the male population decreased to almost 1% by 2001. However, within ten generations (in around five years), the males developed an immunity resistance to this parasite, increasing the population to 40% by 2007.
Scientific Classification
- Family: Nymphalidae
- Genus: Hypolimnas
- Common names: Great Eggfly, Common Eggfly
- Scientific Name: Hypolimnas bolina