The black rajah is a medium-sized butterfly with a 70- to 80-mm wingspan. Above, the butterfly is dark brownish black with greenish or white discal bands across both the wings. The band is broken into spots towards the apex of the fore wing. The hind wing has two similar-sized tails at veins 2 and 4. These tails are longer in the females and more pointed in the males.[5]
Egg
Its egg is transparent yellow and spherical, with longitudinal ridges. It has a dark red, uneven band around its upper half.
Caterpillar
The caterpillar is dark green with irregular rows of yellow tubercles. The caterpillar is cylindrical and may have a round white blotch on the seventh segment. The head is curved out and has horns and spines. The pupa is short and dark green, with a lateral longitudinal line marbled with white.[6]
The black rajah is generally a low-elevation butterfly and can be found at altitudes up to 1950 m (6500 feet) ASL.
The caterpillars generally feed on Fabaceae, such as tamarind Tamarindus indica.[6] At least on Borneo but probably elsewhere too, adults do generally not visit carrion or old fruit to drink liquids.[9]
^ abHaribal, Meena (1992). The Butterflies of Sikkim Himalaya and Their Natural History. Gangtok, Sikkim, India: Sikkim Nature Conservation Foundation. p.151
^Haribal, Meena (1992). The Butterflies of Sikkim Himalaya and Their Natural History. Gangtok, Sikkim, India: Sikkim Nature Conservation Foundation. p.151
^Hamer, K.C.; Hill, J.K.; Benedick, S.; Mustaffa, N.; Chey, V.K. & Maryati, M. (2006): Diversity and ecology of carrion- and fruit-feeding butterflies in Bornean rain forest. Journal of Tropical Ecology22: 25–33. doi:10.1017/S0266467405002750 (HTML abstract)
Gaonkar, Harish (1996). Butterflies of the Western Ghats, India (including Sri Lanka) - A Biodiversity Assessment of a Threatened Mountain System. Bangalore, India: Centre for Ecological Sciences.
Gay, Thomas; Kehimkar, Isaac David; Punetha, Jagdish Chandra (1992). Common Butterflies of India. Nature Guides. Bombay, India: World Wide Fund for Nature-India by Oxford University Press. ISBN978-0195631647.