The White Dragontail (Lamproptera curius) is a species of swallowtail native to parts of South Asia and Southeast Asia. It belongs to the Dragontails genus, Lamproptera, of the Swallowtail (Papilionidae) family. It is not rare.
Upperside dull brownish black. Fore wing: a broad outwardly oblique white transverse band that crosses from a little beyond the basal third of the costal margin to the dorsum, its outer half hyaline, followed by a hyaline triangular area that does not reach the costa or the termen but is traversed by conspicuously black veins. Between the semihyaline transverse band and the hyaline area the black forms a more or less oven band slightly narrower in the middle; the black edging to the costa and termen broad, broadened towards the apex ; cilia black.
Hind wing: the transverse white band of the fore wing is continued straight across and ends in a point on the outer half of vein 3, but is not hyaline along its outer margin; posterior half of the wing dull dark brown, irrorated towards the base of the long narrow tail at vein 4 with white scales ; cilia black, white below vein 5 and along outer side of basal half of tail, the latter tipped white.
Underside similar, but the ground-colour opaque brownish black; a broad outwardly ill-defined earthy-grey streak along the base of the wings produced slightly down the dorsal margin of hind and along the costa of the fore wing; the oblique white band on the hind wing joined by a cross sinuous short white line from the dorsal margin to its apex; below this latter a number of irregular white spots on the tornal area. Antennae, head and thorax black, abdomen dark brownish black; beneath, the palpi, thorax and abdomen greyish; claws of the tarsi bifid. Male with sex-mark.
The butterfly is found in India from Assam to Burma. It is also found in Thailand, Laos, Vietnam, Southern China, Kampuchea, Malaysia, Indonesia, Brunei, and Philippines. source