Ceylon birdwing

Description

Male forewing: adnervular pale streaks not prominent on the upperside,more distinctly marked on the underside.Hindwing black,with a very broad discal slightly curved silky-yellow band or patch that extends beyond the cell from interspaces 2 to 7,and is composed of elongate outwardly emarginate yellow markings that are divided only by the black veins.In most specimens the inner margin of this band crosses the apex of the cell,but in many the cell is entirely black.Abdomen with some black markings beneath and a lateral row of black spots. Female: Differs from cerberus female in the much greater extent of the black on the hindwing.Interspace 1 with a pale dusky-white patch in the middle;interspace 7 with an inner and an outer yellow spot;cell entirely black or nearly so,sometimes,but rarely,with the yellow extended into the apex. Wingspan of 165–175 mm.