About Aporia agathon (Gray, 1831)
The typical form of Aporia agathon (Gray, 1831) has a black upperside; both the forewings and hindwings have white or greenish-white streaks and spots located in the discoidal cells and interspaces. On the forewing, there is a broad streak in the cell, and two more or less confluent streaks below it in interspace 1, which are obscurely divided by a diffuse blackish line. This is followed by an upper discal series of five short lines in interspaces 3, 4, 5 and 10, and a complete subterminal series of elongate narrow spots. Both the discal and subterminal series curve inwards anteriorly. In most specimens, the streaks in interspace 1 and in the cell are irrorated with black scales. On the hindwing, there is a broad streak along the dorsum divided by vein 1a, two narrow long streaks in interspace 1, a much broader elongated oval streak in the cell, another elongate broad streak above it in interspace 7, a discal series of five narrow elongate spots beyond the apex of the cell, followed by a complete subterminal series of more or less oval spots. On the underside, the ground colour and markings are similar to the upperside, but are more clearly defined. On the forewing, markings are generally broader and whiter, except that the anterior one or two streaks or spots of the discal and subterminal series, along with all markings on the hindwing, are strongly suffused with bright yellow. In addition, the precostal area on the hindwing is bright chrome yellow. Antennae, head, thorax and abdomen are black; the underside of the abdomen is white, and the anterior legs have one or two white spots. The variety caphusa Moore, found in Sikkim, Kumaon, and from Mussoorie to Simla and the Kangra region, differs from typical A. agathon on both the upper and under sides by having much wider and more extended greenish-white markings in the discoidal cells and interspaces of the wings. On the upperside of the forewing, the streak in interspace 1 shows no black dividing line, and both this streak and the short streaks of the discal series tend to coalesce with the subterminal elongate spots. On the underside, the spots near the apex of the forewing and those on the hindwing are only faintly, not clearly, suffused with yellow; the chrome-yellow spot at the base of the hindwing matches that of A. agathon. Antennae, head, thorax and abdomen match A. agathon, though the abdomen is darker brown rather than black. Variety phryxe, Boisduval is the palest variety in the A. agathon series. The greenish-white streaks and spots in the cell and interspaces, which are considerably longer and broader in variety caphusa, with interspace markings showing a tendency to coalesce, become very broad and white in phryxe. As a result, the discal series of short streaks on both wings extend to and completely coalesce with the greatly broadened spots of the subterminal series. In fact, this variety can be described as white on both the upper and under sides, with veins broadly bordered in black, and black terminal margins formed by the expansion and coalescence of black at the apices of the veins; the discoidal cell of the forewing has a large black patch at the apex. The black along the veins of both the forewing and hindwing suddenly broadens on the discal area; on the underside of the hindwing, this black almost forms a connected transverse discal black band. The chrome-yellow spot on the precostal area matches that of A. agathon. Antennae are black, head and thorax are dusky grey, abdomen is white; on the underside, head and thorax are blackish, and abdomen is white. This species has a wingspan of 84–98 mm. Aporia agathon is found in the sub-Himalayan region, ranging from Assam, Sikkim, Bhutan, and Nepal in the east to Mussoorie and Kumaon in the west.
