About Atrophaneura varuna (White, 1842)
Atrophaneura varuna, commonly called the Common Batwing, has a wingspan ranging from 88 to 136 mm. Both males and females are tailless. Males have a rich velvety blue black upperside. Outward toward the forewing terminal margin, and across the entire hindwing except the dorsal area, the wings show a rich dark purple bloom in some light and a very dark green bloom in other light. The dorsal area and the entire inner side of the sexual fold are opaque brownish black. The outer half of the forewing has more or less prominent pale adnervular streaks. The underside matches the upperside, but the pale adnervular streaks on the forewing are broader, more prominent, and extend further inward well up to the terminal margin. The ground colour of the hindwing underside is more uniformly blue black than the upperside. Males are unmarked bluish black on the upperside. They have a scent patch located within a rounded black-brown dorsal fold; when this fold is opened, the white lower half of the scent patch is visible. Their antennae, head, thorax, and abdomen are black; the front, sides, and underside of the head, plus the sides of the thorax and abdomen, are rich crimson. The underside of the thorax and abdomen is black, and the crimson sides of the abdomen also have additional lateral black spots. The abdomen bears white stripes, and the head is rose coloured. Females are also tailless, with a grey brown upperside that has dark stripes between the veins, and a large pale patch below vein 2 on the upper forewing. Female uppersides are dull black, with very broad, prominent pale greyish-green streaks that extend into the cell, and are especially broad in interspaces 1 and 2. The female hindwing is more uniform, with a dark dull blue bloom that appears dark green in some lights. The female underside matches the upperside, but the forewing streaks are broader and paler, and the hindwing is more uniform, duller, and opaque. Female antennae and thorax are black, the abdomen is dull brownish black, and the head is crimson; the underside matches that of the male, but the crimson colouring is less bright, especially on the abdomen sides, and the abdomen lacks the lateral black spots found on males. In Sikkim, this species occurs from low elevations in the Terai up to 7,000 feet (2,100 m). Its nearly uniform dark colour makes it inconspicuous in jungle, so it is unclear why it is further protected by a disagreeable smell, and likely also a disagreeable taste. James Wood-Mason recorded that females have a strong and disgustingly rank musky odour. The range of Atrophaneura varuna includes Eastern Nepal, northern India from Kumaon to Sikkim, Myanmar, Thailand, northern Laos, northern Vietnam, Bangladesh, and Peninsular Malaysia. The Common Batwing's habitat extends from the Terai up to an altitude of 7,000 feet. Its recorded food plant is Aristolochia kaempferi, belonging to the plant family Aristolochiaceae.
