Introduction The genus Parthenos comprises of 3 species, sylvia, tigrina and aspila. The latter 2 are endemic to Papua New Guinea, while sylvia in comparison has an extremely wide distribution being found in Sri Lanka, India, Myanmar, Thailand, Malaysia, Borneo, Sumatra, the Philippines, Sulawesi, Java, Bali, Papua New Guinea and Irian Jaya. Habitats This species is found in primary rainforest, usually in the vicinity of rivers, at elevations between sea level and about 300 metres. Lifecycle The larva is brown, speckled with white dots, and has broad greenish dorsal and lateral stripes. Each segment bears 4 multi-branched spines, purplish brown at the base and red on the outer half. The larval foodplants include Adenia ( Passifloraceae ) and Tinospora ( Menispermaceae ). The chrysalis occurs in 2 forms, either pale green or dark olive. It is rather plain in appearance, without protuberances, and is suspended by the cremaster from beneath a leaf. Adult behaviour The Clipper is a powerful and fast flying butterfly. The flight consists of short periods of gliding, alternating every few seconds with shallow but rapid flickering wing beats. On the Kinabatangan river in Borneo I have observed hundreds of these magnificent butterflies circling and gliding around tree tops along several kilometres of the river edge. Both sexes commonly nectar at Lantana and other flowers. Males will also settle on the ground to imbibe moisture. If disturbed they fly up immediately, circle around at a height of about 3 metres, and then resettle nearby.
Male and female. Upperside : ground-colour a bright purple, the subhyaline white spots near the apex of cell in the fore wing more opaque, the broad discal band of large white spots proportionately more basal further from the termen and very irregular, the spots, especially towards the hinder part of the wing, more widely separated, the spot in interspace 5 more acutely triangular and smaller, the two spots above shifted obliquely inwards towards the costa, making the outer margin of the discal band angulate at interspaces 5 and 6. Hind wing: the postdiscal and sub-terminal markings broader and more diffuse than in P. gambrisius, giving a dark shade to the whole of the apical half of the wing. Underside pale greenish grey. Fore wing: the spots and markings except the basal black streaks as on the upperside, the groundcolour fading to an ashy grey towards the terminal margin. Hind wing similar to the underside of hind wing of P. gambrisius, but the discal transverse sinuous black line very broken and incomplete, the postdiscal, subterminal and terminal black markings somewhat better denned. Antennae black; head, thorax and abdomen bronze green, barred with black above ; beneath whitish.