Polyura is the genus of nawab butterflies. They belong to the brush-footed butterfly subfamily Charaxinae, or leafwing butterflies.
Polyura hebe chersonesus [species in Malaysia], Polyura hebe plautus [species in Singapore] are medium sized robust butterflies.
Life History of the Plain Nawab [Polyura hebe plautus] can be found on Butterflycircle blog.
Photo: Penang Butterfly Garden, Malaysia 2002