About Nacaduba pavana (Horsfield, 1828)
Scientific name: Nacaduba pavana (Horsfield, 1828)
Males: The upperside is purple with a frosted silvery-blue sheen, very similar to that of N. macrophthalma. The forewing has a slender black anteciliary line. On the hindwing, the costal and dorsal margins are somewhat broadly dull brown, and it has an anteciliary black line matching that of the forewing. The subterminal black spots located in interspaces 1 and 2 of the underside are visible through transparency in most specimens. The underside's ground colour and markings are similar to those of N. macrophthalma, but are far more slender and more neatly defined. Antennae, head, thorax, and abdomen match the features of N. macrophthalma.
Females: On the upperside of the forewing, the costa is broadly brown, while the apex and termen are brown over an even broader area; a narrow edge of pale brown runs along the dorsal margin; the remaining area of the wing is grey, and flashes with iridescent blue in certain lighting. The hindwing is pale brown, much paler than the brown on the forewing. Its base is very obscurely tinted with iridescent blue; the costal and dorsal margins are brownish white. A transverse subterminal series of black spots is edged both inwardly and outwardly with slender white lines. Two tiny spots in interspace 1 are geminate (paired), while the spot in interspace 2 is large. These three spots are crowned inwardly, beyond the white edging, with an additional dusky spot. The underside is very similar to that of the male, but has a paler ground colour and broader transverse white strigae.
Both male and female Nacaduba pavana have an immaculate basal area of the forewing, within the transverse white strigae that line the inner side of the discocellulars, matching the condition seen in N. macrophthalma and N. kerriana.
Distribution: Charles Thomas Bingham (1907) recorded this butterfly from Sikkim, Bhutan, Assam, Cachar, Burma, Tenasserim, and the Andamans. The species was originally described from specimens collected in Java. According to Savela, the butterfly's range extends across Tibet, India to Myanmar, Thailand, Malaysia, Singapore, Langkawi, Sumatra, the Philippines (Mindanao), and Sulawesi.
