Common Sailer ( Neptis hylas)

Common Sailer ( Neptis hylas): 

Photo from Bashhajari taal, Chitwan National Park. Nepal

Heptis hylas
upper-side
underside
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Lepidoptera
Family:	Nymphalidae
Genus:	Neptis
Species:	N. hylas
Binomial name
Neptis hylas (Linnaeus, 1758)
Synonyms
Neptis varmona, Moore, 1872 Neptis eurynome (Westwood, 184

• Wingspan 43-57 mm
• Altitude: 450-10200 ft.
• Season: January to December,
• Very Common
• Habitat: Everywhere. It is cetrainly the commonest of the Sailers.
• Note that they are Sailer of the skies as distinct from Sailors of the seas.
• The clear distinction here is that the white bands on the under-side have clear black edging.
• Neptis hylas, sometimes known as the Common Sailer, is a species of nymphalid butterfly found in South Asia and Southeast Asia. 
• It has a characteristic stiff gliding flight achieved by short and shallow wingbeats just above the horizontal.
• Dry-season form
• Upperside black, with pure white markings. Fore wing discoidal streak clavate, apically truncate, subapically either notched or sometimes indistinctly divided; triangular spot beyond broad, well-defined, acute at apex, but not elongate ; discal series of spots separate, not connate, each about twice as long as broad; postdiscal transverse series of small spots incomplete, but some are always present. Hind wing: subbasal band of even or nearly oven width ; discal and subterminal pale lines obscure; postdiscal series of spots well separated, quadrate or subquadrate, very seldom narrow. Underside from pale golden ochraceous to dark ochraceous almost chocolate ; white markings as on the upperside, but broader and defined in black. Fore wing: interspaces 1 a and 1 from base to near the apex shaded with black, some narrow transverse white markings on either side of the transverse postdiscal series of small spots. Hind wing a streak of white on costal margin at base, a more slender white streak below it; the discal and subterminal pale lines of the upperside replaced by narrow white lines with still narrower margins of black. Antennae, head, thorax and abdomen black; the palpi, thorax and abdomen beneath dusky white.
• Wet-season form
• Differs only in the narrowness of the white markings and in the slightly darker ground-colour and broader black margins to the spots and bands on the underside.This species has been observed to make sounds whose function has not been established.
• Structure:
• Head larger than anterior segment, vertex with two short pointed spines, cheeks obtusely spined; third, fourth, sixth and twelfth segments armed with a subdorsal pair of stout fleshy spiny processes, those on the fourth segment longest. Colour pale green ; face, tip of processes and segments slightly washed with pale pinkish, a slight pinkish oblique lateral fascia from anal process ; a small, dark, lateral spot on sixth segment.