Neptis hylas, the common sailor,[1][2] is a species of nymphalid butterfly found in the Indian subcontinent and southeast Asia.[1][2] 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. Forewing discoidal streak clavate (club shaped), 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 (united), each about twice as long as broad; postdiscal transverse series of small spots incomplete, but some are always present. Hindwing: 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. Forewing: interspaces 1a 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. Hindwing 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.[3]
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.[3][4]
More than 20 subspecies have been described.[5] [6] [7]
Mating pair, Bangalore, India
In Dumbara, Rathnapura, Sri Lanka
N. h. luculenta
Taiwan
This species has been observed to make sounds whose function has not been established.[8]
Throughout continental India; Sri Lanka; Assam; Nepal; Myanmar (Tenasserim), extending to China and Indomalaya.[1][2]
Race varmona = eurynome. Frederic Moore describes this from a drawing by Samuel Neville Ward as follows:
"Head larger than the 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, the tip of processes and segments slightly washed with pale pinkish, a slight pinkish oblique lateral fascia from an anal process; a small, dark, lateral spot on the sixth segment."[3]
"Rather short; head-piece bluntly cleft in front, vertex pointed; thorax dorsally prominent and angular; dorsum angular at base; abdominal segments slightly angled dorsally; wing-cases somewhat dilated laterally. Colour pale brownish-ochreous, with lateral thoracic golden spots."[3]
Neptis hylas, the common sailor, is a species of nymphalid butterfly found in the Indian subcontinent and southeast Asia. It has a characteristic stiff gliding flight achieved by short and shallow wingbeats just above the horizontal.