MORPHOLOGY

External characteristics

Male
Forewing length (mm): 37-46. Wingspan (mm): 53-66.
Forewings: Upperside black with blue band consisting of median spots from hind margin to apex, widest at hind margin, confluent, but uppermost spots separate, no other spots; underside similar, but ground color brown Hindwings Crenulate, no tail but hindwing longest at end of vein 4; upperside black with blue (upper part whitish) band from costa (where it is about as wide as half length of costa) narrowing to just before costa, submarginal spots present as blue crescents (in space 7 reddish), no further markings; underside ground color as underside forewing, as upperside, but ground color paler and with some median spots present as indistinct to conspicuous red markings; red bar near wing base from costa to cell.

Female
Similar to male.

Subspecies and variation

Varies considerably over its huge distribution area (India to Japan, Solomon Islands and Australia; about 18 subspecies are recognized, of which 11 are found in the Malaysian region.

Similar species

The only species it could be confused with is G. monticolus, an endemic from Sulawesi where G. sarpedon does not occur. G. monticolus has better developed submarginal spots, but the further separation as separate species is mainly a matter of taste.

_{source: Jan Moonen, peronal communication 2020}