MORPHOLOGY
External characteristics
Male
Forewing length (mm): 46-68. Wingspan (mm): 78-108.
Forewings: Upperside basal 1/5 to 1/2 green, turquoise or bright blue, followed by a broad, black band from hind margin and tornus to middle of costa or beyond, again followed by a paler, brownish apical area which may be densely powdered by greenish scales; underside, basal 2/3 to 3/4 dark brown, may be inconspicuously speckled with golden scales, apical /4 to 1/3 paler, more grayish brown. Hindwings Crenulate with strong spatulate tail at end of vein 4; upperside, basal 1/5 to 1/2 sky blue to green, vaguely passing into black outer area with or without faint indications of greenish submarginal spots; underside grayish brown, darker in basal 2/3 (and there inconspicuously speckled with golden scales) and along margin, small black median spots from inner margin to space 6, more or less accompanied by reddish scales, particularly so at inner margin.
Female
Forewing length (mm): 46-61. Wingspan (mm):79-105.
As male, but submarginal spots on hindwing usually better developed, particularly so in green forms.
Subspecies and variation
Apart from some individual variation in extension and intensity of wing markings, there is a pronounced geographical variation in the color of the basal wing parts on the upperside: green in the western part of the distribution area (particularly Java), turning to more bluish in the Lesser Sunda Islands and particularly Tanah Jampea (ssp. intermedius), becoming bright blue on Sulawesi (ssp. insulicola in SW Sulawesi and ssp. adamantius in N Sulawesi). The situation in the Lesser Sunda Islands is confusing. The populations of Bali and Alor are known and ssp. transiens, but on Bali specimens may be green as well as more bluish, and moreover, in the area between Bali and Alor two other subspecies have been distinguished, one from Sumbawa (ssp. fannius) and one from Lombok and Flores (ssp. fulgens), west and east of Sumbawa! A revision seems appropriate.
Similar species
The green form is unmistakable. In the eastern Lesser Sunda Islands another Papilio species occurs with a large part of the wing area on the upperside sky blue. There are three Papilio species in the Malesian area with brilliant blue on the wings, viz. P. pericles, P. ulysses and the blue forms of P. peranthus. Of these, P. ulysses has the brightest, iridescent blue color, while the outer edge of the blue area is sharp and strongly toothed; moreover, P. ulysses does not occur in the Lesser Sunda Islands, but in the Moluccas and further east and south. In P. pericles and P. peranthus the edge of the blue area is straight and not sharp, but rather diffuse. In P. pericles the blue area is more extensive, reaching well beyond the middle of the costa of the forewing, while in P. peranthus it reaches considerably less that far.
source: Jan Moonen, peronal communication 2020