MORPHOLOGY
External characteristics
Male
Forewing length (mm): 52-55. Wingspan (mm): 93-96.
Forewings: Upperside dark gray, almost black, very inconspicuous paler stripes between the veins 4 and 8, with or without subapical spots; underside similar. Hindwings Crenulate and tailed; upperside same color as forewing, large grayish-white patch from space 1b to costa, with toothed outer margin along the veins and convex inner margin extending just into cell; underside, same ground color, veins inconspicuously outlined in a lighter gray, grayish white spots with sharply hollowed outer margin in the middle of spaces 4 to 6, submarginal spots in spaces 1b and 2 discernible as small concentrations of yellow spots, some indistinct bluish lines around grayish white spots.
Female
Forewing length (mm): 60. Wingspan (mm):111.
Similar to male.
Subspecies and variation
There is a geographic variation in the presence or absence of subapical spots on the upperside of the forewing: in ssp. albinus (most of New Guinea) there are none, in ssp. lesches (Port Moresby area in Papua New Guinea) there are white subapical spots.
Similar species
Unmistakable.
source: Jan Moonen, peronal communication 2020