MORPHOLOGY

External characteristics

Male
Forewing length (mm): 75-85. Wingspan (mm): 130-151.
Forewings: Upperside black with seven conspicuous brilliantly green arrows pointing to the outer margin and flanking the veins; underside black with violet-blue streak from wing base to under vein 2 and along costa in basal part, internervular turquoise/green streaks in spaces 2-5. Hindwings Hindwing upperside black with large brilliantly green area from inner margin to vein 6 or just beyond, green area may have bluish sheen near wing base; underside black, greater or smaller briljant blue area in basal part, white 'hourglass' submarginal spots. Prothorax and head, and underside of metathorax, conspicuously red.

Female
Forewing length (mm): 82-110. Wingspan (mm):144-178.
Less brilliantly colored, whitish between veins in apical part forewing and with more or less visible whitish submarginal spots on hindwing, best developed in spaces 5 and 6, blue sheen at base of green area better developed.

Subspecies and variation

Varies geographically in the extent and intensity of the green and white areas; five subspecies are recognised: ssp. brookiana (Borneo), ssp. trogon (Sumatra), ssp. mollumar (southern W Malaysia), ssp. albescens (central W Malaysia) and ssp. natunensis (Natuna).

Similar species

Can only be confused with its congener Trogonoptera trojana. The male of the latter has the green more bluish, while the green area on the hindwing is a band that does not enter the cell. The female of T. trojana is brown instead of black with much more white along, between the veins, also on the hindwing. The two species do not occur together.

_{source: Jan Moonen, peronal communication 2020}