Genus: Terinos Boisduval, 1836
Species: terpander Hewitson, 1862
Subspecies: robertsia Butler, 1867
Wingspan of Adult Butterfly: 60-70mm
Caterpillar Local Host Plant : Rinorea anguifera (Violaceae).
Physical Description of Adult Butterfly:
The wings are angled with the hindwing slightly toothed at the end of vein 4. Above, the wings are rich purplish blue with two white spots in spaces 3 and 4 on the hindwing. Underneath, the wings are purple-brown with reddish brown and pale blue (shiny in fresh specimens) fasciae crossing both wings. The hindwing has a white submarginal band which is broader and more lunulate in spaces 2 to 4, and a series of dark purple brown post-discal spots which are ringed in orange.
Field Observations of Butterfly Behaviour:
The Royal Assyrian is moderately rare in Singapore. The species is usually encountered in parts of the nature reserves where its host plant, Rinorea anguifera, is growing. The adults have been observed to visit flowers for nectar. When resting, the adults typically perch on the underside of a leaf with its wings closed. The males have also been observed to puddle on damp patches.