Centaur Oakblue

Arhopala pseudocentaurus aglais (C.& R.Felder, [1865]) (= Arhopala setsuroi Hayashi, 1981), commonly called Centaur Oak Blue or Centaur Oakblue.

The Centaur Oakblue can be differentiated from the other Arhopala species by the silvery green lines edging the markings in the cell on the underside of the forewing. The male is purple-blue with a very narrow black border on the forewing. The paler and more purple female has broad dark borders. The species has a symbiotic relationship with ants during its larval stage. The green caterpillar has a brown saddle mark. The caterpillar is attended by ants, in particular, the 'Fire Ant' or Kerengga (Oecophylla smaragdina). The caterpillar exudes a honey which is 'milked' by the ants in return for protection. No predator would normally risk tackling these aggressive biting ants to get at the caterpillar. The butterfly has been observed both in the nature reserves and in areas outside where its host plant and the Kerengga ants abound.