Blue Triangle or Common Bluebottle
(one synonym : Chlorises helena Swainson, 1851)
PAPILIONIDAE , PAPILIONOIDEA
This species is probably named after Sarpedon, the king of Lycia in Ancient Greek mythology.
The Caterpillar starts life as a white, yellow, or greenish round egg which is laid on the new shoots of its food plant. It is often found on the introduced
although its other food plants include Australian natives such as:
The female butterfly is quite particular, usually only laying her eggs on a food plant. Occasionally however she makes a mistake, and we have found the eggs on
on which the young caterpillars cannot always successfully develop.
The caterpillars at first are dark grey and hairy, with a pale yellow tail.
As they grow they become green with a humped thorax, tapering from the thorax rearward. The yellow tail develops into a pair of white spikes. Paired black spikes also develop on each of the three thrax segments. The spikes on the metathorax are longer than the others, and become connected by a conspicuous yellow bar. The sides of a mature caterpillar are marked by a whitish line just above the legs. The caterpillar grows to a length of about 3 cms.
When it is disturbed, the caterpillar often rears up on its rear legs. It may also extrude a pair of pale translucent yellow or green fleshy horns ( an osmeterium) from a dorsalpocket in the prothorax, just behind the head. These smell strongly of camphor, and are retracted quickly after a second or two.
The caterpillar pupates on the underside of a curled leaf of the food plant. The pupa is green with a few yellow lines that converge to a spike on its head. The pupa is held by a silk girdle around the middle, and a cremaster at the tail.
Within three weeks in summer, the adult emerges, having a wing span around 7 cms. The wings are black above and brown below, with large turquoise patches in the middle of both fore and hind wings. These patches seem to form a triangle, with the apex pointing towards the body.
The underside of the wings are similarly marked with turquoise patches, and each hind wing has some red dots on its underside.
Specimens reared in captivity are usually smaller and not as blue as wild forms. The reason for this is unclear: perhaps sunlight is necessary for maximum growth and full pigment development.
The species is found as several subspecies all over south-east Asia, including :
as well choredon (Felder & Felder, 1864) on the eastern tropical and subtropical seaboard of Australia, including:
Hong Kong 1979
Solomon Islands 1982
This species is featured at Coffs Harbour Butterfly House. Butterflies of this species may be purchased for release at weddings etc.
Further reading :
Michael F. Braby,
Butterflies of Australia, CSIRO Publishing, Melbourne 2000, vol. 1, pp. 259-260.
Letter, Butterflies and Other Invertebrates Club Newsletter,
Issue 32 (March 2004), pp. 17-18.
(updated 15 March 2013)