Orange Palm Dart
(one synonym : Pamphila ulama Butler, 1870)
HESPERIINAE, HESPERIIDAE, HESPERIOIDEA
egg, highly magnified
(Photo: courtesy of Ken Walker, Melbourne, Victoria)
This animal starts life as a cream hemispherical egg, with a diameter just over 1 mm. The egg develops red areas as it nears hatching. The egg is laid singly on the undersides of fronds of one of its foodplants, which are various species of Palms (ARECACEAE), especially :
The caterpillar when it hatches, is light green, with translucent smooth skin, and a prominent black head. As it develops, its head changes to grey with a faint pattern, and finally to white with a black V mark. It lives by day within a shelter made by using silk to join fronds of its foodplant, which conveniently fold together and bend across each other naturally. It feeds nocturnally, growing to a length of about 4 cms.
The translucent skin enables the male and female caterpillars to be distinguished. The males have a yellow pair of developing sex organs visible through the skin at abdominal segment five.
The caterpillar turns into a pupa within its palm shelter. As it forms the pupa, it creates a quantity of white chalky powder. The pupa has a length of about 3 cms. After about two weeks, the butterfly emerges.
The species has different male and female forms for the adult butterflies.
The adult males have brown wings with large areas of orange markings. The abdomen of both sexes has brown and orange or yellow bands.
Underneath, the markings are less pronounced, and the dark brown area is restricted to a patch along the hind margin of each forewing, and a spot near the tornus of each hindwing. This latter spot is not visible when the butterfly is in its normal resting posture.
The females are slightly larger than the males, have more rounded wings, and are usually dark brown with a few sparse yellow marks. The females have some variation in colour, some specimens being light brown with orange markings just as extensive as those of a male. The wingspan of the female is about 4 cms. The male is somewhat smaller.
Various races of this species are found from Indonesia to the Solomons
The subspecies sperthias Felder 1862, is found around the coast of mainland Australia, including
Further reading :
Michael F. Braby,
Butterflies of Australia, CSIRO Publishing, Melbourne 2000, vol. 1, pp. 230-231.
Baron Cajetan von Felder,
Lepidopterorum Amboienensium species novae diagnosibus,
Sitzungsberichte der Akademie der Wissenschaften in Wien,
Volume 40, Part 11 (1860), p. 461, No. 51.
(updated 21 August 2011, 22 September 2013, 26 July 2016, 18 May 2020, 4 September 2021)