Ios or Mauve Line Blue
(one synonym : Nacaduba obscura Grose-Smith, 1894)
POLYOMMATINI, POLYOMMATINAE, LYCAENIDAE, PAPILIONOIDEA
(Photo: courtesy of Bob Miller and Ian Hill)
These Caterpillars are mainly green, but have a dark brown first abdominal segment. The abdomen has deep grooves between segments. The caterpillars have been found feeding on the open flowers of:
In captivity, the caterpillars died if offered only flower buds rather than open flowers. The caterpillar grows to a length of about 1 cm.
The pupa is greenish-brown with dark brown markings. It is attached by anal hooks and a central silk girdle. It has a length of about 1 cm.
The adult male butterflies of this species are iridescent purple on top. The females are similar but bluer, and shading to black at the wing margins. Underneath, they are both fawn with lots of squiggly white lines, and two black spots at the tornus of each hind wing. The male wingspan is about 2 cms. The females have a wingspan of about 2.5 cms.
The eggs are laid singly on flower buds of the foodplant. The eggs are white, round and flattened, and covered in knobs. The eggs have a diameter of about 0.5 cm.
This species is found across south-east Asia, including
and in the tropical north of Australia, including
Further reading :
Michael F. Braby,
Butterflies of Australia,
CSIRO Publishing, Melbourne 2000, vol. 2, pp. 781-782.
Neue Tagschmetterlinge der Indo-Australischen Fauna,
Correspondenz-blatt des Entomologischen Vereins "Iris" zu Dresden,
Volume 1, Part 3 (1886), p. 63, and Plate 5, fig. 18.
P. R. Samson & T.A. Lambkin,
The immature stages and seasonality of Petrelea tombugensis (Rober) (Lepidoptera: Lycaenidae),
The Australian Entomologist,
Volume 30, Part 4 (December 2003), pp. 181-183.
(updated 3 July 2008, 22 November 2013, 6 August 2020)