Jalmenus icilius

Jalmenus icilius Hewitson, [1865]
Amethyst Hairstreak
(one synonym : Ialmenus aeneus Tepper, 1882)
ZESIINI, THECLINAE, LYCAENIDAE, PAPILIONOIDEA

Don Herbison-Evans,
(donherbisonevans@yahoo.com)
and
Stella Crossley

Jalmenus icilius
caterpillar with attendant ant
(Photo: courtesy of Alice Ewing, Craigieburn, Victoria)

These Caterpillars are a variable dull green, with white diagonal lines on each segment, and white lines along the sides. The caterpillars have a dark grey thorax, and there are pairs of tubercles on the thorax and the tail.

The caterpillars are always attended by the small black ants :

Iridomyrmex rufoniger ( DOLICHODERINAE ).

The caterpillars have been known to feed on a variety of plants, such as :

Punty ( Senna nemophila, CAESALPINIACEAE ),

Spiny Bitterpea ( Daviesia benthamii, FABACEAE ), and

Australian Blackwood ( Acacia melanoxylon, MIMOSACEAE ).

The caterpillar usually pupates between leaves or in the debris at the base of the foodplant.

pupa
(Photo: courtesy of Alice Ewing, Craigieburn, Victoria)

The pupa is fawn with dark brown speckles. It has a length of about 1 cm.

female
(Picture: courtesy of CSIRO Biodiversity)

The adult male and female butterflies look very similar. On top, they are basically dark brown, with a blue iridescent sheen. The females are rather bluer, and have a more rounded margin. The trailing edge of each hindwing has a pair of short tails. Beside one tail is a small black eyespot.

male
(Photo: courtesy of CSIRO/BIO Photography Group, Centre for Biodiversity Genomics, University of Guelph)

Underneath: the butterflies are fawn with faint bands of white-edged darker spots running across the wings. The hindwings each have two black and orange eyespots with black marks between them. The butterflies have a wingspan of about 3 cms.

(Photo: copyright of Brett and Marie Smith, Ellura Sanctuary, South Australia)

The eggs are round and flattened with a diameter of about 0.6 mm. They are pale green, and each covered by a white spiky polygonal network. The eggs are laid in clusters on a foodplant.

egg, magnified
(Photo: courtesy of Ken Walker, Ararat, Victoria)

The species occurs across most of mainland Australia, including

South Australia, and

male, underside
(Specimen: courtesy of the Macleay Museum, University of Sydney)