Theclinesthes onycha

Theclinesthes onycha (Hewitson, [1865])
Cycad Blue
POLYOMMATINI , POLYOMMATINAE , LYCAENIDAE

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

(updated 13 May 2008)

Theclinesthes onycha
(Photo: courtesy of Don Ashton, Mudgeeraba)

The caterpillars of this species are initially green with a dark reddish dorsal line edged in paler green. Later instars are brown The species is unique in that it is the only Australian butterfly caterpillar that feeds on Cycads, namely species from the families CYCADACEAE and ZAMIACEAE such as :

Ceratozamia robusta,

Cycas media, and

Macrozamia spiralis.

The caterpillars eat the young shoots and stems, feeding mainly nocturnally. By day they hide in the base of the plant or under the fronds. The caterpillars are often attended by various species of green or black ants.

(Photo: courtesy of Don Ashton, Mudgeeraba)

The adult butterflies are brown with a lilac or purple sheen. There is often an obscure arc of dark spots around each hindwing margin. The undersides are brown with pale wiggly lines. The hindwings each have a little tail near the tornus, and one or two orange-edged black spots on each hindwing beside the tail. The butterflies have a wingspan of about 3 cms.

Macleay Museum, University of Sydney)

Males are reported to fly around hilltops, while the females can more often be seen around the foodplant. The species occurs in Australia and shows much variation, especially between seasons.

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

Eggs are very pale blue and disc-shaped. They are laid singly on young growth of a foodplant.

(Photo: courtesy of Don Ashton, Mudgeeraba)

Two subspecies have been recognised :

capricornia in the northern half of Queensland, and

onycha in southern Queensland and New South Wales.