Opodiphthera helena

Opodiphthera helena (White, 1843)
(one synonym : Antheraea intermedia)
Helena Gum Moth
SATURNIIDAE

Don Herbison-Evans ( donherbisonevans@yahoo.com )
and
Miguel de Salas & Stella Crossley

(updated 31 May 2008)

Early instars of this Caterpillar are very pretty: they are pale brown with double white lines along the back and sides, paired yellow spots on the back, yellow scoli along each side, and seven black tubercles ringed in red : three on the thorax and one on the tail.

Later the ground colour becomes green, and they develop red tubercles on the thorax, and dark patches on the first and last abdominal segments.


contented	threatened

At this stage, when they feel threatened, they curl the head under, exposing the spines on the thorax.

The final instar of this Caterpillar is green with a pale pink lateral stripe, red spiracular openings, and is covered in short white bristles. There are small paired spikes on the thorax and on the eighth abdominal segment.

The Caterpillar feeds in broad daylight on:

various species of Gum Trees ( Eucalyptus, MYRTACEAE ),

and has also been reportedly found on

Birch ( Betula species, BETULACEAE).

However, in an experiment with newly hatched larvae, groups of five were placed in petri dishes with different food plants:

Pepper Tree ( Schinus molle, ANACARDIACEAE),

Silver Birch ( Betula pendula, BETULACEAE),

English Oak ( Quercus robur, FAGACEAE ),

Privet ( Ligustrum vulgare, OLEACEAE ), and

Plum ( Prunus domestica, ROSACEAE ).

They refused to even nibble at any of them except Oak, on which that group started feeding immediately, and kept doing so. They were all later transferred to

Ribbon Gum ( Eucalyptus viminalis ).

as they grow better on their natural food plants. They grow to a length of about 8 cms.

The Caterpillar pupates in a hard cocoon between leaves or attached to the trunk of its food tree. Inside the cocoon is a brown pupa. The resting period of the pupa has been found to vary between three weeks and two years.

female(left) and male(right) cocoons

The female cocoon has a lenght of about 4 cms. The male has a length of about 3 cms.

male

The adult moth is brown with wrinkled wingtips, and a single brown eyespot in the middle of each forewing. The hind wings also each have an eyespot which is much more spectacular.

male underside

If disturbed, a resting moth will deflect its head and body, incline its wings forwards displaying its hind eyespots, and rhythmically raise and lower its wings. The moths have a wingspan from 13 to 17 cms.

female moth resting, with hindwing eyespots hidden
(Photo: courtesy of Rev'd Jan St James, Neerim, Victoria)

disturbed female moth, with hindwing eyespots exposed
(Photo: courtesy of Rev'd Jan St James, Neerim, Victoria)

One female we reared was so laden with eggs that she could not fly.

The species is found along Australia's eastern coast, in:

Victoria, and