Speiredonia spectans

Speiredonia spectans (Guenée, 1852)
Granny's Cloak Moth
(previously known as : Sericia spectans)
CATOCALINAE , NOCTUIDAE

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

These caterpillars are smooth and brown, and covered in black dots, and have several black-edged white spots on each segment. The caterpillars have been found feeding on:

Wattle ( Acacia, MIMOSACEAE ), and

Yellow Tulip ( Drypetes deplanchei, EUPHORBIACEAE ).

The moth of this species likes to hide in a dark place during the day and frequently is found in sheds and garages. The adult moth has brown wings with zig-zag patterns all over. The wing scales appear to have a finely grooved pattern that diffracts light to give the appearance of different colours depending on the angle of view. On each wing there is a pronounced eye spot, complete with eyelid!

(Photo: courtesy of Evan Harris, Ipswich)

Alternatively, if the spots on the forewings are imagined to be eyes, then those on the hind wings might be thought of as the nostrils of some large reptile. The moths even show a human-like face if viewed upside-down.

Either way, the appearance may deter possible predators. The moth has a wingspan of about 7 cms.

The adult moths are quite gregarious and seem to like resting in groups of at least a dozen or so. Pheromones probably are involved in this grouping behaviour, but also individuals that hatch on the same host plant (whatever it may be) at the same time would be subject to the same stimuli (light, plant odours etc) and therefore would move together in response. although moths of this size could travel many kilometres so this idea might not be deserving of too much credence.

However, once they find a place where they are secure they don't seem to travel very far in the subsequent days, so maybe they do not generally fly very far at all. When they rest in groups: all the individuals tend to orient themselves in the same direction. If they are on a wall they are head-up near the ceiling (or eaves of the roof) and they hold their wings so that the patterns have maximum impact if approached from slightly below - the direction from which a bird would approach.

The moths also favour dark places such as caves, to rest during daylight hours, but suffer predation by bats in these places.

The species occurs over most of the north-east quarter of Australia, including:

Northern Territory,

Queensland, and

New South Wales, being quite common in Sydney.