Friday, 17 August 2012

Things lepidopterological

Recent night trips on cold (16C!) winter's nights have provided observations to compensate from the distinctly non-tropical temperatures.
 Roadsides in the  mixed woodlands not far from the rainforest have been clothed in a blanket of bright yellow with the flowering wattles (Acacia spp.). Close examination of the flowers revealed a yellow caterpillar consuming the blossoms.
 The arching gait suggested a looper, a member of the Geometridae.

Traminda rubra Holloway: Geometridae; Sterrhinae                
B Richardson photo

A few were removed with some blossom and after a few days they formed a chrysalis and about 10 days later the moth emerged. This moth has two colour morphs. The brown one shown above and a green morph. It is not uncommon and is often found at lights in the rainforest where there are also acacias but of different species. [Thanks to Ted Edwards for noting the name change for this moth.]

 This little moth, a member of the huge family Oecophoridae, was common sitting on grass blades after dark on a very cold evening in the Davies Creek area, Qld. Grass of several species was deep and green.
 One might think the moth is therefore associated with grasses. Well it might be but a female was observed ovipositing (egg-laying) in the bark of a Baker's Oak,  Allocasuarina torulosa.
Ovipositing female.

Perhaps, the eggs hatch and the tiny larvae drop to the ground and live on grass roots until they emerge and then sit on the grass blades after dark. Laying ones eggs in bark at the base of a tree like Baker's Oak is a rather precarious activity late in the winter at this locality. Soon the "fireies" will be setting the habitat ablaze with their "prescribed" burning. From the looks of the trees in the area, this a regular process. It would be very lucky for the eggs of this moth to survive what appears to be ahead for this habitat. But then, obviously some do survive such treatment.


Ian McMillan said...

Oecophoridae feed mainly on decaying leaf litter and vegetable matter, so your little moth's hatchlings probably drop straight onto the forest floor, where their job is to decompose what your lovely firies would call 'fuel load.' At this task they are extremely efficient.

Mr. Smiley said...

Wish they would put the firies out of business!