A Fairy Moth. Note the super-long antennae. Size - very small, body about 8 mm long.
Thanks to Tony D., Ken W., Russell B. and Axel K. for help with the identification.
Update from Axel: "It is Nemophora topazias, not sparsella! It is a species from Acacia that seems to be more often seen in autumn. N. sparsella does not have the yellow basal spot, feeds on Bursaria and flies in early summer."
Possibly larva of a Spilosoma sp. moth. Feeding on a Senecio plants in the forest. Quite a few in the area. Five pairs of prolegs (non-jointed) and 3 pairs of true (jointed) legs near its head - Caterpillars only have 6 (true) legs like all insects!