Natureguy we are taking part in moth week in two weeks time where we are asking people to collect and care for caterpillars so that they can be matched to a species of moths. For 95% of our caterpillars we don't know to what species of moth they belong. Instruction can be found at https://citizenscience.org.au/2021/06/08/moth-matchmakers-needed/
Thanks Michael, I saw this and actually put this caterpillar in a small old fish tank to raise. Unfortunately it didn't survive, partly because I didn't really know what to feed it as it was on a dead log. I tried some different Eucalyptus and Acacia leaves as well as a log with Lichen and some apple slices but it didn't seem to eat any of those. Always good to learn and I will probably not take caterpillars if they are not on a food plant as I don't want to kill them. Also I'll find a smaller container to make it easier to monitor.
Thanks Nature Guy this site gives a clue to what caterpillars in teh same genera or family are eating which could be a good place to start http://lepidoptera.butterflyhouse.com.au/arct/annulata.html
I'm wondering whether this may be Spilosoma glatignyi. The hairs appear clumped as they are in the caterpillars of that species (see Sighting No 4262074) and there a similar fine white dots visible.
The later instars of the caterpillar of Spilosoma glatignyi usually have a brown head, brown hairs, and a set of large paler verrucae along each side. The caterpillars of some Amata sp. have a black head like this one, black hairs, and dark lateral verrucae which are shiny and in some lighting conditions reflect an apparent white dot.
If the caterpillar declined to eat apple slices, it was probably infected with something, maybe even a coronavirus. Any caterpillar you find on walkabout is usually either about to pupate, or its behaviour has been altered because it is infected. Its death was not your fault. Caterpillars in the wild have a 99% mortality rate from predators. It is always better to take a caterpillar into protective custody than leave it in the wild.
Thanks Michael, Don, and Ian for the useful information on the identification and care of the caterpillar. Maybe it was unwell, this would explain why it was on a dead log, on the ground, a fair distance from vegetation. Always a good learning experience, regardless of the outcome (positive or negative) and I can improve for future attempts.