it's probably been eaten by now, I just left it on the ground! I'll be clearing a few Acacia baileyana over winter (invasive woody weed locally). How do you rear them in captivity?
A good way is in a clean bottle with a piece of fabric over the top held by an elastic band. Give it a piece of the wood you found it in, to munch on. See some more general comments in; http://lepidoptera.butterflyhouse.com.au/faqs/care.html
I think E. leucomochla larvae usually feed underground on Wattle roots. Above ground I think you are more likely to find E. encalypti larvae, which despite their name, feed on Wattles.