Can you take a lateral view photo showing the legs, as then that may allow the determination of the family. Can you take it into protective custody please, and rear it to the adult, then we may well be be able to determine the species ? As you can see from http://lepidoptera.butterflyhouse.com.au/plants/pitt/pittosporaceae.html not many species are known that feed on Pittosporacae. I think this is not one of the Lycaenidae, so it might well be Cardamyla carinentalis.