Suggesting M. anthracitaria based solely upon similarity to the 'green form' larva as per 'Flying Colours' by Pat and Mike Coupar. Have been unsuccessful in locating any images/information re an 'orange form' larva however.
No signs of feeding on the L. attenuatus but a bit of silk around. The plant is under a large Eucalyptus nortonii. Permits are required to collect flora/fauna from Nature Reserves. Michael: Thank you for the plant id. Will update.