@RogerF Looking at iNat (I couldn't find any online records for Mastigapha) it looks like it could be Narea kungaree. Perhaps the modern name of the same critter?
The Psudophyllinae were revised by Rentz, Youning & Ueshima in 2015 when Mastigapha (Karsch) was synonymised with Narea (Walker). A useful summary of the Pseudophyllinae by Matthew Connor is found in i-naturalist.
@RogerF @Csteele4 Narea kungaree seems correct. See https://www.inaturalist.org/taxa/956866-Narea-kungaree/browse_photos It was a cool day and a lot of insects were not on their natural food source. Perhaps having fallen and not had the energy to move.
Also https://bie.ala.org.au/species/https://biodiversity.org.au/afd/taxa/75221c11-bff7-464f-8bf7-3ef10d4827c4#gallery