Thanks Aaron and thanks to Donna who tagged an expert on this species, Martin Lagerwey. Here is his response for the benefit of others ...
"I think this is Callidemum. The genus does intimidate me because it is mostly rainforest species, not my strength, as a Victorian. Callidemum are hard to define and get switched in an out of similar genera like Calomela and Platymela. FYI Here is an extract from Dr. Chris Reid (2006) "Number of species: approximately 70 have been seen in collections, 50 have been described. Host-plants: Elaeocarpaceae (Elaeocarpus, Sloanea); Fabaceae (Acacia); Rutaceae (Citrus); Sapindaceae (Dodonaea); Surianaceae (Guilfoylia). Most species of Callidemum are confined to rainforests, but C. hypochalceum feeds on Dodonaea throughout semi-arid southern Australia." Since yours was found on Acacia, it is probably not C. hypochalceum. but still a known foodplant for Callidemum. Last month i went to FNQ with Callidemum one of several target beetles. I saw only three... Well, that's hardly scratching the surface. https://www.inaturalist.org/observations?locale=en...