It's quite confusing, Harvey. Atoichus was erected in 1915, and the type species is A. bicolor, which has exactly the size and colouring of this sighting if material in the ANIC is correctly identified. But your sighting keys out to Pemanoa (a 1955 genus) in Matthews & Bouchard's 'Tenebrionid beetles of Australia...' (2008), as follows: 'Head abruptly constricted basally, forming distinct neck; antennomeres subtriangular... : Atoichus; Head gradually and only slightly narrowing basally; antennomeres more elongate... : Pemanoa'. Pretty slim differences I reckon, and the ANIC material doesn't easily fall into one or the other in many cases.