Diemenia rubromarginata and Notius depressus are similar in colour. Adult N. depressus have full-length forewings, reaching to the apex of the body; a more oblong body; and the red lateral margin on the thorax is very narrow. D. rubromarginata has short wings; a rounded outline to the body; and the red margin on the thorax is wider.
@MichaelBedingfield @MichaelMulvaney @DianneClarke Michael, I created a new category and reassigned most of the incorrect IDs and replaced the species page images that have been misguiding users. Alison