We are looking for pale dots in the black area, near the outer margin about half way across the hindwing. see http://lepidoptera.butterflyhouse.com.au/heli/punctigera.html no dots - upper surface hindwings http://lepidoptera.butterflyhouse.com.au/heli/armigera.html pale dots - upper surface hindwings I know from experience how tricky this is. At least there is a feature that can be used in live specimen images. Dissecting genitals is usually the preferred method (or now Barcoding/DNA) of Entomologists especially with similar looking things
Thank you for your message. I am aware of this issue, for what it is worth I have looked at many of these moths in and around Canberra these last few weeks, these moths are everywhere, along with bogongs, not seen one individual yet this spring with the pale dots on the hindwings.