I have usually attributed Canberra based records of P. arabella as apparently 'Philobota undescribed species near arabella' out of deference to the text and photographs of the similar undescribed species as described on page 64 of 'Moths in the ACT' (Cocling et al 2022), The photographs there showing the observed variation locally I think are essentially indistiguishable from this record on sight alone.
Yes, I saw that text too, but it was very confusing to me. Do they mean that both or only the unnamed relative exists in the ACT? The pictures in the book are both for Philobota sp. near Arabella variations (the unnamed relative?), which both look a bit different than the one here - but there clearly are variations. The moth shown above has the coloured costa edge that is mentioned in the book. I think it looks more like the pictures of the close relative available on NatureMapr, but I'm far from an expert on this.
I have been trying to look at the BOLD records to see if there have been a lot moved due to DNA analysis. There seem to be 3 different sp that look like this. I have not worked it all out. If I can?