Don, thanks for your ID suggestion , how certain are of this ID? I understand that the Arcloa malloi moth feeds exclusively on Alligator Weed, which is a rare species in Canberra and is a weed that we are trying to eradicate and is not known from the location where this photo was taken - but perhaps we should go out and take a look?
Arcola malloi seems to be a very variable species, so I think it could be that. However, the posture of your moth looks to me more like that of a Crambinae than a Pyralidae, I think out of the 125 named species in Crambinae, it is not one of the 15 that I might recognise, so it could be one of the other 110.