Comparing the many specimens of both on BOLD, I would say the markings on many of the A. nigrirenalis have a greater contrast with the background, and the background tends to be paler and slightly orangish. That being said, there seem to me to specimens of each on BOLD that could well be the other. Anyway, bearing my former comment in mind, I am now more inclined to think this Canberra specimen is A. affinitalis.