Other Common Names
Australian Gull, Northern Gull

This was a bit of a fortunate one for me. I spotted the butterfly feeding from Lantanas at the bottom of a bank next to the path I was walking along. I was able to get a couple of photos, and at the time I thought the butterfly was a female Appias paulina, so I was pleasantly surprised when I downloaded the photos to see that it was actually this species instead.
This species was common in some spots around Darwin, especially East Point. Their undersides were noticeably whiter than specimens seen in Queensland.

Sightings
Cairns - April 2006, September 2008, December 2008
Townsville - December 2017
Darwin - April 2018