Notes

Other Common Names
Lesser Monarch

To my mind this is one of the most attractive butterfly species around. They can be rather difficult to photograph, because although they land often enough, they are wary and tend to fly off as I approach.
There were hundreds of the things at Mount Annan when I went there in April, though not quite so many early in May. They breed on the milkweeds there, and the larvae could sometimes be found on the same plants as D. plexippus larvae. There were still large numbers of them in June 2004 at Mount Annan, including literally dozens of them feeding from a large thistle.

At Mount Annan, I noticed what appeared to be the opposite of hill-topping behaviour. Close to the biggest hill in the Botanic garden is a low, flat area where the garden staff dump plant prunings etc. It's a sheltered spot that gets the sun, and these butterflies gather there in numbers. I wasn't sure if they were courting, as though they would flit around together at times I didn't see any mating couples there.

Sightings
Adults, Larvae and Pupae - Mount Annan Botanic Garden - April, May, June, August, September 2004.
Adults - Ingleburn - April 2004
Darwin - April 2018