I photographed a "butterfly" feeding on one of my Milkmaids Burchardia umbellata the other day, and after the butterfly talk by Valda Dedman at our last Social Evening, I decided to identify it.
I couldn't find it in any of my sources, so I checked Mary White's paintings in the library and found my MOTH.
It was the Senecio or Magpie Moth Nyctemera amicus, a moth of the Arctiidae family. It is found in South-east Asia, Oceania, and most of Australia.
The larvae feed on Fireweed Groundsel Senecio linearifolius and Cotton Fireweed Senecio quadridentatus, in our neck of the woods, and other Senecio species elsewhere. These foodplants contain pyrrolizidine alkaloids, making the larvae unpleasant to taste and poisonous to birds. (Source: Wikipedia)