Last week I came across this mating pair of Caper White butterflies Belenois java teutonia resting on a Chocolate Lily that had gone to seed. The female (lower one) is a bit larger than the male and has wider black borders on wings.
The Caper White Butterfly Belenois java teutonia is a seasonal spring migrant to Victoria and SE Australia from NSW, central Australia, Queensland and South Australia where their host plants naturally occur. Larvae feed exclusively on their host plant which includes the shoots and leaves of the Native Orange Capparis species and native Currant Bush Apophyllum anomalum both of which do not occur in Victoria. They can also breed here on ornamental plantings. (Elaine Bayes provided me with this information.)