Danaus plexippus plexippus
Common name: Monarch
Unknown.
Occurs from Perth to Cape Leeuwin. There are populations at a number of other Western Australian localities, usually around populated areas.
The caterpillars grow to approximately 70 millimetres long. The adults can have a wingspan of up to 93 millimetres.
Occurs in a wide variety of habitats. The caterpillars are known to feed on Asclepias physocarpa, Gomphocarpus cancellatus, Calotropis gigantea, Stapelia grandiflora, Stapelia variegata and Araujia hortorum.
We have seen it feeding on Gomphocarpus fruticosus.
The Complete Guide to Butterflies of Australia. Michael F Braby. 2004
Atlas of Living Australia https://bie.ala.org.au/species/https://biodiversity.org.au/afd/taxa/127ae005-62ed-4868-b947-b1a981d5e579
Butterfly House https://lepidoptera.butterflyhouse.com.au/nymp/plexippus.html