We had masses of these caterpillars feeding on Indigofera australis in our front yard during 2014 and 2015. After eating every single leaf and killing one of the Indigofera plants, they moved on to other plants in the garden, including a standard white rose that this one is eating.
Long time reader, first time uploader. I am fairly confident this is a hybrid between Acacia paradoxa and Acacia stictophylla- both species are found in the reserve (Hillview Bushland Reserve). There were a number of similar individuals in close proximity. Please excuse my hand!