This is possibly even the same beetle that I hatched inside and photographed before I let it go a few days ago. If so, it has darkened considerably and is now a deep, rich colour. It was found on the same young Eucalyptus mannifera. Paropsisterna brunnea?
This is the adult beetle (from the previous two observations), one day after 'hatching', when I let it go and put it back on to the tree I had taken it from as a larva. It is thought by Martin Lagerwey to be Paropsisterna brunnea.
A green larva from my previous observation was kept and these photos are of its transition from a larvae into a beetle. It stopped eating on 3 March and shed its skin and became a pupa (as in first photo here) on the evening of 6 March. The last three photos were taken on the 15 March as it emerged as a beetle, which has been thought by Martin Lagerwey to be Paropsisterna brunnea.
Because I thought this larvae looked 'different' I kept one and will put other observations on Natureshare of the resultant beetle, which has been thought by Martin Lagerwey to be Paropsisterna brunnea.
This is Paropsisterna brunnei, a brown leaf beetle with very smooth elytra and a black head. They usually have faint pinstripe lines along the elytra. This particular specimen is without the usual lines.