This pale green nymph with wing buds and banded antennae was about 18mm excluding antennae.
Eucalyptus tree. Spotted on the tip of a branch with young shoots.
This is probably the 5th instar. Most of these nymphs are seen at tips of young eucalyptus shoots sucking the sap and causing the tips to wilt. The tips of the fresh shoot is seen to be wilting (pic #2). The web reference states that this could be the instar of a tip-wilter mimic - this requires clarification.