Photo added 11/3/23. Is this a pre-pupal stage? Otherwise, I might have fed them the wrong eucalyptus leaves and they are dying of food poisoning or starvation.
Hi Mike, I've found that they will eat almosst any Eucalyptus leaves. However, if not given fresh leaves often enough they will go into the pupae stage and still transform into beetles (unless very young). The resulting beetles can then be much smaller than would otherwise be expected. I would continue to add fresh leaves but otherwise then just keep an eye on them and see what emerges. It may take a while. The larvae did look quite mature, so yes they may be going into the pupal stage.