I raised this species on eucalptus gunni, you are in a bad way trying to switch foodplant. Good luck, when I raised mine I had hopes of breeding, but the females hatched and started laying ova without calling.
In any event, you have nothing to lose by trying everything you can find that's going to last another 4 weeks or so by the looks of those larva.
Trimming leaves and tricking them into drinking water may work to get them eating, although you may end up simply dragging out the inevitable, I've had larva nibble for weeks and eventually expire on something they didn't care for.