Gum emperor moth

Order: Lepidoptera
Family: Saturniidae

Caterpillar host plants are eucalyptus, pepper trees, silver birch, apricot, grape vines
Damage can be extensive if there are large numbers of caterpillars
For the adult to emerge from the hard, nut–like cocoon, it must rasp through the tough exterior. The sound of this process has been likened to a rat gnawing