@Mike Hi Mike, As I commented on Heather's sighting (Gonipterus scutellatus (Eucalyptus snout beetle, gum tree weevil)), I have suspected that these are weevil larvae. I did Google weevil larvae search recently and read that they pupate underground, though a Google search tonight suggests that they are the larve of Gonipterus scutellatus (weevil). Have collected some to raise to adult.