They are full of protein, fats and other nutrients to the local small native animals, as these moths are large and fat they are attractive as food to birds,owls and frogmouths as well as cats and rats that have a feast at this time. They were a food of local Aborigines also. They taste somewhat like butter & sawdust! Other people describe their taste differently.
The larva are called Bardi grubs and are huge. They are famous as bait for Murray Cod fishing but are also a great native wild food, but you have to know how to eat them or you will be so sick you will wish you hadn't.
Bardi Grubs are large grubs that live in the ground for many years, feeding on tree roots. The female moths drop the eggs around large gum trees. The newly hatched grubs burrow into the ground where they feed on tree roots. As they grow larger the burrow in which they live also becomes progressively larger, up to several centimetres in diameter. Other creatures, such as Trap-door and Wolf Spiders also make similarly sized holes, but Bardi Grub holes can be distinguished from these as they are lined with a lining somewhat resembling felt. This is a much better way to identify a hole in the ground than sticking ones finger in! Old fishermen who seek Bardi Grubs say that if you place your finger in the hole and ‘pop’ it, the hole makes a hollow sounding popping sound, like a child’s pop gun, if the hole is occupied by a grub. Apparently an empty hole makes no such sound. However this is not recommended to those unsure of the identity of the hole. For instance, if the hole is occupied by a large Wolf Spider, it may feel included to defend its home! Fishermen also said that Bardi Grub holes were only found in ground that was not waterlogged. Therefore they were only looked for around trees growing on higher ground, rather than land that was frequently flooded.
The adults often emerge after rain, typically in autumn, so the adults are often called Rain Moths. They usually leave the empty pupal case sticking out of the ground,
The moths have grey-brown wings with two variable ragged silver flash markings across each forewing. The forewings often also show intricate sinuous patterns of pale lines. The wingspan of the males can reach 12 cms and the females can reach 16 cms.
The adult females deposit large numbers of eggs. Indeed, this species holds the World Fecundity record for the greatest number of eggs being deposited by a non-social insect. One dissected female had 44,100 eggs. It is thought that they are laid in flight.