This large cossid moth had a wing span of at least 70 mm. There were no patterns on its grey wings however, the wings looked like sand-paper. The hind wings were shorter and a beautiful purplish brown. some of this colour was also seen in the abdominal segments nearer the thorax. Abdomen was very thick. antennae were short, feathery and brown.
It was interesting to see this moth in flight - lifting its heavy body into the air after a short "taxiing". On ground, the moth could be heard fluttering from several metres away.
Spotted under bright lights near a national park. Need help to ID this large cossid. thanks.