The Huhu grub grows to between 40-50 mm long. The Larvae feed in dead rotting wood and pupate in a cavity excavated in the log.

The larvae or "Huhu grub" is considered a delecaseie to some Maori. When grilled it has a taste very similar to peanut butter.

Adult does not eat and lives about 2 weeks. The beetles are most active at night and are often heard flying into window panes with a loud thump, they are attracted to light.