The Rainbow Stag beetle gets the name from its unique coloring, which appears to change color when looked at in different angles and in different light within its also unique, metallic-looking body. It is native to Japan, New Guinea and northern Australia. Metallic green and purple body, very rarely is either color absent but several dark blue specimens have been recorded, and rare examples that were very dark in color. A small percentage of non-teneral adults displays a shift in color to either increased red or green.As an expression of percentage of total length, male mandibles vary between 19 - 32 %, irrespective of beetle size.
Named after the strong, antler-like, curved mandible jaws. These are notably longer in the male than the female. They are nocturnal and sometimes attracted to lights.The males 'antlers' are used as levers during conflict. Each tries to pass them under the rival's body to raise and dislodge them. Males may adopt a threatening position stance by rising up on the mid and hind pairs of legs, with forelegs outstretched and mandibles working like scissors.Stag beetles are mainly vegetarians. Adults feed on nectar, young leaves, sap and fruit.