Rainbow Stag Beetle

The Rainbow Stag Beetle (*Phalacrognathus muelleri*) is native to the rainforests of northeastern Australia. They thrive in the tropical, humid environments of Queensland, where they feed on tree sap and rotting wood. They are a prominent species in the Australian Lucanidae family.

The beetle's brilliant shifting colors of green, gold, and red are caused by structural coloration rather than chemical pigmentation. Microscopic structures in their exoskeleton reflect light in a way that creates this stunning metallic effect. This makes their appearance shift depending on the angle of the light hitting them.

In the wild, adult Rainbow Stag Beetles primarily feed on tree sap, while their larvae develop inside and consume rotting hardwood logs. In captivity, breeders usually feed the adults sweet fruits like bananas or specialized beetle jelly. This high-sugar diet provides the energy needed for their active breeding behaviors.

These beetles exhibit significant sexual dimorphism, with the males growing much larger than the females. A male Rainbow Stag Beetle, equipped with large mandibles, can reach lengths of up to roughly 68 millimeters (about 2.5 inches). Females remain significantly smaller and lack the massive mandibles.