Rainbow Stag Beetle

Phalacrognathus muelleri, the rainbow stag beetle, is the sole species in its genus and belongs to the family Lucanidae. Native to the rainforests of northern Queensland, Australia, and New Guinea, it is celebrated for its remarkable iridescent coloration, appearing in red, green, blue, or black forms depending on the individual. Adults reach 30–65 mm in length and inhabit tropical forest canopies, feeding on tree sap and fruit. In captivity, small to medium enclosures are suitable, furnished with pieces of bark and wood to prevent toppling. Egg-laying occurs directly in fine-particle fermented substrate packed to a depth of at least 10 cm. Optimal temperature is 20–25°C, and adults live one to two years—an unusually long lifespan for stag beetles. Its spectacular coloration, manageable size, and straightforward husbandry make it one of the most sought-after display beetles worldwide.

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Jelly (adult) / Fungus bottle or fermented substrate (larva)