Red-back Stag Beetle

Hexarthrius mandibularis is the largest species in its genus and one of the largest stag beetles in Southeast Asia, native to Borneo and Sumatra. Males display extraordinarily long, curved mandibles extending well over half the body length; total length including mandibles reaches 50–120 mm. Body coloration is a deep glossy black with a powerful, robust build. The species is notably aggressive—one of the most combative stag beetles—and must be handled with extreme caution. Optimal captive temperature is 20–25°C. Large enclosures furnished with soft hardwood logs are appropriate; females preferentially deposit eggs in softer wood. Larvae develop in fermented substrate or fungal substrate bottles. Mating must be closely supervised due to the male's fighting instinct. Adults eat beetle jelly and live approximately 6–12 months. The combination of record-proportioned mandibles and fierce temperament makes H. mandibularis a prized trophy species for advanced stag beetle collectors.

Tree sap, beetle jelly