Phalacrognathus muelleri

Size: Approximately 3–7 cm for males and 2.3–4.6 cm for females. Difficulty (Keeping): Easy to Moderate; hardy and adaptable when provided with appropriate humidity, ventilation, and suitable substrate. Breeding Difficulty: Moderate; adults breed readily when mature, but successful breeding requires suitable decayed hardwood or fermented beetle substrate for egg laying and larval development. Temperature: 20–26°C (68–79°F). Humidity: High; approximately 60–80% for adults, with moist but well-ventilated conditions. The substrate should remain damp without becoming waterlogged. Note: Phalacrognathus muelleri, commonly known as the Rainbow Stag Beetle or King Stag Beetle, is a spectacular Australian stag beetle known for its metallic green, red, blue, bronze, and black colouration. Males can become considerably larger than females and develop impressive mandibles. Adults feed on beetle jelly or soft, ripe fruit, while larvae develop in decaying hardwood or suitable fermented beetle substrate.