Metallic Stag Beetle

Cyclommatus metallifer (Boisduval, 1835) belongs to Lucanidae in Coleoptera. Museums Victoria holds an identified specimen collected in Central Sulawesi, Indonesia, on 5 December 1989. [1]

The adult has a lustrous brown exoskeleton. Males carry long, slender mandibles and a broad head containing enlarged jaw muscles; females have a smaller head and short mandibles. The male weapons can approach the length of the rest of the body. [1][2]

The species inhabits Sulawesi’s tropical forests. The Museums Victoria voucher provides a specific occurrence in Central Sulawesi. [2][1]

In male contests, the mandibles grip an opponent and the front legs help pitch the body upward to throw the rival backward. The enlarged head shifts the male’s centre of mass forward. In a laboratory comparison, males used shorter, more frequent strides than females at equivalent normalized speeds. [2]

Bite measurements found that males reduced jaw-muscle force by 18% when biting at the slender tips rather than at the larger teeth halfway along the mandibles. Finite-element models supported a reduction in cuticular stress from this force adjustment. [3]

Microscopy found mechanoreceptors distributed through the jaw surface. Their spatial distribution correlated strongly with the calculated pattern of material stress during biting, supporting a sensory feedback mechanism for controlling force. [4]

Models based on laboratory walking trials estimated a mechanical cost of transport almost 40% higher in males than in females. The longer male front legs did not restore the stability lost through the heavy head and jaws. [2]

Keep the enclosure closed and display it in indirect light, away from heat and damp conditions. Handle the frame by its edges and clean only its exterior according to the maker’s instructions.