Prosopocoilus is a genus within the family Lucanidae, a group commonly known as stag beetles. Comprising over 100 distinct species, these insects are recognized for their appearance and considerable size, which has made them popular subjects for insect collectors and hobbyists.
Distinctive Physical Traits
A defining characteristic of the Prosopocoilus genus is pronounced sexual dimorphism. Males are typically much larger than females and are distinguished by their exceptionally long mandibles. These antler-like jaws are not for feeding but are used as weapons in combat with other males over territory or mating rights, while females possess small mandibles suited for creating spaces to lay eggs.
Prosopocoilus giraffa, the giraffe stag beetle, is a prime example and the world’s largest stag beetle. Males of this species can reach up to 119 millimeters in length, with their mandibles accounting for roughly half their total body size. Coloration across the genus is subdued, with most species displaying shades of black or reddish-brown, allowing them to blend into their surroundings.
Natural Habitat and Geographic Range
Members of the Prosopocoilus genus are found in the tropical and subtropical forests of Asia. Their geographic range stretches from India across Southeast Asia and into Indonesia. For instance, various populations of Prosopocoilus giraffa inhabit distinct territories from the Indian subcontinent to the Indonesian archipelago.
These beetles thrive in moist, forested environments where decaying wood is abundant. The presence of rotting logs and stumps is a requirement for their survival. Their lifestyle is tied to the natural decomposition processes on the forest floor, and the health of these ecosystems directly impacts stag beetle populations.
Life Cycle and Diet
The life of a Prosopocoilus beetle has four stages: egg, larva, pupa, and adult. A female lays her eggs within soft, decaying wood. Once hatched, the larva, or grub, spends its developmental period inside the rotting log, which can last for many months. During this time, the larva feeds on the surrounding wood to accumulate nutrients for its transformation.
Upon reaching adulthood, the beetle’s diet shifts. Adult Prosopocoilus do not eat wood; instead, they seek energy-rich liquids. They feed on tree sap or the juices of ripe and fermenting fruits. This diet supports adult activities like reproduction and dispersal.
Care in Captivity
To raise Prosopocoilus beetles, their natural environment must be replicated. An appropriate enclosure, like a well-ventilated terrarium, should be filled with a deep layer of substrate formulated for stag beetle larvae. This material, made of fermented wood flakes and soil, provides food for the grubs.
Adult beetles have simpler dietary needs. They are fed commercially produced beetle jellies high in sugar and nutrients, and slices of fruit like bananas or apples can be offered as a supplement. Maintaining adequate humidity and a stable temperature within the enclosure is necessary for the health of both larvae and adult beetles.