Prosopocoilus giraffa
The giraffe stag beetle — the longest stag beetle species in the world, with mandibles to match.
About Prosopocoilus giraffa
Prosopocoilus giraffa holds the record as the longest stag beetle species, with large males reaching up to 120mm including mandibles. Native to Southeast Asia — India, Indonesia, and surrounding regions — they are glossy dark brown to black with long, toothed mandibles that give them their common name. Several subspecies exist, varying in size and mandible shape.
This is a Lucanidae (stag beetle) species, so their larval care differs fundamentally from flower beetles and rhinoceros beetles. If your experience is only with Cetoniidae, read the larval care section carefully — the substrate requirements are different.
Larval care
Like all stag beetles, P. giraffa larvae feed on decaying hardwood — not flake soil. The preferred substrate is kinshi (fermented hardwood blocks colonised by white-rot fungi) or well-decayed hardwood in moist substrate.
- Kinshi bottles or blocks are the gold standard for this species
- Alternatively, provide chunks of soft, well-rotted deciduous hardwood
- Never use softwood (pine, cedar) — it is toxic
- House larvae individually — males in particular can be cannibalistic
- Replace kinshi every 3–4 months as it is consumed
- Maintain 23–25°C for best results
Temperature plays a significant role in adult size. Cooler rearing temperatures (22–23°C) tend to produce longer larval periods and larger adults. Warmer temperatures shorten development but often result in smaller males with less impressive mandibles.
L3 larvae construct a pupal cell within the wood or substrate. Once a larva stops feeding and begins to shrink slightly, pupation is imminent. Do not disturb the container. The pupal period lasts 4–6 weeks.
Adult enclosure & feeding
Adults are primarily nocturnal. Provide a ventilated enclosure with 5–8cm of moist coconut fibre, bark for hiding during the day, and branches for climbing. Males are aggressive and territorial — never house two males together, as fights can result in lost limbs or death.
Feed beetle jelly as the primary food source. Soft fruit (banana, apple) can supplement. Males will guard food sources, so provide multiple feeding stations if housing a pair.
Breeding
Place a mated female in a container with soft, decaying hardwood pieces partially buried in moist substrate. Females chew into the wood to lay eggs. Remove the female after 4–6 weeks and leave the wood undisturbed — L1 larvae will emerge over the following weeks. Separate larvae once they are large enough to handle.