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Hexarthrius forsteri
A two-pronged stag beetle from Indonesia's Maluku Islands. Features large, well-developed bifurcated mandibles and a glossy body. Closely related to the red-back stag beetle, and similar keeping methods can be applied. A popular species.
Hexarthrius forsteri is a fork-jawed stag beetle distributed across India, Indonesia, and the Moluccas. It features large, forked mandibles and a glossy body, and the same husbandry used for related fork-jawed stags applies. Care uses a small to medium enclosure with oviposition logs and fermented substrate. Adults are fed insect jelly, and larvae reared in fungal substrate bottles or fermented substrate can grow large. The long, powerful mandibles call for careful handling. With an impressive appearance and manageable care, it is a popular exotic fork-jawed stag beetle.
Source: Wikipedia (CC BY-SA 4.0)
The Forster's Stag Beetle lives Adult 6mo-1yr.
The Forster's Stag Beetle grows to 40-100mm.
The ideal temperature for the Forster's Stag Beetle is 20〜27℃.
Origin
India to Indonesia (including the Moluccas)
Lifespan
Adult 6mo-1yr
Size
40-100mm
Temperature
Captive record (♂)
90.7 mm
Wild record (♂)
86 mm
Record source: BE-KUWA 2025 edition (Forster nyishi captive-bred 90.7mm 2021 / wild 86.0mm)
Notable localities
Regional subspecies
Captive records are updated annually in the BE-KUWA (Mushi-sha) contest. Individual value varies significantly by locality, generation (CBF/WF/WD), and size.
Generation codes
Edited & verified by: BreederDirect editorial team
The taxonomic, regulatory, and husbandry data on this page are compiled and verified against the authoritative primary sources below.
Accepted name: Hexarthrius forsteri (Hope, 1840)
Synonyms: Lucanus forsteri Hope, 1840
Authority databases: GBIF
Nomenclature follows global taxonomic authority databases.
Plant Protection Act: When importing live specimens of Scarabaeoidea (including rhinoceros beetles, stag beetles, flower beetles, etc.), a species identification certificate issued by the exporting country government agency or equivalent must be attached in accordance with the Invasive Species Act (import ports are limited to Narita, Chubu, Kansai, Fukuoka, and Kagoshima airports). This species itself is not a designated invasive species, and import is possible upon submission of the certificate.
Sources: Ministry of the Environment, Invasive Species Act: "Guidance for Those Importing Live Insects in Scarabaeoidea" / CITES Appendix (checklist.cites.org)
Regulations may change. Always verify the latest information with the relevant authorities.
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20〜27℃
Humidity
60〜80%
Tree sap, beetle jelly
Raise in fermented mat or fungal bottle
Sharp bifurcated mandibles are dangerous; handle with care
Keep at 20-27°C. It is easiest when held in the same stable temperature band as the related Hexarthrius species.
Set up a small to medium case with a breeding log and fermented substrate. Add bark or wood as footing so adults can right themselves.
Feed adults beetle jelly. Raising larvae in kinshi bottles or fermented substrate lets you aim for large adults.
Laying in a breeding log is the norm. Bury the log in substrate and split it only after the larvae have grown.
Intermediate. This is an intermediate-level species. Some prior experience and knowledge of environmental management are recommended.
The ideal temperature for Forster's Stag Beetle is 20〜27℃. Avoid sudden temperature changes and maintain a stable environment.
The average lifespan of Forster's Stag Beetle is Adult 6mo-1yr. With proper care and nutrition, they can live a long and healthy life.
Forster's Stag Beetle typically reaches 40-100mm as an adult. Size may vary depending on care conditions and individual genetics.
Forster's Stag Beetle feeds on: Tree sap, beetle jelly. Aim for a balanced diet with appropriate feeding frequency.
The price of Forster's Stag Beetle varies significantly depending on bloodline, size, captive-bred generation, and sex. Check our market price page for the latest pricing information.
Last updated: August 31, 2026