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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)
Origin
India to Indonesia (including the Moluccas)
Lifespan
Adult 6mo-1yr
Size
40-100mm
Temperature
20〜27℃
Humidity
60〜80%
Tree sap, beetle jelly
Maintain 20-27°C
Captive record (♂)
90.7 mm
Wild record (♂)
86 mm
Record source: BE-KUWA 2025年度版(フォルスター nyishi 飼育90.7mm 2021 / 野外86.0mm)
Notable localities
Regional subspecies
飼育レコードは BE-KUWA(むし社)のコンテストで毎年更新される。産地・累代(CBF/WF/WD)・サイズで個体価値が大きく変動する。
Generation codes
Sources:
Edited & verified by: br-choku 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: コガネムシ上科(カブトムシ・クワガタムシ・ハナムグリ等)の生きた個体を輸入する際は、外来生物法に基づき輸出国政府機関等が発行する種類名証明書の添付が必要(輸入港は成田・中部・関西・福岡・鹿児島の各空港に限定)。本種自体は特定外来生物ではなく、証明書の添付により輸入可能。
Sources: 環境省 外来生物法「コガネムシ上科に含まれる生きた昆虫を輸入される方へ」 / CITES 附属書(checklist.cites.org)
Regulations may change. Always verify the latest information with the relevant authorities.
Find listings for this species
Raise in fermented mat or fungal bottle
Primarily lays in breeding logs
Sharp bifurcated mandibles are dangerous; handle with care
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℃. Recommended humidity is 60〜80%. 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 morph, size, and lineage. Check our market price page for the latest pricing information.
Last updated: June 23, 2026