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Dorcus grandis formosanus
A giant stag beetle endemic to Taiwan, treated as the Taiwanese subspecies of Dorcus grandis. Wild males measure about 38–78 mm, captive-reared males can exceed 80 mm, and it is kept in almost the same way as the Japanese giant stag beetle.
The Taiwanese giant stag beetle (Dorcus grandis formosanus) is a giant stag beetle endemic to Taiwan, described by Yushiro Miwa in 1929. It has long been treated as the Taiwanese subspecies of Dorcus grandis, although recent classifications place it as a subspecies of D. hopei. Wild males measure about 38–78 mm and females about 35–48 mm, and captive-reared males over 80 mm have been recorded. The body is glossy black all over; the inner tooth of the mandible sits slightly further forward in larger males, and pronotum shape varies between individuals. It inhabits broadleaf forest on the main island of Taiwan at roughly 200–2,000 m. Adults are active from April to September, are nocturnal, gather at sap flows on trees of the beech family (Fagaceae) and also come to lights. Larvae develop over 1–2 years in large, lightly decayed broadleaf logs. In Taiwan it is listed as protected wildlife under the Wildlife Conservation Act, and collecting in the wild is restricted. It has been kept in Japan for a long time; rearing and breeding are almost the same as for the Japanese giant stag beetle, and larvae do well in fungus (kinshi) bottles.
The Taiwanese Giant Stag Beetle lives Adults 2–4 years.
The Taiwanese Giant Stag Beetle grows to Males 38–78 mm, females 35–48 mm.
The ideal temperature for the Taiwanese Giant Stag Beetle is 18〜28℃.
Origin
Broadleaf forest at about 200–2,000 m on the main island of Taiwan (endemic subspecies)
Captive record (♂)
84.3 mm
Wild record (♂)
78.3 mm
Record source: BE-KUWA 2025 edition (grandis Taiwan Large - captive 84.3 mm Mieda Takatoshi 2012 / wild 78.3 mm)
Notable localities
Taiwan large stag beetle (Dorcus grandis formosanus, Taiwan subspecies of grandis). Captive breeding records are updated annually through BE-KUWA (Mushi-sha) competitions. Individual value varies significantly depending on locality, generation (CBF/WF/WD), and size.
Generation codes
Sources: BE-KUWA Certified Breeding Records (Mushi-sha, FY2025 edition, JA)
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.
Primary sources
Accepted name: Dorcus grandis formosanus Didier, 1926
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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Lifespan
Adults 2–4 years
Size
Males 38–78 mm, females 35–48 mm
Temperature
18〜28℃
Humidity
60〜80%
Insect jelly
Rearing and breeding are almost the same as for the Japanese giant stag beetle. It is said to be relatively short-tempered for a giant stag beetle, so watch that the male does not injure the female during pairing.
Aim for 18–28°C. Keep it above 10°C in winter and below 30°C in summer. Egg-laying needs 20°C or more (ideally 23–25°C). Keep the substrate moist enough to hold together when squeezed but crumble when pressed.
Feed adults beetle jelly; in the wild they feed on sap from trees of the beech family. Larvae grow well in fungus bottles, with 1.4 L bottles recommended for males. They can also be raised on fermented flake substrate.
Pair mature adults at least six months after emergence, then place the female in a laying setup with buried sawtooth oak or konara oak logs, or artificial kawara (Trametes) logs. She lays in the wood; remove her after about a month and break open the logs 2–4 weeks later.
Adults live a long 2–4 years and can be kept for several years. Because it can hybridize with the Japanese giant stag beetle, never release captive individuals outdoors. Keep it out of direct sunlight.
Intermediate. This is an intermediate-level species. Some prior experience and knowledge of environmental management are recommended.
The ideal temperature for Taiwanese Giant Stag Beetle is 18〜28℃. Avoid sudden temperature changes and maintain a stable environment.
The average lifespan of Taiwanese Giant Stag Beetle is Adults 2–4 years. With proper care and nutrition, they can live a long and healthy life.
Taiwanese Giant Stag Beetle typically reaches Males 38–78 mm, females 35–48 mm as an adult. Size may vary depending on care conditions and individual genetics.
Taiwanese Giant Stag Beetle feeds on: Insect jelly. Aim for a balanced diet with appropriate feeding frequency.
The price of Taiwanese Giant 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: September 28, 2026