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Chew's Long-jawed Stag Beetle
AdvancedCyclommatus chewi
A Cyclommatus from Borneo whose wild record of 87.0 mm ranks among the largest in the genus. Described only in 1994, it is a relatively recent species with long, gently curved mandibles, and one for experienced keepers.
Difficulty
Advanced
Temperature
20〜28℃
Lifespan
Adults 4-6 months (typical for the genus)
Size
Males 25.0-87.0 mm (wild record 87.0 mm; the captive record is 82.0 mm)
Humidity
60〜80%
Diet
Beetle jelly (in the wild it visits flowers of herbaceous plants)
About
Chew's long-jawed stag (Cyclommatus chewi) was described from Borneo in 1994, and every specimen record in GBIF comes from Sabah in Malaysia. BE-KUWA gives a wild record of 87.0 mm, a captive record of 82.0 mm and a projected maximum of 92 mm, which puts it among the large species of the genus alongside the metallifer and elaphus groups. The smallest certified beetle is 25.0 mm, and the long sweeping mandibles of a major male look nothing like the short jaws of a minor. Care follows the genus: a firmly packed set with a soft log buried in fine fermented substrate. Condensation inside the box shortens life, so keep it cool and well ventilated. Rearing larvae in wood is an option for size, but emergence comes two to six months later than on substrate.
Source: Wikipedia (CC BY-SA 4.0)
Lifespan of the Chew's Long-jawed Stag Beetle
The Chew's Long-jawed Stag Beetle lives Adults 4-6 months (typical for the genus).
Size of the Chew's Long-jawed Stag Beetle
The Chew's Long-jawed Stag Beetle grows to Males 25.0-87.0 mm (wild record 87.0 mm; the captive record is 82.0 mm).
Basic Info
Origin
Borneo (Sabah, Malaysia)
Lifespan
Adults 4-6 months (typical for the genus)
Size
Males 25.0-87.0 mm (wild record 87.0 mm; the captive record is 82.0 mm)
Temperature
Care Specifications
Breeding Records & Localities
Captive record (♂)
82 mm
Wild record (♂)
87 mm
Record source: BE-KUWA 2025 edition (Chew, captive 82.0 mm, 村上真一 2022 / wild 87.0 mm; projected maximum 92 mm. Smallest record 25.0 mm, 石田航一郎 2025; literature minimum 31.4 mm)
Notable localities
Sabah, Borneo (Malaysia)
The captive record of 82.0 mm is still 5 mm short of the 87.0 mm wild record, and with a projected maximum of 92 mm there is room left to grow this species larger.
Generation codes
- WD
- Wild-caught
- WF1
- Offspring of a wild-caught female
- F1〜
- Captive generations (same locality)
- CBF1
- Cross-locality captive-bred (reset)
Sources: BE-KUWA Certified Breeding Records (Mushi-sha, FY2025 edition PDF, JA) / Cyclommatus - Wikipedia (JA)
References & Sources
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
- Wikipedia
- Ministry of the Environment, Invasive Species Act: "Guidance for Those Importing Live Insects in Scarabaeoidea"
- CITES Appendix (checklist.cites.org)
- BEETLE SCHOOL - Rearing Cyclommatus (egg-laying set, larval rearing, larval period, adult lifespan, breeding cautions)
- Ben's Beetle Breeding Pages - Cyclommatus chewi (distribution)
- BE-KUWA Certified Breeding Records (Mushi-sha, FY2025 edition PDF, JA)
- GBIF
Taxonomy & Authority
Accepted name: Cyclommatus chewi Mizunuma, 1994
Authority databases: GBIF
Nomenclature follows global taxonomic authority databases.
Regulations & Conservation Status
Not CITES-listed
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.
Chew's Long-jawed Stag Beetle Listings
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