AI-generated image
Iki Flat Stag Beetle
IntermediateDorcus titanus tatsutai
A subspecies of Dorcus titanus from the Iki Islands, Nagasaki. Its long mandibles recall the Tsushima form, but body and jaws are a little shorter and stouter; captive males exceed 85 mm, among the largest Japanese flat stags.
Difficulty
Intermediate
Temperature
20〜26℃
Lifespan
Adults 1-3 years
Size
Males 50-85.1 mm (including captive; wild up to 81.6 mm) / females 30-42 mm
Humidity
60〜80%
Diet
Tree sap, beetle jelly
About
The Iki flat stag (Dorcus titanus tatsutai) is a subspecies of Dorcus titanus confined to the Iki Islands of Nagasaki (Iki, Nagashima and Oshima) and was described only in 2001. Males measure 50-81.4 mm and females 30-42 mm; the BE-KUWA captive record is 85.1 mm (2025) and the wild record 81.6 mm, making it one of the largest Japanese subspecies after the Tsushima form. It resembles the Tsushima flat stag with long, fairly straight mandibles, but body and jaws are slightly shorter and stouter. Like other flat stags it gathers at sap in broadleaf forest, is nocturnal and hides in tree hollows and under bark. Females lay in the buried base of dead standing hardwood or under fallen logs; larvae take 1-2 years and adults live 1-3 years. Keep at about 20-26 C and breed with logs and fermented substrate. It is very aggressive with a crushing grip, and males often kill females, so keep singly except for pairing. The population is limited to Iki, and releasing captive beetles would contaminate mainland or other island subspecies, so never release them.
Source: Wikipedia (CC BY-SA 4.0)
Lifespan of the Iki Flat Stag Beetle
The Iki Flat Stag Beetle lives Adults 1-3 years.
Size of the Iki Flat Stag Beetle
The Iki Flat Stag Beetle grows to Males 50-85.1 mm (including captive; wild up to 81.6 mm) / females 30-42 mm.
Temperature & humidity for the Iki Flat Stag Beetle
The ideal temperature for the Iki Flat Stag Beetle is 20〜26℃.
Basic Info
Origin
Japan (Iki Islands, Nagasaki: Iki, Nagashima, Oshima)
Care Specifications
AggressiveSolitaryBreeding: Easy
Sources: beetlebreeding.ch - The Breeding/Rearing of Dorcus titanus palawanicus by Kay (species-level guidance for D. titanus) / Dorcus titanus - Wikipedia (JA)
Breeding Records & Localities
Captive record (♂)
85.1 mm
Wild record (♂)
81.6 mm
Record source: BE-KUWA 2025 edition (Iki flat stag, captive 85.1 mm, ミント 2025 / wild 81.6 mm, 松尾良一; projected maximum 93 mm)
Notable localities
Iki Island (Nagasaki)
Regional subspecies
- Dorcus titanus tatsutai — Iki Islands (Iki, Nagashima, Oshima)
One of Japan's largest subspecies after the Tsushima form. Morphological differences from Tsushima stock are small, so beetles without locality data are hard to assign.
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) / Dorcus titanus - 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.
Taxonomy & Authority
Accepted name: Dorcus titanus tatsutai Shiokawa, 2001
Synonyms: Serrognathus titanus tatsutai
Authority databases: GBIF
Nomenclature follows global taxonomic authority databases.
Regulations & Conservation Status
Not CITES-listed
Sources: CITES Appendix (checklist.cites.org)
Regulations may change. Always verify the latest information with the relevant authorities.
Iki Flat Stag Beetle Listings
Loading latest listingsFind listings for this species
