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Yaeyama Saw Stag Beetle
IntermediateProsopocoilus pseudodissimilis
One of Japan's four saw stag species, found only on Ishigakijima and Iriomotejima. The mandibles curve only weakly, even in large males, and most beetles are medium or small males of around 50 mm.
Difficulty
Intermediate
Temperature
20〜28℃
Lifespan
About two to three months from the start of feeding
Size
Males 22.4-63.5 mm (wild record 63.5 mm; the captive record is 63.3 mm) / females 19.9-33.5 mm
Humidity
60〜80%
Diet
Sap of Clerodendrum and Mallotus; beetle jelly
About
The Yaeyama saw stag (Prosopocoilus pseudodissimilis) lives on Ishigakijima and Iriomotejima and is one of Japan's four saw stag species, described in 1976. Males run 22.4-63.5 mm and females 19.9-33.5 mm. It is smaller than the mainland Japanese saw stag; beetles in the 63 mm class are uncommon and most males are medium or small at around 50 mm. The mandibles curve only weakly, drawing a gentle arc even in large males much as in the Okinawa saw stag, though the small inner teeth are somewhat more numerous towards the front. It is a separate species from the subspecies of the Amami saw stag that range across the south-western islands, and is told apart by a clypeus that is not forked. Adults fly from May to September, gather at sap of Clerodendrum and Mallotus, are active by day and night and come to lights. Larvae are found in and around rotten wood on the forest floor.
Source: Wikipedia (CC BY-SA 4.0)
Size of the Yaeyama Saw Stag Beetle
The Yaeyama Saw Stag Beetle grows to Males 22.4-63.5 mm (wild record 63.5 mm; the captive record is 63.3 mm) / females 19.9-33.5 mm.
Basic Info
Origin
Japan (Ishigakijima and Iriomotejima, Yaeyama Islands, Okinawa)
Lifespan
About two to three months from the start of feeding
Size
Males 22.4-63.5 mm (wild record 63.5 mm; the captive record is 63.3 mm) / females 19.9-33.5 mm
Temperature
20〜28℃
Humidity
Care Specifications
AggressiveSolitaryBreeding: Moderate
Sources: Mushinavi - Yaeyama saw stag (size, season, lifespan, difficulty rating, JA) / Prosopocoilus pseudodissimilis - Wikipedia (JA)
Breeding Records & Localities
Captive record (♂)
63.3 mm
Wild record (♂)
63.5 mm
Record source: BE-KUWA 2025 edition (Yaeyama saw stag, captive 63.3 mm, 里 由一 2008 / wild 63.5 mm, 花谷達郎; projected maximum 68 mm. Smallest wild record 22.0 mm, 杉原由一 2012)
Notable localities
Ishigakijima (Okinawa)Iriomotejima (Okinawa)
The captive record of 63.3 mm, set in 2008, still falls just short of the 63.5 mm wild record; BE-KUWA sets the dream size at 68 mm.
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) / Mushinavi - Yaeyama saw stag (size, season, lifespan, difficulty rating, 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: Prosopocoilus pseudodissimilis Kurosawa, 1976
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.
Yaeyama Saw Stag Beetle Listings
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