Titan stag beetle
In the largest males, curved mandibles can reach nearly half the beetle's total length, used to lever rival males off sap-oozing oak trunks.
| Where | Forests across Japan and Southeast Asia |
|---|---|
| Size | 32 to 111 mm body length |
| When | March and May to October and December |
Males of this stag beetle carry long, curved, antler-like mandibles with an inner tooth partway along their length, while females have short jaws and a more rounded body. Both sexes are a uniform dull black.
Adults feed on sap oozing from oak trunks, where males use their jaws to lever rivals away from a feeding spot, and larvae spend roughly a year developing inside rotting logs. It ranges from Japan and Korea through China and much of Southeast Asia.
Traits
Habitat
Woodland
Colour
Black
Active
Day and night
To people
Mild
Both sexes can pinch firmly with their mandibles if handled roughly, though the bite is not venomous and the pain passes within an hour.
Activity through the year
Often confused with
Dorcus hopei has smooth, tooth-free mandibles between the tip and a single large inner tooth set near the base, while Serrognathus titanus shows a row of small serrations along the inner mandible edge leading to the tip.
Questions
Is the Titan stag beetle dangerous to people?
Mild. Both sexes can pinch firmly with their mandibles if handled roughly, though the bite is not venomous and the pain passes within an hour.
When can you see the Titan stag beetle?
The Titan stag beetle can be seen from March and May to October and December, by day and at night.
Plate retouched from a museum specimen photo by Swiss Natural History Collections - SwissNatColl, CC BY 4.0, GBIF Licence
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Beetles›Stag beetles›Serrognathus
Last updated 2026-09-27. Every entry is checked against published sources.