🪲 Lucanus formosus

Common Name: Formosan Stag Beetle

Region: Taiwan

Appearance: Shiny black body with thick, curved mandibles that vary by region—northern morphs are more slender, southern morphs broader.

Size: Males typically 45–80 mm (1.8–3.1 inches)

Habitat: Wooded areas of Taiwan; favors rotting logs and tree stumps

Behavior: Nocturnal crawler; relatively docile but territorial when challenged

Feeding: Adults feed on tree sap; larvae burrow through decaying hardwood

Taxonomy: Family Lucanidae | Genus Lucanus

Sexual Dimorphism: Males exhibit extreme mandible variation tied to geography

Life Cycle: Adults live 3–4 months; larvae develop over 8–12 months

Collection Note: Highly prized for size and mandible form