Adults may reach roughly 35–75 mm including the male’s mandibles.
Fine-art photographic collection
Prosopocoilus astacoides
A beetle whose mother carries a cultivated yeast in a specialised internal pocket and plants it into her offspring’s nursery wood.
About this species
Prosopocoilus astacoides(Hope, 1840)
Information reviewed15 July 2026
Prosopocoilus astacoides is a large Asian stag beetle. Its larvae grow inside decaying wood, assisted by a vertically transmitted yeast symbiont carried by females in a specialised organ called a mycangium.
Taxonomy
Animalia · Arthropoda · Insecta · Coleoptera · Lucanidae · Prosopocoilus
Accepted taxon. · checked 2026-07-15
South and Southeast Asia; the photographed population is from TaiwanBroad range and selected reference localities — not a complete occurrence map.
South and Southeast Asia; the photographed population is from Taiwan
Broadleaf forest with decaying trunks and stumps.
Adults visit sap flows and ripe fruit; larvae remain concealed in wood for many months.
Adults drink sap and fruit juices; larvae consume microbially softened wood.
Solitary; males compete at feeding and mating sites.
What makes this species remarkable?
A female stores symbiotic yeast in an internal mycangium and inoculates the wood where her larvae will feed, transmitting a microbial partner directly to the next generation.
The yeast helps process xylose and other difficult wood-derived compounds, allowing a pale grub to extract nutrition from a material most animals cannot digest.
Male mandibles become enormous combat weapons while the female retains shorter cutting jaws better suited to preparing wood for eggs — two radically different tools built from the same mouthparts.
Sources and scientific references
More photographs
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