Tropical Bess Beetle

• The adults prepare their larvae's food by chewing the wood and mixing it with their faeces, which are laden with the microorganisms that make it digestible.
• It stridulates by rubbing its abdomen against its wings, and the whole family communicates inside the log by means of those sounds.
• Its role as a decomposer is fundamental in the rainforest: it speeds up the recycling of dead wood and with it that of the soil's nutrients.
• Like its North American relative, it is subsocial: adults and larvae live together in the same gallery, and the parents feed the young with pre-digested wood.
• It stridulates to communicate inside the trunk, in total darkness, where sight is of no use at all.
• Its body is flattened and very glossy, adapted to moving through narrow galleries.
• It contributes significantly to the decomposition of dead wood in the American rainforests, a role that on other continents is played by termites.

Skeleton type

Invertebrate - chitin exoskeleton (insect)

Habitat and environment

Rotting logs in humid Neotropical forest

Gestation / incubation

The larvae feed on the microbe-rich frass and the finely chewed wood paste that the adults produce, in what has been described as an external rumen; the adults re-ingest their own frass once it has been processed by fungi and bacteria

Litter / clutch size

It lives in subsocial family groups inside the galleries, with overlapping generations and cooperative care of the brood; the parents protect the larvae, which are defenceless, and these pupate inside the tunnels

Sources consulted: Schuster y Schuster, revisiones de Passalidae; Universidad de Florida, Featured Creatures; Ecology and Conservation of Passalidae (Springer); guias de la familia Passalidae; Nardi et al. 2006; UWM Field Station

Best time: Present all year inside very rotten hardwood trunks in tropical and subtropical forest; it comes out onto the surface of the trunk by day or when looking for a new one

The pins mark the parks where its presence is documented.