Onymacris plana

Onymacris plana
Onymacris plana, Namibia
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Coleoptera
Suborder: Polyphaga
Infraorder: Cucujiformia
Family: Tenebrionidae
Subfamily: Pimeliinae
Tribe: Adesmiini
Genus: Onymacris
Species:
O. plana
Binomial name
Onymacris plana
(Péringuey, 1888)
Synonyms
  • Adesmia plana Péringuey, 1888

Onymacris plana is a species of darkling beetle in the family Tenebrionidae, endemic to the Namib Dune Sea in southwestern Namibia.[1][2]

The small beetles (10-15 mm in diameter) live on sparsely vegetated sand dunes, feeding on wind-blown detritus. The beetles are diurnal, typically feeding during the day when nocturnal predators are not active.

While they are flightless, the beetles are known for running at high speed for their small size (around 2.5 mph or 1.2 m/s). Males sometimes follow females as they run across the dunes. It has been determined that the fast running reduces their body temperature. This is beneficial because the solar radiation generates a surface temperature on the dunes of 50°C (122°F) or more during 8 months of the year. Body cooling is aided by their relatively long legs, which lift the body above the surface, and their flat body shape, which exposes more of the body's surface area to the air.[3]

References

  1. ^ Lamb, Trip; Bond, Jason E. (2013). "A multilocus perspective on phylogenetic relationships in the Namib darkling beetle genus Onymacris (Tenebrionidae)". Molecular Phylogenetics and Evolution. 66. doi:10.1016/j.ympev.2012.10.026. Retrieved 2025-10-18.
  2. ^ "Namibia Biodiversity Database, Onymacris plana". Retrieved 2025-10-18.
  3. ^ Roberts, Carole S.; McClain, Elizabeth L.; Seely, Mary K.; Mitchell, Duncan; Goodall, Victoria L.; Henschel, Joh R. (2025). "Beetling the heat – the diurnal Namib Desert beetle Onymacris plana cools by running". Journal of Experimental Biology. 228. doi:10.1242/jeb.250379. PMC 12401538. Retrieved 2025-10-18.
  • Citizen science observations for Onymacris plana at iNaturalist
  • Media related to Onymacris plana at Wikimedia Commons