Namib Fog-basking Beetle

Onymacris unguicularis is a Namib Desert darkling beetle in Tenebrionidae. The species includes geographically differentiated forms traditionally named O. u. unguicularis and O. u. schulzeae. [2]

Adults have a dark body and long legs. Their wing covers are almost smooth anteriorly, with broad grooves and narrow ridges over the posterior portion. [1][2]

The species inhabits the coastal Namib’s sand-dune systems. The 2013 study compared geographically separated populations in the northern and southern dune regions. [2]

During fog, the beetle faces into the wind with its rear elevated. Deposited droplets run down the body towards the mouth. In a controlled comparison of four Namib species, only O. unguicularis adopted this fog-basking posture. [1]

Microscopy and wetting tests found the examined wing-cover surfaces to be hydrophobic. The study attributed successful harvesting chiefly to the beetle’s posture, rather than a specialised pattern of water-attracting bumps. [1]

Morphological differences between the two named subspecies coincided with mitochondrial genetic differentiation in the 2013 population sample, supporting their treatment as distinct geographic lineages within one species. [2]

Hamilton and Seely published the species’ headstanding water-collection behaviour under the term fog basking in 1976. [1]

Keep the enclosure closed and display it in indirect light, away from heat and damp conditions. Handle the frame by its edges and clean only its exterior according to the maker’s instructions.