''Stenocara gracilipes'' is a species of beetle that is native to the
Namib Desert
The Namib ( ; pt, Namibe) is a coastal desert in Southern Africa. The name is of Khoekhoegowab origin and means "vast place". According to the broadest definition, the Namib stretches for more than along the Atlantic coasts of Angola, Nami ...
in southern Africa. This is one of the most arid areas of the world, receiving only of rain per year. The beetle is able to survive by
collecting water on its bumpy back surface from early morning fogs.
To drink water, the ''S. gracilipes'' stands on a small ridge of sand using its long, spindly legs. Facing into the breeze, with its body angled at 45°, the beetle catches fog droplets on its hardened wings. Its head faces upwind, and its stiff, bumpy outer wings are spread against the damp breeze. Minute water droplets (15-20 µm in diameter) from the fog gather on its wings; there the droplets stick to
hydrophilic
A hydrophile is a molecule or other molecular entity that is attracted to water molecules and tends to be dissolved by water.Liddell, H.G. & Scott, R. (1940). ''A Greek-English Lexicon'' Oxford: Clarendon Press.
In contrast, hydrophobes are ...
(water-loving) bumps, which are surrounded by waxy,
hydrophobic
In chemistry, hydrophobicity is the physical property of a molecule that is seemingly repelled from a mass of water (known as a hydrophobe). In contrast, hydrophiles are attracted to water.
Hydrophobic molecules tend to be nonpolar and, t ...
troughs. Droplets flatten as they make contact with the hydrophilic surfaces, preventing them from being blown by wind and providing a surface for other droplets to attach. Accumulation continues until the combined droplet weight overcomes the water's electrostatic attraction to the bumps as well as any opposing force of the wind; in a 30 km/h breeze, such a droplet would stick to the wing until it grows to roughly 5 mm in diameter; at that point it will roll down the beetle's back to its mouthparts.
Researchers at the
Massachusetts Institute of Technology
The Massachusetts Institute of Technology (MIT) is a private land-grant research university in Cambridge, Massachusetts. Established in 1861, MIT has played a key role in the development of modern technology and science, and is one of the ...
have emulated this capability by creating a textured surface that combines alternating
hydrophobic
In chemistry, hydrophobicity is the physical property of a molecule that is seemingly repelled from a mass of water (known as a hydrophobe). In contrast, hydrophiles are attracted to water.
Hydrophobic molecules tend to be nonpolar and, t ...
and
hydrophilic
A hydrophile is a molecule or other molecular entity that is attracted to water molecules and tends to be dissolved by water.Liddell, H.G. & Scott, R. (1940). ''A Greek-English Lexicon'' Oxford: Clarendon Press.
In contrast, hydrophobes are ...
materials. Potential uses include
extracting moisture from the air and creating fog-free windows and mirrors. A company called NBD Nano is attempting to commercialize the technology.
Lately, it has been shown that these beetles may also obtain water from dew (i.e. from humid air without fog).
See also
*''
Onymacris unguicularis
''Onymacris unguicularis'', the head-stander beetle, is a species of fog basking beetle that is native to the Namib Desert
The Namib ( ; pt, Namibe) is a coastal desert in Southern Africa. The name is of Khoekhoegowab origin and means " ...
'', another fog-basking Namib desert beetle
*''
Physosterna cribripes
''Physosterna cribripes'', the desert toktokkie or woestyntoktokkie, is a flightless species of desert-dwelling darkling beetle or Tenebrionid found along the West coast of Namibia and Angola. This species has a body length of some 18.4 mm ...
'', another fog-basking Namib desert beetle
References
Further reading
*
*
*
*
{{Taxonbar, from=Q18398452
Tenebrionidae
Beetles described in 1835
Beetles of Africa