Trenches Gather Water

Biological Strategy

Darkling beetles

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Capture, Absorb, or Filter Liquids

The most common liquid used by living systems is water, which they require to survive. But there are many other liquids that provide nourishment, play a role in defense mechanisms, or serve other purposes. Water varies in its availability; it is sometimes plentiful and sometimes very scarce or only available as fog or mist. To minimize the energy required to capture, absorb, or filter liquids, living systems have strategies that take advantage of the unique properties of the given liquid. For example, water moves from a gaseous to liquid state when it encounters a surface colder than the air. Plants in forests that experience fog and clouds more than rain have strategies that condense liquid water from moist air.

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Insects

Class Insecta (“an insect”): Flies, ants, beetles, cockroaches, fleas, dragonflies

Insects are the most abundant arthropods—they make up 90% of the animals in the phylum. They’re found everywhere on earth except the deep ocean, and scientists estimate there are millions of insects not yet described. Most live on land, but many live in freshwater or saltwater marshes for part of their life cycles. Insects have three distinct body sections: a head, which has specialized mouthparts, a thorax, which has jointed legs, and an abdomen. They have well-developed nervous and sensory systems, and are the only invertebrate that can fly, thanks to their lightweight exoskeletons and small size.

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Trenches created by the flying saucer trench beetle collect water because the edges are above the sand surface and perpendicular to fog-bearing wind.

“A third method involves uptake of free water directly from fog-moistened sand. The most elaborate procedure is used by the genus Lepidochora (Seely and Hamilton, 1976) (Fig. 3 c). These flat, circular, short-legged beetles construct a shallow trench 2-4 mm deep in the moist sand surface during fogs. The ridges of the trench, elevated above the sand surface and oriented perpendicularly to the direction of the fog-bearing wind, attain a higher water content than the undisturbed surrounding sand. The beetles then return along the trench ridge, flattening it as they extract part of this moisture.” (Seely 1979:219-220)

http://www.orusovo.com/guidebook/content6.htm
http://www.sciencemag.org/cgi/content/abstract/193/4252/484
http://www.springerlink.com/content/x34r526hn5075653/