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Flies-divers

In order not to drown in the lake verhalen, flies, sand Martin became superhydrophobic.


Fly Ephydra hians waterproof “suit.” (Photo: Floris van Breugel / Caltech.)

Flies Ephydra hians at Mono lake. (Photo: J. Maughn / Flickr.com.)

Mono Lake. (Photo: CEBImagery / Flickr.com.) ”

Mark TWAIN in his scene of the novel “Light”, among other things, describes some of the flies that he saw at the lake Mono in California: “There are more flies, like our room flies… They can be kept under water as much as you want – they are not offended, on the contrary, proud of it. When they were released, they pop up to the surface as dry as the report of the office of patents and removed so calmly, as if they deliberately taught this trick to give the person a mind enriching entertainment”*. Although it is known that the story is Light in places, is a pure fiction about fly-divers mark TWAIN did not lie – this really is .

Flies Ephydra hians, of which he had seen, belong to the family of fly-by-beregovushki – as is clear from the name, they like to live around ponds. And some, such as the genus Ephydra, prefer rather extreme habitats, preferring very salty lake (because it’s sometimes called “salt”, “alkaline” or “sea flies” to distinguish it from other beregovushki). Mono lake – not just for them: the water is three times saltier than the ocean, is extremely rich in sodium carbonate and sodium tetraborate, which is also known as borax. Sodium tetraborate is quite a strong detergent, it can be used as a detergent. Sodium salts make the water in the lake extremely alkaline, so that to the touch it seems oily.

No more or less large animals in Mono, of course not, but it is planktonic algae, bacteria and some small crustaceans. For flies this is the perfect place to eat: lots of food (including dead organic matter that settled to the bottom) and no predators. It remains only to solve the problem of how to go into the water so as not to drown.

The insect body is usually covered with short hairs waxed, which is not wetted so the insect can stay dry in the rain and fog, and not be afraid that the water will close the breathing holes on the body. But in the Mono lake water is difficult. As shown by the experiments of researchers from the California Institute of technology, ordinary flies water from the lake passes easily through the hydrophobic protection: the cuticle of flies carries a weak positive charge, attracting the negative carbonate ions, which is very rich in Mono – and along with the negative ions to the body squeezes and water. Simply put, ordinary insect to drown in Mono is much easier than anywhere else.

But flies E. hians has a trick. Michael Dickinson (Michael Dickinson) taped to E. hiansincluded under the water, and made a number of experiments, immersing flies in different chemical solutions. In an article in PNAS says that flies are crawling under the water, wear some sort of suit, something light, breezy suits that covers the entire body except the eyes. The thing was that E. hians, first, much more hairy, and secondly, in their waxes that coat the hair and the cuticles, contains more short hydrocarbons, which is better carbonate repel water. If flies to deprive them of the hydrocarbon coating, water penetrated to the body and replaced the air held by the hairs, the insects lose their air diving.

In other words, E. hians became superhydrophobic in order not to drown in supermasive water, and they became such due to the increased hairiness and special chemical coating on the body. Perhaps tricks of the flies, scuba divers will help in the future to create new materials that will remain dry even under water.

* – translation Toper and T. V. Litvinova.

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