Cobweb – all signs associated with a spider’s network. Folk signs of autumn Why spiders weave webs in autumn

So autumn has come. A quiet and clear “Indian summer” will soon come - every autumn there is an anticyclone brings us the warmth of the Mediterranean. During this period of time, the air becomes especially clean and transparent and cobwebs begin to fly everywhere.

It's time to study them.

You will need:

- Black or dark blue cardboard

- Scissors

- Hair fixation spray

- Gardening gloves

- A good helper (for example, this could be your friend or parents)

Experience:

First, be sure to read something about the spiders that are found in your area. Some of them may also be poisonous. It is better not to touch such spiders and their webs. The main types of web are concentric, triangular and fine-mesh. Poisonous spiders They usually weave a concentric web.

1. Choose a suitable web. If you see a spider, try to identify it. Carefully drive the spider away with a thin twig or twig. Then, wearing gloves, hold the black paper up to the back of the web. An assistant with scissors and hairspray should be nearby.

2. After carefully spraying varnish on the web and paper, you need to cut the main threads holding the web.

3. Fix the web with varnish and leave overnight to dry.

Advice:If you don’t have hairspray, you can take “velvet” paper and carefully place the web on it.

Result:

The web on paper should be beautiful and clear. Individual parts of the web can be carefully examined with a magnifying glass.

Explanation:

Over millions of years, spiders have learned to weave webs of various patterns. Each web is tailored to the spider's living conditions and is best suited for its favorite food. The spider begins to weave a web from its main parts - axial threads and fastening threads. Then he fills the gaps between the main threads with a mesh of thinner threads. The web threads are formed in a special organ on the spider's abdomen.

All collected cobwebs can be placed in frames under glass and written where they were found. And if you add some dry leaves and flowers to the cardboard, you can get a beautiful panel.

Do you know?

1. The web is very stable, very durable and very strong. It is stronger than silk, stronger than any synthetic fiber and stronger than steel wire. If you spin a rope the thickness of a pencil lead from the web of a cross spider, then to break it you will need a load of about 250 kilograms, that is, you can hang a small cow on such a rope. On a silk rope of the same thickness you can hang only 35 kilograms, on a nylon rope - about 50-60, and a little more on a steel wire.

2. In 1973, American astronauts boarded space station Skylab took two cross spiders. Arabella and Anita, as the spiders were called, each separately, wove several webs in zero gravity, almost the same as on Earth. There were differences in the first web made - irregular cells, but when weaving the second and third, the spiders adapted to the new conditions and constructed quite ordinary trapping nets.

Interestingly, the idea of ​​this experiment belongs to the American schoolgirl Judith Miles. She also took part in the development and study of the results of the experiment.

The material was prepared based on the book by Glen Vecchione "Do it yourself! 100 of the most interesting independent scientific projects"

In warm weather sunny days September, a lot of interesting things can be seen in the forest and in the field. And the first thing that catches your eye these days is a cobweb.

Cobwebs are everywhere: on bushes, on hedges, on stubble, on a mown meadow, on grass. Everywhere lie threads of cobwebs, either separate or huddled together in flakes.

There are a lot of cobwebs floating in the air. Sometimes whole clouds of it float in the wind and shimmer in the sun’s rays.

Catch a few cobwebs with your hand. There's one cobweb falling from above... Failure! The lower end of the web suddenly rose, and the entire web flew upward. As if she ran away from an outstretched hand. Caught it - an empty web. I caught another one - a tiny spider on the web. Oh, where is he? Again the cobweb “ran away” from my hand.

Did the spider really manage to climb up? Of course not. He simply broke away from the web and descended to the ground. And the web lost its load and quickly took off.

There are so many flying spiders in the fall that the “flying web” is one of characteristic features"Indian summer"

In the clear autumn days on fences, on bridge railings, on lonely bushes, sedges, and reeds you can see tiny spiders preparing to fly.

How and why do these spiders fly?

Climbing higher, the spider first of all makes supporting threads. It tightly presses the end of the abdomen with arachnoid warts to the surface of the platform on which it is located. Carries out several short transverse threads. Having made them, the spider runs to the leeward side of the area, attaches the tip of the web here and hurries back.

The wind picks up the web and stretches it. The spider clings tightly to the supporting threads with its paws and gradually releases the thread.

The wind blows - the web stretches, becoming longer and longer. The web's loop is blown by the wind.

When this loop reaches ten to fifteen centimeters in length, the spider runs to the edge of the area and bites the web thread here. The web flies into the air at one end, and the other remains connected to the spider's abdomen. Everything is stronger and stronger wind pulls the web, which the spider continues to release.

The thread grows and grows. Finally, the spider can no longer stay on its platform: the web has become so long that the wind is pulling it.

The spider unhooks from the supporting threads and presses all eight legs at once. A gust of wind - and the web takes off, taking the tiny pilot with it.

Two to three meters of spider thread is enough to hold a tiny spider in the air.

The flight has begun.

The spider can always go down. To do this, he only needs to lengthen the web - release a new portion of the thread. Running across the web, he changes the “center of gravity”, and the web either rises or falls.

It is not always possible for a spider to immediately successfully release a web and fly away. Sometimes the web gets tangled, sometimes it gets caught on something. Sometimes the spider tries to take off several times - and everything is unsuccessful.

Eventually he will fly.

In particular convenient places sometimes dozens of spiders immediately prepare to fly. Often their webs get tangled, and none of the spiders can rise into the air. Then they bite the webs and begin to produce new threads. And tangled webs form flakes or knotty tufts, which are often visible on fences and bushes. Not all spiders fly on cobwebs in the fall. Young wolf spiders, sidewalkers and small species of web spiders usually fly.

Flying on a spider's web is a journey for young people. Just in time for autumn, spiders that have recently hatched from eggs grow up. They hatched in a bunch at once, they need to spread out: predators need space. Spiders don't walk well. Air travel is a great means of relocation.

The flights of spiders are especially impressive in South America. Here in the fall the sky sometimes seems covered with cobwebs: there are so many spiders flying.

Spiders can fly for a long time, and they sometimes fly very far. There are cases when spiders were caught tens of kilometers from the coast, in the open sea, where the wind carried their webs.

Aeronautics

And the obvious is not easy to understand! What people have not thought and what tales they have not told about this web flying in the sky! For a long time they could not understand where it came from.

Pliny wrote: “In the year that Paulus and Marcellus were consuls, it rained wool.”

They thought: maybe this is how the dew evaporates? Some old poets liked this idea, and they quickly wove “thin threads of evaporating dew” into their poems. But Edmund Spenser, Shakespeare’s compatriot and contemporary, assured that this was not evaporating, but, on the contrary, “dried dew.” In 1664, the famous British scientist Robert Hooke, in a report to the Royal Society (that is, the Academy of Sciences), wrote: “It is possible that the large white clouds that appear in summer time, may be from the same substance” as the web flying over the fields.

Another naturalist, Dr. Stock, passed through young coniferous forest and saw that it was all covered with thin threads of cobwebs. The day before there had been a northern lights, and he decided that “under its influence” the cobwebs had settled out of the air, “unless it was the exudation of pine trees.”

Others argued:

It's the beetles that put so much cobwebs into the sky.

No, aphids!

No, not aphids or beetles. This is a special kind of viscous matter, thickened by the rays of the sun.

The most profound, perhaps, and most incomprehensible of all was the natural philosopher Heinrich Stephens who discussed the flying web in 1822:

“Just as the fresh life of the leaves excites and supports a one-sided animal, manifested only in mobile functions, although a moderate process, so while the whole plant is immersed in the quiet oxidative process of withering, in contrast to this, atmospheric vegetation is formed - the flying web, the very name which already denotes the impression of universal generation.”

In the abstruse nonsense, science at that time often revealed its helplessness when, faced with a new, as yet inexplicable fact, it tried to outflank it, hiding behind a pile of stillborn words.

Even in our beautiful century (but in the “ugly” times - during the years of the First and Second World Wars), people are frightened by ever new models secret weapon, cobwebs floating in the sky were mistaken for special kind toxic substances. Dr. Bristow, as an expert on all kinds of natural webs, was called to the British War Office to consult on this matter. Only after his examination they canceled the prepared circular from the surveillance service.

But this one funny story revealing the secrets of spider aeronautics (so simple, but so difficult for us to understand!), as often happened with other mysteries of nature that were not immediately known, took the right path from the very beginning. When zoology was just being born, the great Aristotle already knew that the celestial web is not an exudation of resin and not a “stringent matter”, but a product of the silk-weaving art of spiders. He could not understand, however, how she rose into the sky. Probably, the great Greek decided, in the fall, heavy, cold air falls down and pushes up the forest cobwebs. His student, Theophrastus, also knew that a lot of spiders flying on cobwebs foreshadowed a coming winter.

Aristotle has been diligently studied throughout the past centuries, but many reacted to this statement something like this: “Do wingless spiders fly?” All this is doubtful!“

About three hundred years ago, Martin Lister, a well-known spider expert at that time, having quelled his doubts, decided not with empty reasoning - whether this is possible or impossible - but with accurate observations to check whether Aristotle was right or not. I went out into the field, caught cobwebs and saw: in fact, tiny spiders were sitting on many of the cobwebs, clinging tightly. Soaring above the ground, others rose higher than the bell tower of York Minster. What for? What drew them to the sky?

Lister decided: flies! Tired of waiting for them in ambush at the snares, the spiders rushed into the fly element to catch as much prey as they wanted.

But time passed, giving rise to new doubts. Lister didn't convince many. Until the 19th century, when science decisively stepped from the cradle of free improvisations into the world of precise experiments, the strangest fables were written and told about the flying web.

“We don’t see any spiders on the aerial webs,” said those about whom the great pathfinder said: “They have eyes, but look, they don’t.”

They searched and did not find. They didn’t find it because they didn’t look hard enough. They searched on threads huddled together, hanging on fences and bushes, and their spiderlings had long since left, having finished safely or started unsuccessfully.

It was necessary to look in the wrong place - on the cobwebs that were still in the air. But even here the spider is not easy to spot. As soon as there is danger, he throws a cobweb and falls down. Otherwise, the swifts and swallows would have caught all the aeronaut spiders.

But when many people had already seen spiders on cobwebs and this fact was recognized by everyone, they immediately came up with several new fantasies to scientifically explain the physical nature of the forces that lift the cobweb balloon into the sky.

Noticing that the spider always seems to release its thread towards the sun, some decided, says Volnogorsky, that the web is pulled out of the spiders’ bodies by the sun’s heat. For John Murray, even this seemed not enough... According to Murray, “the flying web is charged with negative electricity, and the soil is charged with positive electricity, and as a result of this, the web thread... rises upward.” Murray put the spider on the sealing wax - the spider seemed to “bounce back strongly.” When I touched the web with sealing wax, it also bounced off. And she was drawn to the polished glass.

They also thought that spiders floated in the sky, as if on water, paddling with their legs, that they inflated themselves with air, like airships, that (this is absolutely magnificent!) They flew like rockets, expelling gases from themselves in a strong stream.

The old ideas of “evaporating dew” did not leave natural philosophy without a trace: having modernized them, they were once again woven into the history of the life of spiders, deciding that, obviously, “the web is carried upward by the evaporation of dew under the influence of the sun’s rays.”

But time passed, people moved science forward, and it soon became absolutely clear that the mysterious spider balloon did not operate on electricity or dew evaporation.

Otto Hermann loved to walk along the chain bridge in Budapest. In spring, and especially in autumn, on clear days, when the Danube is caressed by a warm breeze, everything on the bridge and above the bridge, like a silk veil, is covered with a silvery cobweb. The breeze sways it, it sparkles, soars over the river, hangs in flakes on wires, on trees, on roofs. And fences, stakes, bushes, sedges, tombstones, bridge railings are “teeming with small spiders.” The weather is flying, and they take off into the sky from all their airfields.

Otto Herman took a magnifying glass in his hand and saw how the spider, before the launch, first tightened the support “cables” so that his balloon would not be blown away by a gust of wind ahead of time. Pressing the spider warts to the right, then to the left, he fastened several transverse threads on some stone or branch. (We’ll see, a little later, caught by a gust of wind, he will hold on to them with all eight legs, like handrails!)

Having thus arranged a reliable anchor for itself, the spider hurries to the leeward edge of the airfield, and there the spider warts again do their job. The spider presses them to a solid support under its feet - and now the balloon thread is glued at one end. He pulls the other one behind him - runs to the anchorage, clings to the “handrails” with all his legs. Now the belly is up - from it a cobweb thread soars into the sky in a loop. More precisely, several spider threads, bent in a loop: after all, one end of them is tied not far away, and the second continues to stretch and stretch from the warts. When it stretches out enough, the spider will bite off the glued end of the thread; flowing upward warm air she is picked up and carried away like a sail cut off in a storm. But the spider still clings with all its might to its anchor (or just to the branch, if, having decided to do without an anchor, it did not weave one). The longer the thread, the more it sails through the air and grows faster from that end, which is lengthened and lengthened by the arachnoid glands. When the thread stretches about two or three meters, the spider gives up its last attempts to resist the force of convection currents, draws in its legs and soars up - backwards forward. It deftly turns over in the air, grabs the balloon thread with its paws and runs along it closer to the middle. Running along a flying carpet, the spider moves its center of gravity: it will run to the middle - it will bend the end of the thread in a loop, and turn back - the loop will stretch into a straight thread.

The aerodynamic properties of the aircraft change, and it either soars up or descends.

No, it is not given to a spider, even if unconsciously running along a thread, to control its flight.

But there is also an anti-doubt:

It's not difficult at all. Everyone who launched kite, knows how easy it is to change its flight by tensioning or moving the fastening threads.

Spiders do not fly on strings to chase flies - they fly to look for new lands. They fly away in all directions so that the nest is not crowded and they do not have to starve and devour each other (and they are quite capable of this). They fly - some a hundred meters, some a thousand, and others even tens of thousands. Where there are especially many spiders, in South America, for example, they sometimes fly up from the ground in such clouds that “the whole sky these days seems covered with cobwebs.”

Charles Darwin wrote: “The ship was sixty miles from the coast under a light but constant wind. There were a lot of spiders on the tackle. It seemed to me that there were several thousand of them on the ship... The little balloonists, once on the ship, ran back and forth, sometimes falling and ascending again along the same fiber; some were busy constructing a small, very irregular net in the corners between the ropes... All of them seemed to be tormented by a strong thirst, and with tense jaws they greedily drank drops of water.”

In our southern Russian steppes, mass flights of spiders are also common. Professor D.E. Kharitonov, a great authority on everything related to spiders, even saw here entire flying carpets, up to ten meters long, made from many tangled threads.

Spider migration is a widespread phenomenon even in middle lane, in warm climate zones this process is fascinating and sometimes frightening, since the scale of resettlement is impressive and sometimes it seems that the sky is covered with a black cloud that does not allow the sun's rays to pass through.

The fact that spiders fly can hardly be called a secret or some kind of scientific sensation; it is a natural, well-studied natural phenomenon that has clear causes and consequences. However, before it became clear to scientists how spiders fly, this mystery of nature gave rise to numerous speculations, sometimes logical, and sometimes downright ridiculous. Thus, according to one version, it was believed that barely noticeable threads flying across the sky are the evaporation of pine resin, the amount of which by the beginning of autumn exceeds the norm that is comfortable for the tree, so it gets rid of the excess in this way. In case of microdamage, which can be caused by a person, a bird, an animal or bad weather, an amber sticky resin begins to intensely appear on the surface of the pine, which hardens in the air, turning into long transparent threads that the wind picks up and carries into the distance.

Another, perhaps the most exotic version, was the teaching about the condensed rays of the sun, which are sent to the planet by a distant patron, helping in such a simple way to preserve heat for the winter. The reason for the theory of the appearance of “condensed rays” was the fact that thin, barely noticeable threads began to actively appear precisely at the onset of Indian summer, that is, a period of warm and sunny weather, after which a long period of cold weather would certainly follow. It was believed that it was at this time that pre-prepared, intensified rays of the sun came to the planet, bringing warmth and light, if not for the entire winter period, then at least for the coldest months.

However, now both of these theories can be called nothing more than good fairy tale for children, since the appearance of thin threads of poutine in the sky has been quite well studied by observations, experiments and experimental tests. This phenomenon can even be used to create a new generation aircraft, which will use mainly solar and wind energy, which will help significantly save the earth's energy resources.

It is important to remember that spider migration through flight is common. natural phenomenon, and in no way a harbinger of problems, illnesses, deprivations and litigation. Even in South America, the continent where this process is taking on incredible proportions, you should not panic and expect the worst, you just need to remember that in a year history will repeat itself.

In the last warm days of September, grown spiders of some species embark on an exciting journey designed to help preserve the population, as well as provide food. Small spiders fly, which have recently hatched from eggs, and are already ready for grandiose changes in their lives; they are the ones who begin to weave a web in an unusual way, so that the wind flow could pick it up and carry it to a new place of residence. A traveler's web is woven like this: having climbed to a high, windy place, the spider begins to make support threads that can hold its weight and a new transverse web on which it will move. Pressing tightly against its abdomen, where special web warts are located, the spider moves to the windiest part of the web, where it then attaches itself tightly. A strong gust of wind blows out a loop of the web and its weaker edge breaks away from the supporting threads; it is at this moment that the spider begins to actively produce a new thread, on which it will go on a journey.

When the length of the thread reaches 10-15 cm, the spider runs to the base and bites it off with strong jaws, and the torn strip of the web begins to float in the currents of cold and warm air, driven by the wind. The distance that a spider will cover can never be predicted accurately, because an unexpected obstacle may arise on the way, or the flight itself may not take place if there is more than one young spider at the starting point. Just don’t think that the flight of spiders is uncontrolled, releasing a portion of the web, thereby lengthening the thread and slowing down the flight due to the increase in mass; the flight can be slowed down, and if you bite off too much, you can quickly gain altitude and increase speed. But the landing, despite all the efforts of the traveler, occurs in the branches big trees, bridge supports, ship masts and building roofs. If, after a thorough inspection, the “owner” remains dissatisfied with his own possessions, then the journey continues until a warm, humid place is found that can provide warmth for the winter.

It is interesting that not all representatives of the order of arachnids engage in migration; this is a favorite activity of side walkers, certain small species of web spiders, as well as wolf spiders; other species prefer to settle nearby and are quite happy with their close proximity.

Migration individual species spiders is caused by their natural survival instinct and the desire to spread out as rarely as possible, that is, to have enough chances to preserve the population, this natural phenomenon falls in autumn, the time when young spiders mature and become ready to reproduce.

What my readers did just fine! It really is a web!

It belongs to the most commonly found spider in homes, the centipede spider.(Pholcus phalangioides). Light beige spiders with an oblong abdomen and very long legs. These are web spiders that weave an absolutely chaotic web, devoid of pronounced stickiness, but due to its confusion, it holds the victim well. And I found such a web in the secluded corners of the loggia, and I placed it under a microscope.


Since last year, I have been planning to write about the autumn movements of spiders. I had a little dream of filming the flight of a spider, but somehow it didn’t work out this year. So, next year you should be lucky.

Now outside the window the wind is tearing off the last autumn leaves, that for now they are holding on to their native branches, not wanting to leave them. And the memories of Indian summer. On a warm, sunny and windy day in September, and sometimes in early October, the branches of bushes are covered with thin threads of transparent silver cobwebs.

Spider looked around, and in the corner

Only a thread remained on the knot

He began to call bugs, call different butterflies,

Jump through a string!

The web came in handy for good.

Now it’s time to end the fairy tale.

Yu. Lyubimtseva

Of course, the aerodynamic principle of flight on a web is used not only by spiders, but also by some plants and seeds, which are equipped with elongated crests. For example, feather grass or straight clematis.


Interestingly, the web is currently a very interesting object for nanotechnologists developing new modern materials.

Scientists compared the web of tenet spiders and the web of orb weavers. Although it is built from the same proteins (spidroins), and is produced in a similar way, it turned out that the web behaves differently under the same conditions. In tenetniks, it acts as a viscoelastic fluid that is resistant to changes in humidity, maintaining stickiness and elasticity.

Web of the Tennis

Orb weaver's web

And the classic was wrong, wrong, claiming that those born to crawl cannot fly)))) I wish you successful autumn discoveries!If you liked it, share the post on social networks.