Why do spider threads fly? How spiders fly on a web. Did you know
In the clear sunny days at the end of August it is often possible to observe thin and delicate threads of cobwebs floating in the air. The wind can carry them very far, but in calm weather they slowly and smoothly fall to the ground, catch on the branches of bushes or spread out over the grass and thorny stubble in the fields.
The cobwebs that have settled everywhere then become one of the characteristic signs of autumn and are especially noticeable in the morning and evening hours, when the sun is close to the horizon and its rays play and shimmer in shiny silky threads, covering, as far as the eye can see, the entire surface of a dead field or meadow. .
Clear and warm autumn days, with a cloudless, blue sky and a special, crystal transparency of the air, are known among us under the name “ Indian summer"(probably because at this time the field suffering ends, which in the old days fell almost entirely to the woman).
The abundance of flying and creeping webs is so closely related to such solar autumn days, that sometimes, for lack of another suitable name, this web is also known as “Indian summer”.
If you carefully pick up a flying spider thread on a stick, you can find small spiders on it, which, sensing danger, hastily flee. This time the web serves as a flying machine for the wingless spider; holding on to the web thread he released, little spider flies through the air in exactly the same way as dandelion and thistle fruits or fluffy fireweed and aspen seeds fly thanks to their “tuft.”
It is clear that we will no longer find spiders on a web that has caught on a bush or landed on the grass: the airship has served its purpose and the passengers have left it long ago.
It is especially interesting to watch how the spider prepares for flight (Fig. 166). On warm sunny days, when there is a light breeze, spiders climb onto some object elevated above the ground, from where they can easily be picked up by air movement.
Such objects will be, for example, the top rails of fences, bridge railings, and boundary posts. Having climbed up, the spider first begins to release a web thread in the usual manner, and then raises the end of its abdomen as high as possible, holding firmly in its place with all eight legs.
A gust of wind picks up the released thread and pulls it into a long loop. Then the spider bites the web at the end with which it was attached to the platform; the freed end begins to flutter through the air, and the thread very quickly grows in length, as the wind forcefully pulls it out of the spider’s arachnoid warts.
When this thread stretches 2–3 m, the spider detaches itself from its platform, draws its legs close to its body, and the web, caught by the wind, carries it along on an air journey (Fig. 167).
Thus, the secreted web helps young and still weak spiders spread over a large space and thereby prevent excessive crowding, which all predators involuntarily have to avoid.
The web is the weather service's litmus test..The future weather is determined by its appearance and behavior in Indian summer.
When the threads of the web are long, the web is wide open - to warmth; if the web continues to spread widely, but its constituent threads are short, dry, sunny weather will last a long time. If in the fall the web flies during the day, be warm; before sunset, it means frost. And in general, it has been noticed that before cold weather, spiders spin their webs especially persistently.
Spiders spin webs for the cold weather
There is such a legend. IN 1794 A "limited contingent" of French armed forces invaded Holland. It was led by General Charles Pichegru. The purpose of the invasion was to restore republican power reign, the overthrow of Stadtholder Wilhelm V, who exercised sole power. The Dutch could not resist the strong French army militarily, but they had a faithful natural ally - the sea. The territory of the Netherlands lies partly below sea level. The country is protected from its formidable power by a system of dams and dams. All you have to do is open the floodgates, and the water will block the path of any aggressor. The Dutch did just that. Pichegru's regiments were forced to turn back. But suddenly the general stopped the retreat. It turned out that he had received a secret report... about the behavior of spiders. They wove a web together, which, according to signs, meant an imminent cold snap. And indeed, after a short time frosts struck, the water froze, and the French moved on the offensive across the ice.
What happened next?
William V emigrated to England. A republic, the so-called Batavian, was proclaimed in Holland. It lasted only 11 years. In 1806, Napoleon Bonaparte gave the throne of Holland to his brother Louis. He also did not rule for long. In 1810, Napoleon removed Louis from power, annexing Holland to France. After the overthrow of Napoleon, the Netherlands regained independence. They were led by William V's son, Prince William of Orange. Thus the oldest republic in Europe became a kingdom again.
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 solar rays came to the planet, carrying heat and light, if not to 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 in the sky thin threads poutines have been studied quite well 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 mainland, 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. strong gust the 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 develop 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 maintain the population, this natural phenomenon falls in autumn, the time when young spiders mature and become ready to reproduce.
Flying spiders in tropical countries a widespread, fascinating, frightening phenomenon. In the middle zone, migration is not so obvious, but it does occur. They don't have wings, so everyone will answer that they can't fly. They crawl well, some jump. But thanks to this, they are able to migrate over long distances – up to several kilometers.
How spiders fly on webs
The animal goes down on a spider's web and waits for a gust of wind. Sometimes the female forms a cocoon, lays eggs there, sits on top, and prepares for the journey. The wind picks up a thin, weightless web and carries it over a long distance. A photo of a flying spider is located below.
It is impossible to predict in advance how the flight will end. There are a lot of obstacles on the way - tall grass, bushes, trees. An animal can fly several meters or kilometers.
Interesting!
During a successful long journey, spiders control their speed by adjusting the length of their web. In the short term the speed increases, in the long term it slows down. If you have a snack, the flight ends. To land successfully, you need to throw a new web onto a plant or tree branches.
Why do spiders fly on webs?
The migration process is a natural phenomenon, but some spiders cannot fly even on a web. Are engaged in flights minor representatives family of arachnids - tenetniki, . All the rest live their whole lives in one area or settle nearby.
Flying spiders prepare to travel in late September. This is how resettlement occurs younger generation, ready to mate, as well as females with a cocoon containing eggs. This desire is related to lifestyle. Many spiders live alone, gathering in pairs only during the mating season. The rest of the time they hunt independently in a certain territory.
After birth, young spiders shed a thin web and hang in the air, waiting for a gust of wind. Air currents carry them away in different directions, dispersing them throughout the surrounding area. Arachnids rise up to 1000 m and fly safely over distances of hundreds of kilometers. In tropical countries, mass flight brings fear to local residents, tourists. The sky seems to be overcast with clouds.
Interesting!
In 2013, UK scientists proved that spider webs can accumulate statistical current. Thanks to this feature, the threads repel and do not tangle. In laboratory conditions, without gusts of wind, the spiders rose. As soon as the electromagnetic field was turned off, they fell.
You can use the web to determine the future weather, like a litmus test. Knowledgeable people draw conclusions based on her behavior and appearance.
Folk signs of autumn
If in the fall you saw a cobweb flying in daytime, then this means it’s warm, and if it’s discovered in the late afternoon, it means it’s going to be very cold. If the web is wide open and its threads are long, then this means warmth. In addition, if the web is spread wide, but its main threads are very short, then sunny and dry weather is expected, which will last for a long time. And in general knowledgeable people they say that, anticipating the onset of cold weather, spiders weave their sticky blanket especially stubbornly.Just before the cold weather, spiders speed up their web weaving
Listen interesting story, as they say on topic. Back in 1797, the occupation corps armed forces France occupied Holland. It was led by General Charles Pichegru. Just like now main goal France in this military campaign was the overthrow of the legitimate ruler, William 5, who ruled with great dignity. The few Dutch troops were unable to prevent the invasion of French soldiers, and they didn’t really try, since they knew very well the area in which their country was located. Holland for the most part lies below sea level and is separated from the terrible violence of the ocean only by man-made embankments and dams.
The Dutch people turned this circumstance to their advantage; the gates of the dam were opened and the unrestrained power of water rushed onto the lands of Holland, blocking the road for Pichegru’s troops. He gave the order to retreat, since swimming across the rapid stream would be madness. However, unexpectedly, the general gave the order to stop the withdrawal of troops. Even his closest comrades were at a loss; they could not understand what their commander was up to.
It seemed to them that the general had received a secret message. However, in reality everything was much simpler. There was a message, but it " sent"Spiders. After all, Pichegru took very seriously folk signs, and that day he noticed increased activity of these insects in weaving webs. This meant cold weather in the very near future. And so it happened, in the coming days they hit severe frosts, the water turned into ice, thus opening the road to the very heart of Holland.