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The abdomen of spiders is movably connected to the cephalothorax by a thin bridge. The limbs, consisting of 7 segments, are also mobile. As a result, the spider’s body is able to produce cobweb thread and quickly close gaps in the trapping network. Comb claws and bristles on the limbs help the spider quickly slide along the web thread, like a carriage on rails, allowing it to appear in time at the site where the web breaks.
The spider weaves a web.
Why do spiders build trapping webs?
The ability to produce a patina is not a primary characteristic of spiders, but web-weaving has become a distinctive feature of arachnids. Spiders are true predators, waiting for their prey in a secluded place.
Thanks to the adhesive properties of the web, a wide variety of animals, ranging from insects and even small birds, get caught in spider webs.
Having stuck to the web, the victim tries to get out of the trap by swinging the web thread. The resulting vibrations are transmitted along the signal thread to the spider, which quickly approaches the prey along the threads and injects digestive juice, which, upon entering the victim, digests the internal contents. Then the spider flies off with its web, forming something like a cocoon. It remains to wait a little until the digestive enzymes make it possible to simply suck out the liquid contents.
Stretching technology
To be effective, a fishing net must be stretched between something - for example, between branches. When the first thread has been made long enough by its creator, he stops spinning and spreads out the spinning organs. So he catches the breeze. The slightest movement of the wind (even from the heated ground) carries the web to the neighboring “support”, to which it clings. The spider moves along the “bridge” (most often with its back down) and begins weaving a new radial thread. Only when the base is secured does it begin to move around the circle, weaving sticky transverse lines into it. It must be said that spiders are very economical creatures. They eat damaged or old cobwebs that turn out to be unnecessary, putting “recyclables” into a second round of use. And, according to the creator, it becomes old quite quickly, since the spider often weaves a web every day (or night, if it is a shadowhunter).
Spiders need webs to reproduce.
During the breeding season, the arachnoid thread secreted by the female allows the partner to find an individual of the opposite sex for mating.
Male webmasters construct miniature mating laces next to the females’ webs, into which they lure spiders for mating, rhythmically tapping their limbs.
Male cross spiders attach their web to the radial threads in the catching net, placing it horizontally. The male then strikes with his limbs, causing vibrations. This is how spiders signal their presence to the female. The female does not show aggression in this case and descends to the male for mating along the attached spider thread.
In the web, one might say, a new spider life is born.
Main functions
The functions of the web are not limited to catching food. It plays a key role in the life of an arachnid, since it is irreplaceable in certain cases.
Hunting for prey
Building webs to catch prey is one of the reasons why spiders need to make webs. Its ability to immobilize the victim depends on the structure of the web. Some species of predators are so small that they themselves become prey to large insects. The poison introduced by the spider into the body of the victim does not act immediately. To prevent the prey from escaping, the predator takes it and wraps it in fiber, after which it waits for the prey’s insides to turn into a liquid state.
If you compare a spider's web and human hair, the former will be thinner. It is comparable in strength to steel wire.
Attracting males
Some types of female arachnids secrete a web secretion containing pheromones during the breeding season. This “mark” attracts the male. Signaling fibers are formed by most species, but in some the initiative comes from the male.
In search of a female for reproduction, males weave a sperm net onto which they first secrete a drop of seminal fluid. To attract a female, males attach their threads to the female’s web and set it in motion. This is how they tell her the purpose of their stay. To mate, the female goes into the male’s web space.
Distracting the attention of predators
Orb-weavers create distracting dummies from nets by gluing leaves and twigs with cobwebs. They place a “decoy” on their web, thereby trying to mislead the predator. The animal hides not far from the dummy and pulls the threads, making deceptive movements with them.
For the first time, a spider capable of making its own double was discovered in the Amazon forests by biologist Phil Torres. He came across a web with what he thought was a strange spider. At first the biologist thought it was dead, but when he got closer, he discovered that it was an elaborate replica made from leaves. The creator of the bait was waiting for prey in another place.
Spider cocoon
From the secretion of the arachnoid glands, predators weave cocoons for their offspring. The quantity reaches 100 pieces, depending on the fertility of the female. The cocoons with the female's eggs are suspended in a safe place. The cocoon shell is formed from 2-3 layers and is impregnated with a special secretion that glues all its parts together.
If necessary, females transfer the cocoon with eggs to another place. It is attached to the spinning organ on the abdomen. If you look at the cocoon closely, it resembles a golf ball. The eggs, under a dense layer of fiber, bulge and form tubercles. The cocoon for offspring is used even by those species of predators that hunt and never spin webs.
Defense mechanism at the entrance to a burrow
Burrowing species of predators dig shelters for themselves in the ground and weave webs around its walls. They use it to strengthen the soil, which helps protect the burrow from adverse weather conditions and natural enemies.
The functions of the web do not end there; the arthropod uses it as:
- Means of transportation. The mobile predator uses it as a vehicle. With its help, he can quickly move between trees, bushes, leaves and even buildings. Thanks to the use of web threads, spiders move several kilometers from their point of departure. They climb to a hill, release instantly hardening fiber and are carried away by the air flow.
- Insurance. Jumping spiders weave openwork fabric to protect themselves while hunting prey. They are attached with a thread to the base of the object and make a jump towards the prey. Some types of spiders, in order not to lose their hole, stretch a fiber from it when leaving and return back along it.
- Underwater shelters. They are created only by water-dwelling species. It is known why they need cobwebs when building underwater burrows - it will provide air for breathing.
- Stability on slippery surfaces. This function is used by all types of tarantulas - the adhesive material on the paws helps them stay on the slippery surface.
Some species do without weaving web threads, they only hunt. But for many, it is an assistant in the process of survival.
The web is a reliable refuge for offspring
The female lays eggs after fertilization in a cocoon woven from one or more silky threads. The cocoon itself is formed by 2 plates - the main and covering plates, connected by their edges. This cocoon structure provides reliable protection for the eggs.
The female first weaves a main plate, similar to the spermatic net for eggs. From above it wraps them with a second layer of web, which forms a covering plate. The shell of the cocoon is formed by silk threads tightly adjacent to each other and impregnated with frozen secretion. The walls of the cocoon become very dense, almost like parchment. In some species of spiders, the female weaves a loose cocoon that looks like a ball of cotton wool.
Spider offspring grow in the webs.
The meaning of a tattoo in prison
One of the reasons why a tattoo with a web on the arm can cause a negative reaction is the prevalence of such symbolism in prison. In Russian colonies this is one of the most significant and respected symbols. Each row of the net represents the year the prisoner spent in prison. If there are several networks, they show that the prisoner is a repeat offender. But the spider descending the thread expresses a desire to break with its criminal past.
Important! In the past, the design of a spider in a web was a symbol of the "general of the underworld", the leader who creates a criminal network. Unauthorized application of such a tattoo was very dangerous, because when going to prison, the wearer had to be responsible for appropriating regalia that was not required by status. However, today this meaning is becoming a thing of the past.
The modern criminal interpretation of this tattoo is closer to the ideas brought from the British and American criminal environment.
There, spider webs decorating a shoulder, elbow or face indicate the wearer’s rejection of generally accepted rules and a desire to resist social pressure. Representatives of the punk movement also used this image as a symbol of the fight against the system. It was from the American prison environment that spider webs entered the subculture. They are worn by modern Nazis, anti-fascists, and bikers. Each wearer attaches its own meaning to the “Web” tattoo. But when choosing such a picture, think about whether you are ready for the misunderstandings that such an ambiguous symbol can give rise to.
Web as a vehicle
Some species of spiders use webs to move through the air. Spiders climb higher on a tree, fence, high stone, roof of a building, lifting their abdomen, they release an adhesive thread. It quickly freezes in the air and the spider, having unhooked, sets off in flight on a light web carried by the oncoming air flow. This is how young spiders find their way to new habitats.
There are known cases of spiders appearing on the deck of a sea vessel sailing in the open sea far from the shore.
Adult spiders in species with small sizes can also migrate. Spiders are able to climb with the help of a web thread caught by the wind to a height of up to 2-3 kilometers. Moreover, spiders most often make their travels on the quiet and calm days of Indian summer. They travel long distances.
How spiders make webs
A large number of arachnoid glands are located in the abdominal cavity of the spider . The ducts of such glands open into tiny spinning tubes that have access to the end part of special arachnoid warts. The number of spinning tubes may vary depending on the type of spider. For example, the very common cross spider has five hundred of them.
This is interesting! The arachnoid glands produce a liquid and viscous protein secretion, the peculiarity of which is the ability to almost instantly harden under the influence of air and turn into thin long threads.
The process of spinning a web involves pressing the spider warts onto a substrate. The first, insignificant part of the released secretion hardens and reliably sticks to the substrate, after which the spider pulls out the viscous secretion using its hind legs. In the process of removing the spider from the site of attachment of the web, the protein secretion stretches and quickly hardens. Today, seven different types of arachnoid glands, which produce different types of threads, are known and fairly well studied.
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How different types of spiders use webs
In nature, there are tenet spiders that weave hunting webs (teneta), but non-netet species are also known that hunt without using a web. But they produce webs during periods of molting, resting, molting, and wintering. Spiders weave protective bags or shelters woven from cobwebs.
The spider needs a web not only to catch prey, but also for shelter.
Web spiders escape when a predator approaches on a web thread, falling down. When the danger has passed, they return back to the web thread and rise up, quickly reeling in their safety rope.
What does it consist of and where is it formed?
The composition of the web includes the following substances:
- organic compounds - fibroin protein, which makes up the main internal thread, and glycoproteins that form nanofibers located around the main thread. Thanks to fibroin, the web is similar in composition to silk, but much more elastic and stronger;
- inorganic substances - chemical compounds of potassium (hydrogen phosphate and nitrate). Their number is small, but they give the web antiseptic properties and protect it from fungi and bacteria, creating a favorable environment in the spider’s glands for the formation of threads.
We recommend reading about why people are afraid of spiders and what the phobia is called.
In the abdomen of the spider there are arachnoid glands, where a liquid substance is formed that comes out through spinning tubes located on the arachnoid warts. They can be observed at the very bottom of the abdomen.
A viscous liquid comes out of the tube and quickly hardens in air. Using its hind legs, the spider pulls out the thread and uses it for weaving. One spider is capable of producing a thread 0.5 km long.
Did you know? Our most common spider, the cross spider, weaves the most famous round trapping net.
The spider always weaves a structure of 39 rays, on which there are 35 spiral circles with 1245 fasteners. Cross workers do this work at night and update the network every 1–2 days.
The web is needed for insurance
Jumping spiders use web threads to attack. They attach a safety thread to an object and jump onto the intended victim. The South Russian tarantula, leaving its hole, pulls behind it a barely noticeable cobweb thread, along which it will always find the entrance to the abandoned shelter. If the insurance breaks, the tarantula is unable to find its hole and goes in search of a new one. Jumping spiders spend the night on web threads attached to the substrate. This is a kind of insurance against predators.
The main task of the web is to catch prey.
The web and its significance in the life of spiders
Spiders can be found in various parts of the world, from deserts to tundras. Spiders can also live near water and in water - silverfish.
The spider, overcoming unfavorable conditions, obtaining food, reproducing, uses the web. With cobwebs he makes his home, traps, and wintering bag. With the help of a web, spiders mate, and the young on it are carried away by the wind.
The evolutionary significance of the web for spiders.
The web was of great importance in the evolution of spiders. The web adaptations changed with changes in living conditions, while the spiders themselves remained almost unchanged.
The arachnoid apparatus of spiders is located on the abdomen. The abdomen is capable of stretching and contains arachnoid glands. The function of removing gland secretions is performed by the abdominal limbs - arachnoid warts. Spider warts are mobile. The abdomen is connected to the cephalothorax by a thin stalk, it is also movable.
The seven-jointed limbs of the cephalothorax provide mobility to the entire body.
It turns out that the spider is a mobile unit for the production of silk and spinning web structures.
The spider has special carding tools: comb claws, bristles on the legs for combing the web.
Spider mites and false scorpions also use the web. Their arachnoid glands are located in the front pair of limbs - chelicerae.
False scorpions are small arachnids, usually not exceeding 2-3 mm in length, in rare cases 7 mm. They are very common in nature, but hardly noticeable, because they live hidden.
When building a bell-shaped nest, false scorpions use cobwebs. They intertwine the walls of the nest with random loops of web. They stretch several transverse threads and hang on them.
Spiders retain arachnoid glands at all stages of life, unlike the caterpillars of some butterflies, which also secrete a lot of silk.
Hypotheses of the origin of spider silk.
Arachnologists are still studying the origin of silk in spiders. No one can prove what the web came from, since it is not preserved in a fossil state. Therefore, only hypotheses are put forward.
It was assumed that the web was released from the mouth opening to lubricate the egg laying. Arthur Dicke proposed a “marine” hypothesis that spiders developed webs even before they became terrestrial, in order to protect their burrows from destruction.
The most probable hypothesis is that of G. Mack-Cook that spiders, when moving, drag along a web thread, which can become a good guide for males.
Chemical composition and physical properties of spider webs.
The secretion of the arachnoid glands is a mass that quickly solidifies upon contact with air.
The chemical composition of the web is close to the silk of silkworm caterpillars. The web contains less adhesive substance, which is soluble in water.
In terms of physical properties, spider threads differ from caterpillar and artificial silk due to their great strength.
The spider can secrete sticky or dry thread of a certain thickness and color.
A special “yarn” or “lace” of cribellate spiders - which have a cribellate plate with thin holes in front of the web warts, from which special silk is released. This "lace" consists of two or four threads surrounded by a wide mucous muff. Another thread twisted into numerous loops is immersed in it. Thanks to this weaving, insects can easily become entangled in their hairs.
The importance of web adaptations during reproduction and dispersal.
As already noted, webs are used by spiders during their breeding season. It was thanks to the web that this process became unique. When searching for a female, the male spider is guided mainly by smell. But when he encounters a cobweb thread on his way, the male unmistakably finds the female who laid this thread. Having discovered a female, the male begins to court her. Courtship occurs differently in different spiders.
Some spiders use webs when mating. The males of some web spiders weave small mating webs near the female’s webs and begin to lure her there with rhythmic movements of their legs. Male cross spiders (genus Araneus) pull a horizontal web thread onto the female's web and drum on it with their feet, rhythmically, beating out repeating melodies. By doing this, they give a signal indicating the presence of a sexually mature male of the same species. If the female is ready to mate, she goes down to the male without showing aggression.
Fertilized eggs are laid in a heap in a cocoon, which the female makes from several layers of web. The cocoon wall is made of tightly fitting straight threads. The cocoon is impregnated with a solidified secretion, which is released through the mouth. The cocoon shell is very dense. The shapes of the cocoon are different - spherical, pear-shaped, disc-shaped.
Having hatched from the egg for some time, the spiders stay together and then disperse. Spiders can be lifted high by air currents and transported over long distances.
Buildings and web devices.
Spiders are divided into web spiders, which make trapping webs, and non-web spiders, which do not use web devices. But there are exceptions when non-web spiders are defenseless - during molts and wintering. When dangerously approaching them, the spiders fall down, leaving behind a web thread, along which they climb back, reeling it in and eating it.
Free-living spiders also use a safety thread, for example jumping spiders, which use a jump to catch prey, and sometimes even spend the night on them. The South Russian tarantula (Allohogna singoriensis) also uses insurance, moving away from the hole, pulling a thread along which it returns; if the spider thread is damaged, the tarantula is not able to find its hole, it is forced to look for a new shelter.
The South Russian tarantula is one of the largest spiders in Russia, up to 25 - 35 mm. , and sometimes up to 40 mm. Poisonous and can bite through human skin. Lives in deep vertical burrows lined with cobwebs. Females live 2-3 years, males die after mating at the end of summer. Females lay up to 200-7 eggs in a white egg cocoon. The spiderlings that emerge after a month stay on the female. She goes out with them in search of water. After giving the spider a drink, she throws them off, and they begin an independent life.
Spiders that dig their own burrows use webs to line the walls of their shelter, which prevents the walls from collapsing. Spiders also make all sorts of web superstructures over the entrance to their burrows to protect them from enemies.
Among the web structures, especially noteworthy is the design of the only water spider - the silver spider; he builds it under water. The spider brings air from the surface at the end of its abdomen in the form of bubbles and builds an air bell underwater among the vegetation. The air in the bell is held in place by a thick web of cobwebs.
Foraging for food using web devices.
All spiders are predators, but since they do not have good eyesight, they lie in wait for their prey. There are several tactics for how spiders behave when hunting. The first is an ambush attack. The second is sneaking up a short distance to throw. These tactics are used by most non-web spiders: side walkers (families Thomisidae and Pilodromidae), jumping spiders (family Salticidae), wolves (family Lycosidae). But spiders are spiders for that reason: to use webs when hunting. The placed nets catch prey larger than the hunters themselves. There are many options for using spider threads to catch victims - from signal threads to skillfully woven snares. There is a spider that hangs on its web like a rope above the ground in the habitats of ants and lies in wait for them. But, for example, there are tropical African spiders that, when catching prey, release a thread up to 2 cm long with a drop of sticky secretion at the end. With the help of a third pair of legs, he quickly swings this thread around himself. The insect, touching this droplet, sticks to it, the spider pulls it up and sucks it out.
There is a tropical spider in Central and South America that holds a web on the tips of its legs and when an insect runs or flies past it, the spider quickly throws a net over it and pulls it towards itself.
Spiders create complex trapping structures; they come in different shapes and types - funnel-shaped, wide-looped, vertical, horizontal, dome-shaped, wheel-shaped.
Arachnologists became interested in the history of the development of web trapping structures back in the 19th century.
Arachnologists still do not have a common view on the history of the formation of spider webs.
Further study of this issue may make our knowledge about the evolution of arachnoid networks and the network-building activities of spiders clearer.
Gossamer Breathing Bell
The silverback spider hunts in water, in which it is necessary to breathe atmospheric air. Sinking to the bottom, the spider captures a portion of air at the end of the abdomen in the form of a small bubble. On plants he builds an air bell, in which the air is held in a densely woven web.
The silverback spider “seals” an oxygen molecule into its web underwater, and thus breathes.
What is it for?
If you ask a person why a spider needs a web, he will answer without any doubt: for hunting. But this does not exhaust its functions. Additionally, it is used in the following areas:
- for insulating minks before wintering;
- to create cocoons in which offspring mature;
- for protection from rain - spiders use it to make a kind of canopy that prevents water from entering the “house”;
- for traveling. Some spiders migrate on their own and send children away from the family on long webs blown by the wind.
Web - to capture the victim
To catch prey, spiders weave trapping nets, but some species use web lassos and threads.
Tarantula spiders, having caught prey, hold it in the chelicerae, then pack the victim into a web.
Spiders that hide in the depths of the hole leave a signal thread. It stretches from the abdomen to the entrance to the shelter. Vibrations of this thread are transmitted to the spider, giving a signal that prey has been caught.
Not only spiders produce webs, but they are the ones who most widely use spider silk, and weaving webs is their distinctive feature.
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How and how long do spiders weave webs?
The spider weaves the most famous circular web for 0.5–3 hours. The duration of weaving depends on the size of the mesh and the weather. In this case, the wind usually becomes the best assistant, carrying the thread released by the spider over considerable distances.
It is in the direction of the wind that the web stretched between the trees is located. A thin thread is carried by the air flow, clings to a nearby tree and perfectly withstands the movements of its creator.
Familiarize yourself with the types of spiders.
He periodically renews the woven net, as over time it loses its ability to hold prey.
The spider usually eats old webs to provide itself with the building material needed to weave a new product. Automatic actions for building a network are laid down at the genetic level and are inherited.
