Meadow cross spider. Is the cross spider dangerous for humans?

The cross spider belongs to the orb-weaving family. They live in almost every country, except for southern and northern latitudes. This type is the most common. There are 2,000 species of this spider in the world; about 10 species live in Russia. Most often this insect can be found in the Republic of Mordovia, Astrakhan, Smolensk and Rostov regions.

Favorite places of the insect: fields, gardens, shrubs near water bodies, groves, forests; in very rare cases they live on the facades of walls and eaves of buildings. Mostly crosses choose places with very high humidity.

The crowns of trees in neglected gardens or impenetrable forests have become the favorite place of the cross spider. You can determine that this is where this spider lives by its wheel-shaped web. Considering that the web itself is destroyed under the influence of other insects, wind, trees, people, they are forced to unravel it every two days and weave it again.

Appearance of an insect

Because of the peculiar cross on the back, the spider got its name - cross. The cross itself is formed from white and light brown spots. The creature's abdomen is round and brown. There are 4 pairs of legs on the body, which are hypersensitive, and 4 pairs of eyes, directed in different directions. The insect's eyes allow it to see the world from all sides. Interesting detail: Spiders have blurred vision, they see only the outlines of objects or their shadows.

Females are almost twice as large as males. For comparison: the size of females varies between 17-26 centimeters, and males - 10-11 cm. After certain periods, cross spiders molt and shed their chitinous cover. This period is characterized by active growth.

Insects are especially active at night; during the day they hide in their shelters. At night they weave webs. During the day, females can also become active. This could be hunting flies and butterflies. The unique creature freezes in one position, which at first glance gives the impression that he is dead, but this is a trick for the victim.

External structure of the cross spider

Spiders have 8 legs, with very sensitive olfactory organs. Their abdomen is round, resembling a droplet. There are spots on the abdomen that form a cross shape. There are 4 pairs of eyes on the head, which provide a wide view. Poisonous hunter spider, so vision is a matter of life and death for him.

What do amazing insects eat?

This species is a carnivore. For food they need aphids, flies, mosquitoes, and midges. Spiders wait for their potential prey in the middle of the web, to which the signal thread is attached. As soon as an insect flies up to the web and gets into it, then trying to get out, they create vibration in the web, thus the cross in the center receives a signal about a potential victim. Considering that the legs of cross spiders have olfactory organs, they can also hear the prey with their legs.

After receiving a signal, the insect approaches the victim and, with the help of a bite, injects poison into the body - chelicerum. Some krestoviki immediately eat the victim, while others leave food in reserve. They wrap the victim in a web and hide it from prying eyes in the foliage.

These insects eat a lot. During the day they need an amount of food equal to their own weight. The cross spider is almost always on duty, hunting. During the day he devotes only a small amount of time to rest, while the signal thread remains tied to the leg.

Cross spiders will not eat insects that are too large for them or poisonous. They throw such people out of the web, cutting it off. Dangerous to these creatures are wasps and flies, which leave their larvae on the body of another animal. If such a fly or wasp leaves its larvae on the spider, then they themselves will begin to eat it and develop.

The main differences between the mysterious creature

These spiders belong to the species of dioecious animals. When mating occurred, then the male dies, and the female is actively preparing the cocoon for future offspring. Most often, small egg spiders appear in the fall. At first, the woven cocoon is on the female’s back, and then she carries it to a secluded and safe place. These may be cracks or small holes in the tree bark. New offspring emerge from the cocoon in the spring. They become young individuals ready for mating by the end of summer, and then the old female dies.

At the first stages of their lives, males actively weave webs to provide themselves with food. But as soon as the mating period arrives, they wander around in search of a female. They eat little, and this is reflected in their difference in weight with the female.

When the spider finds a female, it carefully approaches her web, and always spins its own thread in case of retreat. Females may perceive a potential suitor as their victim. and lunch. Then the male very carefully tugs the web and as soon as it reacts and throws it at the prey, he runs away along his woven web.

Such games can continue for several minutes until the female realizes that it is her groom who has come. Next, mating occurs, and here the male needs to be alert. Once the process has taken place, the female becomes a hunter again, and the male can become her victim. Therefore, he has to quickly run away after mating is finished.

How do cross spiders reproduce?

From 300 to 800 eggs are placed in a cocoon prepared in advance. They have an interesting amber color. Since the cocoon has rather thick walls, future spiderlings are not afraid of either frost or water. In this way, the eggs are stored until spring, and with the onset of warmer weather, young offspring are born. For some time, young spiders sit in a cocoon. This is due to ignorance environment, and their fear of learning new things, but over time they all leave the shelter and begin an independent life.

Considering that insects have very large offspring, natural competition arises for the right to life. Some young spiders get caught in the webs of their relatives and are eaten, and some cannot get food and also die. Therefore, the farther a young spider goes from its cocoon, the better environment it will find and the more chances it will have to survive and develop.

The individuals in question perform all movements only thanks to their web, this is due to the fact that their legs are very weak. They also travel with the help of a fair wind. Interesting fact: On its web, the cross spider can fly up to 400 kilometers.

Cross bite for humans

The cross spider bites and injects its poison not only into insects, but also into humans. Most often this occurs in the case of direct contact between an individual and a human hand. It is worth knowing some rules to avoid unpleasant contact with this poisonous spider:

If you are bitten by a crusader spider, the following symptoms will appear within 5 minutes:

• Headache;
• General weakness;
• Aches in the joints, pain throughout the body;
• The bite site begins to itch and tingle;
• Subcutaneous hemorrhages may be observed.

For humans, the bite of a poisonous cross spider is not fatal, but first aid should not be neglected. The following manipulations should be done:

1. The bite site is washed with soap and water. To avoid additional infection;
2. If possible, ice or any other cold object is applied to the bite site;
3. If you felt headache or a slight increase in temperature, you can take regular paracetamol;
4. If you are allergic, then take any antihistamines to avoid a possible exacerbation;
5. If a child is bitten by a cross spider, do not wait for the body’s reaction; seek help from a doctor.

Benefits of the cross spider for humans

Although spiders can inject venom into human body and pose a danger, their web has beneficial features and can be used in various fields.

Spider web has an excellent antibacterial effect, so it can be used to disinfect wounds.

In optical instruments where ultra-precision in calculations is needed, the web of this spider is used.

Microbiologists made a discovery and developed a unique air analyzer based on the crusader's web. Exactly the web catches all microparticles, which are in the air, and the composition of the air is determined from them.

Cross spiders are unique animals that can be useful to humanity.

Cross spider. Structure. Tarantulas. Karakurt

Spiders are the largest order of arachnids in terms of the number of species. The body is divided into a fused cephalothorax and a fused abdomen. The cephalothorax is connected to the abdomen by a constriction formed by the seventh segment of the cephalothorax. Chelicerae are hook-shaped, with ducts of poisonous glands. Pedipalps are short. Eight simple ocelli are most often located on the cephalothorax. The respiratory organs of most spiders are represented by one pair of lungs and one pair of tracheas; in some tropical species - only lungs. On the underside of the abdomen there are arachnoid warts. Spiders use webs to build their shelters, trapping nets, egg cocoons, spermatophore shells, etc. Spiders are characterized by complex behavior.

rice. 1.
1 - female, 2 - male.

The female is larger than the male, 20-25 mm long, she has a large rounded abdomen with a characteristic pattern in the form of a light cross on a dark background. The body length of the male is 10-11 mm (Fig. 1).

Eight simple ocelli are located in two rows on the front part of the cephalothorax. The cephalothorax has six pairs of limbs: chelicerae, pedipalps and four pairs of walking legs. Chelicerae consist of two segments, the terminal segments look like curved claws. At the base of the chelicerae there are poisonous glands, the ducts of which open at the tips of the claws. Spiders use chelicerae to pierce the integument of their victims and inject poison into the wound. The pedipalps have the appearance of segmented limbs. In males, on the terminal segment of the pedipalp there is a copulatory apparatus with a reservoir, which the male fills with seminal fluid. During copulation, the male inserts the pedipalps along with seminal fluid into the female's spermatic receptacle. Walking legs are seven-membered.

In the abdominal cavity there are arachnoid glands that produce Various types cobwebs.

rice. 2.
1 - simple ocelli, 2 - venom gland, 3 - chelicerae, 4 - brain,
5 - mouth, 6 - subpharyngeal nerve ganglion, 7 - blind processes
midgut, 8 - pulmonary sac, 9 - ovaries, 10 - arachnoid
glands, 11 - arachnoid warts, 12 - anus,
13 - Malpighian vessels, 14 - glandular protrusions of the middle
intestines (liver), 15 - heart, 16 - sucking stomach.

To catch prey, the crossweed weaves a network from cobwebs in the crown of trees. Prey is flying insects. The body of a victim caught in a web is pierced by spiders with chelicerae and injected with poison and digestive enzymes. salivary glands and liver. The pedipalps serve to hold prey. Under the influence of enzymes, the tissues of the prey are digested, the spider absorbs the semi-digested food, and only the integument remains of the victim.

The anterior section of the intestine, lined with cuticle, consists of a pharynx, esophagus and sucking stomach equipped with strong muscles. The ducts of the salivary glands open into the pharynx. The midgut in the cephalothorax has 5 pairs of long blind lateral protrusions, allowing spiders to absorb large amounts of food. In the abdominal region, the midgut forms paired glandular protrusions - the liver. It not only secretes digestive enzymes, but also serves as a site of intracellular digestion (liver cells are capable of phagocytosis). The terminal portion of the midgut forms a swelling into which the channels of the Malpighian vessels flow. Thus, spiders have extraintestinal, intestinal and intracellular digestion.

The circulatory system is not closed, the heart is located on the upper side of the abdomen, has 3 pairs of ostia. The anterior aorta arises from the anterior end of the heart. The terminal branches of the arteries pour hemolymph into the system of lacunae, from where it enters the abdominal sinus, washing the pulmonary sacs, from there into the pericardial portion of the body cavity, and then through the ostia into the heart.

The respiratory organs are represented by a pair of pulmonary sacs forming leaf-shaped folds and two bundles of trachea. The respiratory openings of the trachea open on the underside of the abdomen.

The organs of excretion are the Malpighian vessels. The main excretion product of arachnids, guanine, is removed from the body in the form of crystals.

Due to the fusion of segments, the ganglia come closer together. The brain is formed by the fused ganglia of the head and chest, the abdominal nerve chain is represented by a large node in the abdomen.

Vision is poor, hearing organs are poorly developed, represented by auditory vesicles. The organs of seismic sense, balance (statocysts) and touch are well developed.

In autumn, the female weaves a cocoon from a special web, into which she lays several hundred eggs. The cocoon hides in the cracks of the bark. After the breeding season, females and males die. The eggs overwinter and young spiders hatch from them in the spring.

rice. 3.

Tarantulas (Lycosa sp.)(Fig. 3) are large (3-4 cm) spiders that live in vertical burrows, the walls of which are covered with cobwebs. The entrance to the burrow can be tightly closed with a lid woven from cobwebs. During the day, tarantulas hide in these burrows and hunt at night. In winter, the hole is deepened, the entrance to it is clogged with earth. Eggs are laid in early summer.

rice. 4. Karakurt (Latrodectus
tredecimguttatus)

Tarantula venom is not dangerous to humans; in the worst case, a slight inflammation occurs at the site of the bite.

(Fig. 4) lives in Crimea, the Caucasus, Kazakhstan, etc. It poses a great danger to humans, cattle, horses and other animals. Sheep are immune to karakurt poison. Karakurts are small black spiders with red dots on the abdomen. The body length of the female is up to 20 mm, the male is up to 7 mm. Favorite habitats are wastelands, ravine slopes, and virgin wormwood. In depressions in the soil, often in rodent burrows, the female makes lairs. At the entrance to the lair, trapping threads are stretched. The eggs overwinter in cocoons.

The most poisonous are sexually mature females, their poison is 15 times stronger than poison rattlesnake. The bite of such a female causes severe pain, severe poisoning and can be fatal.

Description of other classes and orders of the Arthropod type:

• Class Arachnida
  • Spider Squad (Aranei)

In the Arachnida class, the cross spider is a typical representative of these animals. You can find out more about the features of this species in our material.

Description and habitat features

There are more than 2 thousand species of cross spiders in the world. There are up to 30 species in Russia and neighboring countries.

A distinctive feature of this species are light spots on the upper side of the body, which form a so-called cross. This is where the name of the species came from - cross.

Rice. 1. External signs cross spider

The females of such spiders are much larger than the male. Its dimensions range from 17 to 40 mm, while the male is up to 11 mm long.

The animal's body consists of two sections: the cephalothorax and abdomen. There are 6 pairs of limbs on the cephalothorax, 4 of which are walking legs. On the abdomen, the limbs are modified into arachnoid warts.

Like most spiders, the cross spider is a predator. He catches his prey on a web, which he weaves quite skillfully. At the time of hunting, it can sit directly on the web, waiting for the victim.

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The digestion process partly occurs outside the animal's body. It injects its poison, along with digestive juices, into the prey and waits until the “dish” is ready. All that remains is to drink the nutritious liquid contents of the insect that is trapped. Favorite treats are small insects.

Rice. 2. An insect caught in a web becomes the spider's food.

Weaving a web

The cross spider settles in the crowns deciduous trees. It uses branches to form the basis of its nets, and leaves make an excellent shelter in which to hide. The web is usually large in size and is located both in the crown of a tree and on shrubs.

After a day or two, the spider itself breaks its web, which becomes unusable, and builds a new one. The fact is that the web is partially spoiled by the prey itself, breaking the threads. It also contains dry leaves, which interfere with hunting.

The spider weaves a new web mainly at night. At this time of day, insects do not interfere, and there are no enemies that can eat the hunter himself. In construction, they are helped by the sense of touch, not sight.

In an adult female, the number of radii and spirals in the web has a certain number. The distance between the turns is also important. From observations it has been established that the spider web has:

• 39 radii;
• spiral turns - 35;
• spiral attachment points and radii - 1245.

Such accuracy is explained by a genetically inherent instinct. Even young individuals can weave a web with the precision of adults.

Rice. 3. Trap net

Is the cross spider dangerous?

The poison of the cross is toxic to both invertebrates and vertebrates. The cross is capable of biting through human skin, but the amount of poison injected into the body will be insignificant. Therefore, a bite may cause mild, quickly passing pain.

What have we learned?

The cross spider is no different in structure from other spiders. He hunts for webs, which he builds quickly and efficiently, updating them in a day or two. The venom of this spider is not particularly dangerous to humans.

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The cross spider, or Araneus, belongs to the orb-weaver family, a genus of araneomorphic spiders. In total, there are more than 1000 species of representatives of this genus in the world, but in Russia and the CIS countries you can find from 15 to 30 species. Crosses live mainly in damp and damp places - in fields, meadows, forests, along the banks of reservoirs and rivers.

The structure of the cross spider

The size of the male is 10-11 mm, the larger female is 17-26 mm. The cross has 8 legs and a large rounded abdomen. On the upper side of the spider's abdomen, white or light brown spots form a semblance of a cross, hence the name of the spider. The cross spider has 4 pairs of eyes, like most spiders; they look in different directions, providing their owner with a fairly broad horizon. However, spiders see poorly, they are myopic and distinguish mainly shadows, movement, and the contours of everything that surrounds them.

Features of the cross spider

Spiders are dioecious animals. After mating, the male dies, and the female begins to weave a cocoon from the web for eggs, which she usually lays in the fall. The cocoon turns out to be quite dense; the female carries it on herself for some time, and then hides it in any safe place - in a crack in the bark of trees or behind a loose piece of bark. In spring, young (juvenile) spiders emerge from the cocoon. They become sexually mature by the end of summer, after which the female that gave birth to them dies.

In the first days of his life, the male cross spider also builds a web - he needs to eat something. But upon reaching maturity, he begins to wander in search of adventure and, of course, noticeably loses weight. During this period, he is driven by only one desire - to find the female’s web.

When the female's web is found, he makes every effort not to get to her for lunch. To do this, he weaves a thread for himself down from the edge of the web - for retreat. Then he carefully tugs the thread. The female immediately rushes in search of prey, and the male retreats down the rescue thread.

This is repeated several times until the female understands that it is not the prey who is pulling the web, but her long-awaited partner. Then she changes her anger to mercy, and the spiders mate. But the male cannot let down his vigilance, because... after mating, the hunting instinct awakens in the female again. If he does not escape in time, he may well be eaten.

Reproduction of the cross spider

The cocoon, which the female weaves in autumn, contains from 300 to 800 amber-colored eggs. Under the protection of the cocoon, future spiderlings are not afraid of either cold or flood - it is very light and does not get wet. The eggs wait out the winter in the cocoon, and in the spring small spiders emerge from the eggs. For some time they sit inside the cocoon, afraid to leave such a cozy refuge. But gradually they spread out and begin to live on their own.

It is clear that it will be very difficult for such a huge offspring to get settled in life. Competition is very high, some will die of hunger, and others will be eaten by their relatives. Therefore, the young spiders face a serious task - to disperse as quickly as possible in order to increase their chances of survival.

Their legs are small and weak, so the spiders move, gliding with the help of their web, like real aeronauts. With a fair wind, a spider can fly a distance of 300-400 km. When the wind subsides, the web falls to the ground, the spider throws it away and begins to settle in a new place. If he is lucky with the site, he will be able to catch up to 500 insects per day with his nets. The hunt is ongoing.

According to naturalists, millions of spiders live in meadows, fields and forests, destroying entire legions of insects, including those dangerous to humans and their households. If it were not for spiders, the number of flies, mosquitoes, gnats, midges, moths and aphids would be several orders of magnitude greater and could seriously poison our lives. Experts do not even exclude the possibility of using spiders in biological pest control.

Web of the cross spider

Cross spiders catch their prey using webs. More precisely, their females - male spiders do not weave webs. Female spiders guard their prey either in the center of the web or sitting next to it, on a signal thread. Mostly flies or mosquitoes get caught in the web. If it comes across prey that is too large and inedible, for example a wasp, the spider can free it by tearing off the web.

The spider either eats the caught prey immediately on the spot, or, if it is not too hungry, drags it into a secluded corner or entangles it in a web. Around the web, under the leaves, you can find a whole food warehouse of flies entangled in the web, stored for a rainy day.

The behavior of the cross spider

How does a spider hunt? When a fly or any other insect gets caught in a web, the spider senses the vibration of the trapping web, it crawls into the victim and kills it with a bite of its poisonous mandibles, or chelicerae. The fly stops shaking the web, and the spider calmly swaddles it with a bundle of thin threads, pulling them out of the abdomen with a pair of its legs.

Having snacked on the surrounding threads, the spider takes its breakfast and goes to the center of the web to have a meal. He crushes his prey, injecting digestive juices into it. When the fly has digested inside its shell, the spider sucks up the semi-liquid contents into which the fly has turned and throws away the victim's skin. During a successful hunt, a spider can eat about a dozen flies in one sitting. The poison of the crosses is dangerous only for small insects, it cannot harm a person.

Habitat of the cross spider

Crossworts live mainly in the crowns of trees, make a secluded shelter from the leaves, and stretch the web between the branches. The wheel-shaped web can be found in a forest, grove or neglected garden. Sometimes it can be found in bushes or in window frames and under the eaves of abandoned houses.

The trapping web constantly requires repair, it is destroyed by both small and large insects, so every couple of days the cross spiders unravel the web and make a new one. They usually do this at night, and by morning the new web is ready for new prey. Thus, at night the spider is relatively safer, because it natural enemies, insectivorous birds, sleep at night. It does not need light to build a web; a well-developed sense of touch is sufficient.

The enemies of the cross spider are also flies and wasps, which lay eggs in the bodies of their victims. For example, the fly Melanophora rugalis - taking advantage of the spider’s immobility, it can fly up to it, sit on its back and in the blink of an eye lay an egg in its body.

Web of the cross

The web of the female cross has exactly 39 radii, 1245 points of attachment of the radii to the spiral and 35 turns of the spiral - no more, no less. The webs of all spiders are as similar to one another as two peas in a pod, because all the necessary data is genetically enshrined in their heredity. Therefore, even small spiders know how to build webs and catch prey.

Any web is not only beautiful in its symmetry and delicacy, it is very rationally arranged. All the threads that form it are very light and, nevertheless, very strong, and are connected in such a way that they only work to break.

How does a spider manage to build such an even, symmetrical web that is several dozen times larger than itself? A spider (more precisely, a cobweb), having climbed onto a branch or tree trunk, releases a long web thread from its abdomen. It is picked up by a stream of air, and the spider waits patiently until the thread catches on something suitable.

If this does not happen and the thread hangs, the spider pulls it towards itself and eats it. Then he runs to another place and tries again. And so on until the thread is caught. Then the spider crawls to the hooked end of the thread and secures it well. Then it descends on its thread to some support. There he also firmly fastens this thread - now 2 threads are already fastened.

The spider returns along the second thread and drags along the third, which he secures in starting point, i.e. where the first thread came from. The triangular frame - the basis of the future web - is ready. Inside this frame, the spider stretches several threads that intersect in the center. The spider marks the center of the web with a lump and begins to extend all its numerous radii from it, fastening them with a spiral thread, and then lays trapping threads. At the intersection points of the spiral and the radius, the spider binds them with its legs.

Note that the angles between all radii and the distance between the turns of the web are strictly constant values. How does such a small creature manage to maintain its web in strict accordance with geometry? For this you need at least the simplest measuring device. And, imagine, the spider has it! This is his first pair of legs that can act as a scale ruler.

While working on the web, the crossmaker regularly checks the distance between the spirals. His natural tool is so precise and reliable that it allows you to work in pitch darkness. The last step in creating a web will be a signal network, the end of which is laid to the spider’s shelter. To build the entire web, the spider requires several hours of painstaking work and approximately 20 meters of web.

From a chemical point of view, the web is a complex protein polymer - fibroin. The many glands of the spider's abdomen form this viscous liquid, which quickly solidifies in air in the form of thin filaments. A spider can produce several different types webs with different properties. For the frame of the web he makes a dry and thick thread, for the cocoon - silky and soft, for the catching spiral - thin and sticky. Why doesn't the spider itself stick to its web? Everything is very simple - he runs only on non-adhesive threads, and diligently avoids touching adhesive spirals.

The polymer liquid comes out from the glands on the spider's abdomen through thin tubes and hardens into very thin threads. If the spider needs special strength, it can weave several of these threads together. Scientists in last years They are seriously studying the properties of spider “silk”. It turned out that it has many unique properties.

The technology for producing spider web threads is similar to the production of synthetic fibers. But in terms of strength, no synthetic fiber can compare with spider fiber - it can withstand loads of up to 260 kg per 1 sq. mm, which is stronger than steel. This is why residents of the tropics make nets from spider webs to catch birds, bats, insects, and even weave fishing gear.

The web is so elastic that it can stretch up to 30% of its length and shrink back to its original length. Its lightness and subtlety are involuntarily amazing, because 340 grams of web is enough to encircle Earth along the equator!

The use of cobwebs in agriculture and medicine

People have long tried to make fabric based on spider webs. In Germany, back in the 16th century, ribbons and various decorations were woven from cobwebs in villages. Then in France, artisans came up with the idea of ​​​​making gloves and stockings from spider webs, which caused complete delight among fashionistas.

But it turned out to be impossible to launch this technology into large-scale production, and this was convincingly proven by the physicist and zoologist Reaumur. For such production to become profitable, it is necessary to contain and feed hundreds of thousands of spiders. But to feed them, it would be necessary to catch several million flies every day, which was completely impossible to implement in practice.

However, people still use the web, even today. For sights (crosshairs) in various optical instruments (microscopes, telescopes, sights, etc.), spider webs are simply ideal. Microbiologists have also found use for it, developing a unique air analyzer using it.

The cross spider is launched onto a special frame, fed, and the spider weaves its web based on this frame. Then air is pumped through a frame with a net, and the thinnest web perfectly captures the microbes that are in the air. This method of air analysis has been recognized as the most effective of all existing in the world.

IN folk medicine Since ancient times, spider webs have been used to disinfect open wounds. Research has confirmed that spider webs kill pathogenic bacteria, and with its help, drugs have been developed that are harmless to animals, but deadly to all kinds of bacteria. As you can see, the cross spider is extremely useful for humans, in every sense.

The cross spider is a representative of the genus of amorphous spiders of the orb-weaver family. More than 2 thousand species of crosses are known.

Characteristic feature appearance this spider has spots of light brown or white, located on the upper side of the belly, which form a cross.

Appearance

The abdomen itself is rounded with no segments. If you look at its lower part, you can see 3 pairs of arachnoid warts, which contain about a thousand glands. It is the glands that are responsible for the production of webs for a variety of purposes: to build a trap, weave a cocoon, or to create a shelter.

Female size exceeds the size of the male. For example, the body length of a female is 17–40 mm, and that of a male.

10–11 mm. This type of cross has a body cavity of a mixed type or, in other words, a mixocoel. This cavity was formed as a result of the merger of the primary and secondary cavities. The body of the crusader is covered with a yellow-brown chitinous shell. During molting, the cross sheds the shell, thereby renewing the chitinous layer.

The cross has 10 limbs:

The cross spider has a very poor vision, despite the fact that he has 4 pairs of eyes. This spider distinguishes only light, shadow and blurred silhouettes. But this does not prevent him from having excellent orientation in space, because he has a well-developed sense of touch. It is carried out thanks to tactile hairs covering the body. Every type of hair has its own function: some perceive sound, others detect changes in air movement, and still others react to various kinds of stimuli.

The lifespan of a spider is from 1 to 2 years and depends on the type of crusader.

Respiratory organs and heart

The crusader breathes using his abdomen, because the organs responsible for this important function, are located exactly there. Respiratory organs are presented in the form of a pair of pulmonary sacs with numerous leaf folds. They contain air and hemolymph circulates, while being enriched with oxygen. This name refers to the fluid that flows in the vessels instead of blood. The respiratory organs of the cross also include trachea-tubes, collected in two bundles. They open through a hole located at the bottom of the abdomen.

The heart, in the form of a long tube, is located in the dorsal part of the abdomen. Large vessels will withdraw from the heart.

Excretory system and digestion

The excretory system is presented as:

• Coxal glands. A system of canals departs from them, which ends in the form of excretory ducts in the area of ​​​​the base of the walking legs.
• Malpighian tubes. With their help, metabolic products leave the crusader's body.

Digestion in the cross spider is external. In other words, the crusader’s body is not able to digest food, so it builds traps from cobwebs.

Features of the web

The crossers are updating their web almost every day, due to the unsuitability of the old one. The reasons why a spider needs to change its web are:

• Gaps due to prey being trapped.
• Holes caused by large insects that are unsuitable for spider feeding.

The web is being weaved at night. This is explained by the fact that at night the crossbird feels completely safe, because birds that feed on insects have been sleeping for a long time. The new prey trap will be ready for use in the morning.

The spider has a scheme for weaving a web, laid down at the genetic level. The web always has a certain number of circles and spirals, and the spaces between the weaves are the same. Young males build webs no worse than adults until they reach sexual maturity.

Reproduction

Spiders begin to mate in the autumn season. A male who has reached sexual maturity, goes in search of a female who is waiting for him in her weaving. As soon as the spider has found its chosen one, it attaches a thread to its web, as if inviting it to itself. For the female, this means that it is time to reproduce and she leaves her network. The male representative dies after mating.

In turn, the fertilized female builds a cocoon where she will subsequently lay her eggs. For several days the cocoon is under the protection of the mother. The female then finds a secluded place in the cracks of the walls, in which the cocoon survives the winter. The female dies, and spiders emerge from the cocoon in the spring. In summer, the new offspring are ready to reproduce.

Description of popular types

Habitat

This type of spider prefers temperate and tropical climates. climatic zones. Different kinds The cross can be found in countries such as:

The cross spider feels comfortable in damp areas, near water, as well as in parks, gardens and forests. In other words, the crusader can be found wherever there are trees . After all, it is between the branches crusader trees and weaves his web. The spider's orb web is found under roofs and in doorways of abandoned houses.

Nutrition

The spider's diet includes:

• flies;
• small grasshoppers;
• vile;
• mosquitoes;

Males do not eat well, so they grow at a slow pace. Females have an excellent appetite. In 24 hours she is able to eat an amount of food equal to her weight.

If food unsuitable for the spider in the form of a poisonous or large insect falls into the trap, then the crusader, as it were, cuts out the object by breaking the threads. Spiders are afraid of wasps that lay eggs on living creatures and avoid them. After all, the body of a spider is a favorable environment for the development of their larvae.

When a spider hunts, it sits not far from the trapping net in the foliage or in the very center of the web and waits for the victim to become entangled in the sticky threads. When prey falls into the web, the spider's hairs pick up the vibrations of the web. The spider then injects into its victim gastric juice and rolls it into a cocoon created from a spider's web, and waits for dinner to be prepared. Stomach juice turns the prey into a solution, which the spider soon drinks.

For whom is the cross spider dangerous?

Crusader venom contains substances such as hemotoxin and neurotoxin, which are fatal only to invertebrates, as well as small vertebrate organisms. For humans, cattle, sheep and other living organisms, the bite does not pose any particular danger, and some do not even notice it. The site of the bite can be recognized by slight pain, which passes very quickly. Spiders never attack first on a person, and bite only in case of protection, if the web was accidentally touched.

• How do crusading spiders move along their own web, since its threads are covered with an adhesive substance? The fact is that this arthropod moves along radial threads on which there is no adhesive substance, so it does not stick.
• The web of the cross can show the composition of the air, which is why it is so actively used in microbiology.
• Spiders aren't the only ones who need webs. Thanks to the strong threads of the cross spider's web, some tropical residents use it to weave jewelry, fishing gear, and also to make fabrics.