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Spiders - red book. Spiders: species, body structure, reproduction. How many legs, eyes does a spider have, how does it weave a web, how long does it live, is it an insect or not? Poisonous and non-poisonous spiders: a list with names

Spiders belong to the order of spiders, the class of arachnids and the type of arthropods. Their first representatives on earth appeared about 400 million years ago. There are many varieties of these arthropods on earth. All of them have different characteristics and color, behavior and lifestyle.

Characteristics and description of spiders

spider body consists of only two parts:

Abdomen. It has breathing holes and wool (spider warts for weaving webs).
cephalothorax. It is covered with a shell of chitin. It contains eight articular long legs. In addition to the legs, there are two leg tentacles (pedipalp). They are used for mating by sexually mature individuals. And there are also two short limbs with chelicerae - poisonous hooks. These chelicerae are part of the oral apparatus. The number of eyes in these arthropods can be from 2 to 8 pieces, depending on the breed.

The sizes of spiders are different: from 0.4 millimeters to 10 centimeters. The span of their limbs can be more than 25 centimeters.

The pattern and color on different individuals depends on the structure of the structural integument of hairs and scales, as well as the localization and presence of various pigments. It is for this reason that spiders can be monochromatic dull or bright in various shades.

Names of spider species

Scientists have identified and described more than 42 thousand species of arachnids. Approximately 2900 species of these arthropods are known in the territory of the CIS countries. This article will discuss several varieties.

This type of spider in its color is the most beautiful and spectacular. These arthropods have the following characteristics:

This species is native to Venezuela but can be found on African continent and in Asian countries. This species of arachnids does not bite, but only in case of danger throws special hairs that are located on the abdomen.

For human life, these hairs do not pose a danger, but burns from them still remain. In appearance, the burn from a tarantula bite resembles a nettle bite. Males of this breed live only for 2-3 years, but females - 10-12.

Spider flower

This species belongs to the sidewalk spiders. Their color can vary from pure white to greenish, pink or bright green. The body length of males reaches 5 millimeters, and females - up to 12 millimeters. This variety is widespread throughout European countries. They are also found in Alaska, Japan and the USA. This arthropod lives in an open area, where there is a wide variety of flowering forbs. And all due to the fact that the flower spider feeds on the juices of caught bees and butterflies.

Refers to tarantulas, which in the natural environment live only in the southern regions of Brazil and Uruguay. This spider is quite massive and can be up to 11 centimeters long. It has a characteristic metallic sheen of hairs and a dark color. Prefers to live only among the roots of plants. What is most interesting, it practically does not pull out its minks. For connoisseurs of exotic pets, fluff often becomes a pet.

Spider Wasp (Argiope Brünnich)

This species of arachnids has a very interesting color of the limbs and calf - in white-black-yellow stripes. It is for this reason that he bears such a name. Male wasp spiders are duller than females. The body size of males in length reaches approximately 7 millimeters, but females (together with paws) - 4 centimeters. These arthropods are widely distributed in North Africa, the Volga region, southern Russia, Asia and Europe. The argiope spider lives on forest edges, as well as in meadows with herbal abundance. Its web is very strong and it is almost impossible to break it. It can only stretch under pressure.

These arachnids are widely distributed on the Eurasian continent. They are found along the banks of reservoirs with slowly flowing or stagnant water. Often settled in gardens with high level humidity, in shady forests or swampy meadows. The body length of females can vary from 14 to 22 millimeters, but the male almost never grows to more than 13 millimeters. The color is almost black or yellowish brown. On the sides of the abdomen are white or light yellow stripes.

Apulian tarantula

These spiders belong to the wolf spider family. They are common in southern Europe: very often they can be found in Spain and Italy, in Portugal they dig holes 0.5 meters deep.

The size of his entire body in length is 7 centimeters. Usually individuals are colored red, less often brown. On their body there is one longitudinal strip and several transverse light colors.

They are common in the subtropics and tropics, in Australia, in the Philippines. in Central America and the southern United States. The body dimensions of females can reach 10–13 millimeters in width, and 5–9 millimeters in length. The length of the entire body of males is only 3 millimeters. Their paws are short, and along their edges there are 6 spikes. These spiders have a very bright color: black, red, yellow, white. On their abdomen is a pattern of black dots.

peacock spider

In the color of this variety, you can find almost all the colors of the rainbow: yellow, green, blue, indigo, red. The females are paler in color. Whole body size adult is 5 millimeters. It is their color that attracts males to females. They live in Australia - in New South Wales and Queensland.

In other words, it is also called a spider with a happy face. For humans, it is absolutely harmless. It is common in the Hawaiian Islands. The entire length of his body is 5 millimeters. The color is different - blue, orange, yellow, pale. This species feeds on small midges, and their bright color helps to confuse enemies (particularly birds).

Black Widow

These arthropods are very poisonous and dangerous to human life. Habitat - North America, Australia, less often - the Russian Federation. The entire body length of females is approximately 1 centimeter, but males are much smaller. The body is black, and on the abdomen there is a spot of red color in the form of an hourglass. Males have a slightly different color: brown with white stripes. The bite of this arthropod is dangerous and can be fatal.

Karakurt

These arachnids are deadly and belong to the genus black widow. The entire body of the female can reach sizes from 1 to 2 centimeters, but the male reaches only 7 millimeters in length. This spider has 13 red spots on its belly. In some varieties, these spots have borders. But in some individuals of sexually mature spots are absent at all, it is for this reason that their body is completely shiny black. These spiders can live in North Africa, in the south of Europe, in the Azov and Black Sea regions, in the south of Ukraine and Russian Federation, in countries Central Asia, in the Astrakhan region, in Kyrgyzstan. And he was also noticed in the south of the Urals, in the Kurgan, Orenburg, Volgograd and Saratov regions.

Where do spiders live

Spiders live everywhere and they are common in all corners of the earth. You can not meet them only in those areas that whole year are under a shell of ice. The number of subspecies in countries with hot and humid climate much more than in cold or temperate. These arthropods are terrestrial inhabitants (with the exception of only a few subspecies). They live in built minks or nests, showing their activity only at night.

Tarantulas and other species of mygalomorphs live in the crowns of equatorial shrubs and trees. The "drought tolerant" species prefer crevices, burrows, and other ground level shelters. Digging spiders live in colonies, settling in individual minks 0.5 meters deep. Some varieties of mygalomorphs close their settlements with special shutters, which are made of silk, vegetation or soil.

Harvest spiders are very fond of settling in dark and damp caves, in abandoned old sheds and cellars, in dens abandoned by animals. Long-legged can be found in residential buildings on the southern warm windows hanging upside down.

And here is the jumping spider can be found anywhere:

In mountainous area.
In desert.
In the woods.
On brick and stone walls of houses.

Karakurt can be found on sagebrush wastelands and fields, where pigs and sheep are often trampled by flocks, on the rocky slopes of ravines, on the banks of artificial irrigation canals.

Spiders - side walkers more time in their lives they spend in anticipation of prey, sitting on flowers. But some representatives of this family can be found on the forest floor or tree bark.

The funnel family has its web on the branches of shrubs or tall grass.

But wolf spiders prefer grassy damp meadows and wooded wetlands more. There they can be found in large numbers in fallen leaves.

The water spider builds its nests under water, attaching it with the help of a web to various bottom objects. It fills its entire nest with oxygen and uses it like a diving bell.

What do spiders eat

These creatures are very original. They eat very interesting way. For a long period, some varieties of these arthropods may not eat. This period can take from 7 days to 1 month, in some cases up to 1 year. But if the spider nevertheless began to eat, then practically nothing will remain of its food. A very interesting fact is that the mass of food that all spiders eat in 12 months can be several times greater than the mass of the entire population on our planet.

Spiders eat a variety of foods. It all depends on the variety and size. Some can build a trap with a woven web. This trap is very difficult for insects to see. Digestive juice is injected into the caught prey, which corrodes it from the inside. After a certain period of time, the hunter draws the resulting cocktail into his stomach. And some species simply spit during the hunt with sticky saliva, which then attracts prey to the hunter.

The main delicacy of these arthropods are insects. Small types feed on grasshoppers, cockroaches, mealworms, butterflies, crickets, flies and mosquitoes. Spiders living in minks and on the surface of the soil take orthoptera and beetles for food, and some species are able to drag them into their homes. earthworm or a snail, and already there calmly proceed to the meal.

Web types

There are several types of different webs in the world. They are:

Round. The most common. It contains minimum number threads. Because of this weaving, it is hardly noticeable, but not every time it is perfectly elastic. Radical cobwebs diverge from its center, which are connected by spirals with a sticky base.
conical. Basically, it is weaved by a funnel spider in tall grass, while itself, waiting for prey, hides in its narrow base.
Zigzag.
Giant. Its dimensions vary from 900 to 28 thousand square centimeters.

And the web is also divided according to the type and principle of its sticking:

Sticky. It is used only for the preparation of jumpers in the nets of hunters. It's very hard to get rid of her.
Strong. It is used for weaving nets that will be used for the hunting process.
Household. From it, these arthropods make doors for dwellings and cocoons.

In our article we want to talk about spiders. With their numerous paws and eyes, they scare people. True, some still dare to keep them at home as a pet. However, scientists believe that there are enough Interesting Facts about spiders. In general, they are charming and amazing creatures.

Our relationship with spiders

There are more than forty thousand different spiders in the world. Some of them live next to us in our homes. And we really do not know anything about these creatures. Of course, their appearance is not very attractive, but most of them did not deserve such a dismissive attitude towards them. They are completely safe for humans, and therefore you should not be afraid of them. Although the world has poisonous species, the bite of which is very dangerous for humans.

So, we want to tell you very interesting facts about these creatures, which you probably do not know.

1. Spiders are useful. Only one such creature kills about two thousand harmful insects a year that fall into its nets. Mostly spiders feed on flies and mosquitoes. We can say that they make a significant contribution to the fight against harmful insects.

2. In Italy in the 15th and 16th centuries, there was a belief that a person who was bitten by a tarantula was insane. This species of spider lives exclusively in the south of the country. However, later scientists came to the conclusion that it was the tarantula that was completely safe. But the tarantula is really poisonous and dangerous creature. However, it lives in completely different regions.

3. The largest spider in the world is the goliath. Imagine that it can reach thirty centimeters. He catches and eats birds, although he can also feast on amphibians, rodents, insects, snakes. The villi are therefore dangerous to people. But their venom is not lethal.

4. There is only one vegetarian spider in the world. This is Bagheera Kipling (this is the name of this species). The jumping spider eats the leaves of plants, especially loves the acacia. Sometimes he can eat ant larvae, but this happens extremely rarely.

5. Spiders live all over the world. Only in the cold of the Antarctic they do not live. This is due to very low temperatures. There are only spider crabs that are not arachnids. But the Arctic is inhabited by more than 1000 species of these creatures.

6. Everyone knows that spiders spin thread. However, not everyone knows that this thread is different in different species. The most durable silk thread is spun by Darwin's spider. It is so strong that it exceeds the strength of the material from which bulletproof vests are made.

7. The most poisonous is the banana spider, which is dangerous to humans. Its venom paralyzes the muscles and respiratory system. However, it does not always inject poison during a bite.

8. Spiders lay several thousand eggs at a time. However, not all newborn babies survive to adulthood. So, out of a hundred eggs, only one spider will grow.

Amazing abilities of spiders

The haymakers, which we often meet, outwardly are very similar to arachnids, but they do not belong to them.

Some varieties of spiders are very good at jumping. The distances they cover are impressive. During the jump, they still have time to unfold their silk thread, which gives them the opportunity to land accurately.

There are water spiders in the world. They can also live underwater. To stay there, the spider forms a bubble of air around itself, which allows it to breathe. It should be noted that it is very poisonous. But, fortunately, it is rare, and therefore does not represent real threat for a person.

Discussing interesting facts about spiders, I would like to say that they have a very special blood, which becomes blue in the air. It is absolutely not similar to the blood of animals and people. In fact, spiders do not have a circulatory system and shelter in the usual sense. They have a hemolymph that provides communication between various organs. So the main substance of hemolymph is copper, which is why in the air, oxidizing, copper particles give such a blue color.

Are spiders edible?

Some arachnids are edible. In Asia, they are cooked and eaten. You can easily buy them in a restaurant or in the market. In Cambodia, for example, fried spider is considered a delicacy. They are served on the table as a delicacy, because under the crust there is delicious meat.

Need to be afraid of spiders or turn it into a pet?

Sometimes spiders are kept in the house as a pet. Some varieties are quite large and are able to develop a decent speed of movement. Imagine that such a creature overcomes a little more than half a meter per second. It's just fantastic!

So how to be? Should spiders be feared or simply, having overcome disgust, treat them with due respect?

Scientists have long established that people are obsessed with the fear of arachnids.

Arachnophobia is Oddly enough, but up to six percent of the human population is subject to such fear. Even an ordinary photograph of a spider can cause panic and hysteria, heart palpitations in people.

Here are some interesting facts about spiders that say that they should not be afraid. Rather, these creatures have more reason to fear man.

Serebryanka

Earlier, we already mentioned the water spider - this is a silver spider. Interesting facts related to his lifestyle. agree that not every Living being adapt to live underwater. Moreover, he builds his own house for himself, weaving a dome of threads. He himself fills it with air in a very interesting way.

The spider has eight eyes, but it does not see well. Therefore, the villi on the paws serve for him. With their help, he gets his own food. Although he does not see, he perfectly feels all the vibrations. As soon as some crustacean gets into his net, he immediately rushes at him and takes him to his dwelling. There he eats it.

Spider-cross: interesting facts

The spider-cross got its name due to the fact that on its back there are peculiar spots in the form of a cross. This creature is extremely dangerous and poisonous. His bite without immediate medical care can lead to the most irreparable consequences for human life.

Listing interesting facts about spiders, I would like to note that they are all different-sex creatures. As for the cross, the male dies after mating. But the female begins to prepare for the appearance of offspring. She spins a cocoon, which she wears on her back at first, and then hides in a secluded place. There are her offspring.

Males at the beginning of their life actively weave a web for food, and by the mating period they begin to roam in search of a mate. That's why they lose weight. In general, females perceive them as potential prey and may well have a snack on them.

On the one hand, the cross is extremely dangerous for humans with its poison. But, on the other hand, there are benefits brought by these creatures. For example, its web has an antibacterial effect, it is used to treat and disinfect wounds.

In addition, the web is used in high-precision optical instruments. Here are some interesting facts about spiders that you can learn by starting to study these small, sometimes dangerous, and sometimes very useful creatures.

tarantula spider

The tarantula is currently exotic pet, which has become fashionable to keep at home. He hails from South America. Completely non-aggressive and quite slow. What interesting facts about the tarantula spider are known?

I must say that the males of this species live only about three years, but the females are much longer, about twelve. The tarantula has a menacing appearance, but its venom is not very dangerous to humans. It can be compared to a bee sting.

Living in the wild, he eats lizards, birds. If he ate a lot, then he may not appear from the hole for a very long time. It is said that in captivity, a spider may not eat for a whole year. But this does not affect his health in any way. Such behavior is inherent in nature.

Now this variety has become popular for home maintenance. But in captivity, spiders do not breed well. Therefore, they are caught under conditions wildlife. The maximum lifespan of a tarantula is thirty years! It's amazing. These are for children you can bring, starting to study arachnids.

I must say that this species is very large. Sometimes it can reach thirty centimeters in diameter. In fact, this is the size of a dinner plate. Their weight does not exceed one hundred grams.

If the spider senses danger, it begins to make menacing sounds like hissing. Thus he warns the enemies.

As a defense, he can throw small fibers into the air. Once on the body, they cause irritation and itching.

Instead of an afterword

In our article, we tried to give the most interesting facts about spiders. Of course, this is very interesting creatures and there's a lot to be said about them. The main thing is that you should not be afraid of them in panic. Yes, some species are poisonous and dangerous, but there are not many of them. And in general, you can get along with spiders.

SPIDERS
(Aranei),
detachment of the arachnid class, which also includes ticks, scorpions, haymakers, etc. Spiders are close to insects in a number of ways, but they clearly differ from them, and these groups are connected only by a very distant relationship. A well-known characteristic feature of many spiders is the ability to weave complex trapping nets (nets) from a silk-like substance secreted by the arachnoid glands. Some spiders, such as the black weaver spider ("black widow") and tropical tarantulas, can inflict very painful bites, fraught with lethal outcome However, most spiders, although they bite, are not dangerous to humans. The name of the class Arachnoidea comes from the Greek. arachne - spider. AT ancient Greek mythology Arachne was the name of a girl who was such a skilled weaver that, having challenged the very patroness of this craft, the goddess Athena, to a competition, she wove a fabric better than she. Annoyed, the goddess turned her rival into a spider, announcing that from now on Arachne and her entire family would spin and weave until the end of time. A total of approx. 30,000 types of spiders. The length of their body is from 0.1 to 5 cm. The main food is the liquid tissues of insects, which the spiders catch by rushing from an ambush or with the help of a web. Spiders are found at almost all inhabited latitudes and elevations: they were found on the slopes of Everest at 6700 m above sea level and caught (juveniles) 600 m from the surface of the earth. Some species live in water. Settling, the juveniles of a number of small species climb onto the ends of blades of grass and other towering objects and, raising their abdomen, begin to secrete a cobweb thread, which is picked up by the air flow and, having reached a sufficient length, carries the animal on itself. Such a year occurs in certain seasons and is especially noticeable " Indian summer"when in the air you can see whole "flying carpets" of dozens of intertwined cobwebs. This peculiar way of settling allows spiders to travel great distances and even reach islands lost in the ocean.

Web and construction of nets. The ability to secrete a spider web - feature almost all spiders. The material for it is formed in special glands located in the back of the abdomen, and the so-called. spider warts. Some spiders produce threads of up to six different types and use each of them for very specific purposes. As the spider moves, it continuously sheds a web, which, like a climber with a safety cable, it attaches from time to time to the surfaces it traverses. That is why a disturbed spider can almost always, with its legs crossed, fall from a support and, hanging on an tensile thread, descend along it to the ground. When prey enters the net, the spider usually wraps it in a web and only then kills it with poisonous claws (chelicerae) and sucks it out. Probably the most interesting feature spiders - the construction of a web of hunting nets. Their forms are very diverse and often very beautiful. Not all spiders use their web to catch insects, but each species weaves it in a specific way, and the resulting design may well serve as a taxonomic feature. The most beautiful, the so-called. wheel-shaped, nets are built by orb-weaving spiders from the family of crosses (Araneidae). First, the spider climbs to a high place, usually near a path or other open space, and secretes a very light thread, which is picked up by the breeze and, accidentally hitting a nearby branch or other support, is braided around it. The spider moves along this thread to a new point, along the way strengthening the web with an additionally secreted secret. In a similar way, two or three more relatively thick "cables" are laid, which make up a closed frame, inside which the trapping structure itself will be located. Usually the webs are oriented more or less vertically, but some spiders build horizontal webs. Radius threads are stretched between the sides of the frame, connecting in the center, like spokes in a wheel hub. Now, starting near this place, the spider moves towards the periphery in a spiral, leaving behind a thread attached to the radii, the distance between the coils of which is determined by the span of its limbs. While the web is not yet sticky, but, having reached the outer frame, the spider again spirals, but with denser coils, returns back to the center, this time forming a thread, which, unlike the previous ones, is covered with droplets of sticky secretion. As this actually trapping spiral is laid, the thread of the first non-sticky spiral is bitten off and thrown away. Obviously, it served only as a kind of scaffolding. When the nets are ready, the spider moves to their center or to a refuge located next to the net and waits for some flying insect to stick to the web. Usually the entire structure works for one night, and by morning it turns out to be torn in many places. One of the most beautiful webs is woven by the common species Argiope aurantia, a large spider with a black and gold pattern on its body. Its extensive spike-shaped nets are characterized by a zigzag thread running vertically through the center of the structure. The shape of the trapping net of other species is completely different. For example, in representatives of the genus Frontinella, it resembles a cup on a saucer. Funnel spiders (family Agelenidae) have a net similar to a net, and spiders of the Gnaphosidae family build tubular shelters from the web under stones and other objects, where they hide between hunting exits. An unusual wheel-shaped network of golden threads is built by the species Nephila clavipes. This large spider, common in the southern United States, is characterized by legs with tufts of hairs. The ability of spiders to secrete a silk-like thread has repeatedly led to attempts to use them like silkworms, but these experiments have not been successful. The main difficulty is that you need to feed the spiders with live insects, and more than 1.3 million spiders are required to get one kilogram of fiber fast enough! At one time, crosshairs were made from cobwebs optical instruments such as theodolites, levels and telescopes. Many spiders do not build webs at all and simply ambush their prey. This is characteristic of representatives of such families as wolf spiders (Lycosidae), jumping spiders (Salticidae) and theraphosid tarantulas (Theraphosidae). Jumping spiders, for example, use their keen eyesight to track down their prey and reach them with a single leap.

WEAVING A NETWORK WITH A SPIDER. From the middle of the upper thread, the spider descends on the cobweb to the lower one. From the middle of this cobweb, which as a result is divided into two "radii", he stretches the third "radius", the second end of which he attaches to the upper thread, and continues such movements to and from the center until he installs all the "spokes" of the wheel-shaped network. He strengthens her "hub" with several spiral turns.

Variety of spiders. Orb-weaving spiders and spiders that do not build webs have already been mentioned above. Let's take a closer look at their various types.
Theraphosides. One of the most interesting American spiders is Dugesiella hentzi. This is a large animal, the leg span of which reaches 15 cm. The color of the body is dark brown, so that in general the animal is, to put it mildly, unattractive. It is customary to be afraid of him, but this spider is relatively harmless: its bite is no worse than a bee's. It is common in the southwestern United States and leads more or less night image life. The main enemy of this species is a wasp from the genus Pepsis, whose name is translated from English as "big blue tarantula hawk". She paralyzes the spider with her sting and drags it into her hole to feed the larva. The bites of some tropical theraphosids are very poisonous even to humans. Members of this family often live up to 20 years.
Ctenizides. In some areas of the United States, interesting spiders from the Ctenizidae family are found. They vary in size and reach a length of 2.5 cm; the color of the massive body is dark. These spiders dig holes in the ground and line their walls with cobwebs. Characteristic such shelters - a tight-fitting door, which is very difficult to open when the spider holds it from the inside. It has been established that in this case the animal can withstand a pulling force equal to almost a pound: for a person it is equivalent to 10 tons. From time to time, ctenizids come out of the mink to hunt. Their main enemy is a type of wasp that can open the door of their lair or attack spiders when they are outside.
True tarantulas (Aviculariidae). This family includes the largest spiders in the world, attacking even chicks in the tropics. The length of their body reaches 5 cm, and the span of the legs is 18 cm.
Spiders are "lasso". Representatives of the genus Mastophora probably use the most in an unusual way catching prey. First, the spider stretches a strong thread of cobweb between the branches, usually over a stream where small midges curl. Approximately in the middle of it, he attaches a trapping thread with a heavy sticky lump at the end and holds it with his front foot. When an insect flies nearby, it swings this thread like a lasso, trying to hook the victim.
Digging spiders. Representatives of the genus Atypus weave from the web a dense tube closed at the ends with a diameter of approx. 2.5 cm, which comes out of their mink and lies on the ground, usually under a tree, continuing for a distance of about 30 cm. The spider hides inside the tube and, when a careless insect sits on it, grabs it right through the web wall.
Side walker spiders (Thomisidae). These spiders are also called crab spiders for resemblance with the latest. They are medium in size, often brightly colored, and usually hide in flowers, where they prey on insects that have flown in for nectar, such as bees.
Water spiders. In the US, relatively large spiders of the genus Dolomedes, which can run on the surface of stagnant water bodies and even dive under water, holding on to plants. These spiders feed on insects, fish fry and tadpoles. In Europe, a silver spider lives, conducting under water in places where the current is weak or absent at all, most life. This is probably the most unusual spider in the world, given that, like all members of its class, it breathes atmospheric air. In the spring, he goes under water and stretches a horizontal web of cobwebs with very small cells between the plants. Then, rising to the surface, it exposes the end of the abdomen, covered with nonwetting hairs. Between them, air is drawn in, which the spider, in the form of a bubble held by its feet, drags into the depths and shakes off under its net. It does not allow the bubbles to float and, after repeated such trips, bends like a bell the size of a thimble and even more, supported from the inside by an air chamber. The spider hides inside it, inaccessible to most enemies, immediately lays eggs, hatches juveniles and hibernates. The bells of the male and female living separately are connected to each other by a web bridge.
Venomous spiders. Spiders are commonly feared. Indeed, almost all of them are armed with poisonous claws, but only a few species are dangerous to humans. In the USA, you need to beware of two of them - " brown hermit"(Loxosceles reclusa) and" black widow "(Latrodectus mactans). The first is only 0.6 cm long. This spider lives in the Midwest, often in dwellings where it hides behind furniture. An ulcer forms at the site of its painful bite, which may never The black widow spider is found throughout most of the U.S. The bite of this species causes severe pain and can lead to death due to the neurotoxin injected into the wound.The body of the female is shiny black with bright red spots.On the underside of the abdomen usually there is a red hourglass pattern.The male is much smaller than the female, but similar in color.The name "black widow" is due to the fact that the female often eats a partner after mating, which, however, is quite common among spiders.This species is not aggressive , and spiders usually try to hide from a person, but if you pick them up, they often bite.
Spider structure.
Outdoor building. Spiders, unlike insects, do not have antennae (antennae) and jaws. The body is covered with an external skeleton (exoskeleton) and consists of two sections - the cephalothorax, formed by the merged head and chest, and the abdomen. They are connected to each other by a narrow stem. At the anterior end of the cephalothorax are simple eyes, the location of which serves as an important classification feature. Most spiders have four pairs. The cephalothorax bears six pairs of limbs. On the front of the head are two downward-pointing, jaw-like chelicerae, each ending in a sharp claw. Poison glands located in these limbs open on it. The second pair are pedipalps, used as palps and prehensile structures. In mature males, their ends are modified and are used for mating. Between the bases of the pedipalps is a small mouth opening. All spiders, unlike insects, have four rather than three pairs of walking legs. The last segment of each of them bears at least two claws, and in some species there are many more. The arachnoid glands open on the underside of the abdomen, usually with six arachnoid warts. In front of them are small respiratory openings - spiracles, or stigmas.

Internal structure. Spiders feed on liquid tissue sucked from their prey, mostly insects. Digestive system spiders consists of a specialized sucking stomach, another stomach with blind outgrowths, and an intestine surrounded by digestive gland("liver") and an anus opening at the end of the body. Circulatory system open. It consists of the heart, arteries, veins and spaces (sinuses) between organs, bathed in colorless blood (hemolymph). The heart is a pulsating tube with holes (ostia) that runs along the dorsal side of the body cavity. Unlike insects, it is not divided into several chambers. Spiders, as already mentioned, breathe air. Their respiratory organs are the trachea and lungs, called pulmonary books. Each such book consists of a bag, one of the walls of which is folded in the form of numerous leaf-like folds resembling pages. They exchange oxygen and carbon dioxide between blood and air. Outwardly, the lungs open with spiracles. The most primitive spiders have two pairs of lung books, while the more advanced ones have one or both of them replaced by tracheae penetrating the body. The excretory system consists of a pair of coxal glands in the cephalothorax and the so-called. Malpighian vessels in the abdomen that open into the intestines. Nervous system similar to that of insects. It consists of the abdominal trunk with branches extending to different organs and ganglia, collected in the cephalothorax into a large sub-pharyngeal node, above which is the supra-pharyngeal - "brain". There are sensory hairs on the pedipalps and walking legs. The reproductive organs are represented by the ovaries in females and the testes in males. Their openings are located at the bottom at the base of the abdomen.

INTERNAL STRUCTURE OF THE SPIDER. Spiders are quite close to insects, but at the same time they are clearly different from them. Their body is divided into two sections - the cephalothorax and abdomen. The cephalothorax bears six pairs of limbs: four pairs of walking legs, a pair of tactile pedipalps similar to them, which in males are modified to participate in mating, and a pair of chelicera located in front of the mouth, armed with claws with ducts of poisonous glands located right there. The digestive tract of spiders passes over their largest ganglion (subpharyngeal) and the main nerve trunks. A special sucking stomach sucks out the liquid tissues of the victim. Behind it is connected to two blind gastric tubes, bent forward and reaching the poisonous glands; on the sides of these tubes, four more pairs of blind outgrowths extend to the bases of the walking legs. They accumulate digestive juice. In the abdomen passes the intestine, into which the ducts of thin digestive tubes flow, forming the "liver". Excrement accumulates in the rectal (stercoral) sac and is excreted through the anus to the outside. The Malpighian vessels function as the kidneys.

Reproduction. Fertilization in spiders is a very complex process. After mating, the female often eats the male. The eggs are laid in a web-like cocoon, which the female carries with her or attaches to a hard object such as a plant. In some spiders, including the species Argiope aurantia mentioned above, these cocoons are clearly visible on trees, especially in winter after the leaves have fallen. Spiderlings hatched from eggs soon begin to weave their own trapping nets or settle through the air, attaching themselves to flying cobwebs.
See also INSECTS.

Collier Encyclopedia. - Open Society. 2000 .

From a scientific point of view, it is believed that spiders are animals that belong to the type of arthropods and the class of arachnids. About 42 thousand varieties of spiders can be found on the planet, including 1.1 thousand fossils. Spiders inhabit almost every corner the globe. They can be found in conditions where no living creature can live. This type of predator feeds on insects, small animal species, as well as amphibians. Among the many varieties there are spiders that feed on the green part of plants. The science that studies the life of spiders is called arachnology.

Spiders: description

These small living creatures can be found everywhere, as in natural conditions, and in a person’s dwelling, in basements, attics, in various outbuildings. Often, due to large sizes spiders are called insects, but if you imagine that in the conditions of the tropics there are representatives of arachnids up to 35 cm in size, then this is a mistake.

In fact, to be precise, spiders and insects represent animals belonging to the arthropod type. They differ only in classes and units. The answer to the question of what kind of living creatures spiders belong to is fundamentally wrong, since we can safely say that spiders are animals that represent a certain class.

To be clear! Many are accustomed to the fact that all sorts of insects are insects, and mammals are animals, which leads to some problems in determining these factors. Since the spider is distinguished by its characteristics of life, they were identified in separate class. The fact that a spider is not an insect is for sure.

The fact that spiders are defined in a separate class "arachnids" should not raise any questions. All animals of this class have a characteristic feature - their body is divided into 2 parts: the abdomen and the cephalothorax.

There is another difference that immediately catches your eye - this is the presence of 8 legs, instead of 6. Arachnids also have chelicerae, which are located in front of the cephalothorax, as well as tentacle-like pelipalps. As a rule, they are located on the sides, differ in size from the front paws, but perform the same functions: with the help of them, the spider holds its prey and moves.

It is important to know! Spiders belong to the class "arachnids" and represent a species of arthropods.

Spiders stand apart, as they have a number characteristic differences, not characteristic of other species of animals or insects in the concept that people have. These differences come down to certain forms of life activity, such as reproduction, nutrition, size, and so on. These differences are also characteristic of other representatives of this family, depending on the species or subspecies.

To characteristic features spiders should include:

The body consists of two parts: the abdomen, various shapes, depending on the species and cephalothorax.
The presence of 4 pairs of legs, 2 chelicerae and pelipalps is characteristic.
Spiders don't have whiskers.
Their feature is the weaving of a web for various purposes, and the pattern of the web can be unique.
Spiders have poisonous glands, the poison of which paralyzes the victim.
Spiders lead a solitary lifestyle. Most females, after fertilization, eat their chosen ones.

Arachnids can be found in almost all corners of our planet. There are also exotic species that are not dangerous to humans and are kept as pets.

Science also knows species that are dangerous to humans, since their bite can be fatal. Usually, similar species inhabit the tropics and other, hotter areas, such as the desert, for example. In our places poisonous spiders are extremely rare. The main types of spiders are real orderlies who fight daily with many insects that are sometimes dangerous to humans. Naturally, the appearance of spiders in a person's home is perceived extremely negatively by family members. This negative reaction is exacerbated by the intimidating appearance spiders, but in fact, most of the species are practically harmless to others.

Not only inquisitive schoolchildren, but also many adults are interested in the question: is a spider an insect or not? Indeed, at first glance it may seem that the answer is obvious, and spiders are one of the varieties of insects, but this is not so. They belong to a separate class of arachnids, because they have a lot of differences with insects.

Spiders appeared on our planet a very long time ago, about 400 million years ago. It is believed that they originated from a crab-like ancestor. Insects appeared almost 100 million years later and created a separate class. Today, about 40 thousand species of arachnids live on earth. If we consider in detail the anatomy of these creatures, then questions like "A spider is an insect or not?" should not occur. Everyone knows that insects have six legs, but arachnids have eight, besides they have eight eyes, only some species have six or two. These creatures have no teeth, but there are hook-shaped jaws with special channels designed to penetrate the poison into the body of the victim.

Doubts about whether a spider is an insect or not will disappear immediately if we consider how it eats. If praying mantises eat caught flies, then arachnids cannot do this, because they have extraintestinal digestion. They inject digestive enzymes into the victim, which turn the insect into soup, and the spiders can only suck out the contents of the shell.

Many creatures know how to spin a web, but they will not make it as strong and elastic as the prey trap that a spider prepares. Reproduction also causes these creatures to weave special cocoons to keep their eggs and little spiders laid. If we compare the web with steel, then the first will be five times stronger than the second, and the pencil-thick threads will not be able to break through the plane that crashed into the network.

It is not clear why many think about the question of whether a spider is an insect or not: there are a significant number of differences between these two classes. The body of these creatures is divided not into three, but only into two sections: the abdomen and the cephalothorax. They make a web from a fluid secreted from warts located at the end of the belly. From this material, spiders build houses for themselves, make a flying carpet on which they travel long distances, weave cocoons for eggs, and hunt insects with nets.

These creatures are quite nimble in their webs, while mosquitoes, flies and other unfortunates just stick to it. The fact is that spiders weave sticky and non-sticky threads, the first ones are needed to catch the victim, and they move along the second ones. Even if they accidentally get on the sticky part, they will not get confused, since their body has a fatty coating.

Modern science has already given an exact answer to the question: "Is a spider an insect or not?", highlighting these creatures in a separate class. AT middle lane There are no arachnids dangerous to human life in Russia, although it is necessary to be careful with them. The spider will never attack first, it only defends itself or bites when frightened. A bite can only be accompanied by burning, severe pain and fever. But there is also dangerous representatives of this species: the most famous are the tarantula and karakurt. Their bite causes general poisoning of the body, which sometimes leads to death.