Spiny orb-weaving spider or “horned spider” (lat. Gasteracantha cancriformis). What you need to know about the karakurt spider? Metallic arboreal tarantula

Spider (Araneae) belongs to the phylum arthropod, class Arachnida, order Spiders. Their first representatives appeared on the planet approximately 400 million years ago.

Spider - description, characteristics and photographs

The body of arachnids consists of two parts:

• The cephalothorax is covered with a shell of chitin, with four pairs of long jointed legs. In addition to them, there is a pair of claws (pedipalps), used by mature individuals for mating, and a pair of short limbs with poisonous hooks - chelicerae. They are part oral apparatus. The number of eyes in spiders ranges from 2 to 8.
• Abdomen with breathing holes located on it and six arachnoid warts for weaving webs.

The size of spiders, depending on the species, ranges from 0.4 mm to 10 cm, and the span of their limbs can exceed 25 cm.

The coloring and pattern on individuals of different species depend on the structural structure of the integument of scales and hairs, as well as the presence and localization of various pigments. Therefore, spiders can have either a dull solid color or bright color various shades.

Types of spiders, names and photographs

Scientists have described more than 42,000 species of spiders. About 2,900 varieties are known in the CIS countries. Let's consider several varieties:

• Blue-green tarantula (Chromatopelma cyaneopubescens)

one of the most spectacular and beautifully colored spiders. The tarantula's abdomen is red-orange, its limbs are bright blue, and its carapace is green. The size of the tarantula is 6-7 cm, with a leg span of up to 15 cm. The spider’s homeland is Venezuela, but this spider is found in Asian countries and in African continent. Despite belonging to tarantulas, this type of spider does not bite, but only throws special hairs located on the abdomen, and only in case of severe danger. The hairs are not dangerous for humans, but they cause minor burns on the skin, similar in effect to nettle burns. Surprisingly, female chromatopelma are long-lived compared to males: the lifespan of a female spider is 10-12 years, while males live only 2-3 years.

• Flower spider (Misumena vatia)

belongs to the family of side-walking spiders (Thomisidae). Color varies from absolutely white to bright lemon, pink or greenish. Male spiders are small, 4-5 mm long, females reach sizes of 1-1.2 cm. The species of flower spiders is distributed throughout European territory (excluding Iceland), and is found in the USA, Japan, and Alaska. The spider lives in open areas with an abundance of flowering herbs, as it feeds on the juices of butterflies and bees caught in its “embraces”.

• Grammostola pulchra (Grammostola Pulchra)

Sidewalk spiders (crab spiders) most They spend their lives sitting on flowers waiting for prey, although some members of the family can be found on the bark of trees or the forest floor.

Representatives of the family of funnel-web spiders place their webs on tall grass and branches of bushes.

Wolf spiders prefer damp, grassy meadows and swampy wooded areas, where they are found in abundance among fallen leaves.

The water (silver) spider builds a nest underwater, attaching it to various bottom objects with the help of webs. He fills his nest with oxygen and uses it as a diving bell.

What do spiders eat?

Spiders are quite original creatures that eat very interestingly. Some types of spiders may not eat for a long time - from a week to a month or even a year, but if they start, there will be little left. Interestingly, the weight of food that all spiders can eat during the year is several times greater than the weight of the entire population living on the planet today.
How and what do spiders eat? Depending on the species and size, spiders forage and eat differently. Some spiders weave webs, thereby organizing clever traps that are very difficult for insects to notice. Digestive juice is injected into the caught prey, corroding it from the inside. After some time, the “hunter” draws the resulting “cocktail” into his stomach. Other spiders “spit” sticky saliva while hunting, thereby attracting prey to themselves.

The main diet of spiders is insects. Small spiders happily eat flies, mosquitoes, crickets, butterflies, mealworms, cockroaches, and grasshoppers. Spiders that live on the soil surface or in burrows eat beetles and orthoptera, and some species are able to drag a snail or earthworm and eat them there in peace.

The queen spider hunts only at night, creating a sticky web bait for unwary moths. Noticing an insect next to the bait, the queen spinner quickly swings the thread with her paws, thereby attracting the attention of the prey. The moth happily hovers around such a bait, and having touched it, it immediately remains hanging on it. As a result, the spider can calmly attract it to itself and enjoy its prey.

Large tropical tarantula spiders happily hunt small frogs, lizards, other spiders, mice, including bats, as well as small birds.

And this type of spider Brazilian tarantulas, can easily hunt small snakes and snakes.

Aquatic species of spiders get their food from the water, catching tadpoles with the help of a web, small fish or midges floating on the surface of the water. Some spiders, which are predators, due to the lack of victims, can also get enough of plant food, which includes pollen or plant leaves.

Haymaking spiders prefer cereal grains.

Judging by numerous notes by scientists, a huge number of spiders destroy small rodents and insects several times more than the animals living on the planet.

How does a spider weave a web?

In the back of the spider's abdomen there are from 1 to 4 pairs of arachnoid glands (arachnoid warts), from which a thin thread of web stands out. This is a special secret, which today many call liquid silk. Coming out of thin spinning tubes, it hardens in air, and the resulting thread turns out to be so thin that it is quite difficult to see with the naked eye.

In order to weave a web, the spider spreads its spinning organs, and then waits for a light breeze so that the spun web catches on a nearby support. After this happens, he moves along the newly created bridge with his back down and begins to weave a radial thread.

When the base is created, the spider moves in a circle, weaving thin transverse threads into its “product”, which are quite sticky.

It is worth noting that spiders are quite economical creatures, so they absorb damaged or old webs, after which they reuse them.

And the web becomes old very quickly, since the spider weaves it almost every day.

Types of web

There are several types of webs, differing in shape:

• The orb web is the most common type, with the minimum number of threads. Thanks to this weaving, it turns out to be unnoticeable, but not always elastic enough. From the center of such a web radial threads-webs diverge, connected by spirals with a sticky base. Usually round spider webs are not too large, but tropical tree spiders are capable of weaving similar traps that reach two meters in diameter.

• Cone-shaped web: This type of web is made by the funnel-web spider. Usually it creates its hunting funnel in tall grass, while it itself hides in its narrow base, waiting for prey.

• The zigzag web is its “author”, a spider from the genus Argiope.

• Spiders from the family Dinopidae spinosa weave a web directly between their limbs, and then simply throw it onto an approaching victim.

• Spider Bolas ( Mastophora cornigera) weaves a thread of web on which there is a sticky ball with a diameter of 2.5 mm. With this ball, impregnated with female moth pheromones, the spider attracts prey - a moth. The victim falls for the bait, flies closer to it and sticks to the ball. After which the spider calmly pulls the victim towards itself.

• Darwin's spiders ( Caerostris darwini), living on the island of Madagascar, weave giant webs, the area of ​​which ranges from 900 to 28,000 square meters. cm.

The web can be divided according to the principle of responsibility of its weaving and type:

• household - from such webs spiders make cocoons and so-called doors for their homes;
• strong - spiders use it to weave nets, with the help of which the main hunt will be carried out;
• sticky - it is used only for preparing jumpers in fishing nets and sticks so strongly when touched that it is very difficult to remove.

Spider Reproduction

As spiders grow, from time to time they shed their tight chitinous shell and acquire a new one. They can molt up to 10 times in their entire life. Spiders are dioecious, with the female being much larger than the male. During the mating season, which lasts from mid-autumn to early spring, the male fills the bulbs located at the ends of his pedipalps with sperm and goes in search of a female. After performing the “mating dance” and fertilization, the male spider hastily retreats and dies after some time.

After two and a half months, the female spider lays eggs, and after 35 days small spiderlings appear, living in the web until the first molt. Females reach sexual maturity at 3-5 years of age.

Among spiders, only poisonous ones pose a danger to humans. In the CIS countries there is one such species - the karakurt, or black widow.

With a timely injection of a special serum, the bite goes away without consequences.

IN Lately It has become fashionable to keep spiders at home. For beginners, we recommend the white-haired tarantula spider, which is a harmless representative of the arachnid class.

• According to statistics, 6% of the world's population suffers from arachnophobia - the fear of spiders. Particularly sensitive people panic when they see a spider in a photo or on TV.
• Frightening-looking tarantula spiders, with a paw span of up to 17 cm, are actually calm and non-aggressive, thanks to which they have earned the reputation of popular pets. However, owners must protect their pets from stress, otherwise the spider sheds its bright hairs, which cause an allergic reaction in humans.
• The most poisonous spiders are considered to be black widows, their variety is karakurt, as well as Brazilian soldier spiders. The venom of these spiders, containing powerful neurotoxins, instantly attacks lymphatic system victims, which in most cases leads to cardiac arrest.
• Many people mistakenly believe that tarantula venom is fatal to humans. In reality, a tarantura bite causes only a slight swelling, similar to a wasp sting.
• Wall crab spiders, named Selenopidae in Latin after the Greek goddess of the Moon, move sideways as well as backwards.
• Jumping spiders are excellent jumpers, especially over long distances. As a safety net, the spider attaches a silk web thread to the landing site. In addition, this type of spider can climb glass.
• When chasing prey, some species of spiders can run almost 2 km in 1 hour without stopping.
• Fishing spiders have the ability to glide across water like water striders.
• Most species of spiders have an individual form of woven web. House (funnel) spiders weave webs in the shape of a funnel; dictine weaver spiders are characterized by angular webs. The web of Nicodam spiders looks like a sheet of paper.
• Lynx spiders are distinguished by a property that is uncharacteristic of spiders: to protect the clutch, females spit on the threat of poison, although this poison does not pose a danger to humans.
• Female wolf spiders are very caring mothers. Until the children gain independence, the mother “carries” the cubs on herself. Sometimes there are so many spiders that only its 8 eyes remain open on the spider’s body.
• The New Zealand cellar spider was immortalized in cinema thanks to director Peter Jackson, who used this species as the prototype for the spider Shelob.
• Very beautiful flower spiders lie in wait for prey on flowers, and adult females, as a camouflage, change their color depending on the color of the petals.
• The history of mankind is closely intertwined with the image of the spider, which is reflected in many cultures, mythology and art. Each nation has its own traditions, legends and signs associated with spiders. Spiders are even mentioned in the Bible.
• In symbolism, the spider personifies deceit and immeasurable patience, and the spider’s venom is considered a curse that brings misfortune and death.

Spiny or horned orb weaving spider - Gasteracantha cancriformi.

This small spider has many names - spiny spider, spiny orb spider, horned spider, etc. The thing is that along the edges of its wide abdomen there are 6 spines (“horns”), which give the spider a rather threatening appearance. appearance.

These spiders are common in tropical and subtropical zones. They can be found in the southern part of the USA (from California to Florida), in Central America(Jamaica, Cuba, Dominican Republic), South America, in the Bahamas, as well as in Australia and the Philippines. As we can see, their habitat is quite extensive. They weave their nets in bushes and trees near swamps and streams.

The appearance of the spider is very unusual. The spider is wider than it is long. So the length of the female’s body is 5-9 mm, and the width is 10-13 mm. These spiders have pronounced sexual dimorphism, i.e. females are several times larger than males. Their body length is only 2-3 mm. Unlike many species of spiders, the horned spider has short legs.

Spiny spiders attract attention not only with their unusual body proportions, but also with the variegated coloring of their abdomen. It can be white, bright yellow, red, black, etc. Their colors depend on the species and habitat. The legs, shield and lower part of the abdomen are black with white spots under the belly. In males, the lower part of the abdomen is gray with white spots.

On the outer part of the abdomen there is a peculiar pattern of black dots, which are arranged in 4 rows. All of them have a mirror arrangement according to the vertical axis of the body.

There are six spines along the edge of the abdomen. They are also called "backbones". They can be black or red. In males they are not so pronounced, and their number may be less - 4-5 spines. They give the spider a more intimidating appearance, which helps scare off potential enemies. Otherwise they may become quite delicious snack. In addition, hard thorns make it difficult to swallow their owner.

They feed on small insects that they catch in their nets. The spider trap is a fairly strong net, reaching a diameter of 30 centimeters. It has practically perfect shape circle, in the middle of which there is a thin network. It serves as a base for the spider. Only females weave webs. The males are located nearby, hanging on several threads.

It is interesting that if these spiders live in a small group, then the caught prey is divided among everyone, regardless of whose net it fell into. But most often they live alone.

As for the reproductive process, scientists still do not understand whether these spiders are polygamous or monogamous (the female mates with one male or several). In nature, sometimes you can see females with up to 3 hanging males around the web.

The male notifies the female of his presence by making peculiar taps on the network. After fertilization, he dies 6-7 days later, unless he becomes the female’s lunch immediately after mating.

The female begins to weave a cocoon on inside leaf near the web, into which it then lays from 100 to 260 eggs. After this, she also dies. Thus, the life expectancy of these spiders is short: for males - up to 3 months, for females - up to a year. Spiders are born in winter. They grow up in 2-5 weeks and scatter in different directions.

The bite of this spider can be painful, but not dangerous. There may be slight redness and swelling at the site of the bite.

Spiders live everywhere to the globe, but in warm regions there are the most species. Almost all spiders are terrestrial animals. The exception is the silverback spider, which lives in water. A number of spider species hunt on the surface of the water. Some spiders build nests, shelters and burrows, while others do not permanent place a habitat. For the most part, spiders are nocturnal animals.

Description

Arachnida (Arachnida) is a class of arthropods that includes spiders, mites, scorpions and other lesser-known subtypes of chelicerates. Scientists estimate that more than 100,000 species of arachnids live on the planet today. Arachnids have two main body sections (the cephalothorax and abdomen) and four pairs of legs. Arachnids differ from insects in that they lack wings and antennae.

It should be noted that some orders of arachnids, for example, mites and ricinules, have only three pairs of legs in the larval stage, and the fourth appears in the nymphal stage. Arachnids have an exoskeleton that periodically moults to allow the animal to grow. In addition to four pairs of legs, they have two additional pairs of appendages (chelicerae and pedipalps) which they use for various purposes such as feeding, defense, locomotion, reproduction or perception. environment. Most arachnid species are terrestrial animals, although some representatives (especially mites) live in fresh and sea water.

Internal construction

In internal structure arachnids secrete nervous, respiratory, digestive, excretory, reproductive system, special venom-bearing and spinning organs. Organization nervous system relatively complex and different different types. Its main feature is the abdominal nerve chain and the brain, which has anterior and posterior sections.

The respiratory organs are tracheas and pulmonary sacs in spiders; representatives of other orders may have only tracheas or exclusively pulmonary sacs, which open on the underside of the abdomen with respiratory openings. Tracheas are tubes that penetrate the body of the animal and are adapted for air gas exchange.

The digestive system consists of the esophagus, stomach and hindgut, ending in the cloaca. The ducts of the excretory Malpighian glands flow into the cloaca. All arachnids are dioecious, fertilization is internal, and development is direct. Most species are oviparous, only a few are viviparous. Many arachnids have venom glands and/or arachnoid glands. The latter release liquid, which is drawn into a thread and quickly hardens. Spiders build a fishing net from webs or line their burrows with it.

Types of spiders

Scientists have described more than 42,000 species of spiders. About 2,900 varieties are known in the CIS countries. Let's consider several varieties:

• Blue-green tarantula (lat. Chromatopelma cyaneopubescens)– one of the most spectacular and beautifully colored spiders. The tarantula's abdomen is red-orange, its limbs are bright blue, and its carapace is green. The size of the tarantula is 6-7 cm, with a leg span of up to 15 cm. The spider’s homeland is Venezuela, but this spider is found in Asian countries and on the African continent. Despite belonging to tarantulas, this type of spider does not bite, but only throws special hairs located on the abdomen, and only in case of severe danger. The hairs are not dangerous for humans, but they cause minor burns on the skin, similar in effect to nettle burns. Surprisingly, female chromatopelma are long-lived compared to males: the lifespan of a female spider is 10-12 years, while males live only 2-3 years.

• Flower spider (lat. Misumena vatia) belongs to the family of side-walking spiders (Thomisidae). Color varies from completely white to bright lemon, pink or greenish. Male spiders are small, 4-5 mm long, females reach sizes of 1-1.2 cm. The species of flower spiders is distributed throughout European territory (excluding Iceland), and is found in the USA, Japan, and Alaska. The spider lives in open areas with an abundance of flowering herbs, as it feeds on the juices of butterflies and bees caught in its “embraces.”

• Grammostola pulchra (lat. Grammostola Pulchra)- a type of tarantula spider that natural environment lives only in Uruguay and southern regions Brazil. A rather massive spider, reaching a size of 8-11 cm, with a dark color and a characteristic “metallic” sheen of hairs. In nature, it prefers to live among the roots of plants, but almost never digs its own burrows. Pulhra often becomes a pet among connoisseurs of exotic pets.

• Argiope Brünnich or wasp spider (lat. Argiope bruennichi) – a spider with an unusual coloring of the body and limbs - yellow, black and white stripes, for which it received its name. True, the male wasp spiders are not so bright, and they are smaller in size than the females: the “young ladies” reach a size of 2.5 cm, and together with the legs - 4 cm, but the male rarely grows more than 7 mm in length. The species is widespread in Europe, Asia and southern Russia, in the Volga region and in North Africa. The Argiope spider lives in meadows with an abundance of grass, on the edges of forests. The web of the argiope is very strong, so it is difficult to tear it, it will only stretch under pressure.

• Hunter bordered (lat. Dolomedes fimbriatus) widespread on the Eurasian continent and found along the shores of bodies of water with standing or very slowly flowing water. Often settles in marshy meadows, shady forests or gardens with high humidity. The body length of the female edge hunter varies from 14 to 22 mm, the male is smaller and rarely larger than 13 mm. The color of spiders of this species is usually yellowish-brown or almost black, with light yellow or white stripes on the sides of the abdomen.

• Apulian tarantula (lat. Lycosa tarantula)– a species of spider belonging to the family of wolf spiders (lat. Lycosidae). Lives in the open spaces Southern Europe: often found in Italy and Spain, digs burrows half a meter deep in Portugal. The size of the tarantula is impressive - up to 7 cm in length, individuals are usually colored red, less often - brown, with several transverse stripes on the body light color and one longitudinal.

• Spiny orb-weaving spider or "horned spider" (lat. Gasteracantha cancriformis) distributed in the tropics and subtropics, in the southern part of the USA, Central America, the Philippines, and Australia. The size of the female is 5-9 mm, the width reaches 10-13 mm. Males are 2-3 mm long. The legs of the spiny spider are short, and there are 6 spines along the edges of the abdomen. The color of the spider is very bright: white, yellow, red, black. On the abdomen there is a pattern of black dots.

• Peacock spider (lat. Maratus volans). This spider comes in all sorts of colors: red, blue, light blue, green, yellow. The coloring of females is paler. An adult reaches a size of 4-5 mm. Males attract females with their beautiful outfit. The peacock spider lives in Australia - in Queensland and New South Wales.

• Smiling spider (lat. Theridion grallator) or a spider with a happy face is completely harmless to humans. This one lives unusual spider on the Hawaiian Islands. Its body length is 5 mm. The color of the spider can be varied - pale, yellow, orange, blue. This species feeds on small midges, and bright color individuals help confuse enemies, especially birds.

• Black Widow (lat. Latrodectus mactans)- it is very dangerous and poisonous species spiders Lives in Australia North America, and is also found in Russia. The size of females reaches 1 cm, males are much smaller. The body of the black widow is black, and on the abdomen there is a characteristic red spot in the form hourglass. Males are brown with white stripes. A black widow's bite is deadly.

• Karakurt (lat. Latrodectus tredecimguttatus)- This is a type of deadly poisonous spider from the black widow genus. The female karakurt has a size of 10-20 mm, the male is much smaller and has a size of 4-7 mm. There are 13 red spots on the abdomen of this scary spider. In some varieties, the spots have borders. Some mature individuals are spotless and have a completely black shiny body. The karakurt lives in Kyrgyzstan, the Astrakhan region, the countries of Central Asia, southern Russia, Ukraine, the Black Sea and Azov regions, southern Europe, and North Africa. Karakurt was also spotted in the Saratov region, Volgograd region, Orenburg region, Kurgan region, and in the south of the Urals.

Lifestyle

All arachnids, with the exception of some mites, are carnivores, usually eating insects and other small animals, which they in most cases catch alive. Only the liquid tissues of the prey are sucked out (external digestion), no solid particles are ingested. Most arachnids are armed with venom glands, although only a few are dangerous to humans.

Of the spiders in the United States, the most poisonous species is the “black widow” ( Latrodectus mactans) and those close to him; their bite is very painful and sometimes leads to death. Some large tropical tarantulas are considered dangerous, but the bites of members of this group living in the southern and western United States are generally comparable to the sting of a wasp. Scorpions, of which only a few are highly poisonous, inflict painful stings with a poisonous sting at the end of their tail. Contrary to popular belief, the large nymphs found in the southwestern United States are not venomous. Some ticks carry pathogens, such as Rocky Mountain fever.

Arachnids, like insects, live everywhere. They are distributed up to 80° N, to the altitudinal limit of life in the mountains, and are even found in the air, thousands of meters above the ground, where they are carried by the wind along with pieces of cobwebs.

Nutrition

The front part of the arachnids' intestine (the pharynx), with strong muscles, acts as a pump. The midgut usually has lateral protrusions, increasing its capacity. Liver secretion and salivary glands arachnids breaks down proteins. It is injected into the body of killed prey and turns its contents into a semi-liquid state, and then such food is absorbed through the pharynx (this method is called extraintestinal digestion).

Spider Reproduction

As spiders grow, from time to time they shed their tight chitinous shell and acquire a new one. They can molt up to 10 times in their entire life. Spiders are dioecious, with the female being much larger than the male. During the mating season, which lasts from mid-autumn to early spring, the male fills the bulbs located at the ends of his pedipalps with sperm and goes in search of a female. After performing the “mating dance” and fertilization, the male spider hastily retreats and dies after some time.

After two and a half months, the female spider lays eggs, and after 35 days small spiderlings appear, living in the web until the first molt. Females reach sexual maturity at 3-5 years of age.

Among spiders, only poisonous ones pose a danger to humans. In the CIS countries there is one such species - the karakurt, or black widow. With a timely injection of a special serum, the bite goes away without consequences.

How do spiders weave webs?

All spiders weave webs. It is used not only for hunting, but also for movement, creating smooth walls in burrows, and building egg sacs. Most spiders have four openings on their abdomen called spinnerets. When a spider releases a web, it appears to consist of a single thread.

In fact, one web consists of many thin threads glued together with a special liquid. Once this liquid enters the air, it hardens. Many spiders use the web thread to climb back into the hole.

Different species of spiders have different webs. It may be sticky, dry, or rubbery. The threads of the web are so strong that some spiders use it to travel many kilometers through the air. Spiders can eat their web if they no longer need it and begin to weave a new one.

Male spiders are smaller in size than females. During mating, males must be very careful. The female may not accept courtship and decide to simply eat her partner. Even if mating has occurred, the female can attack later, so males usually try to retreat faster. But this doesn't happen too often.

Spiders lay from 2 to 1000 eggs depending on the species. Almost all females spin a web and place the eggs in a "blanket", then hang the sacs somewhere safe and guard it. When the little spiders hatch, they often stay inside the sac to grow a little more. Some females immediately leave the egg sacs unattended and do not monitor them.

What is arachnophobia?

Arachnophobia, which is the name given to the fear of arachnids, is a completely new disease, manifests itself as special case isectophobia (fear of insects in general). Since ancient times, man has experienced fear of the unknown, of something unlike him. A certain fear of insects is inherent in every person on an instinctive level. We are all initially afraid of what seems to us unidentified and unexplored. Someone, having learned more about spiders, ceases to be afraid of them, realizing the harmlessness of most species. And some people remain with their insectophobia for a long time; spiders begin to seem like something that poses a huge danger and threat.

Arachnophobia is very common, affecting almost half of all women and a fifth of all men. Scientists suggest that fear of spiders is so common in women because they are more sensitive to tactile sensations and have more sensitive skin. The sensation of being touched by an insect leaves a greater impression on them, which plays into their fears.

Arachnophobia is often combined in a person with other fears:

• myrmecophobia – fear of ants;
• blattophobia – fear of cockroaches;
• Lepidopterophobia – fear of butterflies.

All these fears have the same root causes; often they are not separated, but are generalized into one disease - insectophobia (fear of insects is also called entomophobia).

Causes of phobia

Arachnophobia is a disease that is very common in the modern world. This is due to the large number of urban residents. This part of the population rarely comes into contact with spiders, which is why it is not always possible to distinguish a dangerous species from a harmless one.

The practical significance of spiders, given the current level of our knowledge about them, actually comes down to the harm they cause poisonous bites some forms. However, many spiders are undoubtedly useful as exterminators of harmful insects, but this role has not yet been accurately assessed. There are also some prospects for the technical use of spiders.

The biological significance of spider venom is mainly to kill prey, so the venom is usually toxic to insects. There are few species of spiders whose venom has a strong effect on warm-blooded animals, but among them there are some that are extremely dangerous for humans and domestic animals. According to the nature of the poisoning caused poisonous spiders are different. The venom of some causes mainly local necrotic reactions, that is, necrosis and destruction of the skin and deeper tissues in the bite area. The poison of others has a strong effect on the entire body, in particular on the nervous system.

The death of people and domestic animals bitten by some large tropical tarantulas has been noted more than once, but the poisonousness of most of these spiders has not been precisely determined. Among them, Phormic-topus has poison in its venom glands that is sufficient to kill 20 mice. It is known that the Bushmen in South Africa They used the venom of spiders from this genus, mixed with the juice of amaryllis bulbs, to poison arrows.

The venom of the spider Mastophora gasteracanthoi-des (family Araneidae), found in Peru, has a strong necrotic effect, where it infects people involved in caring for vineyards. The bitten person feels a sharp pain, then severe swelling appears and subsequently tissue destruction occurs in the affected area, so that the internal organs. Death, noted in a number of cases, probably occurred from secondary wound infection. A similar picture is caused by the bite of the Brazilian Lycosa gar-toria (family Lycosidae).

The general effect on the body is characteristic of the venom of the Brazilian Ctenus nigrivent-ris (family Ctenidae), whose bites are dangerous. Even more dangerous is the small (4–5 mm) racer Dendjyphantes noxiosus, found in Bolivia. Its bite causes inflammation and severe pain, as if from a hot iron; Blood appears in the urine, and death occurs within a few hours.

Very strong general action possesses the venom of spiders of the genus Latrodectus (family Theridiidae), which includes the karakurt (L. tredecimguttatus), found in our desert and steppe zone in Central Asia, the Caucasus, Crimea and also common in Iran, Afghanistan and along the coasts Mediterranean Sea. In America, an equally poisonous species of the same genus is widespread - L. mactans, which there received the name “black widow”. Other species are found in tropical countries.

The most terrible spiders in the world

Yellow (Golden) Sak

The main habitat is Europe. Do not grow more than 1 cm in volume. The color is golden, translucent. Yellow Sak can crawl around in a residential building for quite a long time, while remaining unnoticed, because its nondescript appearance and small dimensions allow this. IN natural conditions he always builds himself a house that looks like a pipe bag. A necrotic wound causing severe pain is guaranteed from the bite of this animal. These symptoms are very similar to the effects of violin spider venom. Saki are prone to self-defense; they attack only when they feel in danger.

Wandering Brazilian spider

It was no coincidence that this nickname was given– constantly change their location in search of prey. These spiders live mainly in South America. This species is considered one of the most dangerous. The wanderers already have quite impressive volumes - about 10 cm. The amount of poison contained in one individual is enough to kill 225 mice. An antidote to it already exists. But its bite, one way or another, will lead the human body to a severe allergic reaction.

The Wanderer is difficult to notice in nature due to its discreet sandy coloring. As funny as it may sound, it is usually found in baskets of bananas, which is why it got the nickname “banana”. The wanderer chooses prey that is an order of magnitude larger than its own size - these can be birds, lizards, or even other arachnids.

Brown recluse (violin)

This type poses a very great danger to humans, since after a bite the poison disperses throughout the body in just one day. If the victim is not hospitalized in time, the outcome will be very disastrous. This spider, like the Yellow Sac, will not attack first unless it feels a threat to itself, but in any case, contact with it should be avoided.

Hermits grow to a maximum of 2 cm, and usually hide in dry and dark places. They can be found in California and other US states. This species can be distinguished by its characteristic shaggy “antennae”; they also have only 3 pairs of eyes, unlike most spiders, which have 4 pairs, i.e. 8 eyes.

Black Widow

As mentioned earlier, the most dangerous spider on earth is female black widow. Its poison is deadly. In size, like the hermit, it can reach a maximum of 2 cm. It is easy to recognize: black, with small spots on the back. And a widow, because after mating she takes the life of her partner. By comparison, poison rattlesnake 15 times less more dangerous than poison this terrible arthropod. The female's bite is so dangerous that if the victim is not injected within half a minute, death may well occur. Black widows are not limited to one country; they can be found in deserts all over the globe.

Tarantula (Tarantula)

Found in desert and steppe areas where they dig deep holes for themselves. Nature has endowed this species with a unique beauty. Its body is colored gray, brown, and orange. Sometimes striped individuals are found. Unlike hermits, tarantulas are completely furry. They usually grow up to 3-4 cm. It has a second name - tarantula, as it feeds on small birds. They hunt at night thanks to their excellent night vision.

Water spiders

Their usual home is ponds in Northern Asia and Europe. They do not grow more than 1.7 cm. They swim very well, which is why they have this name. They live underwater, where they weave their nets in the algae. They eat a variety of small aquatic life. Its poison is absolutely not dangerous for humans, but it looks scary.

Crab spider

There are over 3 thousand species in the world. They are large in size and have a wide variety of colors, which, oddly enough, are similar to their habitat. They are like chameleons and can blend into almost any surface, be it greenery or sandy terrain.

Rooted in three places:

• Southern Europe
• North America

Crab spiders do not pose a strong threat to people, but they are often mistaken for poisonous hermits, so they are truly feared no less than others dangerous species. They were named after crabs, as they are similar in appearance and very mobile, like these decapod crustaceans. Like Brazilian spiders, they do not weave webs, but prefer to hunt. I can only move backwards and to the sides.

Wall tegenaria

Quite a rare species today, however, the most close-up view in Europe. Its dimensions range from 12.5 to 16 cm in straightened limbs.

The abode of this spider is as follows:

• Uruguay
• North Africa
• central Asia

You can accidentally stumble upon tegenaria in caves or old buildings. In England, this spider was called “cardinal”: according to legend, the once-living Cardinal Wolsey, seeing this spider, experienced a very strong fright. Tegenaria move very quickly. The structure of their web is very thick, so the caught insects have practically no chance of escape.

Cerbal Arabian

It was first found at the end of 2010 in Israel. It can be found in sand dunes. It has a large, silver-gray body with distinctive stripes on its legs. The coloring is quite scary. To date, little is known about their lifestyle. According to scientists, they are especially active during the hottest time of the year.

Giant baboon spider

Has a second name – Red Cameroon. The length of the body is 10 cm, and the legs are approximately 20 cm, which in general gives the spider a size of as much as 30 cm. The baboon spider belongs to the tarantula family and loves subtropical forests.

Quite a few colors predominate in color:

• orange
• grey
• brown
• black

Its legs, unlike its body, are covered with small hairs. The diet is quite large, it can feed on insects, but will not refuse mice and other similar living creatures. It injects a killing poison into its prey.

Of all the above, the title of the most deadly spider on earth was awarded to the “Black Widow”. The title of the most terrible, without a doubt, belongs to the wandering Brazilian spider.

The spiny spider (Gasteracantha cancriformis) belongs to the arachnids.

Spread of the spiny spider.

The spiny spider is distributed in many parts of the world. It is found in the southern United States from California to Florida, as well as Central America, Jamaica and Cuba.

Habitats of the spiny spider.

The spiny spider is found in forests and bush gardens. Many individuals inhabit citrus groves in Florida. They often live in trees or around trees and bushes.

External signs of a spiny spider.

The sizes of female spiny spiders range from 5 to 9 mm in length and from 10 to 13 mm in width. Males are small, 2 to 3 mm long and slightly smaller in width. Six spines are present on the abdomen. The color of the chitinous cover depends on the habitat. The spiny spider has white spots on the underside of the abdomen, but the color of the back may be red, orange or yellow. In addition, some individuals have colored limbs.

Reproduction of the spiny spider.

Mating in spiny spiders has only been observed in laboratory conditions, where there was one female and one male. It is assumed that mating occurs in the same way in nature. However, scientists are not sure that these spiders are a monogamous species.

Laboratory research mating behavior show males visit female webs and use a 4-fold vibrating rhythm on the silk web to attract a female. After several cautious approaches, the male approaches the female and mates with her.

Mating can last 35 minutes, then the male remains on the female's web.

The spider lays 100 - 260 eggs, and then dies. In order for the eggs to develop, the female creates a cobweb cocoon. The cocoon is located on the underside, sometimes on the top side of a tree leaf, but not on the trunk or the top of a branch. The cocoon is oblong in shape and made of loosely woven thin threads that are firmly attached to the underside of the leaves with a strong disc. The eggs are contained in a loose, spongy, tangled mass of yellow and white threads, attached on one side to a disk. The top of the cocoon is covered with a layer of several dozen coarse, hard, dark green threads.

These threads form various longitudinal lines on the body of the cocoon. The structure is completed by a covered mesh canopy located above the cobweb mass, connected to the leaf. The eggs develop during the winter. The hatched spiders learn to move correctly for several days, then disperse in the spring. Young females spin webs and lay eggs, while males are needed only for fertilization. Both males and females are able to reproduce between 2 and 5 weeks of age.

This type of spider does not live in nature for very long. In fact, they live only until breeding, which usually takes place in the spring after winter. Females die immediately after weaving a cocoon and laying eggs, and males die after six days.

Peculiarities of behavior of the spiny spider.

Spiny spiders build their hunting web every night, testing the strength of the web threads. They weave webs mainly on adult females, because males usually sit on one web thread of the female's nest. The spider hangs on the web below, waiting for her prey. The network itself consists of a base warp, which consists of a single vertical thread. It connects to the second main line or along the main radius. In both cases, the structure is pulled into a corner, forming three main radii. Sometimes there are more than three main radii in a network.

After creating the base, the spider constructs an external network arranged in a spiral.

All spider threads are connected to the central disk. There is a difference between the thickness of the main and secondary threads.

Feeding of the spiny spider.

Female spiny spiders build webs that they use to capture prey. The female sits in the web, waiting for prey on the central disk.

When a small insect gets caught in a web, it rushes towards it, feeling the hesitation of the victim.

Having determined its exact location, it bites, injecting a toxic substance. The female then transfers the paralyzed prey to the central disc. If the prey is smaller in size than the spider, it simply paralyzes it and then sucks out the contents without packaging it in the web. If the caught prey is larger than the spider, then packaging and moving to the central disk is required.

Sometimes several insects get caught in the net at once, then the spider must find all the victims and paralyze them. The spider does not tolerate them in order to immediately suck them out, but appears only when necessary. The spiny spider can only consume the liquid contents of the insides of its prey. The chitinous cover of eaten insects hangs on the web in a mummified state. The main food of spiders: fruit flies, whiteflies, beetles, moths and other small insects.

Ecosystem role of the spiny spider.

Spiny spiders hunt small insect pests that damage plant leaves and control the number of such insects.

Meaning for a person.

This tiny spider is interesting view for study and research. In addition, the spiny spider hunts small insects in citrus groves and helps farmers get rid of pests. This type of spider forms various morphological forms in different habitats. Researchers can study genetic variations, the effects of temperature changes, and adaptations to specific environmental conditions.

The spiny spider may bite, but the bites do not cause much harm to humans.

People are afraid of the spiny growths, which can scratch the skin upon contact with the spider. But the frightening appearance is compensated by the benefits that spiny spiders bring, preserving the harvest of citrus crops.

Conservation status of the spiny spider.

The spiny spider is found in abundance throughout the western hemisphere. This species has no special status.

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The spiny spider is an orb weaver or horned spider (Gasteracantha cancriformis). The genus name Gasteracantha comes from the Greek words γαστήρ ("belly") and ἄκανθα (spinous process of a vertebra, "thorn"), while the species epithet cancriformis comes from the Latin word cancer ("Crab").

This type of spider has a fairly long list of different names, for example: spider crab, spiny crab, jewel spider, spiny belly spider, box spider, and even a smiley spider. Many of these names apply equally to all other spider species

Both sexes of the horned spider show a clear dimorphism in size: if the female has a height of 5 to 9 mm with a width of 10 to 13 mm, then the male is only 2 to 3 mm tall. In contrast to the female, the male has a more elongated body.

Depending on the area of ​​distribution, the color and shape of this species vary quite greatly, but in females you will always find six protruding spines. The underside of the abdomen of these spiders is most often painted black with white spots.

The legs of spiders are also black in most cases, although there are individuals with colored limbs. The upper side of the carapace (shell) varies in color, and can be white-yellowish with black spots and red spines, yellow or white. The stings can also be red, black, orange or yellowish.

Males are similar to females in color, but have a gray belly with white spots, and the number of short spines varies from 4 to 5.

Spiny orb weaving spiders are widespread throughout the southern United States, from California to Florida. They can also be found in Central America, Dominican Republic and on some islands Bahamas, in Jamaica and Cuba. They prefer to settle on the edge of the forest and in bushes. In Florida, these spiders often colonize citrus groves.