A species from the family of web spiders enjoys not quite deserved notoriety. The spider karakurt received such fame for the reason that there are much more dangerous and poisonous species arachnids. But in the Soviet Union for a long time was considered. There were no developed means of communication then, and people knew little about the fauna of other continents and countries.

Description

Karakurt spider (Latrodectus tredecimguttatus) belongs to the genus. The name is of Turkic origin and is used on the territory of the CIS and adjacent countries Central Asia. The first part of the word "kara" does not cause discrepancies and means "black". The second part is usually translated as "worm". And here doubts arise. Depending on how the first letter of the word “kurt” is written in Latin: k or q, the meaning of the word changes. In addition to "worm", it can mean "beetle" or "wolf". Two recent titles more suitable for a spider.

On a note!

In Europe, tracing paper from the Latin name is more popular: thirteen point widow. This name is based on appearance Asian karakurt.

area

Karakurts are steppe spiders that prefer dry terrain with warm winter. The territories where karakurts live occupy the entire dry belt of the Eurasian continent: from Spain to the steppe part of China.

In Russia, the northern boundary of the distribution of karakurts is 50 ° N. sh. But in the hot summer, these spiders were also met to the north. They even came across on the shores of Lake Onega.

Interesting!

With a high degree of probability, arthropods penetrated the north not by themselves, but with the help of humans. They cannot take root there and die in winter.

In Central Asia, 3 types of karakurts live on the same territory at once:

  • thirteen-pointed (Latrodectus tredecimguttatus);
  • Dal's karakurt (Latrodectus dahli);
  • white (Latrodectus pallidus).

Thirteen-point is divided into 2 subspecies: Asian and European. The second name of the latter is the European widow.

Appearance

Karakurts are medium-sized spiders. The body of the female is 1 to 2 cm long. The male is only 4-7 mm in size. The female has a very large, almost spherical abdomen and long paws sticking out from under it. In the photo of the karakurt spider, you can see that the longest are the first and last pair. On the posterior surface of the abdomen are arachnoid warts, through which the silk thread is released into the external environment.

The cephalothorax appears very small compared to the body. But the spider has very powerful chelicerae designed to bite through the chitinous shell of a large locust.

Internal structure

In this respect, karakurt does not stand out among others. In the cephalothorax are located:

  • poison gland;
  • esophagus;
  • sucking stomach;
  • gastric outgrowths;
  • anterior aorta.

The spider's heart is located in the abdomen, like all other organs:

  • liver;
  • ostia;
  • posterior aorta;
  • intestines;
  • spider gland;
  • trachea;
  • female's ovaries.

The genital opening and the seminal receptacle are located on the underside of the abdomen, closer to the cephalothorax.

Color

The European and Asian subspecies of Latrodectus tredecimguttatus differ from each other in the color of the spots on the abdomen. The Asian has large red spots in the amount of 13 pieces. Sometimes these spots are outlined by a white border. The European subspecies has mild white spots. Both subspecies coexist in the same territory and often interbreed.

On the territory of Central Asia, Latrodectus tredecimguttatus shares its range with two other species: Dal's karakurt and white karakurt. The photo and description of these spiders coincide almost completely. The exception is color. Karakurt Dalia - black without any marks. White karakurt is the only light representative of the genus of black widows and the color of its abdomen is really white. The head is light brown.


On a note!

White karakurt is the least poisonous representative of the genus of black widows.

Lifestyle

Karakurts can hunt both at night and during the day. Its not the correct form, like, but a disorderly heap of trapping threads. The web is also oriented not like other netters - vertically, but in a horizontal plane. The main prey of spiders are locusts and grasshoppers. These invertebrates usually move on the ground. A web located horizontally near the habitat of the arthropod is better suited for catching such game. The karakurt itself can wait for the victim, located in a shelter above the web. For a dwelling, the karakurt chooses rodent burrows or ventilation system openings.

On a note!

Karakurt are fertile. The female can lay 1000-1300 eggs per year. Once every 10-20 years there is an outbreak of arthropods.

The life span of karakurts is less than a year. The juveniles hatched in April become capable of breeding in June. At this time, spiders begin to migrate, looking for secluded places protected from heat. In shelters, they weave temporary webs for mating.

After fertilization, the female eats the male and goes in search of a suitable place where she can lay her eggs. Having found a suitable shelter, the spider hangs 2-4 cocoons with eggs in it. In April, hatched young growth to new habitats.

In the same area, that is, throughout Eurasia, there are spiders that look like karakurt in appearance and size. These are web spiders from the same family Theridiidae as karakurts. But they belong to the genus steatodes. Since steatodes look almost like karakurts, they received the unofficial name "false widows".

On a note!

Large steatoda (Steatoda grossa) has pale light spots on the abdomen, similar to the color of the European subspecies of karakurt.

The color of the abdomen in steatodes can be:

  • with beige or white spots;
  • with a thin red line covering the abdomen along;
  • with a yellow stripe down the back;
  • with small red spots.

Because of the last steatoda and taken for poisonous spider karakurt. But the steatoda is not so poisonous, and it does not entail serious consequences. According to initial signs: increasing pain, sometimes nausea and headache- the action of the poison of steatoda and karakurt is similar. This also makes it difficult to distinguish one spider from another. But from the poison of steatoda, the body can recover on its own in a few days.

Bite symptoms and first aid

The male karakurt is not dangerous to humans, as it is not able to bite through the skin. The female bites to a depth of 0.5 mm. The venom of these arthropods rarely leads to lethal outcome, especially after the appearance of anti-karakurt serum, but the victim is provided with a lot of unpleasant sensations.

Females are not aggressive and attack only when threatened. But they can consider the accidental touching of the web as a threat.

On a note!

Camels and horses are especially sensitive to poison.

But sheep can be used as an anti-karakurt weapon. They are insensitive to poison and trample spider nests on pastures.

Symptoms

The action of the poison is instantaneous. A burning pain appears at the site of the bite of the karakurt, which spreads throughout the body within 10-15 minutes. There are very severe pains in the chest, abdomen and lower back. There is a spasm of the abdominal muscles. There are signs of general poisoning of the body:

  • rapid pulse;
  • heartbeat;
  • dyspnea;
  • vomit;
  • tremor of the limbs;
  • pallor or, conversely, the face turns red due to the rush of blood;
  • heaviness in the chest area;
  • pupil dilation;
  • uncontrolled movement of the eyeball;
  • in men, priapism is possible;
  • bronchial spasm.

On a note!

Later, you can notice a delay in urination and defecation. In the later stages, nervous excitement is replaced by severe depression. Perhaps the appearance of delirium and clouding of consciousness. Fatal outcome is rare, but it cannot be ruled out.

Treatment and first aid

Treatment is carried out in stationary conditions. In the absence of antikarakurt serum, novocaine, magnesia and calcium chloride are administered intravenously. The victim still needs to be taken to the hospital, and for this you need to know what to do if you are bitten by a karakurt somewhere far from civilization.

First aid can only be provided for the first 2 minutes. The affected area is cauterized with a burning match. Under the influence high temperature poison is destroyed. But in this case, the victim must be taken to the hospital as soon as possible.

The Latin name of the species conveys external morphological features: thirteen dots or spots on the upper side of the abdomen.

Description

Karakurt has average value: female 10-20 mm, male 4-7 mm. The body is black, the male and female have red spots on the abdomen, sometimes with a white border around each spot. Fully sexually mature individuals sometimes acquire a black color without spots, with a characteristic luster (due to crossings within the genus Latrodectus, including with European widows).

habitats

They are found in Kyrgyzstan, the desert zone of Kazakhstan, in the steppes of the Astrakhan region, the Krasnodar Territory, Central Asia, Iran, Afghanistan, along the banks mediterranean sea, in North Africa, Southern Europe and in the south of Russia and Ukraine (Black Sea and Sea of ​​Azov). There have been cases of people being bitten in the south of the Urals, territories bordering with Kazakhstan (in the city of Orsk, Orenburg region, the city of Kurtamysh, Kurgan region, left-bank districts of the Saratov region), and there have also been attacks in the Donetsk region, in the city of Mariupol. In the last decade, cases of karakurt bites have also been recorded in Azerbaijan. IN Lately the number increased in the Rostov region, finds of this species appeared in the Altai region and Novosibirsk region. In 2010, they were also found in the Volgograd and Saratov regions.

In hot years, karakurt can also migrate to more northern regions, such as the Moscow region. And even at much higher latitudes it can sometimes be found, but it can only live there until winter. Ideal Conditions habitats - where hot summers and warm autumns.

The main habitats are virgin sagebrush, wastelands, banks of ditches, slopes of ravines, etc.

The enemies of the karakurt are wasps, riders, hedgehogs, their clutches are trampled down by flocks of sheep and pigs, apparently not suffering from their bites.

reproduction

Karakurt is very prolific, and periodically (every 10-12 or 25 years) outbreaks of its mass reproduction are observed.

For habitation and breeding, the female builds a lair in the depressions of the soil, often in rodent burrows and drainages of ventilation systems, stretching trapping nets from incorrectly interlaced threads at the entrance. Eggs overwinter in cocoons, which are hung in the lair two to four. Juveniles emerge in April and are dispersed on the web by the wind. By June, the spiders become sexually mature. With the onset of heat, females and males migrate, looking for protected places where temporary mating nets are arranged. After that, the females wander again in search of places for a permanent lair, where cocoons are placed.

Danger to humans and animals

It does not attack animals and humans unless disturbed. The bite acts immediately: people have a burning pain that spreads throughout the body in 10-15 minutes. Patients usually complain about unbearable pain in the abdomen, lower back, chest. A sharp tension of the abdominal muscles is characteristic. Among the symptoms of general poisoning: shortness of breath, palpitations, increased heart rate, dizziness, headache, tremor, vomiting, pallor or flushing of the face, sweating, a feeling of heaviness in the chest or epigastric region, exophthalmos and mydriasis. Priapism, bronchospasm, urinary and defecation retention are also characteristic. Psychomotor excitation in the later stages of poisoning is replaced by deep depression, blackout of consciousness, delirium. Deaths have been reported in humans and farm animals.

For treatment, anti-karakurt serum is used, good results also gives intravenous administration of novocaine, calcium chloride and magnesium hydrosulfate.
P. I. Marikovsky suggested cauterization of the bitten place with a flammable match head, but not later than two minutes after the bite. From heating, the poison that did not have time to be absorbed is destroyed, as the spider bites through the skin with its chelicerae to a depth of only 0.5 mm. In any case, medical assistance must be provided.

To protect the sleeping karakurt from creeping, a canopy is used, well stretched and tucked with edges under the bed. Cattle suffer greatly from the bites of karakurt, especially camels and horses, which usually die. During the years of mass reproduction of this spider, a significant loss of livestock occurred more than once, and animal husbandry suffered great losses. Now, in the breeding grounds of the karakurt, it is destroyed by spraying the soil with insecticides.

The chemical composition and mechanism of action of the poison

The composition of the poison includes neurotoxins of a protein nature, as well as enzymes - hyaluronidase, LD 50 of α-latrotoxin is 45 μg / kg for mice.

α-Latrotoxin is a presynaptic toxin. The point of application of its action is the presynaptic nerve ending, where the toxin binds to a protein receptor having M r~ 95,000. At the temperature of the human body (37 ° C), the dimeric neurotoxin molecule binds to two receptor molecules, and this binding is very strong ( TO e ~ 0.1 nmol). With a decrease in temperature, the neurotoxin binds to only one receptor molecule, and less firmly ( TO e ~ 0.3 nmol).

The "neurotoxin - receptor" complex forms a channel for Ca 2+, which enters the nerve ending and triggers the release of the neurotransmitter. Under the action of the neurotoxin, a 1000-1500-fold increase in the release of the neurotransmitter is achieved, which leads in 30-50 minutes. to the depletion of its reserves in the nerve ending and the development of a complete block of neuromuscular transmission. Neurotransmitter depletion is supported by data electron microscopy, indicating the almost complete disappearance of synaptic vesicles during the second phase of the action of the neurotoxin. The ability of α-latrotoxin to induce the permeability of biomembranes for divalent cations is confirmed by experiments on bilayer lipid membranes.

In addition to α-latrotoxin, the venom of karakurts (L. pallidus and L. dahli) also contained β-latrotoxin with M r ~ 75 000. Amino acid compositionβ-latrotoxins of different types of karakurt are found a high degree homology.

Dwelling on the lands of the former Soviet Union karakurt (Latrodectus tredecimguttatus) and tropical black widow (Latrodectus mactans) belong to different types one spider genus - the Black Widow. Perhaps that is why the generic name stuck firmly to much less ferocious domestic individuals.

Geography of Black Widows

Representatives of the genus have a bad reputation for being the most poisonous arachnids. The statement is true for arthropods inhabiting the islands of Oceania, Australia and North America. The natives would rather step on a rattlesnake than a black widow with her powerful poison(exceeding the snake by 15 times).

Karakurt live in the steppes and deserts of Afghanistan, North Africa, Iran and southern Europe, including certain regions of the Mediterranean.

Local black widows are well known to residents of neighboring countries:

  • Central Asia.
  • Kazakhstan.
  • Southern regions of Ukraine.
  • Caucasus.

Karakurts reached the south of the Urals, biting people in areas bordering Kazakhstan: in Orsk ( Orenburg region), Kurtamysh (Kurgan region).

These spiders are dispersed throughout the Southern Federal District, including the Crimea, Astrakhan, Volgograd and Rostov region, Krasnodar region.

Arthropods were seen in the Moscow region, Saratov and Novosibirsk regions, as well as in the Altai Territory.

Appearance and reproduction

The male is two or even three times smaller than his female. Some female specimens grow up to 20 mm, while male specimens barely reach 7 mm. It is not surprising that the female, after a successful sexual intercourse, devours the male without regret, like waste material.

The general color of the rounded body (including 4 pairs of tentacles) is black, with a characteristic sheen. Often, on a black background, red spots of various configurations are observed, bordered by narrow white stripes.

A person with poor eyesight can easily confuse a spider with its paws tucked in with a blackcurrant berry.

Karakurts reach sexual maturity in June, starting to look for secluded places to weave temporary nets intended for mating.

After intercourse, the females again go in search, but now - a protected shelter for offspring. Spider eggs will have to survive the winter in cocoons hung (2-4 pieces each) in the nest. Young spiders will appear in April to fly away on the web into adulthood.

Habitats of karakurt

The spider equips housing among stones, dry branches, in the upper layer of soil, often in other people's minks, tightening the entrance with trapping nets of randomly interwoven threads.

He likes to settle on untouched lands, including virgin areas, slopes of ravines, wastelands, banks of ditches. Haymaking, plowing of the steppes and cattle grazing sharply reduce the number of karakurt.

Adult spiders also die from insecticides that pollinate farmland. True, chemical reagents do not act on cocoons: they can only be burned by fire.

With the onset of autumn, black widows, who prefer a nocturnal lifestyle, move closer to warmth - to basements, sheds, cellars, outdoor toilets, houses and apartments.

In pursuit of comfort, the spider climbs into shoes, linen, bedding, kitchen utensils. And this is a direct threat to human life.

Spider activity

Its peak is recorded from July to September. During the migration of females (June/July), the number of people and animals affected by their "kisses" increases dramatically.

Outbreaks of mass reproduction of karakurt are recorded once every 25 or once every 10 years, while the main danger is fraught with adult females.

Our karakurt, of course, cannot be compared with a real black widow in terms of the strength of the poison, but its bites sometimes end in deaths.

So, in October 1997, 87 residents of the Kherson region were bitten by karakurts: all of them were treated in a hospital, but one could not be saved.

Then zoologists suggested that mass attack was provoked by downpours that drove the spiders out of their shelters.

Along the way, it turned out that post-war years Karakurt felt like the master of the Don steppes and disappeared for a long time due to their active development.

The revival of the black widow population began with the collapse of the USSR: they breed intensively in abandoned fields and farms.

Second favorable factor- global climate change, in which the arid zone is moving north. This plays into the hands of spiders that avoid heavy rainfall that is fatal to their burrows.

Extraction of karakurt

It becomes both insects and small rodents, the living space of which the killer occupies without remorse.

The spider paralyzes the victim, allowing the poison, which acts as a digestive secret, to spread through its tissues. After the insect becomes soft enough, the black widow will stick its proboscis into it and begin to suck out the contents.

During the meal, the spider can be distracted by other activities, move away from the “table” and return again, turn the victim over, sucking it from different sides.

A hole covered in cobwebs signals danger. The spider will not attack without a reason, which can be any careless intrusion into its private space.

Action of the poison

A barely noticeable red dot from a bite will launch chain reaction throughout the body: after a quarter of an hour, burning pain will cover the whole body (especially in the chest, abdomen and lower back).

Typical symptoms will appear:

  • tachycardia and shortness of breath;
  • redness or pallor of the face;
  • dizziness and tremor;
  • headache, vomiting and sweating;
  • heaviness in the chest or epigastric region;
  • bronchospasm and priapism;
  • inhibition of defecation and urination.

Later, intoxication turns into a depressed state, clouding of consciousness and delirium.

Antidote

by the most effective drug was considered to be anti-karakurt serum produced by the Tashkent Bacteriological Institute.

Good results were obtained with the introduction (intravenous) of calcium chloride, novocaine and magnesium hydrosulfate.

If the bitten person is away from the first-aid post, it is recommended to burn the affected area with a lit match head within the first two minutes. It is believed that the poison that did not have time to penetrate deeply is destroyed by exposure to high temperature.

Spider karakurt especially dangerous for small children. If help is late, the child cannot be saved.

Animals die from close “contacts” with a black widow, among which camels and horses are considered the most vulnerable.

Breeding karakurt

Only very self-confident and fearless people can keep these arthropods at home. If you are able to tell the difference between a male and a female, form a spider alliance to observe the breeding.

Yes, and do not forget to protect the male: the spider will regularly encroach on his life.

For an artificial lair you will need:

  • terrarium or aquarium;
  • sand mixed with gravel;
  • moss, twigs and dry leaves.

You will have to catch flies and cockroaches in order to throw them immobilized into the web to your pets. In winter, spiders do not need to be fed - they sleep, but they need to be slightly warmed (with an electric lamp or warm air).

In the spring, the terrarium will require cleaning. Send the karakurts to the jar and get rid of the garbage in their nest.

Spider black widow as a business

On the Internet there are rumors about low-cost and fabulous profitable business- breeding karakurt to obtain poison.

Those who wish are explained “on the fingers” what milking of poisonous arthropods looks like, assuring that this is a simple and safe process that can be mastered on your own.

In fact, specially trained people are engaged in obtaining poison, in industrial conditions and on expensive equipment.

To do this, they buy a special gas (to put the karakurts to sleep) and an “operating table” installation with electrodes necessary to supply a discharge to the chelicerae so that the poison leaves.

The most expensive part of the scheme(several tens of thousands of dollars) - a unit for drying poison, which should turn into crystals.

500 karakurts from one milking give 1 g of dry toxin, which costs up to 1200 euros on the black market.

Undoubtedly profitable business, but it is not for self-taught, loners and amateurs.

Spiders are one of the most ancient land animals on our planet; they descended from a crab-like ancestor. Now the detachment of spiders includes more than forty thousand different species.

Karakurt belongs to the class of arachnids, order - spiders, is a representative of the genus Latrodectus, the poison of these spiders deadly to animals and humans.

The habitat of the karakurt includes territories tropical zone Africa, Central and Western Asia and southern Europe. In our country, these spiders live in the Caucasus, Crimea, in the south of the Urals, but recently their range has expanded to the north. They are met in the Moscow region, in Rostov-on-Don, in Orel. Karakurt loves to settle in wastelands, in ravines, on the banks of reservoirs.


The structure of the karakurt is practically no different from the structure of other spiders. Its body is divided into two sections: the front section of the body, with four pairs of eyes, is covered with a hard chitinous shield. The second section is the abdomen, which is covered with an elastic membrane. Spider glands are located in this part of the body. On the head of the body there are two pairs of modified limbs - chelicerae and pedipalps, behind which are walking legs. Spiders have eight of them.

Chelicerae consist of one limb, at the end of which there is a claw, where the poisonous gland opens. They are designed for grasping and holding prey, as well as for protection from enemies.

Pedipalps are similar to legs, but shorter. They are the organ of touch, they usually do not take part in the movement. In mature males. They are somewhat modified.

Lifestyle

The main difference between a male and a female in karakurt is size. The female is almost twice the size of the male. It can reach two centimeters in length, while the male does not grow more than seven millimeters. In addition, the male has red spots on the abdomen. The female has a deep black body. Karakurts, like other spiders, are good runners, and can cover fairly long distances and at high speed. This is all the more surprising, because muscle fibers are completely absent in the spider's limbs.

In addition to locomotion, the spider uses its legs to dig holes and weave webs. There are also olfactory and tactile organs on the legs.

Karakurts, like all spiders, are predators. They catch their prey with webs. Spiders pierce their prey with chelicerae, releasing venom and digestive juices. Having entangled the victim with a web, they leave it for a while. Digestive juices quickly digest the prey, after which the spiders suck out the resulting broth.

mating games

The female karakurt, before the mating games, leaves the nest, and is in constant motion, leaving behind a special double thread, along which the male finds her.

Process mating games preceded by long enough dances. The male twitches his abdomen, briskly moves his pedipalps.

The spider approaches its partner with the greatest caution, but the females show aggression only when they are not ready. Females do not attack partners, but favorably accept courtship.

Male rivalry during mating season is a common occurrence. One female collects near her up to ten applicants fighting among themselves. The strongest and most agile drives away other males and proceeds to mating games.

During mating games, the female karakurt enters a state of catalepsy and remains motionless for quite a long time. In this state, it is not dangerous for the male.

Caring for offspring


Caring for offspring in females of karakurt is pronounced during the incubation period. First of all, they look for a place for future masonry, digging a nest in the ground, or adapting abandoned rodent burrows for this. Before entering the nest, she pulls on trapping nets. And only then lay cocoons with eggs. Females remain in the nest for the entire incubation period. Usually juveniles appear in April.

With the advent of offspring, the maternal functions of the female are fulfilled and the juveniles, attached to the cobwebs, are carried by the wind. By the beginning of summer, young karakurt reaches maturity and is capable of mating.

Natural enemies of karakurt

Karakurts have many enemies in wild nature. Herds of grazing animals trample the grass and destroy the nests of karakurts. Hedgehogs are not susceptible to the poison of karakurt so they feed on them fearlessly. A large number of beetles and wasps lay their larvae in spider cocoons, destroying the entire brood.

Karakurt and man

The poison of the karakurt has a neurotoxin in its composition and is close in action to the poison rattlesnakes. Hyperemia occurs at the bite site, which quickly disappears. A quarter of an hour later, sharp pains appear in the abdomen, chest, legs go numb. All this is accompanied by mental excitement, convulsions, headache. The heartbeat slows down, arrhythmia appears, blood and protein appear in the urine. The victim's condition becomes critical. Most effective tool is an anti-karakurt serum. With timely administration, the patient's condition quickly normalizes.

It should be noted that karakurts are never the first to attack. Spiders are only aggressive when disturbed. The most dangerous are the bites of females. The largest number of bites occurs in June-July - the time of annual migrations.

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Black, scary and ominous, with long thick legs, with shiny black eyes, and a bright red stripe on the abdomen - these spiders terrify Almaty residents. As employees of the Institute of Zoology told a NUR.KZ correspondent, these spiders are not so dangerous. These are the so-called "false karakurts".

False karakurts are very similar to the "original" - rather large, black, with long paws spiders. But one thing distinguishes them: a bright red stripe on the abdomen. In a real karakurt, the whole body and paws are not as glossy as those of a false one, but velvety, and there are red stripes only on the lower part of the abdomen, or even they do not exist at all.

In addition, a real karakurt prefers to settle away from a person, while a false one, on the contrary, settles within the city and feels great among people. Unlike false, real karakurt loves the steppe, and settles under stones or in rodent burrows. Around his lair there is always a web, in which dead grasshoppers and other insects usually hang.