Black and white spiders in the house: how do they reproduce and what do they eat?

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The white karakurt is one of the most dangerous creatures on earth.
Despite the fact that outwardly it does not seem so threatening, the poison of this arthropod is deadly. In this regard, a spider bite for animals such as a horse or shelter will definitely end in death. For a person, an insect bite can also be fatal if the required amount of qualified medical care is not provided in a timely manner. However, researchers and scientists argue that the poison of the white karakurt is somewhat less dangerous than that of the black representative of this species.

Origin of the species and description

Photo: White Karakurt

The white karakurt belongs to the arachnid arthropods, is a representative of the order of spiders, the family of web spiders, classified in the genus of the black widow, the species white karakurt.

Scientists do not have reliable information about the origin of these representatives of arthropods. The most ancient finds of the distant ancestors of the Karakurts date back to the Carboniferous Age, which is about four hundred million years ago. They are rightfully considered representatives of some of the most ancient living creatures preserved on earth.

Video: White karakurt

Some scientists suggest that the most ancient ancestors of modern poisonous spiders, including karakurts, lived in water. However, during the Paleozoic period, they moved into thickets of huge grass and impenetrable bushes. In thickets of dense vegetation they hunted various insects. Later, spiders appeared that could weave webs and entangle eggs with them for protection.

Interesting information. The strength of the poisonous substance of karakurt venom is 50 times greater than the strength of karakurt venom and 15 times the strength of rattlesnake venom.

About two hundred and fifty million years ago, arthropods appeared that learned to weave webs to create traps. With the onset of the Jurassic period, spiders learned to weave multiple webs and hang them in dense foliage. To make webs, arthropods used a long, thin tail.

Spiders spread widely across the earth during the formation of Pangnea. Later they began to be divided into species depending on the region of their habitat.

Medium poisonous spiders

banana spider

Giant tree spider

goldweaver

Tarantula

Spider wasp (Argiope brunnich)

Females are larger (especially in late summer, before eggs are laid), and the thorax is brightly colored with yellow, black and white stripes, reminiscent of a wasp. Males are tiny and do not look like females. Weaving webs in high meadows. The network is characteristic, with an obvious zigzag pattern. As a rule, they feed on grasshoppers and other insects caught in the net.

Appearance and features

Photo: White karakurt spider

The white karakurt really looks ominous. It inspires fear, and what’s worst is that, thanks to its color, it goes unnoticed. A distinctive feature of this particular type of arachnid is its body in the shape of a large ball, as well as long and thin limbs. There are four pairs of limbs. The first and last pair of legs are the longest. This spider is the only representative of its genus that has a white, grayish or yellowish tint.

Compared to black widows, white karakurts do not have an hourglass-shaped pattern. On the surface of the back you can see four small depressions in the shape of a rectangle.

The lower part of the body is always white or milky in color. The rest of the body may be gray or yellowish. These arthropods have pronounced sexual dimorphism - males are significantly smaller than females in size. The size of the female can reach 2.5 centimeters, while the size of the male does not exceed 0.5-0.8 centimeters.

The head is small, significantly smaller than the body, most often brown. On the head there are chelicerae, which are highly powerful and can easily bite through the chitinous shell of even large locusts. In the back of the abdomen there are several arachnoid warts, through which the web is released into the environment.

The white karakurt has a body structure typical of all other arachnids. It is divided into two parts - the cephalothorax and abdomen. Each of them contains vital organs. The cephalothorax contains: a gland that secretes a poisonous secretion, the esophagus, the sucking stomach, food outgrowths, and the anterior aorta.

The abdomen contains:

• Arachnoid gland;
• Liver;
• Intestines;
• Ostia;
• Ovaries in a female;
• Trachea;
• Posterior aorta.

Internal structure

There is no complete circulatory system. Blood too. It is replaced by lymph. There are 3-4 holes in the heart, called ostia. Through the ostia, lymph from the animal's body enters the heart, and from there, through the arteries, the heart drives lymph into the spaces between the internal organs. From the spaces, lymph enters the pericardial region of the body and returns again to the heart. Lymph has a mechanism that additionally supplies the spider with oxygen.

Spider structure

The respiratory system has a peculiar appearance. The lung sacs have plates and look like books. The breathing holes that open the lungs are equipped with protective covers. There are also long tracheal tubes that transport oxygen from the openings to the organs of the spider's body.

Being a predator, the spider has a well-developed central nervous system and a significant brain volume. In the cephalothorax of the arthropod there are 2 nerve ganglia, from which many nerves diverge, leading to the organs of the spider. These nodes are the brain of the animal.

Interesting!

The volume of the brain occupies 20-30% of the total volume of the cephalothorax.

Where does the white karakurt live?

Photo: Animal white karakurt

There is an opinion according to which the white karakurt lives only in uninhabited regions of the Naimb desert. However, this is not true. Changing climatic conditions have led to an expansion and change in the habitat of white karakurts.

Geographical regions of arachnid habitat:

• Southern regions of the Russian Federation;
• Northern part of the African continent;
• Southern part of Ukraine;
• Crimea;
• Iran;
• Mongolia;
• Türkiye;
• Kazakhstan;
• Azerbaijan.

White karakurts prefer areas where there is little precipitation and there is no severe frost. Favorite habitats are steppes, ditches, and ravines. They try to avoid flat, open areas in every possible way. Like the vast majority of arachnids, it chooses secluded, inaccessible places.

Likes to hide in burrows of small rodents, crevices, gaps between walls, and other remote, secluded corners. Karakurts do not tolerate severe frosts and harsh climates. They try to avoid excessive moisture, too light areas, and too hot climates.

It is quite possible to meet a white karakurt on the territory of plowed farm lands, abandoned or residential buildings, in attics, under the roofs of houses and barns.

Other arachnids

Central Asia and Africa are home to large arthropods, which are unknowingly confused with spiders. In fact, these are salpugs or, as they are also called, camel spiders. Unlike spiders, these living creatures do not have poisonous glands or glands for creating webs, but they are armed with teeth.

Spiders cause a feeling of fear in many people, but this is more likely due to ignorance. In fact, these are quite harmless living creatures.

10 Most Amazing Spiders in the World

What does the white karakurt eat?

Photo: White Karakurt

The source of food for the white karakurt is insects that get caught in the web it weaves.

What is the power source:

• Arthropods are small in size;
• Cicadas;
• Locust;
• Grasshoppers;
• Flies;
• Horseflies;
• Beetles;
• Cicadas;
• Small rodents.

White karakurts have an extraintestinal structure of the digestive tract. When a victim enters the web, it pierces its body in several places and injects a poisonous secretion so that the victim's entrails are completely digested by the poison. After this, the spiders eat the liquid part of the body of their victim.

A horizontal web is most often used to catch insects. It is characteristic that the web does not have a typical trapezoidal pattern, but has a chaotic arrangement of threads that does not form any pattern. The white karakurt can create several such webs of traps. Most often they are placed among the foliage in such a way that it remains invisible to most insects or small rodents. Such traps are often left in burrows, small depressions in the ground.

The process of assimilation of food proceeds quite quickly, since almost everything has already been digested under the influence of the poisonous secretion. Among the variety of food sources, locusts and grasshoppers are singled out and given preference. White karakurts literally manage to live without food, or eat a very modest amount of food. White karakurts can live for about 10-12 months practically without food.

Funny classification

Among lovers of large tarantula spiders, there is an interesting division of pets into categories according to their speed characteristics:

• For beginners. Slow spiders that people like to show on video. These arthropods sit calmly on the palm, and if they try to escape, they move slowly.
• For the advanced. If the spider of this group decides to escape, then the owner can only notice the direction in which the animal disappeared.
• For professionals. The escape of a spider is noticed by its absence from the place where it was just sitting. Where it went is known only to the arthropod itself.

Spiders
The last group suggests that not all breeds of spiders have yet been discovered by scientists. It's hard to see a fast spider if you don't even know it's there.

Features of character and lifestyle

Photo: White karakurt spider

White karakurts are active regardless of the time of day or weather conditions. They can be active and go out in search of food, as well as eat it, both in the light and in the dark. Males are less active. They use spider webs to make traps. Spiders weave it not in the form of certain shapes and figures, but by simply winding threads. It can get food like a hunter, that is, hiding behind bushes or in thickets of dense vegetation.

Burrows of small rodents, cracks in walls, ceilings, depressions in the soil, pits, etc. are chosen as places of residence. These representatives of arachnids have very acute hearing. This is why human bites have been reported. Spiders react sharply to unknown noise and, for the purpose of self-defense, try to attack first. Due to the fact that when people meet them they become a source of unnecessary noise, spiders attack them for the purpose of self-defense.

They do not tolerate frost and extreme heat well. In the spring-summer period, large migrations are observed in the habitat regions. They are due to the fact that spiders are trying to escape from extreme heat. After the white karakurt finds a safe shelter, the females entwine it with a web and begin to prepare for the appearance of offspring.

Deadly poisonous

In most cases, spiders do not pose any danger to humans. Unless they get tired of weaving cobwebs in the corners. But classification according to the degree of toxicity is more practical, since there are some species that are deadly even to humans.

Truly poisonous spiders:

• black widows, including karakurt;
• Brazilian spiders;
• brown recluse spider.

Black widows are so named because the female eats the male after mating. Spiders of this genus are common on all continents. Prey is caught using the web as a lasso. Not all species of this genus are dangerous to humans. The American black widow has received the greatest celebrity.

North American black widow

There are 5 species of black widows living on the northern continent. The main color of these spiders is black with red spots on the abdomen.

Important!

Not all black widows are black in color.

This genus of spiders can be distinguished by a characteristic feature: long legs, which are clearly visible in the photograph.

North American black widow

A spider bite feels like a pin prick. After half an hour, muscle spasms appear, spreading throughout the body. Before the serum appeared, 5% of victims died from black widow bites.

South American black widows

There are 8 species in South and Central America. The life and appearance of these populations have been little studied, since the places where these spiders live are sparsely populated and have not been seriously studied.

Karakurt

18 species of varying degrees of toxicity live in Eurasia and Africa. In Eurasia, black widow spiders are called karakurt.

The name of the spider is of Turkic origin and means “black worm” in Russian. The “classic” black karakurt Latrodectus tredecimguttatus lives in the southern regions of the continent, including the Mediterranean and Crimea. Due to global warming, it began to appear in Azerbaijan, Altai and the Novosibirsk region. The ideal habitat for this karakurt spider is warm autumn and hot summer.

The name and photo of the spiders are somewhat inconsistent with each other: this type of karakurt has large red spots on the dorsal side of the abdomen. Coloration can vary greatly: Eurasian species interbreed and the spider can be pure black.

Karakurt black and white

On a note!

There is a white karakurt (Latrodectus pallidus). Since white karakurts look uncharacteristic for these types of arthropods, you can ignore them. White karakurts are less poisonous than black ones, but their bite can cause trouble for children or people suffering from allergies. The habitat is combined with the territory where the black karakurt lives.

Oceania and Australia

Three species, one of which was introduced to Southeast Asia. The Australian black widow is also considered one of the most dangerous species.

Latrodectus geometricus

A species of black widow distributed on all continents. The color on the dorsal side is brown. There is a red spot on the underside of the abdomen. The paws are yellow-brown with black stripes on the folds. Of all the black widows, they are the least poisonous and dangerous only to children and the elderly.

Brazilian wandering spider

Until 2010, the black widow was considered the most poisonous spider, but the Brazilian soldier spider took the prize cup away from it. The genus of Brazilian wandering spiders has 8 species. The distribution area is very limited: the tropics of South and Central America. The hunting method is active. They don't weave a web.

Brazilian wandering spider

Interesting!

The last species was discovered only in 2001.

The final stage of soldier spider venom causes muscle paralysis and suffocation. When poison enters the bloodstream, cardiac arrest occurs in 85% of cases after a bite.

Recluse spider

Lives on the North American continent. The leg span can be 6-20 mm. Color brown, dark yellow, gray. One of the species that has fewer than 8 eyes. The hermit has only 3 pairs, which can be seen in the close-up photo of the cephalothorax.

Recluse spider

It is nocturnal and hides under roots and stones during the day. The hunting method is active, but it weaves nets that it uses as shelter. Likes to settle into human housing. At night he may accidentally climb into bed. If you press him down, he will bite.

The consequence of bites is the development of necrotic ulcers. The affected area heals for 3 years. A bite can be fatal if the victim is a child or a person with a weakened immune system.

Social structure and reproduction

Photo: Little white karakurt

The mating period for this representative of arthropods is seasonal and occurs in the middle - late summer. Males try to attract the attention of representatives of the opposite sex with the help of special pheromones. In selected shelters, females hang out poutine. This is necessary so that young individuals can gain a foothold on the web and fly away in search of their home. After the end of the mating season, the female individual lays eggs. Their number can reach 130-140 pieces.

When the autumn season arrives, the female dies. The laid eggs independently wait for spring in selected secluded burrows and other shelters. In the spring, with the arrival of wind, which helps get rid of the egg shell and give birth to young individuals. The hatched spiders do not scatter in different directions, but calmly remain in the hole to get stronger and acquire the necessary skills for independent survival. For this period, they have enough food that their mother prepared in reserve.

After the mother's reserves are depleted, the spiders begin to actively eat each other. As a result, only the strongest individuals survive. They leave the cocoon only the following spring, and by the summer of the same year they become sexually mature. The white karakurt is considered a very prolific representative of arachnids. The female can give birth to offspring up to two times a year.

Nutrition

99% of spiders eat animal food. They prefer insects. On average, they eat 650 tons per year. Digested externally. The esophagus of spiders is very thin. Able to pass only liquid food. The straining apparatus in the pharynx does not allow large pieces (more than one micron) to pass through. The digestive enzyme is secreted by the liver. This function is also performed by the labial gland (located on the upper lip).

Did you know that spiders can distinguish tastes? They do this thanks to a group of receptor cells in the walls of the pharynx. Spiders reject flies coated with table salt and quinine. But they enjoy eating elderberry core soaked in meat broth.

Spiders of different species prepare their prey in 2 ways. Most creatures inject the enzyme into an insect, then knead it and tear it apart with chelicerae. This procedure is carried out several times. After each manipulation, drops of nutritious juice appear on the surface. The spider eats them with its rostrum.

Spiders that feed on hard-shelled insects simply inject secretions into the wound. Then all the nutrient fluid is sucked through one hole.

The tarantula enzyme can dissolve 3-4 grams of mouse meat in 24 hours.

These arachnids are predators. The exception is a species of jumping spider called Bagheera Kipling. They sometimes feed on nectar. But most often with the tips of acacia leaves, as they are rich in proteins. In addition, 60 species were caught occasionally consuming “vegetarian” food.

Natural enemies of white karakurts

Photo: White karakurt spider

Despite the fact that these representatives of arthropods are practically the most dangerous in the world, they still have enemies in natural conditions, these are:

• Small livestock - sheep, goats. They are not exposed to the poisonous secretions of arthropods;
• Wasps are sphex. They tend to attack karakurts with lightning speed and inject their poisonous secretion into them;
• Insects are riders. They tend to lay eggs in the cocoons of this representative of the arthropod family;
• Jerzy. Not exposed to toxic secretions.

Most often, farmers who fear mass destruction of cattle due to the bites of white karakurts first allow sheep or goats to graze on a certain pasture. These animals are not sensitive to their bites, so they are often practically used to protect pasture for grazing cattle.

In some regions, there are large numbers of arthropods that can destroy an entire herd of cows.

Prevention measures

The main guarantee of the absence of spiders in the house is cleanliness. Predators do not like it, since dirty and dark places with high humidity are acceptable to them. Therefore, it is imperative to carry out general cleaning and if cobwebs appear in the corners, sweep them away immediately, because arthropods do not like to be disturbed and leave such houses.

It is better to store food products wrapped in cling film or in containers. Then there will be no spiders or midges in the house.

You should get rid of various insects; if predators have nothing to eat, they will not settle in the apartment.

Let's celebrate! Spiders are amazing creatures. They have their own taste preferences, methods of catching prey, and even mating customs. Although for the most part such predators are not dangerous for people, after they appear in the house, it is better to get rid of them and think about the cleanliness of the apartment and the extermination of other insects.

Far East

A striking representative of the spiders of the Far East is:

Digger spider

The name of the spider speaks for itself. It is found in the Khabarovsk and Primorsky Territories, in the Sakhalin Region. The mole rat can be identified by its very massive and prominent chelicerae; they are 2.5 times the thickness of the legs. Size – from 1 cm to 1.5 cm, color – reddish brown. They live in groups. The place of residence is an earthen burrow, covered from the inside with a cobweb, which protrudes to the surface in the form of a tube.

Diggers are very shy and unsociable; the likelihood of meeting them is negligible. All his time he sits in ambush in his underground house, waiting for prey. Despite its terrifying appearance, the mole rat is harmless to humans.

Pamphobetus platioma

A huge spider whose paw span can reach twenty centimeters. This absolutely beautiful spider was included in our selection thanks to its soft, plush purple fur. However, only males have such an unusual color; females are content with a rather mediocre brown color.

These spiders are not suitable for keeping at home, because they absolutely cannot tolerate human touch - they immediately want to attack the one who dares to invade their personal space. If you try to pull the spider out of its hiding place, you cannot avoid a bite.

How do they winter

Some spiders can lead an active lifestyle in winter.
Spiders are able to hibernate in different ways. Some survive frosts in the foliage and bark of trees. Spiders also try to escape the cold by settling in different buildings. In the cold, the predator produces a special chemical that acts as antifreeze. If a female lays eggs before the onset of cold weather, she tries to hide them in a secluded place where the temperature will still remain above zero in the winter.

Interesting fact : in the cold, spiders fall into a state similar to suspended animation. Because of this, processes in the body slow down and they age more slowly.

Martinique mahogany

Newborn Martinique mahogany spiders are dark blue with white stripes. However, as it matures, many red areas appear on it. Mature individuals have metallic green hairs - it seems that these beautiful spiders just love experimenting with coloring.

The sting of a Martinique mahogany tree feels the same as a wasp sting. They attack only in a desperate situation, when they feel a threat to their own life.

Kipling's Bagheera

Everything about this spider is unique. In addition to his beautiful appearance, he stands out for his ability to build nests for himself and his fellow tribesmen. A small group moves into such a house and establishes a common life. In particular, males are involved in the process of caring for little “heirs”. In addition, Kipling's Bagheera is the only known vegetarian spider. Most of its diet consists of shoots of shares leaves. But as an exception, in unfavorable weather conditions, he can also feast on his relatives. Herbivorous spiders live in Central America.

Metallic arboreal tarantula

The huge electric blue tarantula is rightfully considered one of the most beautiful spiders on the planet. It is often kept in home terrariums; many exotic lovers dream of getting such a miracle.

However, we would not recommend that you buy such a non-standard pet. The metal tree tarantula is very poisonous, and its bite can cause not only unbearable pain, but also lead to such unpleasant consequences as arrhythmia, tachycardia, disorientation, convulsions and tumors. No fatalities from the bite have ever been recorded.

Maevia inclemens

These are small spiders that live in Canada and the USA. They made it into our selection due to their huge eyes, which make them look like cartoon characters.

The body length of females is up to eight millimeters, males – up to seven millimeters. The abdomen is beige, with sparse orange hairs and black stripes. There are males with a black body.

Maratus personatus

This is probably the cutest spider on the planet. We're willing to bet that these amazing creatures can make even the most ardent arachnophobe smile.

These furry babies do not grow more than five millimeters. But small sizes and non-standard colors are not all of their advantages.

The most beautiful thing about these spiders is the way the males court the females. They perform amazing dances, lifting their paws up - believe me, it looks very funny.

Which houses do arthropods prefer?

Most often, arthropods are found in houses with or without collapsing foundations. They are damp, warm and full of insects that live under the floor.

The more cockroaches, midges and flies in the rooms, the more arthropods there will be. If you get rid of insects, then the spiders will go away.

When cleaning your home, you can use a vacuum cleaner to remove cobwebs. But the bag must be shaken out immediately so that the arthropod does not get out and weave new networks.

We collect cobwebs with a vacuum cleaner.

Brazilian white-knee tarantula

A very large spider with quite interesting coloring. The body length of an adult individual reaches nine centimeters, and the paw span can be up to twenty centimeters. Brazilian white-knee tarantulas can be quite aggressive, but due to their natural slowness and clumsiness, they are not considered dangerous.

Of course, this giant is poisonous, but its poison cannot pose any danger to humans. The most unpleasant thing that can happen to you after contact with a Brazilian white-knee tarantula is irritation and itching.

These spiders are often purchased by lovers of exotic pets, and can live in captivity for up to fifteen years - the care of their owners benefits them.

Black Eresus

These spiders have an unusual black and red color and look like ladybugs. They grow to a maximum length of 2 cm. The body of spiders has a rich black color, and there are 4 black dots on the red abdomen, which gives them a resemblance to the famous insect. But only males who are ready to mate have such a striking appearance. Females are usually completely black with a brown spot in the eye area. The entire body of Eresus is covered with hairs, which makes it seem velvety, and you just want to stroke it. But it is better not to do this, since the spider has an aggressive character and can bite very painfully. You can meet these handsome guys in many European countries.