Spiders exist on the planet for more than 380 million years and are an important component of the ecosystem for any climate zone. There are many types of spiders, some are absolutely harmless, others are deadly to others. One such creature is the black widow spider. The only good thing is that there are few deaths from the bites of these animals, since they prefer to flee rather than bite an opponent.
general characteristics
This is an animal from the order of arthropods. Widespread in North America. Oceania and Australia, other regions would never know of the existence of such a spider if it had not been brought there randomly with goods, fruits and vegetables.
About the black widow spider say still - karakurt. And this is the biological designation of this species. A spider’s “popular” name was given to the fact that after mating the female instantly cracks down on her boyfriend by killing and eating. Although according to the observations of biologists, this is not always the case.
The question of what a black widow spider looks like is very simple to answer - like most of the other arthropods. It has 8 long legs. The spider is small, about 38 millimeters in length, legs up to 12 mm. They live no more than 3 years, an average of 24 months.
Females are much larger than males and much brighter in color. Females have red markings on the belly, very similar to an hourglass, themselves black. The males are somewhat paler, and the markings are orange or yellow. Until the spider reaches puberty, the spots on the body have a white edging.
The spider has strong paws, very similar to crests, with bristles. They allow you to tighten the web over the caught victim.
The visual organs of the spider are arranged in two rows, each with as many as 4 eyes. In this case, the spider sees very poorly, the lateral eyes can only distinguish between movement and light. Therefore, arthropods in the hunt process are guided only by the vibrations that emanate from the cobweb into which the victim fell.
A karakurt bite is about 15 times more poisonous than a rattlesnake bite.
What feeds on
Like most arthropods, this predator eats other species of spiders, small insects that fall into the web. These can be flies and mosquitoes, caterpillars and small bugs.
As a rule, the female hangs upside down, boldly displaying her bright markings, but the prey is rarely afraid of the toxicity of the spider.
As soon as the victim is in the web, karakurt wraps it with threads and pierces it with his chelicera. In the spider’s teeth there are digestive enzymes that allow the insect to dissolve. Now you can start the meal and suck all the liquid.
Another interesting feature of most spiders: a black widow can go without food for a long time. There are cases of "fasting" up to 1 year.
Life cycle
Mating of animals occurs mainly at the end of spring, but largely depends on the region of habitat. Then the female lays the eggs on the web in a silk ball of gray color. Balls can be from 5 to 15 pieces, each has an average of 700 eggs. After 15-30 days, small individuals appear, but few will live to mature age. The spider is a cannibal and, because of its excellent nutritional qualities, eats its own children.
They grow up for 3 months. During this period, they molt several times, first changing the white color to orange and finally to black. After growing up they leave the web and weave their own in a new place.
Closer to fall, if the female is no longer young, she dies, rarely anyone of this type of spider lives for more than one year. The males are even less fortunate; their life course ends approximately in the second month after attaining puberty.
Most of these spiders live in hot countries. Occur in the Caucasus and Central Asia, in Ukraine. For the house they choose cracks in stones and walls, mink of small rodents, steppes and saline wastelands, sometimes they even settle on arable land. Spiders can be found in courtyards.
These animals do not like overgrown shrubs and dense grassy meadows, deserts.
You can find nests on grass stalks closer to the ground. This place is preferred by spiders, here they set a trapping web and lay eggs.
Black widow spider in Russia
Despite the fact that the expanses of Russia can not boast of an abundance of solar heat, recently there have been numerous cases of human bites from karakurt.
In 2015 alone, 20 cases were recorded. Part of the victims were in intensive care. Moreover, people suffered not only in the southern regions, but also in the Novosibirsk and Moscow regions. And all this is happening against the background of a steady increase in temperature; spiders flee from the heat from the Central Asian steppes.
Currently, a huge number of spiders recorded in the Volgograd region. There are still a lot of them on the Black Sea coast, especially in the Crimea.
Recorded cases of bites in the Saratov and Orenburg regions in the Urals.
Despite the terrible statistics, yet not so often people die from the bites of this predator, especially in our country. At risk are sick people, children and old people, that is, those who have a weakened or incompletely formed immune system.
Symptoms after bite
The poison of a black widow spider is deadly to humans. However, the spider never attacks a person, unless you step on it. If you do not ask for help, it will inevitably be fatal after 2 days.
Immediately after contact with the spider, nothing happens. After 15 minutes, the victim begins to feel pain in the lumbar region, chest and abdomen. Then there are difficulties with breathing, convulsions. Body temperature and blood pressure may rise.
In the case of a bite, it is recommended to burn this place with a burning match to try to destroy the poison. But it will help if you take action for 2 minutes from the moment of contact with the animal. Further, urgent hospitalization is required.
If medical assistance is provided in a timely manner, then full recovery occurs in a couple of weeks.
Home maintenance
In pursuit of the exotic, many people forget about their safety and start a black widow as a pet spider. By and large, no special conditions for the maintenance of this arthropod creature are required: put in a terrarium and do not forget to feed. If the spider escapes, then catching him even in a small apartment will be quite problematic. Also, one should not hope to see the whole life cycle. They breed in captivity very rarely.
Rules of conduct in nature
Probably, once again you should not make a description of a black widow spider, most likely, after seeing it, everyone will recognize it. In order not to become a victim of a predator, choose a better place for parking, where there are no animals mink, where there is high vegetation, that is, areas that are unsuitable for spiders. Do not sleep in the open ground and walk barefoot in places where there is a spider web.
Collecting brushwood and flowers, it is better to wear gloves and boots. If there are stones in the area, then you should not touch them with your bare hands, turn them over. Before going to bed in a tent, it is better to shake all things and bedding properly.
The same rules apply to those who like to work in the garden: getting rid of weeds is better to wear gloves and not to leave shoes between garden beds.
False widow
In scientific sources this spider is called steatod. Indeed, the two types of arthropods have a tremendous external resemblance, but the false widow does not have the distinctive feature of black — the red mark and has a slightly lighter color.
The area of distribution are warm countries, relatively recently it was brought to the European continent, particularly to England, whence the fame of this animal began. In the XIX century steatod in England recognized the most poisonous arthropods. Although it is known for certain that after a bite a person will only observe a certain ailment for a few days. At the site of the bite, irritation and swelling may appear, reaching the size of a billiard ball. However, no deaths after contact with the false widow were recorded.
Black widow before the beginning of the widow period: how do these spiders breed
As you know, the mourning name of this spider is not accidental: cannibalism towards the male left its mark on the female's reputation.
During her life, the female black widow can only be fertilized once, but she can preserve the genetic heritage of the male for a long time, self-fertilizing eggs.
The breeding season usually occurs from July to August, when the female spider is engaged
the formation of cocoons with offspring. During the summer, a black widow can form from 4 to 9 cocoonshaving dimensions comparable to her own, each of them can contain from 20 to 600 eggs.
Spiders hatch in 2-4 weeks and already from birth are ready to eat their own kind. So only a few of them can see the sunlight: only 1–12 spiders.
Widow for permanent residence: where these spiders prefer to settle
For a long time, black widows' spiders preferred to choose Central Asian steppes and deserts as their habitat, less likely to settle in Crimea or in the Caucasus.
But now, when there is a tendency towards mass migrations of many arachnid species, it is increasingly possible to meet a black widow in the most unexpected places. For example, in 2005 a real spider invasion took place in Taganrog, although previously the inhabitants of this region had never seen them and had not heard of them.
Buffet for spider: what feeds arthropods
The black widow prefers to hunt her victim, placing the spider snares close to the ground, and her favorite places are:
- recesses under the stones
- slots and various holes, up to the holes left by rodents,
- thick of a vine,
- over small, squat plants.
The black widow prefers to be nocturnal, and in the daytime to hide in her shelter.
Insects are usually the victims of the black widow., although she will not refuse to eat and woodlice, and their relatives. If the prey caught in the network, then it is doomed to ruin: the spider puts a deadly bite on it, and then takes it aside to quietly enjoy the meal.
Cannibal or the Good Samaritan: Is there a Good Spider?
Given the fact that an average spider eats as much per day as it weighs, its role in the fight against harmful insects is quite obvious.
Also, human research has been greatly benefited by studies of poisonous spiders: based on them, medicines are developed that destroy vascular thrombi, often leading to a heart attack.
Black widow bite: sentence or temporary inconvenience
The bite of a black widow is extremely dangerous for a person, especially for children and the elderly. The poison of these arachnids is neurotoxic, which means that you can only feel the place of the bite, but it will be extremely difficult to see it.
After half an hour after the bite, extremely sensitive muscle spasms begin, starting from the places close to the bite point, and subsequently spreading to larger and more distant muscles. Then the pain passes into the abdominal cavity, characterized by a powerful spasm in the anterior abdominal wall, while the palpation of the abdomen does not bring painful sensations.
The following symptoms may also be noted, which may indicate a black widow bite:
- increased salivation,
- dyspnea,
- vomiting
- tachycardia,
- headache,
- weakness,
- feeling of anxiety.
The pain will subside within 12 hours after the bite, but in the following days it may intensify many times.
As a first aid for a black widow's bite, you can use a match cauterization of the wound, which is an effective method to neutralize the poison, but only in the first minutes after the bite.
It is better, of course, to immediately seek help in the hospital, because if help is not provided in a timely manner, the consequences may be the most adverse.
When a bite is necessary to act very quickly, there is a risk of an allergic reaction to the poison. In this case, the antidote must be administered within an hour after the bite.
And remember: in order not to face such an unpleasant “lady” as a black widow, you just need to follow some rules:
- if there is a chance of meeting a spider or you are in its habitat, then you need to dress so as not to leave a single open area of the body,
- in the case of outdoor recreation, make sure that the resting and overnight place is not located in the zone of various soil depressions, rodent holes and webs on plants,
- after walking in the zone of probable habitat of the spiders, carefully check your clothes so as not to bring the poisonous guest into the folds of the fabric,
- if you meet a spider on your way, then in no case touch it and its cocoons.
Flower wasps feed on pollen and nectar. Detailed description of the species read here.
What is the difference between wild and domestic bees? To learn this, and many more interesting things, read the article on this http://stopvreditel.ru/yadovitye/pchely/dikie.html link.
Interesting Facts
- At the moment, black widows' spiders of the genus continue to live in the Rostov region in the amount of about 2,000 individuals, and over the past years even 2 cases of their attack on humans have been recorded.
- If the black widow feels even the slightest danger, then she immediately falls out of the cobweb and pretends to be dead. The female of this spider feels very insecure and awkwardly outside the usual environment.
- During an attack on a victim, a black widow inflicts a wound on her with the help of chelicera, and then sprinkles digestive enzymes into her. After some time, the victim's body liquefies, and the spider drinks it like a nutritious cocktail.
- Previously, the black widow was considered the most poisonous spider on the planet, but recently it was replaced by a Brazilian spider soldier from its pedestal.
Know: a black widow will never attack unnecessarily, so treat her with respect and limit yourself to observation, because even with spiders you can learn something.
Characteristic
Black widows are a genus of spiders, numbering 31 species, and they inhabit all continents without exception. Among them are special representatives, the bite of which is very dangerous for humans.
The description of a black widow spider will largely depend on its species, however, they all have characteristic features of a kind.
- Dimensions - the body length of adult male spiders is about 1.2-2 cm, the length of the legs is approximately the same as the body size. Males are smaller than females approximately twice.
- Legs - the black widow has 8 legs. Characteristic - paws, ridges. On the back pair of legs are strong bristles of a curved shape that help the spider to close the web over the prey.
- Color - the body of an adult black widow spider, as can be seen in the photo, is colored black with one red or orange spot, which resembles an hourglass in shape, or with several red spots. In females that have not reached puberty, the red spots have a white edging. In European species, the stain is colored white-brown. The body of young spiders is white or yellowish-white, after a regular molt, it acquires a darker shade.
- Vision - the eyes of a black widow are arranged in two rows, each of which has 4 eyes. The average pair is the main, the side can distinguish only light and movement.
On a note! Despite the large number of eyes in general, the black widow spider sees very poorly. The presence of the victim, he recognizes only by the vibration that she creates, being in the web!
Black widows prefer loneliness, communication between females and males occurs exclusively during the mating period
A fertilized female folds her eggs in a cocoon of cobwebs, which she fastens near her hunting net. The cocoon itself is a grayish ball with a funnel outlet. The laying is under the constant control of the mother until the spider appears from the eggs.
Development in the egg takes from 2 to 4 weeks. The young offspring, just released from the eggs, immediately enters the struggle for life. Stronger individuals eat the weak, so far from all survive. As a result, only a small handful of young black widows, often up to 12 spiders, leave the cocoon.
As mentioned above, immediately after the birth of the body of young individuals painted white. And only after a few molts they will darken enough and will look like adult spiders from the black widows.
Survivors of the spiders emerge from the cocoon in spring, and at this time they are especially aggressive.
Spread
In Russia, there is also a certain type of black widow spider, which is known as white karakurt. It can be recognized by its characteristic spherical abdomen, painted white or yellowish. At the same time, there is no bright spot for this black widow. Instead of drawing a white karakurt on the surface of the abdomen there are four grooves forming a rectangle.
White Karakurt is not aggressive
Important! Несмотря на то что яд белого каракурта гораздо менее токсичен, чем у прочих черных вдов, он может быть смертельно опасным для стариков и детей!
Однако в последнее время из-за значительного потепления многие виды этих паукообразных поменяли свои привычные места обитания. It is becoming increasingly common to hear the appearance of the black widow spider in the Crimea, the Caucasus, Taganrog, the Southern Urals, and Rostov regions.
These spiders prefer to hang their web in dark dry shelters and settle mostly in poorly lit places. Therefore, a meeting with them can occur in barns, garages, toilets, located on the street, as well as in abandoned animal burrows, hollow stumps and even in dense thickets of grass.
On a note! With the arrival of cold weather, the black widow spider always moves to a warm room, and therefore in winter they can be found even in a residential building!
For the web of a black widow, random weaving is characteristic and, as a rule, it is stretched in the horizontal plane.
Bite effects
Black widow females are always more aggressive than males, but if you accidentally disturb the latter, even he is able to attack and bite a man. At the same time, the risk of an attack from the side of the spider increases many times in the fall, when it moves to residential premises.
A black widow spider bite is moderately painful - it feels like a pin prick. Characteristic symptoms are:
- dilation of the capillaries, which causes a slight reddening of the skin,
- swelling develops almost immediately,
- after half an hour - an hour, muscle spasms appear in the affected area, which are accompanied by intense pain,
- further tense the muscles of the anterior abdominal wall, the pain continues to grow and becomes painful.
On a note! This symptom is often mistaken for a sign of peritonitis, but the palpation of the abdomen is painless!
Two small red dots appear at the site of the bite.
Perhaps the development of some additional symptoms, among them:
- high blood pressure
- intensive salivation,
- rapid sweating
- vomiting
- an attack of sudden shortness of breath,
- heart rhythm disturbance with an increase in heart rate,
- anxiety,
- general weakness
- headache,
- urinary incontinence,
- muscle twitching
- skin sensitivity disorder: from tingling and "goosebumps" to complete numbness.
An allergic reaction to the poison is also possible. After the bite, it is desirable to introduce an antidote as early as possible. After three hours there is a big risk of aggravation of the already serious condition of the victim, up to a lethal outcome.
On a note! In the best case, the delay is fraught with irreversible trauma to the nervous system and the deterioration of the mental state without the possibility of its restoration or even minimal improvement!
In order to avoid trouble, watch the spiders when you spend time outdoors or in a country house, and under no circumstances take them in hand.
