The female small black spider has a bad reputation and there are various rumors about her. Here are some of them: she is capable of inflicting a fatal bite on a person, for lunch she eats her husband as the main course.
Unfortunately, these stories are more or less true. Black spiders are distributed throughout the world. Of course, there's little chance that a black spider will make a nest in your home, but what if... There's something to see here: it's a shiny black spider with a red, yellow or orange pattern on its abdomen, often in the shape of a watch glass.
Description and features of the black widow
The black widow spider is famous for its unusual appearance. We can say that it is the most poisonous and dangerous spider in all of America. This spider received such a terrible name for the reason that female widows eat their males after mating and that is why the life expectancy of a male individual is negligible.
The female also eats the male when she mistakes him for food. Scientists say that by eating the male, the females receive the necessary proteins, which will be useful for the little spiders in the future.
Males approach black widow webs with great caution. If the female is not hungry, then she will gladly allow the future father of her children into her territory and share the marriage bed with him, and if she is hungry, then she will immediately eat the sluggish groom. To prevent this from happening, cavalier spiders dance a kind of mating dance, shaking their bodies and legs, swaying slightly from side to side.
The black widow leads a hidden lifestyle and never attacks people without reason. Most often, people suffer from spider bites that have crawled into clothes or shoes. The only reason can be if a person tries to disturb her home. In this case, the black widow's attack will look like self-defense.
When you see a black widow spider in the photo, you can’t help but notice the red marks located on the “widow’s” rounded belly. The large red spot is worn only by females. They are considered the most poisonous and dangerous than males.
The photo shows a male and female black widow spider
The description of the black widow spider is very interesting. The black widow spider has 8 legs, like all arachnids. Females are noticeably more elegant and larger than their males. Has a shiny black outfit with a bright red mark on its abdomen, which is shaped like an hourglass.
The male black widow spider looks much paler, has a faint yellowish color and is several times smaller than the female. It is rarely possible to see it, since for the most part they are eaten for the sake of procreation of the future race. Females reach 40 mm in length.
Another distinctive feature of the black widow spider is its very hairy legs. On the hind legs there are small bristles with which they can crawl towards their prey.
Black widows lay eggs in peculiar balls. One such ball usually contains from 250 to 800 eggs. The cubs are born completely whitish, but after some time they become similar to their parents.
In the photo there is a ball with black widow eggs
Being children of their parents, little spiders have an innate cannibalism. While still in the embryo, they eat each other. Therefore, from a huge number of eggs, only about 10-12 spiders hatch. The black widow spider is poisonous . A black widow spider bite can seriously affect human health.
After the poison enters the body, a rash appears throughout the body, attacks of nausea occur, and a fever may rise. This state lasts up to 12 hours. It is best to quickly take care of the antidote. The venom of a female has a stronger effect on the body than that of a male. Thanks to modern medicine, it has been possible to reduce the number of deaths from bites.
New weirdness of spider love
Recently, Uruguayan zoologists discovered interesting spiders, the males of which are much larger and more aggressive than the females. Interestingly, unlike the classic situation in which the spider eats her husband after mating, in these animals the opposite happens. A male can eat a female he doesn’t like, not after mating, but during the process.
This "wrong" spider, Allocosa brasiliensis, lives in South America, right on the border of Brazil and Uruguay. It belongs to the ecological group of wolf spiders, which do not weave trapping webs, but hunt insects from ambush or chase down prey. These ruthless hunters are active at night, and during the day they hide in earthen burrows located at the roots of bushes or among turf. Moreover, the male's burrow is always larger and more noticeable than that of the female.
In representatives of this species, everything is arranged differently from typical spiders. First, the male Allocosa brasiliensis is larger and more aggressive than the female. Secondly, during reproduction, it is not he who comes to the burrow of his chosen one: on the contrary, the spider herself comes to visit him. In addition, males can fertilize several females, but spiders usually visit only one gentleman each season.
Dr. Anita Eisenberg, who leads a group of arachnologists studying the behavior of Allocosa brasiliensis, believes that it all depends on the conditions in which this species of spider lives.
However, the situation when the male is larger than the female in spiders can be considered unique. There are several cases where spiders are the same size as their suitors, although usually the female is still several times larger than her suitors. By the way, contrary to the widespread stereotype, she does not always eat the male after mating.
In another cross spider, Araneus marmoreus, the male often escapes from the deadly jaws of his girlfriend by jumping onto her back after copulation and sitting there for some time. And male nurse spiders (Pisaura mirabilis) are often saved by giving gifts to their chosen ones. Before mating, they bring the spiders a dead insect wrapped in a web. Having presented a gift, gentlemen often immediately pretend to be dead and fall at the feet of the spider.
However, some males of Pisaura mirabilis deceive their female friends by bringing them in a package not an insect, but a tightly packed sliver or pebble. Interestingly, they often manage to escape alive and unharmed. It turns out that deception is sometimes evolutionarily beneficial for procreation.
Male tarantula spiders almost always leave the scene of a “love battle” alive and healthy. At the same time, during mating, some stroke the female with their pedipalps along the “erogenous zones” on the front legs, putting them in a state close to a trance. In order to come to their senses after this, they need about half a minute. During this time, the male always manages to escape. Some of the male tarantulas, whose girlfriends live in earthen burrows, lure her out by tapping her paws on the threshold, and when she just sticks out of the burrow, they immediately begin fertilization, and they do it with lightning speed. So when the spider fully appears on the surface, the male manages to run away to a safe distance.
Read the most interesting things in the “ Science and Technology ”
Add Pravda.Ru to your sources in Yandex.News or News.Google , or Yandex.Zen
Quick news in the Telegram channel of Pravda.Ru . Don't forget to subscribe to stay updated on events.
Source
Lifestyle and habitat of the black widow
The black widow spider lives all over the globe. Their usual habitats are: Europe, Asia, Australia, Africa, America. The black widow spider in Russia was previously exotic and could only be seen in insectariums, where scientists studied them.
However, it has now been confirmed that they are quickly emigrating to Russia. Recently, female and male spiders have been discovered in the Urals and Rostov region.
The black widow loves to penetrate human buildings and weave her webs there. Their favorite places are dry and dark shelters, such as basements and sheds.
The spider can settle in an old stump or mouse hole, as well as among the dense vegetation of a vineyard. In winter, they look for warm conditions and are able to penetrate even a person’s home.
The risk group for the black widow is considered to be children and the elderly, who, due to their lack of understanding or curiosity, can come into contact with this poisonous creature. To avoid the disastrous consequences of your enemy, you need to know by sight.
How do black widows reproduce?
A black widow spider spins silk for eggs. (Image credit: Department of Biology, University of California, Riverside)
According to Canadian Geographic, black widows are mostly solitary except in late spring when mating occurs. When ready to mate, males first spin silk, which they soak with sperm, and then coil appendages called palps near their head. When they find a receptive female, they insert their sperm-covered palps into her reproductive opening. ()
The female then creates egg sacs that can contain many hundreds of eggs, which hatch in about 30 days, according to the NCC. The spiderlings are whitish or pale yellow after hatching and darken with each moult; females reach maturity in about 90 days and live for about 180 days thereafter, while males mature in about 70 days and then live for another 30 days.
However, black widows Latrodectus mactans are known to live up to three years in the wild and up to four years in captivity. ()
Types of black widow spider
Karakurt is the second most poisonous representative of black widows. It is most active in the summer months. The spider is not aggressive and rarely attacks first, only when it feels a threat to life. An interesting fact is that karakurt poison does not affect dogs, but can easily kill an adult camel.
The brown widow is a type of black widow. Their power extends from the northern part of America to the borders of Texas. Their color mainly ranges from light brown to dark brown. On the lower part of the abdomen there is a bright orange mark. The brown widow is considered the safest of all widow spiders. The poison poses no danger to humans.
The red katipo is another relative of the black widow. There are only a few of them left on the entire planet. Katipo means one that stings at night. Their size is not large. The female is black and has a red stripe on her back. Habitat: New Zealand. The web is triangular in shape. Diet: insects.
Australian black widow - habitat Australia. The female is small (10 mm), the male is much smaller than the female (4 mm). In Australia, this type of spider is considered very dangerous. When bitten, a person feels severe pain. There is an antidote that removes the mortal danger, but as it turned out, the pain after the bite still does not go away.
Western black widow spiders are poisonous. Habitat: America. Females are not large (15 mm). Color black with a red spot. Males are painted pale yellow. Females weave very strong webs.
Females are three times more poisonous than males
The venom of a female black widow is three times stronger than that of a male. Therefore, the bite of a male black widow is not so dangerous to humans. A bite from an adult female black widow from her much larger venom sacs can cause some problems. The size of female black widows, which is approximately 38 centimeters, is also almost twice that of males.
Female (top) and male black widow spiders
Black widow nutrition
About the black widow spider, we can say that they feed like other arachnids. The spider's diet consists of insects. They hang upside down and wait for their prey. Don't mind eating flies, mosquitoes, midges, beetles and caterpillars.
As soon as potential food falls into the web, the spider sneaks up in order to tightly wrap the vital food in the web. Spiders pierce their prey with their fangs and inject their poisonous solution into the victim’s body, which liquefies the body of the prey, and it dies.
An interesting fact is that the black widow spider can go without food for a long time. If there is no food nearby, the spider can live for about a year without food.
Reproduction and lifespan of the black widow
During sexual intercourse, the male uses the pedipalps to transfer sperm into the female's body. Sometimes only one mating occurs, but the female can store the seed in her body and use it, for example, after a few months.
The female black widow spider lays her eggs in silky balls, where the eggs are completely safe. Females incubate their babies for one month. The lifespan of female karakurt spiders is five years, and the lives of males are much shorter than those of female black widow spiders .
The lifespan of spiders depends on many factors. This may be a lack of food, the nature that surrounds them, but most importantly, this is their home for spiders. In the absence of a reliable home, which for them is a strong, silky, dense web, the Karakurt black widow spider definitely dies.
How does reproduction occur in spiders?
The copulatory organs are formed on the male's pedipalps only during the last molt. Before mating, the male secretes a drop of sperm from the genital opening onto a specially woven arachnoid mesh, fills the copulatory organs of the pedipalps with sperm, and during mating, with their help, introduces sperm into the seminal receptacles of the female.
Interesting materials:
How to send many photos to iPhone? How to send a regular message from iPhone to iPhone? How to send a video on Skype? How to send a request on Instagram for a live broadcast? How to send a parcel via DHL? How to flip an image in Illustrator? How to edit your post on Instagram? How to repair a scratch on a refrigerator? How to transplant guppy fry? How to sort channels on a Sony Bravia TV?
