The spiders of the black widow can disappear, but the venomous brown widows are increasing
The most aggressive species attack - and eat - their timid cousins.
Black Widow: The very thought of the brilliant and brilliant body of the spider of half a -butt which carries a pattern of hourglass Crimson Telltale hits fear in the hearts of arachnophobes - and anyone with an attic or wood. Latrodectus Mactans is known as the deadliest spider In North America, but they disappear. According to a new study, the Amerindian species is threatened by the young people who are reaching a closely related species, the widow Brune ( Latrodectus geometricus ).
Brown widows - As poisonous , but less, did he arrive in the southern United States of South Africa in the 1930s. In certain suburban and urban areas, their number increases, while their cousins become rare. Do brown widows take control by force? Read the rest to hear the experts.
Read this then: If you notice it in your courtyard, pay attention to poisonous spiders .
Black widows are poisonous but shy.
Black widows are feared because of their poisonous bite, but also because of their affection to live near humans in the hangars and the corners of the house. AE0FCC31AE342FD3A1346EBB1F342FCB
Although their venom is 15 times stronger that the Seakers' venom in sonnette, according to Smithsonian Magazine, their small size means that, although it can be very painful, their bite is only a real risk for very young and old people. These are reclusive creatures and do not bite except disturbing actively.
Brown widows have thousands of babies.
The tightly linked brown widow is smaller than her cousin in black and cream, with a marking of orange or distinctive yellow hourglass on her abdomen and her geometric marks on the back and sides.
According Entomology today , a female brown widow spider can produce an average of 22 egg bags - With up to 282 eggs per bag - on average throughout his life, and an egg bag every four days at the start of his reproductive life. This is added to thousands of spiders.
Like black widows, brown widows often choose to live around people. Brown widows are less poisonous than their native cousins, but they are not at all shy.
Read this then: If you live here, pay attention to this toxic spider in your home .
Brown widows are much more aggressive, especially when they are young.
The young brown widows proved to be extremely aggressive towards black widows, attackers and eating them with little or no provocation.
According to New York Times, The aforementioned recent study, published in the Annals of the Entomological Society of America , shows that "young spiders of the widow brunette have a tendency To seek and kill their American cousins. ""
The study reveals that, over several decades, black widows have disappeared, their brown parents growing in the population until they are more numerous than the black widows from 20 to one in certain regions of the United States , the writers of the study noted that each time the two species overlapped, the black widows finally disappeared.
Black widows do not retaliate and they pay the price.
According Charles Van Rees , conservation scientist and editor -in -chief of Gulo in nature , The case of brown and black widows is "an example of a manual of competitive interactions of invasive species".
"In other words, while certain invasive species cause an environmental damage by acting as a predator towards a species which has no defenses, others cause damage by competing with their native counterpart," explains Van Rees. "In general, the more linked two species, the more likely they are to have similar lifestyles and occupy similar niches."
The problem, says Van Rees, is that non -native brown widows have advantages compared to black widows: they are able to produce about twice as many young people each time they happen again, and these young people are much more aggressive And will challenge the spiders nearby and attack those who do not defend themselves.
Since black widows are relatively non -aggressive, they are victims of this assault. When they occupy the same living spaces, brown widows will kill or hunt black widows.
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The most aggressive species take over, but there can be a solution.
The observation of the two species in various places gives the same result: shy black widows often withdraw, but their brown cousins attack tirelessly.
In the South and West American, black widows are likely to lose ground in urban and suburban areas, where brown widows are starting to be more numerous than the most numerous.
So will black widows become extinguished? According to Van Rees, although they have already disappeared from certain areas, scientists think that the greater preference of the black widow for drier climates and the desire to live in rural areas could keep some of them out of scope of aggressive invaders.
Van Rees calls this a new example of "niche partitioning, when two species are able to coexist because they manage to occupy slightly different niches".
This niche partitioning could be a silver lining for the population of an intimidated and besieged black widow, because they can live in deserts and woods, where their brown cousins are not also likely to follow them. When brown widows take control of the attic and cubby holes in your neighborhood, their cousins may well luggage and go to the hills.
