Large black-and-yellow spiders from Asia have spread across the eastern coast of the United States in recent years, but don’t panic, although their appearance may seem frightening, they are not dangerous and could help the local ecosystem.
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Scientists have been studying the invaders, which are also colored in shades of bright red and dark blue, since their arrival in Georgia around 2013.
Within a few years, huge webs of guru spiders became common in the forests of this region. Woven to the height of humans, it can be more than a meter in diameter, and can serve as a kind of parachute, to fly long distances thanks to the air currents.
“The reason to start this project is because they fell into our arms,” Andy Davis of the University of Georgia told AFP. “They’re pretty much everywhere here in North Georgia, they’re scattered all over my yard.”
Perhaps arriving on a container or truck, they must now continue to colonize America, and head north.
The researchers sought to trace their presence in the United States. Specimens have been observed in South, North Carolina, Tennessee, and even Oklahoma.
Without any help, these spiders would likely take about 20 years to reach Washington, D.C., according to Mr. Davis. But he believes that this is likely the case faster, because sometimes these little monsters unwittingly find themselves passenger cars, and thus are transported over hundreds of kilometers.
The study by Andy Davis and his colleague Ben Frick also detailed these spiders. They feed on small insects (midges …) and can survive short periods of frost. In general, being from Japan, they can adapt to temperate climates.
plea for clemency
Invasive species are often associated with negative consequences in people’s minds. This for example is the case of lycorma delicatula, a Southeast Asian native insect that landed in Pennsylvania in 2014, known to exterminate fruit trees and other plants.
But according to Andy Davis, guru spiders shouldn’t be a cause for concern.
He compares them to another species that landed in the United States 160 years ago from the tropics, the golden silk spiders (Trichonephila clavipes).
The latter is now found “everywhere in the southeast.” [du pays]and cause no harm,” the researcher explains. “They’ve been there for a long time, they’ve integrated themselves into the ecosystem, and guru spiders could be on the same path.”
It can even become the meal of some predators, such as lizards or birds.
Andy Davis, who advocates indulgences, also emphasizes that they are not dangerous to humans.
“I really don’t think guru spiders deserve to be crushed or killed,” he says. “They’re really not after us, and it’s not their fault they’re here.”
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