Some spiders die when cold weather hits, but scientists warn that invasive species from Asia may survive and continue to invade the United States.
Scientists at the University of Georgia froze more than two dozen eight-inch-long guru spiders spotted on the East Coast to see if the black and yellow creatures could survive harsh winters.
The experiment showed that approximately 75% of the spiders were unaffected, while the rest showed some injuries.
Researchers told DailyMail.com they now “see no barrier” to the invasive species' march north.
University of Georgia scientists predict that the Goro giant spider will expand its territory as far north as Canada and as far west as Washington state
The researchers' assessment was based in part on the results of a chilling scientific experiment, in which more than two dozen giant spiders were frozen for two minutes each — with every spider guru alive to tell the tale. (Above, a Guru resident battles the cold in Japan)
The golden web of “Guru” spiders took over yards across north Georgia in 2021, alarming some residents, and they were soon spotted in South Carolina and other states.
But biologists and entomologists now expect the creature to expand its territory as far north as Canada and west as far as Washington state.
“Their native range in Asia includes much of western China and the entire Korean Peninsula, so the spiders are clearly well adapted to fairly cold climates,” one researcher told DailyMail.com.
Scientists Andrew Davis and Benjamin Frick of the University of Georgia tested 27 guru spiders against 20 of their North American competitors in the food web: the golden silk spider.
Both creatures are recluse spiders, a class of spiders known for their circular, wheel-like webs.
Of the 27 Guru spiders, nearly three-quarters (74.1%) passed this freezing experience completely unscathed, with the remaining seven surviving, albeit with icy injuries.
“We evaluated the ability of each species to tolerate short periods of below-freezing temperature,” Davis and Frick explained their experiment to the Journal of the Royal Entomological Society. Physiological entomology.
“The spiders were held in 50 ml falcon tubes and placed in a freezer, which we treated to undergo a gradual drop from above freezing to below freezing.”
Of the 27 Guru spiders, nearly three-quarters (74.1 percent) passed this freezing experience completely unscathed, with the remaining seven surviving, albeit with icy injuries.
However, only 10 out of 20 golden silk spiders managed to survive.
The researchers found that four of them died instantly, while six others faced similar partial injuries, including “loss of leg function, abdominal lacerations (from ice crystals) and loss of orientation.”
The researchers said one explanation for this difference may be that the golden silk spider (Trichomonas clavipes) first came to the southern United States through the tropics.
However, even in those warmer climates, the guru spider (Trichophyton clavata) may still be a fierce competitor for its nested ecological niche.
Of the 27 Guru spiders, nearly three-quarters (74.1 percent) made it through the freezing experience completely unscathed with the remaining seven surviving albeit with ice injuries. However, only 10 out of 20 golden silk spiders managed to survive, and four of them died instantly.
“The southern part of the original range extends into subtropical Indochina,” Professor Will Hudson, an entomologist and colleague of Frick and Davies, told DailyMail.com.
“I wouldn't say they're moving north faster than south at this stage,” Professor Hudson said.
“I see no impediment to eventual expansion to include almost all of the eastern United States with the possible exception of northern New England and the northern Great Lakes.”
However, last month, other ecology and entomology researchers in New York, Tennessee, Texas, and South Carolina pooled their resources to predict how quickly and how far the invasive Guru spider is likely to spread.
Their findings were published in the journal Environment and evolutionThe study's lead author, biologist Dr. David Nielsen, was left convinced that the yellow-and-black spider would likely pass through the Great Lakes and become endemic in Canada.
“Our models suggest two possible things,” Dr Nelson told DailyMail.com.
“First, the area in Asia that Goro currently inhabits may not be the only area they are likely to inhabit. Their range may be limited due to competition with other large spiders occupying the same areas.
“Second,” Dr. Nelson continued, “Gurus are native to Korea and Japan, with areas with a climate similar to Michigan.”
“Therefore, it is not surprising that our models indicate that it could continue to spread northward.”
But while the majestic Guru spider is likely to survive, doctoral student and ecologist José R. Ramírez Garofalo, who is currently conducting research for Rutgers Lockwood LaboratoryHe warned against excessive demonization of these gentle giant species.
“Although this is always a concern about new invasive species, the Goro spider does not appear to pose a significant threat to local biodiversity,” Ramirez Garofalo told DailyMail.com.
Although gores are venomous, experts point out that they do not threaten humans, dogs or cats, and will not bite unless they feel threatened.
“In fact, if you look at the literature, there have been no documented deaths, nor any notable bites that are medically significant,” Ramirez Garofalo told DailyMail.com.
“Given their behavior (they are very reluctant to bite) and the evidence from the literature, they actually pose no threat to humans or our pets,” he said.
Last month, other environmental and entomology researchers in New York, Tennessee, Texas and South Carolina pooled their resources in an attempt to predict how quickly and how far the invasive Guru spider might spread. The short answer is far and wide throughout the United States
While the Guru spider is likely to survive, ecologist José Ramírez Garofalo, who conducts research at Lockwood Laboratory at Rutgers, cautions against demonizing this gentle giant: “There have been no documented deaths, nor any notable bites of medical significance.” .
Ramirez Garofalo, who also serves as vice president of the Conservators of Pine Oak Woods in Staten Island, added that the guru spider's locomotion and parachuting methods will certainly take them further than some other invasive species.
“Since the main ways they spread are either 'ballooning' into the wind or riding in cars, they will generally spread to where the wind is blowing, or where there are humans,” the ecologist said.
The Guru spider feeds mostly on flies, mosquitoes, and stink bugs—the latter of which are not only a threat to crops, but a threat that is currently free to control without natural predators in many parts of the United States.
In fact, some researchers believe that the guru can be a blessing in disguise for farmers and should be left alone.
“There's no real reason to crush them effectively,” said Benjamin Frick, a researcher at the University of Georgia.
“Humans are the root cause of their invasion,” Frick said. “Don't blame the Guru.”
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