By now, you’ve likely read some breathless headlines about the threat of invasive Joro spiders raining down over the East Coast this summer.
They’re huge and scary-looking, and could soon be moving into most of the Eastern Seaboard of the U.S., according to new research.
A regional online local news network recently ran a story under the headline “Invasion Of 3-Inch Spider Likely To Parachute Along East Coast” and Axios posted one that screamed, “Giant Spiders Expected to Drop from Sky Across the East Coast This Spring.”
At least in Pennsylvania, however, there’s no clear indication that Joro or any spiders will be pouring from the skies like rain during a summer thunderstorm.
The bright yellow Joro spiders that can grow up to three inches in diameter are an invasive pest from Asia and were likely introduced to North America as stowaways on shipping containers over the past decade or so, with the first confirmed discoveries happening in Georgia in 2014. In the years since, the spiders have spread to other Southern states, including Alabama, North Carolina, South Carolina, and Tennessee.
But don’t worry too much: Joro spiders are harmless to humans — and even do some good.
“People should try to learn to live with them,” Andy Davis, a research scientist in the Odum School of Ecology and one of the authors behind the recent study, told UGA Today, a publication by the University of Georgia.
Published in the journal Physiological Entomology, the study says that the palm-sized joro spider, which has been largely confined to warmer southeastern states for nearly a decade, could soon be expected to colonize regions with colder climates.
That’s because researchers have discovered the large arachnids, with their brightly hued blue-black and yellow striped legs, have a higher probability of surviving a brief freeze than other closely related species of the same genus.
More details from AWM:
Joro spiders are originally found in Japan, which has a climate similar to parts of the United States.
“Just by looking at that, it looks like the Joros could probably survive throughout most of the Eastern seaboard here, which is pretty sobering,” University of Georgia study co-author Andy Davis said in a statement.
Joro spiders are also known as trichonephila clavate and are famous for their masterful webs, which are highly organized and shaped like wheels. These spiders are quite common in Japan, China, Korea, and Taiwan. The females are very colorful, with yellow and red markings on their black bodies. Females can grow to be three inches. Males have a plainer look with a brown body.
“The potential for these spiders to be spread through people’s movements is very high,” Benjamin Frick, co-author of the University of Georgia’s study on the spiders, said in a statement. “Anecdotally, right before we published this study, we got a report from a grad student at UGA [the University of Georgia] who had accidentally transported one of these to Oklahoma.”
But even if you are freaked out by spiders, you may be happy to know the Joro isn’t known to hurt humans or pets.
“They are harmless to people as they are reluctant to bite and, if bites do occur, the venom is weak and not medically important,” the Penn State Extension notes on its website.
This spider tends to eat brown marmorated stink bugs, Korman said. And so far, there’s no evidence the Joro will damage any trees or plants, “although their large webs might have a negative aesthetic effect.”
Watch the video below: