Invasion Of 3-Inch GA Spider Likely To Parachute Along East Coast

GEORGIA — The invasive Joro spider — which stretches to 3 inches long as an adult — and known to give some Georgians the "heebie-jeebies," may have plans to conquer new territory.

New research from the University of Georgia suggests that these big, creepy crawlies could soon spread beyond Georgia and likely colonize the entire East Coast. The spiders’ golden webs will be all over power lines, in trees and on porches this summer.

Joro spiders don't hurt people or pets, and are good food for birds. The creatures won’t bite unless cornered, and their fangs are often not large enough to break human skin, UGA said.

“There’s really no reason to go around actively squishing them,” said Benjamin Frick, an undergraduate researcher. “Humans are at the root of their invasion. Don’t blame the Joro spider.”

Published in Physiological Entomology, a study by UGA researchers compared the Joro spider with its relative, the golden silk spider, which first moved to the Southeast from the tropics around 160 years ago.

Joro spiders use their web like a parachute to carry them via the wind to new locations, a behavior called ballooning, a researcher told WGCL.

According to UGA, the golden silk spider hasn’t been able to spread beyond the Southeast due to its vulnerability to cold. Before the study, scientists didn’t know whether the Joro spider faced similar geographical limitations.

To find out, researchers tracked sightings of the spiders across Georgia throughout the year. They also performed tests to compare the species’ cold tolerance, including measuring the arachnids’ metabolic, heart and survival rates during a brief freeze.

The study found that despite their similarities, the Joro spider has about double the metabolism of its relative, has a 77 percent higher heart rate and can survive a brief freeze that kills off many of its cousins.

These findings mean the Joro spider’s body functions better than its relative in a cold environment. As a result, the Joros can likely exist beyond the borders of the Southeast, UGA researchers said.

"It looks like the Joros could probably survive throughout most of the Eastern Seaboard here, which is pretty sobering," Andy Davis, a corresponding author of the study and a research scientist at the Odum School of Ecology, said in an article by UGA.

It’s not just cold-hardiness that makes the Joro likely to spread beyond its current region, UGA researchers said. Humans may help spread them to other regions.

“The potential for these spiders to be spread through people’s movements is very high,” Frick said. “Anecdotally, right before we published this study, we got a report from a grad student at UGA who had accidentally transported one of these to Oklahoma.”

The Joro spider first arrived in the state around 2013, UGA researchers said. Native throughout parts of Asia, researchers believe the first Joros to arrive in the U.S. were likely stowaways on shipping containers.