Joro Spider, A Giant Flying Arachnid, Could Invade Connecticut

CONNECTICUT — It's the stuff arachnophobe nightmares are made of — a huge flying spider that swarmed Georgia by the millions last summer could soon be on the move. Now, this invasive arachnid is crawling to take over much of the East Coast.

The Joro — or Trichonephila clavata — is part of a group of spiders known as orb weavers for their highly organized, wheel-shaped webs. Joro females have colorful yellow, blue and red markings on their bodies and can measure 3 inches across when their legs are fully extended.

Now, according to new research published in February by the University of Georgia, these spiders and their golden webs could soon spread beyond Georgia and likely colonize the entire East Coast. But how?

The study found the Joro, native to East Asia, actually has a high-enough metabolism to survive the colder temperatures that kill off many of its cousins. This means the Joro's body functions better than its relatives in a cold environment, and it also means Joros can likely exist beyond the borders of the Southeast.

"They could be spread domestically in a similar way, as stowaways on luggage or in vehicles," said Katherine Dugas, an entomologist with the Connecticut Agricultural Experiment Station, which tracks meddlesome bug migrations locally.

The first Joro to make landfall in the United States hitched a ride here inside a shipping container in 2013. The critter gets its name from Jorōgumo, a Japanese spirit that disguises itself as a beautiful woman to prey upon gullible men — and that's probably a factoid that's not very helpful to most arachnophobes, sorry...

"The potential for these spiders to be spread through people’s movements is very high," said Benjamin Frick, co-author of the study and an undergraduate researcher with the University of Georgia. "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."

When it's not hitching a ride, the Joro can take flight. The bug doesn't have wings, it flies using its web. In fact, when Joro hatchlings emerge in the spring, they ride the wind across enormous distances — sometimes up to 100 miles — using web "parachutes," allowing it to colonize new terrain.

But as far as potential environmental concerns, it looks like the Joro spider hasn’t had much of a reported impact on local ecosystems in the southeast, according to Dugas. They're big, colorful, spin huge webs, ride the wind, but aren't actively harmful to people.

"Orb weaver spiders are not aggressive and are quick to flee when any large disturbance hits their web," Dugas said. "Bites are incredibly uncommon, and usually due to the spider being physically crushed against bare skin and unable to escape. The bite of the Joro spider is not considered medically significant."

Also, instead of lovesick men, Joros kill off mosquitoes, biting flies and other invasive species including the brown marmorated stink bug, which damages crops and has no natural predators, according to Live Science.

CAES has yet to receive any reports or confirmations of the Joro spider in Connecticut, Dugas said, but added, "I’m sure we’ll be fielding some concerned calls from citizens this summer."

Some experts aren't convinced a large-scale U.S. invasion will ever happen, according to a CNN report.

"Although it can withstand somewhat colder climates, I doubt it could withstand the climatic conditions found in the northern and western U.S.," Paula Cushing, a senior curator of invertebrate zoology at the Denver Museum of Nature and Science, told CNN.

Also, Joro spiders can tolerate a brief freeze, but not much more, Anne Danielson-Francois, an associate professor at the University of Michigan in Dearborn, told CNN. Danielson-Francois was not involved in the study.

"In my opinion, I do not think they would be found further north than North Carolina or towards the west," she told the network.

With Patch Editor Megan VerHelst