Huge Invasive Spiders Expected to Spread to Boston. Should We Be Worried?

A new study suggests the Joro spider is well suited to colder temperatures

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Researchers say a large spider native to East Asia that proliferated in Georgia last year could soon spread to much of the East Coast, including Boston.

The Joro spider's golden web took over yards all over north Georgia in 2021, unnerving some residents. The spider was also spotted in South Carolina, and entomologists expected it to spread throughout the Southeast.

A new study suggests it could spread even farther than that. The Joro appears better suited to colder temperatures than a related species, researchers at the University of Georgia said in a paper published last month.

It has about double the metabolism, a 77% higher heart rate and can survive a brief freeze that kills off its relatives, the study found. The researchers also noted that Joros are found in much of Japan, which has a similar climate to the U.S.

“Just by looking at that, it looks like the Joros could probably survive throughout most of the Eastern seaboard here, which is pretty sobering,” study co-author Andy Davis said in a statement.

What is a Joro spider?

The Joro — 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 three inches across when their legs are fully extended.

Dr. Jessica E. Garb from UMass Lowell says a large spider native to East Asia that proliferated in Georgia last year could soon spread to much of the East Coast, including Boston.

How did they get to the U.S. to begin with?

It’s not clear exactly how and when the first Joro spider arrived in the U.S. or why they were so abundant in Georgia last year.

Their impact on native species and the environment is also not clear, though some researchers believe they are benign.

Will they eventually arrive in Boston? And when?

Davis told The Boston Globe that there's a good chance the joro spider could get to Boston by ballooning — spinning silks to fly through the air — or by hitching rides on people's cars.

“Our study really did not tell us how far the joros will go, but based on the temperatures in the Boston area, I would say there is a pretty good chance they will make it there sometime in the next 5-10 years,” Davis told the Globe. “That is, if they don’t hitch a ride on a car first — that is very likely.”

Should we be worried?

According to Adam Larson, an NBC News writer and science communicator, there's nothing to worry about. He said Joro spiders can be a nuisance, but they don't seem to cause any major problems for ecosystems and the economy.

But that doesn't mean people who are afraid of spiders will be happy to see them.

Larson said Joro spiders might actually benefit the Northeast, as they could help control populations of more harmful invasive species like stink bugs, which are capable of wiping out entire crops of corn, peppers, tomatoes, apples and peaches. Joro spiders eat stink bugs.

The Associated Press contributed to this report.

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