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What are Joro spiders? The invasive species spreading in the US

(NewsNation) — A large yellow spider native to East Asia is taking hold in the Eastern U.S. and is heading north, according to scientists.

The Joro spiders are sometimes called “parachuting” spiders because they can move by shooting out a long strand of silk that gets caught in the wind and carries them through the air.


What are Joro spiders?

The Joro — trichonephila clavata — is part of a group of spiders known as “orb weavers” for their highly organized, wheel-shaped webs. Common in Japan, China, Korea and Taiwan, Joro females have colorful yellow, blue and red markings on their bodies. They can measure 3 inches across when their legs are fully extended.

The Joro appears better suited to colder temperatures than a related species, researchers at the University of Georgia said in a paper published last year.

Are Joro spiders dangerous?

According to scientists, the Joro spider only poses a threat to the things that get caught in its web. This can include butterflies, cockroaches, stink bugs and wasps but not humans.

“We have no evidence that they’ve done any damage to a person or a pet,” Clemson assistant professor Dave Coyle said.

While all spiders have a bit of venom, the Joro spider is relatively harmless to humans.

“From what I gather, it feels like a bee sting,” said Andy Davis, a research scientist at the University of Georgia. “I’ve handled about 500 of them. I haven’t been bitten yet. You’d have to manhandle the spider for it to bite you, but same with a bee. If you leave it alone, it will leave you alone.”

However, their presence can have an ecological impact. Areas with high populations of Joro spiders have been found to have lower populations of native spiders.

Where are the Joro spiders found?

It is unclear how and when the Joro spider first arrived in the U.S. It was first identified in Georgia in 2014 before it spread across the state.

Joro spiders have now been spotted in Alabama, Maryland, North Carolina, Oklahoma, South Carolina, Tennessee and West Virginia, according to NewsNation affiliate PIX11.

“Data shows that this spider is going to be able to inhabit most of the eastern U.S.,” Coyle said in a news release. “It shows that their comfort area in their native range matches up very well with much of North America.”

Ecologists say they prefer to be outdoors, so you are unlikely to find one in your home.