Joro spiders, invasive species from Asia, spreading in Eastern US

(NewsNation) — It’s the size of your palm, spins golden webs and could be in your backyard in the near future.

A large spider native to East Asia that first appeared in the Southern U.S. is taking hold in the eastern part of the country and spreading north, according to researchers and scientists.

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.

It’s not clear exactly how and when the first Joro spider arrived in the U.S. In Georgia, a researcher identified one about 80 miles northeast of Atlanta in 2014, and the species began to take hold in the state two years ago. They have also been found in South Carolina and more recently as far north as Maryland.

Andy Davis, a research scientist at the University of Georgia, told the New York Times it’s “only a matter of time” before the spiders make their way to New York. Likewise, ecologist José R. Ramírez-Garofalo said in a SILive.com report they could begin appearing in the state “possibly even next year.”

That’s also the consensus among a group of Clemson researchers who created a model to predict the future spread of the Joro throughout the United States.

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

The peer-reviewed study published in Ecology and Evolution concluded that the spider was most likely introduced in northern Georgia around 2010. Since then, the spider has spread to a range “that spans at least 120,000 square kilometers,” the researchers said, occurring across Georgia, South Carolina, North Carolina and Tennessee.

There have also been sightings in Alabama, Maryland, Oklahoma and West Virginia.

The spiders use a process called “ballooning” to travel, sending a string of web into the air and letting the wind whisk them away.

So far, the impact of the invasive species appears to be “nuanced,” according to the Clemson researchers. While it may eat other invasives like the spotted lanternfly — which has become abundant in New York — it also eats just about everything else, too.

“These spiders don’t seem to care what gets in their web; they’re just as likely to eat brown marmorated stink bugs as they are to eat a Monarch butterfly. To say they’re more beneficial than another spider is just simply wrong — they’re a spider — and if something gets caught in their web, it’s going to get eaten,” Coyle said.

The study found that where Joro spiders are concentrated, other native spiders are not.

“These are not just benign spiders coming to catch and kill bad things; these are pushing out native species and catching and killing whatever happens to get in their webs,” Coyle said.

While they may look intimidating, Joro spiders are rather shy, according to a University of Georgia study. Researchers there compared more than 450 spiders’ responses to a brief and harmless disturbance and found that while most froze for less than a minute, Joro spiders remained motionless for more than an hour.

They are considered harmless to people and pets.

The Associated Press contributed to this report.