Giant flying venomous spiders invading the East Coast? There’s no need to panic

Reports of giant flying venomous spiders spreading throughout the East Coast this summer are sparking panic for people on social media.

Some of the reports appear to stem from a New Jersey Pest Control article published earlier this year that says Joro spiders could potentially reach New Jersey in 2024. 

But others say fears about these spiders are overblown. For example, social media posts claim the spiders don’t pose a danger to people or pets.

VERIFY is answering some of the top questions about Joro spiders, including if they are guaranteed to arrive on the East Coast this summer and whether they can actually fly. 

THE SOURCES

• University of Georgia articles
• Penn State Extension article 
• iNaturalist, an online social network of people sharing biodiversity information
• Andy Davis, Ph.D., assistant research scientist at the University of Georgia’s Odum School of Ecology
• David Coyle, Ph.D., an assistant professor at Clemson University’s Department of Forestry and Environmental Conservation 
• Linda Rayor, Ph.D., a senior lecturer and senior research associate at Cornell University’s Department of Entomology
• Terminix, a pest control company
• 2022 study on Joro spiders published by University of Georgia researchers
• 2023 study on Joro spiders conducted by Coyle and other researchers

QUESTION #1

Have Joro spiders been found in some U.S. states before this year?

THE ANSWER

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Joro spiders are not native to the United States, but they have become established here over the last decade. 

The large, brightly colored Joro spiders are native to Japan, Korea, China and Taiwan. They have black legs with yellow-orange stripes, bright yellow bodies with bluish-green stripes on their backs, and red markings on their undersides. Adult female Joro spiders’ bodies can grow up to one inch long and their leg span can be up to four inches, according to a Penn State Extension article. 

It’s unclear exactly how or when these nonnative spiders arrived in the United States, but experts say they were first spotted in Georgia in 2013.

Scientists at the University of Georgia suspect the Joro spider arrived in the U.S. by accident either in shipping containers, among packing materials like pallets and crates, or on live plant material. 

Since their arrival in Georgia, Joro spiders have spread into adjacent states, including Alabama, North and South Carolina, and Tennessee, the Penn State Extension article says. Sightings have also been reported in Oklahoma, West Virginia and Maryland, according to iNaturalist. 

The spiders are increasingly spreading since they can hitch rides on cars and trucks, Andy Davis, Ph.D., an assistant research scientist at the University of Georgia’s Odum School of Ecology, said.

QUESTION #2

Are Joro spiders going to invade the East Coast this summer? 

THE ANSWER

Though scientists like David Coyle, Ph.D., an assistant professor at Clemson University’s Department of Forestry and Environmental Conservation, believe Joro spiders will be able to make more East Coast states their homes in the future, there’s no way to know exactly when this would happen.

Data from a 2023 study conducted by Coyle and other researchers found that Joro spiders are “going to be able to inhabit most of the eastern U.S.,” Coyle said. 

“It shows that their comfort area in their native range matches up very well with much of North America,” he added. 

Research from the University of Georgia also suggests that the spiders can survive in cooler areas and could eventually appear in many states along the East Coast.

Still, “there’s no way to predict how quickly they will get there, if ever,” Coyle said. Davis added that “some of these stories about the Joros are projections and guesses, rather than facts.”

RELATED: No, a study on Joro spiders doesn’t say they will colonize the entire East Coast by this spring

QUESTION #3

Are Joro spiders particularly dangerous to people or pets?

THE ANSWER

Joro spiders are “relatively harmless” to people and pets, University of Georgia scientists say. That’s because the spiders’ venom is weak and their fangs likely aren’t large enough to pierce human skin. 

Joros won’t bite people unless they are cornered, according to the University of Georgia scientists. But if they do, their bites are less painful than a bee sting and only produce localized pain and redness that goes away quickly, the Penn State Extension article says. 

Coyle also said a Joro spider bite would “probably be akin to a mosquito bite" and you’d “probably need to be really irritating” for the spider to even bite you in the first place.

It is possible that some people could be allergic to Joro spider venom. But the Penn State Extension article’s author “could not find any published reports of allergic reactions associated with Joro spider bites.”

Pets could also have an allergic reaction to a Joro spider bite, though the spiders are unlikely to puncture their skin, the pest control company Terminix says. 

QUESTION #4

Do Joro spiders fly?

THE ANSWER

Joro spiders don’t fly like birds, but they can use their silks to carry them across the wind to new locations through a process called “ballooning.” 

Young Joro spiders “release silk and are picked up by the wind,” the Penn State Extension article explains. Ballooning spiders can travel long distances, especially if they are carried by strong winds and storms, but Linda Rayor, Ph.D., a senior research associate at Cornell University’s Department of Entomology, says they are “unlikely to balloon for many hundreds of miles.”

When the young Joro spiders eventually land somewhere, they build webs, Rayor said. 

Unlike some other spiders, Joros do not want to go inside your home, Coyle and Rayor said. Instead, they will make a web on the outside of your home or another structure.

The spiders’ diets include a variety of insects, such as mosquitoes, stink bugs, yellow jackets and biting flies. Once a small insect gets tangled in their web, Joro spiders will wrap the prey in silk and use their venom to subdue it, Terminix says. 

This story is also available in Spanish / Lee este artículo también en español: ¿Arañas gigantes venenosas y voladoras invaden la Costa Este? No hay necesidad de pánico