Venomous flying spiders now spreading across East Coast

The Northeast United States (US) is bracing for an invasion of giant venomous spiders with 4-inch-long legs, known as Joro Spiders, that can parachute through the air.

New Jersey Pest Control has warned that large and vividly colored Joro spider Joro spiders, originally from Southeast Asia, are making their way up the East Coast and expected to arrive in New York and New Jersey this summer.

A peer-reviewed study published in October 2023 by David Coyle, a scientist and assistant professor in the Department of Forestry and Environmental Conservation at Clemson University in South Carolina, found that the invasive species is “here to stay” and “spreading like wildfire.”

As of October 2022, the study noted, the species’ range spanned at least 120,000 square kilometers across multiple states, including Georgia, South Carolina, North Carolina and Tennessee. There were also reports of Joro spiders in Alabama, Maryland, Oklahoma and West Virginia.

“(The data from the study shows) that this spider is going to be able to inhabit most of the eastern U.S.,” Coyle said recently. “It shows that their comfort area in their native range matches up very well with much of North America.

Joro spiders have twice as high a metabolism and a 77% higher heart rate when exposed to low temperatures. They can also survive better in a brief freeze, suggesting they can exist in a colder climatic region than the Southeast.

Researchers are working to manage the Joro spider invasion by monitoring their spread and studying their behavior.

“Understanding the biology and ecology of these spiders is essential in developing effective strategies for mitigating their impact,” New Jersey Pest Control said.

Coyle said Joros spiders aren’t harmful to people or animals.

Nelsen, who led the research alongside Coyle, noted evidence showed native species are negatively affected by Joros. That means more research is needed to determine why, as well as what should be done about it.

If that’s the case, researchers say it may pose a challenge for native species and stress already fragile ecosystems.