Giant Joro Spiders Seen Near NJ: What To Do If You See One

NEW JERSEY — No, it's not an early Halloween trick...giant Joro spiders have been spotted close to New Jersey, according to a research center that monitors invasive species.

These venomous spiders can grow to as large as a human palm, and have been spreading north since being first spotted in Georgia in 2014. And though the spider’s venom doesn’t pose a danger to humans or pets, its sheer “unusually large” size can be frightening alone - and may soon be terrifying arachnophobic New Jerseyans, as they've been spotted in the Philadelphia metro area.

There were six Joro spiders seen in Bucks County on Sept. 5, according to the Center for Invasive Species and Ecosystem Health — which developed an interactive monitoring program called Joro Watch. A local entomologist confirmed the sighting.

Joro spiders also use wind currents to travel while parachuting, a method of silk production that allows them to travel in the wind. So, they don't exactly fly...but seeing one parachuting or "ballooning" through the air might make you think they do.

This species is most commonly seen building large webs in September and October, and the females lay egg sacs beginning in mid-October through November, the Joro Watch website explains.

This species, which is native to East Asia, craft wheel-shaped webs and is part of the orb-weaver family of arachnids. Female Joro spiders are easily spotted, as they are brightly-colored with red, blue and yellow hues. The body of an adult female of this species can be over an inch long — with a four-inch leg span, according to Scientific American.

Male Joro spiders are brown, and grow to about a quarter of an inch, according to Joro Watch.

The Mid-Atlantic states would make sense as a breeding ground for the spiders, as the region is the same latitude as places in Asia where they thrive. The species can can survive a brief freeze that kills off other spiders and has about double the metabolism of its relatives, according to one study.

What To Do If You See This Spider

Despite their startling appearance, researchers say that Joro spiders are docile and shy, and do not pose a threat to people or pets. If you do get bitten, the bite would not require medical attention unless you have an allergic reaction, according to Erin Grabarczyk, a biologist at Valdosta State University in Georgia.

“They are not going to hurt you," Grabarczyk told Scientific American. "They are not going to hurt your kids, they are not going to hurt your pets.”

It's possible that Joro spiders may actually be beneficial and prey on the invasive spotted lanternflies that have become a pest in the Mid-Atlantic states, Grabarczyk added.

Andy Davis, a University of Georgia scientist, told Scientific American that the spiders are better left alone, and don't threaten agriculture in the way lanternflies do. He said seeing a Joro spider could even be "an unprecedented educational opportunity" for nature enthusiasts and for kids.

"Show your kids that spider," he suggested. "Show them what spiders do."

If you do want to get rid of Joro spiders that may be spinning webs around your home and garden, researchers at the University of Georgia said certain insecticidesare effective against them, including Zevo Spider and Wasp spray and Green Light Insecticidal Soap.

Or, you could use a broom, rake, or long stick to take down both the web and the spider.

"The manual technique of wrapping them up in the web and stepping on them is very effective," UGA researchers said. "Simply destroying the web is not effective, as they rebuild in short order. Moving them to another area where they are less problematic can work but that has to be a good distance away or they will come back."