Another Joro Spider Sighting Confirmed In Eastern PA

BUCKS COUNTY, PA — Another Joro spider sighting has been confirmed in Bucks County, 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. The Joro spider’s venom doesn’t pose a danger to humans or pets, though its sheer “unusually large” size can be frightening alone.

The Georgia-based Center for Invasive Species and Ecosystem Health developed an interactive monitoring program called Joro Watch, which allows people to report if they've seen one of the web-spinners in their home or garden.

And according to this site, another Bucks resident saw a female Joro spider in a web outside their home on Sept. 24.

Penn State University entomologist Dr. Michael Skvarla confirmed that it was a Joro spider on the following day, and noted that what looked like a male spider was also seen in the web.

Skvarla told Patch that this particular spider was at a home in Warminster.

"I connected the homeowner with a local entomologist, who removed the spider," he said.

Another Bucks sighting was reported on Sept. 2, but Skvarla took a look at photos and determined that this arachnid was not a Joro spider.

The first confirmed sightings of these spiders was at a resident's garden in Northampton Township on Sept. 5, where another entomologist confirmed the presence of multiple Joro spiders.

The above map was put together by the Early Detection & Distribution Mapping System at The University of Georgia - Center for Invasive Species and Ecosystem Health. You can also view the map here.

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.

More On Joro Spiders

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.

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, 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.

Related article — Invasive Joro Spiders Spotted In Bucks County: What To Know