Have Joro Spiders Arrived In NJ? Tracking These Giant Web-Spinners

NEW JERSEY — As the giant, brightly-colored Joro spider creeps up the East Coast, Patch has been keeping an eye out to see if any sightings have been confirmed in the Garden State.

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. They've recently been spotted in the Philadelphia area, and there was one reported sighting in South Jersey a few weeks ago that was not confirmed.

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 spiders in their home or garden.

The presence of another Joro spider has been confirmed in Bucks County, just across the Pennsylvania border — but as of Wednesday morning, Joro Watch does not list any verified sightings in New Jersey.

It may only be a matter of time, though. People have been keeping an eye out, and one person in Gloucester County thought they saw one on Sept. 28, according to Joro Watch. But, Rebekah Wallace of the UGA Center for Invasive Species and Ecosystem Health told Patch that the reported sighting was reviewed, and determined to not actually be a Joro spider.

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.

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.

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