'Unusually Large' Spiders Heading To Northeast: Here's What To Know In CT

CONNECTICUT - The Joro spider, a Post-It Note-sized arachnid that has burgeoned in southern U.S. states since 2021, is slated to make its debut in the Northeast as soon as this summer, according to multiple reports.

The species, which is native to East Asia, can grow as large as the size of a human palm and craft wheel-shaped webs. While the spider’s venom doesn’t pose a danger to humans or pets, its sheer “unusually large” size can be frightening alone.

The spiders swarmed Georgia a few years ago, and have been spotted as close as Maryland last October, but arachnophobes in Connecticut needn't get their webbing in a bunch quite yet.

Katherine Dugas, an agricultural research technician with the Connecticut Agricultural Station, is keeping tabs on the critters and doesn't like their chances of making it this far north so soon.

"Joro spiders don’t travel too far on their own," Dugas told Patch. "Like many other spiders, the newly hatched spiderlings ‘balloon,’ creating thin silk strands that catch the wind and help distribute them. Ballooning won’t spread them incredibly long distances, such as all the way from Georgia to Connecticut."

If a Joro spider were to make it to Connecticut this year, it would be through anthropogenic means — a hitchhiker that was brought here through human activity, Dugas said.

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

If you did happen to vacation in the Carolinas and a Joro did happen to crawl into your carry-on, it's not likely its presence would be secret for too long. They are hardly masters of camouflage.

Joro spiders are large, with a body up to 1-1/4 inches long. When the legs are extended, the spider's span can be 4 inches. A Joro spider’s abdomen has horizontal stripes of blue-green and yellow, and the legs are long and black, usually with yellow bands. Females are brightly colored with red, blue and yellow hues while males are brown. Their webs are very large and have a golden color, according to Dugas.

The entomologist recommends that Patch readers who do stumble across a Joro take a photo and email it either to her (katherine.dugas@ct.gov) or Dr. Gale Ridge (gale.ridge@ct.gov).

"Don’t disturb the spider," Dugas suggested.