The good news: The Joro spider is a timid creature and won’t bother you if you leave it alone, experts say.
It’s unclear why anyone would want to disturb a spider that, fully grown, covers the average human palm and has been known to spin a “golden yellow” web 8 feet across.
People living in Illinois might soon get a chance to test their comfort level with the black-and-yellow spider, native to Japan and now infesting Georgia and elsewhere in the Southeast.
“Homeowners are just up in arms down here. The [webs] are everywhere here,” said Andy Davis, a University of Georgia scientist who co-authored a piece about the spider in the latest edition of the scientific journal Physiological Entomology.
“Unfortunately, they really change the experience of walking in the woods because you basically have to walk with a stick in front of you along a path because there are just webs everywhere.”
Davis’ study suggests the spider does quite well in cold temperatures, meaning it is likely to spread up and down the Eastern seaboard — and, possibly, to the Midwest.
Chicago weather “doesn’t look much different from what these spiders would experience in Japan,” Davis said. “It’s within the realm of possibility.”
If they do make it here, it’s likely they’ll hitch a ride, scientists say. The Joro began showing up in Georgia in about 2013 — near warehouses and distribution centers.
“We suspect that, because the spider is a good hitchhiker, that it probably hitched a ride on some sort of pallet or crate or vehicle that ended up in north central Georgia,” said Richard Hoebeke, associate curator and collection manager at the University of Georgia’s Museum of Natural History.
Hoebeke agrees these spiders generally are timid — but they will bite if disturbed.
“I know of a couple of individuals who have been bitten. The bites become red and a little swollen,” Hoebeke said. “One individual even had fever. It depends largely on the individual.”
The Joro is an outdoor spider, needing lots of space to weave its webs.
“Some people have said they’ve seen hundreds of them on their property,” Hoebeke said. “They are doing well.”
Patricia Straley, a retired engineer, lives on a 10-acre plot about 20 miles north of Atlanta. Straley said she first started seeing a few of the spiders in 2020.
“By last summer, they had pretty much decimated the local Golden Orb spider,” she said.
Straley grew up on a farm, so she’s not particularly bothered by critters.
“What freaks me out is walking through the cobwebs,” Straley said. “It’s like, ‘What was that?’ They are very, very sticky.”
Petra Sierwald, the Field Museum’s myriapod and arachnid expert, said she’s not convinced the spider would survive around Chicago because summers are too short to allow it to fully mature.
“It could perhaps survive here for the summer, but I don’t know whether it would be able to eat enough in order to mature,” Sierwald said. “It would have to change its life cycle.”
