Large, brightly colored Joro spiders have continued expanding their range across the United States, raising questions about whether they could eventually become a familiar sight in Allegheny County.
The invasive spiders are native to East Asia and have gradually spread in this country since being discovered in Georgia. While seeing one in Allegheny County would not be considered normal right now, Pennsylvania may offer conditions where the species could eventually establish itself.
Dr. Michael Skvarla, associate research professor with the Insect Identification Lab in Penn State University’s Department of Entomology, said the spider’s native range provides an important clue.
“The region of Asia where Joro spiders are native has a similar climate
to eastern North America and models based on climactic variables predict that they will be able to survive throughout Pennsylvania,” Skvarla said.
The spiders can spread naturally when young spiderlings “balloon,” using silk to travel on the wind. Skvarla said that generally moves them only a few miles to a few dozen miles, depending on conditions.
Humans could bring them much farther.
“Joro spider egg sacs are relatively innocuous and overlooked,” Skvarla said, explaining an egg sac could accidentally hitch a ride on something like an RV traveling from the Southeast to Pennsylvania.
Despite their intimidating size, Joro spiders are not considered a significant danger to people.
Residents wondering how close the spiders are getting can also follow the University of Georgia’s Joro Watch project, where users can view reported sightings and submit possible Joro spiders they encounter.
This story was produced by reporter Gabby Sartori, [gsartori@usatodayco.com], with the assistance of Artificial Intelligence (AI). Journalists were involved in every step of the review, editing and publishing process. Learn more at cm.usatoday.com/ethical-conduct.
This article originally appeared on USA TODAY: Are Joro spiders headed to Allegheny County?
