How Boston's first Joro spider probably got here — and why you shouldn't freak out

The Joro spider was officially shipped to Boston.

The palm-sized, neon yellow spider from Southeast Asia was first spotted weaving its distinctive web by a photographer on Beacon Hill this month. Experts say this is the northernmost confirmed sighting of a Joro spider in the United States

Scientists believe the species first arrived in the southeastern United States via shipping containers about a decade ago. The spider likely arrived in Boston when a female spider laid an egg sac on something that was being transported to the area. And that means the specimen seen in Beacon Hill is probably not alone, according to ecologist Benjamin Frick, who studies Joros at the University of Georgia in Athens.

“It's probably quite likely that if you saw a spider and it made it to adulthood, others probably did too. The likelihood of it being just one (Joro spider) is probably pretty low,” Frick said.

But don't panic. Although Joro spiders are technically poisonous, the “Nerf footballs with legs,” as Frick calls them, are considered harmless to people and pets.

The chances of it being just one (joro spider) are probably pretty slim.

Benjamin Frick, an ecologist at the University of Georgia in Athens

“They have the ability to bite you. However, they will run away from you every chance they get. They’re very shy spiders,” Frick said.

Although Joros are sometimes referred to as “flying spiders,” they do not have wings. Instead, their population often expands when the wind carries young animals the size of rice grains on nets. Experts believe that this mode of locomotion only carries the baby spiders about a mile.

Frick said most people probably wouldn't notice the hatchlings flying around: “So if a spider were to land on you, not only would you not notice it. You would also probably accidentally kill the baby spider by scratching your head.”

Joros are known as a type of orb weaver spider. They are often found on their classic wheel-shaped webs, which can be up to 3 meters wide and are often found in open areas, such as along power lines and under tree canopies.