Could major cities like New York and Boston soon see an invasion — of giant spiders? A species of large spiders that spin golden webs is ready to invade cities along the U.S. East Coast. Researchers say this creepy development could rewrite the playbook on urban wildlife adaptation. The invasive Joro spider, first spotted in the United States around 2013, is currently flourishing in Georgia and throughout the Southeast, and now they’re poised to expand their territory! Despite the hustle and bustle of urban environments, these spiders are not just surviving in cities — researchers say they’re thriving.
The Joro spider, known for spinning striking golden webs across powerlines and other structures, has been a subject of fascination and concern since its stateside appearance. Originating in Japan, this orb-weaving arachnid has shown a remarkable ability to multiply in areas that are typically hostile to wildlife, including alongside busy roads and amidst the clamor of city life.
University of Georgia scientists shed light on this phenomenon, revealing that Joro spiders possess an unexpected tolerance for the vibrations and noise that are part and parcel of urban landscapes.
“If you’re a spider, you rely on vibrations to do your job and catch bugs,” says study corresponding author Andy Davis, a research scientist in UGA’s Odum School of Ecology, in a university release. “But these Joro webs are everywhere in the fall, including right next to busy roads, and the spiders seem to be able to make a living there. For some reason, these spiders seem urban tolerant.”
This tolerance is crucial for the Joros’ success in human-dominated environments. The study involved simulating prey vibrations using a tuning fork and observing the spiders’ response. Despite the constant hum of traffic, Joro spiders near busier roads showed only a slightly reduced propensity to attack simulated prey compared to their counterparts in quieter areas. This minor behavioral adjustment does not seem to impact their health or body mass, indicating that Joro spiders can effectively compensate for the challenges posed by their urban surroundings.
Joro spiders are regularly spotted in locations where native Georgia spiders are absent, such as between powerlines, atop stoplights, and above gas station pumps. This adaptability to urban noise and activity is a significant factor in their spread.
“It looks like Joro spiders are not going to shy away from building a web under a stoplight or an area where you wouldn’t imagine a spider to be,” notes study co-author Alexa Shultz, a third-year ecology student at UGA. “I don’t know how happy people are going to be about it, but I think the spiders are here to stay.”
The implications of the Joro spider’s spread are vast, with the species showing potential to expand beyond the Southeast. Factors such as a high metabolism, heart rate, and cold tolerance — traits that allow Joro spiders to survive brief freezes that kill many other orb-weavers — are instrumental in their rapid population growth. Previous research from Davis’ lab highlighted these characteristics, suggesting that Joros are well-equipped to colonize most of the Eastern Seaboard.
While the idea of an invasive species making such strides might raise concerns, researchers emphasize that Joro spiders are relatively timid, and their proliferation should not be overly alarming.
The study is published in the journal Arthropoda.
