The New York tri-state area should prepare for some large, eight-legged visitors this summer. Experts predict the arrival of the invasive Joro spider (Trichonephila clavata) in parts of New York and New Jersey. Despite their striking size and vibrant colors, these arachnids pose no threat to humans.
The Joro spider is native to several parts of Asia, holding particular cultural significance in Japan, where it is associated with the mythical shape-shifting creature, jorogumo. These spiders spin intricate, multi-layered orb webs with golden-yellow silk. Female Joro spiders are larger than males, boasting a body length of up to one inch and legs reaching four inches, resulting in a potential leg span of up to eight inches. Their abdomens display distinctive yellow, black, and red patterns, complemented by yellow and blue/black bands on their legs.
Joro spiders employ a dispersal technique called ballooning, using their webs to catch the wind and travel miles from their original location, typically shortly after hatching. This method allows them to quickly colonize new territories with suitable environmental conditions. Much of the U.S. appears to offer a welcoming habitat.
First sighted in Georgia around 2013, the Joro spider has since spread to Alabama, Tennessee, North and South Carolina, and Maryland. Their cold tolerance, allowing them to survive brief winter freezes, has led experts to believe they will eventually inhabit the entire Eastern seaboard. Their arrival in New York is anticipated as early as this summer.
“Right now, we are seeing them dispersing into Maryland, so soon enough, possibly even next year, they should be in New Jersey and New York,” José Ramírez-Garofalo, an ecologist at Rutgers University, told the Staten Island Advance. “It is a matter of when, not if.”
Fortunately, these spiders are more show than threat. Research indicates Joro spiders and their relatives are among the “shyest” spiders, unlikely to display aggression towards perceived threats, including humans. They typically freeze in place, sometimes for up to an hour, when disturbed. Even if bitten, their mouthparts are generally too small to penetrate human skin, and their venom is not considered harmful to humans or pets.
The environmental impact of the Joro spider remains uncertain. Invasive species can disrupt ecosystems due to a lack of natural predators, potentially outcompeting native species and depleting resources. However, there is currently no clear evidence of significant ecological damage caused by Joro spiders. They have even been observed preying on other invasive pests, such as the spotted lanternfly. For now, they can be viewed as a novel addition to the local fauna.
“It’s a bigger spider than we’re used to, but it has pretty colors,” Louis Sorkin, a retired arachnologist from the American Museum of Natural History, told Gothamist.
Once established in the Big Apple, these spiders are expected to thrive. A recent study found Joro spiders can tolerate the high vibrations common in cities and near busy roads, maintaining their insect-hunting abilities.
