Will Joro Spiders Return to Massachusetts This Year?

Researchers from the University of Georgia are advising residents of Massachusetts to remain vigilant for the potential arrival of Joro spiders this season, noting that the invasive arachnids could establish populations in the state as they continue their northward expansion from the southeastern United States.

First detected in Georgia around 2014, the Joro spider (Trichonephila clavata) is native to East Asia and has since spread across several southeastern states, including South Carolina, North Carolina, Tennessee, and Alabama. Known for its striking yellow and black coloration and large, golden webs, the species has drawn public attention due to its size and visibility, though scientists emphasize it poses little threat to humans or pets.

According to a 2023 study published in the journal Insects, Joro spiders have demonstrated a remarkable tolerance for cold temperatures, with laboratory tests showing they can survive brief exposure to freezing conditions. This physiological trait, combined with their ability to disperse via ballooning — a process where spiderlings release silk threads to catch wind currents — has enabled their gradual spread beyond the Southeast.

Dr. Andy Davis, a research scientist at the University of Georgia’s Odum School of Ecology who has studied the species extensively, said in a recent interview that while no confirmed breeding populations have yet been documented in Massachusetts, the spiders’ expanding range makes their appearance in the state increasingly plausible.