Massive Joro Spiders Spreading Across Southern California

The palm-sized arachnids can soar through the air and are now spotted in Santa Barbara County

Apr. 12, 2026 at 12:52am

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An abstract, highly structured painting in soft earth tones, featuring sweeping geometric arcs, concentric circular patterns, and precise botanical spirals, conceptually representing the intricate web-building and dispersal mechanisms of the Joro spider.The Joro spider's remarkable web-building and dispersal capabilities are visualized in an abstract scientific diagram, highlighting the complex natural engineering of this invasive arachnid species.Santa Barbara Today

A new species of spider known as the Joro spider, which can grow as large as the palm of a human hand and can disperse itself by 'ballooning' through the air, has been spotted in Southern California, including recent sightings in Santa Barbara County. While the spiders are not dangerous to humans, their large size and web-building abilities have raised concerns among local residents.

Why it matters

The rapid spread of the Joro spider across the United States, from its native range in Asia, highlights the potential risks posed by invasive species introductions through global trade and transportation. While the Joro spider does not pose a direct threat to humans, its presence could disrupt local ecosystems and impact native spider populations.

The details

The Joro spider, scientifically known as Trichonephila clavata, is native to eastern Asia but has been spreading across the United States since it was first spotted in Georgia in 2014. The spiders are known for their large size, with female Joro spiders reaching up to 1.25 inches in body length, and their ability to 'balloon' by releasing silk that catches the wind, allowing them to travel long distances. Recent sightings of the Joro spider have been reported in Santa Barbara County, California.

  • The Joro spider was first spotted in the United States in 2014 in the state of Georgia.
  • The spiders have since spread to parts of the South, Midwest, and Appalachia.
  • Recent sightings of the Joro spider have been reported in Santa Barbara County, California, as recently as October 2026.

The players

Trichonephila clavata

Also known as the Joro spider, this is a species of spider native to eastern Asia that has been spreading across the United States since 2014.

Pat Wooden

The insect identification lab manager at Virginia Tech, who has studied the spread of the Joro spider in the United States.

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What they’re saying

“The Joro spider was likely brought to this country in shipping containers from China, Taiwan, Japan and South Korea.”

— Pat Wooden, Insect identification lab manager, Virginia Tech

What’s next

Researchers and wildlife experts will continue to monitor the spread of the Joro spider in Southern California and across the United States, as well as study the potential impacts of this invasive species on local ecosystems.

The takeaway

The rapid spread of the Joro spider, a large and unique arachnid from Asia, highlights the ongoing challenges posed by invasive species introductions. While the Joro spider does not pose a direct threat to humans, its presence could disrupt native wildlife populations and ecosystems, underscoring the importance of vigilance and proactive measures to address such issues.