Large invasive Joro Spiders found in Great Smoky Mountains National Park

TOWNSEND, Tenn. – A spider known for its unique coloring and large size has been spotted twice recently in Great Smoky Mountains National Park. 

The Joro Spider, known scientifically as Trichonephila clavata, has been reported in the U.S. since 2014, when the spider was first found in Georgia. 

According to officials from the National Park Service, the spider was first seen in the park on Oct. 17, and again more recently. Both sightings were reported in Cades Cove, a scenic valley in Townsend, Tennessee, in Great Smoky Mountains National Park. 

The spiders are native to East Asia, NAISMA said, and in the U.S. they have been found in Georgia, South Carolina, Tennessee, North Carolina and Maryland.

The spider species is quite large, with adult female spiders reaching an average of 3 inches across, according to the North American Invasive Species Management Association (NAISMA). Female Joro Spiders are distinctive, with bright yellow bodies covered in horizontal grayish-blue colored stripes. The female spiders also have black and yellow striped legs. The spiders develop their color once they reach adulthood, in the summer, NAISMA said. 

FILE – An adult female Joro spider on a web in Boston, Mass. on September 25. 

(Stuart Cahill/Boston Herald / Getty Images)

Adult male Joro Spiders do not get as large as females do, NAISMA said. The male spiders also remain a brown color. 

The spiders are often reported to be seen parachuting, officially called “ballooning.” It’s an act where spiders are carried by wind on their silk, NAISMA said. However, only tiny, hatchling Joro Spiders will be seen doing this, according to NAISMA. 

Many spider species can be found ballooning when they’re small, the association said. 

The spiders are known for creating large webs as well.

FILE – An adult, female Joro spider on a web seen outside a home in Boston, Mass. 

(Stuart Cahill/Boston Herald)

NAISMA said the spiders are not a danger to people or pets. 

The Joro Spider is an invasive spider species, NAISMA said. However, the ecological impacts on the spider are still being researched. 

NPS officials said they are currently assessing the presence of Joro Spiders within Great Smoky Mountains National Park to determine if management actions are needed.

The park recently sustained damage during Hurricane Helene in late September. The park saw impacts such as flooding, downed trees, damaged power lines and hazardous trail conditions, according to the NPS. Portions of the national park closed while NPS surveyed and cleaned up the damage. Some trails remain closed due to storm damage. For a list of trail closures, click here.