Joro Spiders Could Land in Delaware This Summer

Photos courtesy the University of Georgia

Despite their impressive, albeit slightly scary size, these colorful arachnids don’t pose a threat to humans. Here’s what to know.

An Asian spider called the Joro hitched a ride to the United States from Asia some years ago, showing up in Georgia and parts of South Carolina in 2013. The palm-size spider, which has a yellow striped body and long black and yellow legs, has since spread, and scientists say it could continue to travel across the U.S.

In a study released by the University of Georgia, researchers suggest the spider could be headed up the East Coast, pointing to the accidental transport of a Joro from Georgia to Oklahoma.

Andy Davis of the Odum School of Ecology, one of the authors and researchers on the study published in Physiological Entomology, says the spiders spin large webs, which can be seen across power lines in the South. However, he says, they do not seem to have a negative effect on local ecosystems and might even serve as a new food source for birds.

- Advertisement -
Joro Spider
Photo courtesy the University of Georgia

The researchers say excessive action to remove the spiders is unnecessary, as they are harmless. In their native Japan, Joro spiders exist across the country, which has similar environments to the U.S.

Like other species, Joros hitch a ride by climbing onto trucks or shipping containers. They also spin huge webs, which allow them to travel on the wind, known as ballooning or parachuting. When baby Joros hatch, they use webs and wind currents to move around, which could land them in new states.

Photo courtesy the University of Georgia

Doug Tallamy of the University of Delaware’s wildlife and entomology department says he hasn’t studied the spider at this point. He says it remains to be seen whether Joros will come to Delaware and be able to survive here.

Studies have shown that Joros can survive cold temperatures in some situations; Georgia researchers note that the Joro has a higher heart rate and metabolism than other spiders, which leads researchers to believe Joros could survive colder northeastern temperatures.

Professor George Uetz of the University of Cincinnati says the spider could spread, but the good news is that it doesn’t pose a threat to humans. It does spin giant webs, which can be a be a nuisance, but its fangs are too small to penetrate human skin.

- Partner Content -
Photo courtesy the University of Georgia

Uetz says while it’s too soon to gauge the Joros’ impact, other non-native species continue to be a great threat in the U.S., including the emerald ash borer and spotted lanternflies.

Delaware has put forth a large effort to reduce and eliminate the invasive spotted lanternfly, with educational material showing people how to identify, report and kill the insect.

Related: The Delaware Bay Is Smooth Sailing for Yacht Club Races

Our Best of Delaware Elimination Ballot is open through February 22!

Holiday flash sale ... subscribe and save 50%

Limited time offer. New subscribers only.