An East Asian spider known for its colorful nicknames and strong, golden silk has moved into the U.S. state of Georgia—the first time the species has been recorded in North America.
New Kid on the Block
Adult female N. clavata are spectacular sights, with striped legs and abdomens that appear as though they've been dipped in a pool of swirling yellow, red, and black paint. In contrast, the males are a relatively colorless brown, and like males throughout the Nephila genus, are dwarfed by the females.
Sometimes four times as big as the males, female N. clavata can reach up to 3 to 4 inches (7.6 to 10 centimeters) wide in their leg spans.
With such a striking appearance, it's not surprising that study co-author Wesley Huffmaster noticed one near his house in September 2014.
After that incident, Huffmaster, Hoebeke, and colleagues began looking for more such suspicious spiders. Over ten days, the team collected or spotted about a dozen Joro spiders and their tough webs in three counties—a wide distribution that suggests the spiders are successfully setting up shop on their new continent.
The team verified the critters' identities photographically and with DNA testing, which indicated that the Georgia spiders all came from the same source in China or Japan.
Finding Joro
It's too soon to say how big the North American N. clavata population is and whether the spider is likely to compete with native species. The vibrant new arrival does have an American relative: Nephila clavipes, a golden silk orb weaver that's native to the southern U.S.
"I suspect it may be more widespread than what our data is initially indicating," Hoebeke says. "It could be anywhere where there are major importing warehouses."
Now, with winter waning and spring on the way, the spiders are about to emerge from their egg sacs. They'll grow over the next few months and be easiest to spot in late summer or early fall.
Hoebeke is hoping for some help in finding them.
"We can't be everywhere looking for this thing, but we can have people take a close look and let us know," he says.
"This is really citizen science at its best."