EXPLANATION

The eruption is imminent, although no one knows exactly when. And there is no need to worry, scientists say.

According to experts, an uninvited guest could soon invade the New York City area in the USA. The only question is how soon.

The Joro spider, which first appeared in the southern state of Georgia a decade ago, is slowly migrating north. And scientists say it could reach the Great Lakes region, the northeastern United States and even Canada in the coming months or years.

But what exactly is the Joro spider? Is it dangerous? And why is it spreading in the USA?

What is a Joro Spider?

The Joro spider, scientifically called Trichonephila clavata, is native to East Asia and is known for its web-weaving skills and distinctive appearance. The Joro spider is often confused with the Golden Silk Spider (Nephila clavipes) as they look similar.

A female Joro spider can have a wingspan of 8 to 20 cm (3 to 8 inches) with legs spread—larger than the human hand. Female Joro spiders typically have a yellow body, while the smaller male spiders are a muted yellow and black or brown color.

How do they spread to new areas?

Joro spiders do not have wings, but their young can use the wind to practically fly.

Using a technique called ballooning, young Joro spiders release silk threads that allow them to ride wind currents, allowing them to move to new areas—sometimes traveling more than 100 miles (160 km) in the process.

The young hatch in spring and summer, which is why these seasons are the most important for the spiders to expand their range of activity.

Joro spiders have another advantage. A 2022 study by ecologist Andrew Davis of the University of Georgia and his colleagues found that they have a high metabolism and heart rate, which allows them to survive in colder climates.

Where are Joro spiders found in the USA?

Since its first appearance in Georgia about 10 years ago, the invasive species has begun to spread north.

According to the nonprofit organization INaturalis, the Joro spider has been spotted in Maryland, West Virginia, Tennessee, North Carolina and South Carolina. It has also been seen in the south-central state of Oklahoma.

In a study published in November Scientist at Clemson University in South Carolina said the colorful arachnid could soon move toward “the Great Lakes region of the United States and Canada, which extends across the Midwest and Northeast of the United States and into Eastern Canada.”

Parts of the northwestern United States and even northwestern Mexico could also serve as favorable habitats for the Joro spider, the scientists said.

Where are you from?

The Joro spider typically comes from Japan, China, Taiwan and South Korea.

It is likely that the spider was a stowaway in a shipping container from one of these areas and eventually ended up in the seaport of Atlanta, Georgia, according to a Study 2015.

Are these spiders harmful?

According to the study by Davis and his colleagues at the University of Georgia, Joro spiders are not harmful to humans or pets.

They are poisonous, but their bites are not fatal and their fangs are too small to pierce human skin.

As with any invasive species, scientists are concerned about their impact on crops and trees, but how Joro spiders behave on farms is still a matter of study.

Should I get rid of Joro spiders?

The Joro spider's life expectancy is about a year, so it doesn't live very long. In most cases, scientists say, it can be safely ignored and its presence is considered more of a nuisance than a pest. However, researchers continue to monitor its behavior in new locations and its migration patterns.

The lifespan of spiders varies. Most live about two years, but there are cases where spiders have lived up to 20 years.