Joro spiders: What to know as the colorful invasive species moves up the East Coast
It was the summer of the cicada — but now, Joro spiders may be swooping in to claim their spot in the headlines. Researchers say these black and yellow arachnids are making their way up from Southern states like Georgia to New York and beyond.
Should you be concerned? Here’s what you need to know about Joro spiders.
🕸️Why are we talking about Joro spiders now?
Scientists who have studied these spiders say they are moving north … though exactly when they’ll reach the U.S. Northeast remains to be seen. Experts say it could be a year, or even a decade, before the spiders become prevalent there.
While these spiders may seem large and scary, the scientists aren’t concerned about any risk to humans. Instead, as with species like lanternflies, experts are worried that the increasing prevalence of this invasive species could harm agriculture and ecosystems.
🕷️Where are Joro spiders right now?
The website JoroWatch monitors where Joro spiders have been spotted around the United States. According to the site, they have appeared in states like North Carolina, South Carolina, Georgia, Tennessee and West Virginia. Spiders have been reported as far north as Maryland and as far west as Oklahoma, but they are mostly clustered in the Southeast.
🫣How big are Joro spiders? What do they look like?
Joro spiders are big, with females being around 1 to 1.5 inches long (excluding their legs), but some can grow up to 3 inches. Male Joro spiders are generally smaller than females, typically ranging from about 0.5 to 0.8 inches in body length, excluding their legs.
These crawlers stand out with their black or dark gray bodies and typically have bright yellow on their bellies. They have round bodies and long, skinny legs. They typically aren’t hard to identify.
🌏Where do Joro spiders come from?
Joro spiders are not native to the United States and originally come from East Asia. However, in 2013, they were spotted in Georgia. Researchers have followed their patterns closely and believe they are making their way up the East Coast due to their preference for colder climates. Experts believe it will be possible to spot Joro spiders in states like New York, New Jersey and Ohio as early as this year.
🎈Can Joro spiders fly?
Not exactly. Instead, they use a technique called "ballooning" in which they release silk threads that catch the wind, allowing them to travel through the air to new locations. This helps them spread to different areas and find new habitats.
☠️How venomous is the Joro spider? Do Joro spiders bite?
Technically, yes — the Joro spider is mildly venomous. The good news? Its venom is not harmful to humans and is mainly used to subdue its prey. It’s worth noting that Joro spiders are shy and would normally only bite a human if they feel threatened.
But the Joro spider does pose a threat to other insects. Joro spiders typically eat a variety of insects, such as flies, mosquitoes, beetles, moths and other small flying insects that get caught in their webs. They can also indulge in a butterfly if they happen to catch one.
🦷OK, but what if I get bitten by a Joro spider?
If you're unlucky and get bitten, the bite may cause minor irritation — similar to a bee sting. Unlike a bee sting, however, there aren’t widespread reports of Joro spiders causing major allergic reactions.
