Are joro spiders headed to Florida? Probably, but they're not as scary as they sound (2024)

Golden silk orb-weavers are big, scary-looking spiders that like to weave huge webs. If you live in Florida, you might have nearly run face-first into a few of these webs while doing yard work.

Thankfully, these spiders are mostly harmless. But what if they were venomous and could fly (sort of)?

We’ve just described joro spiders, known as Trichoephila clavata, and they look nearly indistinguishable from golden silk spiders.

Joro spiders have been in the news recently because the invasive species is expected to invade areas in the Northeast U.S. this year. Do Floridians need to worry about this species, too? Here’s what to know.

What are joro spiders?

Joro spiders are scientifically known as Trichoephila clavata. They share the same genus as golden silk orb weaver spiders, and they’re often mistaken for each other.

Unlike golden silk orb weavers, which are often called banana spiders, joro spiders are native to East Asia and are often found in countries like China, Japan, Korea and Taiwan. Researchers began witnessing joro spiders spreading across North America within the past decade.

Joro spiders are venomous and large. Females grow to be larger than their male counterparts. Their bodies can grow up to 1 inch in length, and their legs can span up to 4 inches.

Their large stature is mostly for show, however. While they look scary, joro spiders are quite timid. They won’t bite you unless they feel threatened. And even if they do, their fangs aren’t able to penetrate human skin.

How are joro spiders different from golden silk orb weavers (banana spiders)?

Deciphering visual comparisons between joro spiders and golden silk orb weavers is like trying to spot the differences between two very similar pictures. It's hard, but it can be done if you know what you're looking for.

Size-wise, these spiders are similar, though golden silk orb weavers have a leg up. Female golden silk orb weavers can reach a length of about 1.5 to 2 inches for the body with leg spans reaching 5 inches or longer. By comparison, female joro spiders get to be about 1.2 inches in body length with leg spans reaching about 4 inches.

One of the clearest ways to spot the difference between the two spiders is to look at their leg joints. Golden silk orb weavers have hairy tufs around their leg joints while joro spiders do not, according to the University of Georgia.

Web placement can be another indicator. Both species of spiders can build huge, beautiful webs, but golden silk orb weavers tend to place their webs higher off the ground, in areas they're more likely to catch their prey.

Joro spiders tend to place their webs closer to the ground, usually between shrubs and low-hanging branches. UGA also states that joro spider webs tend to look more chaotic, with an irregular mesh of silk.

Why are joro spiders considered invasive?

On paper, joro spiders actually sound kind of great. They’re pretty to look at (from a distance, for most of us), they aren’t dangerous and they love to eat mosquitos, flies, stink bugs and other critters humans consider to be nuisance.

However, species are considered invasive due to competition with native wildlife. When a new species is introduced into an environment, it upsets the delicate balance of nature. Native species suddenly have more competition than previously, and if the invasive species is better suited for the environment, it could drive native species out.

In a 2023 Clemson University study about joro spiders, researchers noted that when you get joro spiders, you don’t get any other spiders.

“These are not just benign spiders coming to catch and kill bad things; these are pushing out native species and catching and killing whatever happens to get in their webs,” David Coyle, an assistant professor in the Department of Forestry and Environmental Conservation at Clemson University said. “Are they bad or good? It’s very nuanced depending on your perspective.”

Can joro spiders really fly?

No, at least not in the same way birds or Superman can fly. These inventive arachnids don't parachute like some headlines might claim. Instead, they employ a technique called "ballooning." The process involves casting out silks that carry the spiders for miles through wind.

Are joro spiders in Florida?

Florida residents don't have to worry about joro spiders yet. While some people have claimed to see joro spiders across the East Coast, scientists have not officially confirmed their presence. However, Clemson researchers believe that it's only a matter of time before they inhabit most of the eastern U.S.