What is this giant, flying spider?
The Joro spider is a large spider in the Araneidae Family, a relative of the golden silk spider. They are easy to identify because they are very colorful, almost like a mix of a bumblebee and black widow were combined in a lab. Their bodies are black with yellow and red markings and a red underside. The long skinny legs are banded with alternating yellow and blue bands. When we say “giant” we mean they can get to be 3 inches across! If one were sitting in your hand (mine would be gloved!) their bodies would be about the size of the tip of your thumb and their legs would reach from one side of your hand to the other.
Can Joro spiders really fly?
Joro spiders don’t fly like bees or birds; they do however parachute from place to place by making a parachute out of their web. This is called “ballooning”. Perhaps you remember a scene from Charlotte’s Web where hundreds of the newly hatched spider babies took to the air. Joro spiders do the same thing.
Where do Joro spiders live now?
Joro spiders are from southeast Asia, but they were introduced into Georgia in the US in 2013. It is likely that they came across the ocean on a shipping container and were able to settle in just fine in the warm Georgia climate. They were only found in Georgia until recently when researchers have confirmed Joro spiders living in South Carolina in Blairsville, Georgia, and Greenville. Blairsville is only 45 miles from Charlotte, NC so depending on how the wind blows, North Carolina may be the next to be “invaded.”
Could Joro spiders “float” up the East Coast?
According to biologists one study found that the spiders are not just floating on the air’s currents, but using electric fields as a means of transportation. They found “wingless arthropods have been found 4 km [2.5miles] up in the sky, dispersing hundreds of kilometers.” 200 kilometers is 125 miles so if Joro spiders do decide to migrate north their itinerary might look like this:
Savannah, GA to Charlotte, SC: 108 milesCharlotte, SC to Myrtle Beach, SC: 95 milesMyrtle Beach, SC to Wilmington, NC: 77 milesWilmington, NC to Virginia Beach, VA: 212 miles (flight distance), long dayVirginia Beach, VA to Washington DC: 220 miles (flight distance), another long day!
However, it is much more likely that Joro spiders will spread up the coast in more of a “float and ride” scenario, ballooning and landing on vehicles like semi-trucks headed north. Being transported by humans is also a common way for species like spiders and scorpions to spread.
Can Joro spiders survive in colder climates?
The recent study out of the University of Georgia compared Joro spiders to golden silk spiders. Golden silk spiders have been in the US for over 160 years, but they have not traveled to the northern states, most likely due to the colder climates. The study found that Joro spiders are much hardier. Their metabolic rates were twice that of the golden silk and their heart rates increased 77% more during a cold-exposure test. Finally, the researchers exposed the spiders to below-freezing (less than 32°) for two minutes. 74% of the Joro spiders survived the brief freeze while only 50% of the golden silks survived. The average daily winter temps of the coastal states gradually gets colder as you go north.
Georgia: 45-50°South Carolina: 45-50°North Carolina: 40-45°Virginia: 35-40°Washington D.C.: 30-35°New Jersey: 30-35°New York: 20-25°
These are the daily temps, with nightly temps getting colder, sometimes by 10-20°. The Joro spiders in the study survived for two minutes at below-freezing temps but if they lived anywhere north of North Carolina they would have to survive long periods of freezing temps.
Can spiders hibernate, like bears?
Some spiders like the black widow do not hibernate, but they “overwinter” a condition in which their metabolism slows down and they conserve less energy.
Is it more likely that these giant, flying spiders invade Florida?
Since the golden silk spider has not moved north but has spread out over much of the southeastern US it is likely that the Joro spider will follow in its footsteps. Because it is from southeast Asia which has a tropical climate it would make sense that the Joro would continue to spread into areas that have a similar climate like Florida. But this latest research gives scientist new evidence that there is a good chance that the Joro spider could move north along the East Coast.
Are Joro spiders venomous?
Joro spiders do have venom that they use to stun their prey before eating them, but Joro spiders are not harmful to humans. They do have fangs, but scientists say their fangs are too small to break through human skin. Pets are safe too for the same reason.
Are Joro spiders going to invade New York and D.C.?
“Invade” might be a strong word but if they do make it to New York or D.C. and are able to overwinter during the cold spells they could make the Northern states their home. Besides spreading their large golden webs all over they are not much of a nuisance. They are an additional food source for larger birds and they are actually beneficial animals because they eat mosquitoes! So if they did land in Central Park, our picnicking family would have a much nicer outing without having to swat so many mosquitoes.
