What Are Joro Spiders?
Joro spiders (Trichonephila clavata) are a new species to the United States. They were first spotted in Georgia in 2014 and have since spread out across the state. Joro spiders are about an inch long or more, with a large body and a small black head. Their bodies are colorful with yellow, black, and red markings. They have long, skinny legs that are striped yellow and blue-black. If you had one in your hand, their legs would reach the edges of your palm. The largest ones have a leg span of 3-4 inches. Male Joros are much smaller than the females, with an average length of ¼ inch, and they are not as colorful as the females.
What Are Writing Spiders?
Writing spiders (Agriope aurantia) are commonly called yellow garden spiders. They get the name “writing spider” from the zigzag design down the middle of their webs. Their bodies are a little heavier than Joros but shorter, with lengths of ¾ to 1 inch. Their bodies are black with yellow markings. Their long skinny legs are reddish-brown near their body and black at the ends. The males are also significantly smaller than the females and are mostly brown.
Similarities Between Joro Spiders And Writing Spiders
Both Joro spiders and writing spiders are orb-weavers. They have an extra claw that helps them weave intricate webs. Joro spiders and writing spiders are about the same size. Joros are a little bigger, but it may be difficult to tell them apart just by size. They both wait for prey to come to them vs actively hunting.
Joro Spider vs Writing Spider: How Do They Get Their Food?
Both the Joro and writing spider wait for their food vs actively hunting. Their large webs can catch flying insects. When an insect lands in their web, they grab it immediately and wrap their silk around it to keep it still. They then use their fangs to inject a venom that paralyzes the insect and inject it with enzymes that liquefy the prey. After that, they suck out the liquid remains. Spiders eat other spiders (even within the same species), but it does not appear that the new Joro spider is a threat to writing spiders.
Joro Spider vs Writing Spider: Are They Harmful To Humans?
Joro spiders are not harmful to humans. They are venomous, but their venom does not seem to have an effect on humans. Their fangs are also so small that they can’t break through the skin of humans. Pets seem to be safe from bites as well since their skin is also too thick for the Joro to pierce. Writing spiders are not harmful to humans either. They are venomous but again not venomous enough to cause a reaction in people. Both spiders prefer to be left alone and are not aggressive towards people or pets.
Differences Between Joro Spiders And Writing Spiders
Although they look similar, a few characteristics can help you tell them apart. Joro spiders have red markings on their back and underside while writing spiders are only black and yellow. Writing spiders have a gray head that is covered in silver hairs. They both have different shapes, with Joros being skinnier lengthwise and writing spiders being more oval. The biggest difference is their webs. If you see a black and yellow spider in a large web, it could be a Joro spider, writing spider, or even a banana spider (another large yellow and black spider). Look for the zigzag shape of the writing spider’s web, and you will be able to tell it is a writer.
Joro Spider vs Writing Spider: Body Size
These spiders are very close in size. Joro spiders are a little longer but skinnier. Joros are about an inch or more while writing spiders are ¾ to 1 inch.
Joro Spider vs Writing Spider: Web Size
Joro spiders spin bigger webs than writing spiders. The golden-colored web of Joro spiders can span between trees and reach widths of 10 feet!
Joro Spider vs Writing Spider: Which One Spins A Fancier Web?
Writing spiders spin fancier webs than Joro spiders! They use the third claw on their feet to spin complex webs with a zigzag design that goes down the middle. When prey lands on the web, the vibrations alert the spider that dinner is served!
Joro Spider vs Writing Spider: Location
Joro spiders and writing spiders live in the same place. They both live in Georgia and South Carolina. Joro spiders are new to the United States. They have only been in the states since 2014 and were probably accidentally introduced by coming over in a shipping container. They are from Japan, where there are large populations of Joro spiders. They also live in China, South Korea, and Taiwan. In the United States, they are mainly in Georgia but have spread to South Carolina. Researchers wonder if these Joros will spread even further this spring and eventually make their way up the East Coast. Writing spiders live throughout the United States (even Hawaii) and are common spiders. They are not found in Japan, China, South Korea, or Taiwan, so there is no overlap with the Joro there. But they both live in the states of Georgia and South Carolina, and if the Joro expands its habitat, they will be neighbors all the way up the Coast.
Joro Spider vs Writing Spider: What Do They Eat?
These spiders eat whatever comes into their webs, but Joro spiders place their webs higher, which might attract different insects. Joro spiders eat aphids, flies, mosquitoes, and stink bugs. Writing spiders eat flies, wasps, grasshoppers, and other spiders.
