The Joro spider and the yellow garden spider are two visually striking species of orb-weaving spiders that have caught the attention of many due to their size and vibrant colors. While they might seem similar at first glance, there are key differences between these two spider species that help distinguish them.
The Joro spider, native to East Asia, has recently gained attention as it spreads across the Southeast United States. Sporting distinctive yellow and blue-black stripes on their backs, along with bright red markings underneath, this spider has gained a reputation online due, in part, to its bright appearance and large size, with females being almost 3 inches across when their legs are fully extended.
On the other hand, the yellow garden spider is a native species commonly found across North America. This large, black, and yellow-striped spider is known for incorporating a unique zigzag pattern, called a stablementum, into its web construction. One notable difference between these two spiders is that immature Joro spiders rarely make a stablementum and adults never do, making it a useful identifying feature of the yellow garden spider.
Joro Spider Vs. Yellow Garden Spider
Identification and Appearance
The Joro Spider (Trichonephila clavata) is a large, yellow-striped spider native to Japan and East Asia1. Its key features include:
- Bright yellow and blue coloration
- Long leg span (up to 4 inches)
- Orb-shaped web pattern
On the other hand, the Yellow Garden Spider (Argiope aurantia) is a common North American species2. Identifiable by:
- Yellow and black coloration
- Zig-zag pattern in their web (also called “stabilimentum”)
- Slightly smaller size compared to Joro spider
Yellow Garden Spiders are native to North America and widely distributed across the continent5. They can also be found in South Carolina and surrounding states.
Habitat and Environment
Both species of spiders are commonly found in gardens and other green spaces, and they both serve as predators of insects. However, Joro spiders prefer warmer climates, with their population density increasing in areas with higher average temperatures6. Yellow Garden Spiders can tolerate a wider range of temperatures and environments.
|Feature||Joro Spider||Yellow Garden Spider|
|Origin||Japan and East Asia||North America|
|Size||Larger, with a leg span of up to 4 inches||Slightly smaller|
|Web Pattern||Orb-shaped||Zig-zag pattern (stabilimentum)|
|Color||Bright yellow and blue||Yellow and black|
|Habitat Preference||Gardens, warmer climates||Gardens, wider range of environments|
Web and Silk Characteristics
Types of Webs
- Jorō Spiders: These spiders rarely make a stablementum (zig-zag pattern) in their webs, and adults never do 1.
- Yellow Garden Spiders: They create orb webs with a trademark vertical zig-zag pattern, known as a stabilimentum 2.
Properties of Silk
Jorō spiders, like all orb weavers, produce golden silk. This type of silk has a unique property of being stronger than steel, is more elastic, and reflects light with a golden sheen. Here are some characteristics of golden silk:
- Stronger than steel
- Highly elastic
- Reflective golden sheen
Yellow Garden Spiders
Yellow garden spiders also belong to the orb-weaver family and produce golden silk like the Jorō spiders. Some of the shared properties of their silk include:
- Strong and elastic
- Golden sheen
- Used to create large orb webs
|Feature||Jorō Spider||Yellow Garden Spider|
|Type of web||Orb web without stablementum||Orb web with vertical zig-zag pattern|
|Silk properties||Golden, stronger than steel, and highly elastic||Golden, strong, and elastic|
Behavior and Ecology
Mating and Reproduction
The Jorō spider (Trichonephila clavata) and the Yellow Garden Spider (Argiope aurantia) have distinct mating and reproduction behaviors. Adult female Jorō spiders are larger and more brightly colored than males. Mating for Jorō spiders usually occurs in early fall, and females lay eggs in a cocoon hidden in vegetation (Penn State Extension). For the Yellow Garden Spider, males may pluck the female’s web to signal their presence, and the fertilized females lay their egg sacs around September (Gardens with Wings).
- Jorō Spider:
- Large, brightly colored adult females
- Mating occurs in early fall
- Yellow Garden Spider:
- Males signal presence by plucking webs
- Eggs are laid around September
Both Jorō spiders and Yellow Garden spiders are beneficial to their ecosystems as they help control insect populations. Jorō spiders feed on various pests in their natural habitats, while Banana spiders (Yellow Garden spiders) consume various insects such as flies, moths, and beetles (Clemson University). Both spiders construct large, orb-like webs to catch their prey.
- Jorō Spider:
- Eats various pests in natural habitats
- Constructs large, orb-like webs
- Yellow Garden Spider:
- Consumes flies, moths, and beetles
- Also constructs orb-like webs
Both Jorō spider and the yellow garden spider exhibit balloon-borne dispersal, known as “ballooning.” Spiderlings of both species release a silk thread that catches the wind carrying them to new locations (University of Georgia). This behavior helps them disperse over a wide area, facilitating the spreading of invasive species like the Jorō spider in the southeastern US.
- Jorō Spider:
- Exhibits ballooning behavior
- Contributes to their invasive spread
- Yellow Garden Spider:
- Also exhibits ballooning behavior
- Not considered invasive species
Danger to Humans and Pets
Venom and Bites
Joro spiders and yellow garden spiders are generally harmless to humans and pets. Their fangs and venom are not considered dangerous, causing only mild irritation and discomfort to humans when bitten.
- Joro spiders:
- Yellow garden spiders:
Comparing the bites between a Joro spider and a yellow garden spider:
|Spider||Bite Effect on Humans||Level of Danger to Humans|
|Joro Spider||Mild irritation and red mark||Low risk|
|Yellow Garden Spider||Mild irritation and red mark||Low risk|
Impact on Native Species
Joro spiders and yellow garden spiders have different impacts on the native species due to their distinct habitats and natural behavior.
- Joro spiders may affect other arachnids or insect populations
- Can survive brief freezes, making them more adaptable5
- Compete with other spiders for resources
- Yellow garden spiders:
- Usually found in gardens, reducing pest populations
- Serve as natural pest control
Thus, while both Joro spiders and yellow garden spiders are virtually harmless to humans and pets, they may have varying effects on the native species in the areas where they inhabit.
Spotting and Managing Joro and Yellow Garden Spiders
In Your Home and Garden
Joro spiders (Trichonephila clavata) and yellow garden spiders (Argiope aurantia) share some similarities, but they also have distinguishing features. Joro spiders hail from East Asia, while yellow garden spiders are more common across the southern United States.
Here’s a comparison table of their characteristics:
|Feature||Joro Spider||Yellow Garden Spider|
|Main color||Bright neon yellow with a splotch of black||Bright neon yellow|
|Body shape||Spherical||More spherical|
|Legs||Brown near body, black tips||Brown near body, prominent black tips|
|Webs||Rarely make stablementum||Build orb webs with trademark zig-zag pattern|
|Location||East Asia; expanding in the southeastern US||Southern U.S., Mexico, and Central America|
In both cases, these spiders are spotted in gardens, backyards, and occasionally near homes.
Control and Relocation
To manage these spiders in your home and garden:
- Avoid touch: While they are not harmful to humans, their bites can be painful.
- Natural predators: Encourage natural predators like birds to keep spider populations in check.
- Physical relocation: Carefully relocate spiders using a stick or other tool, avoiding direct contact with human skin.
- Limit prey: Reduce the number of other insects in your garden to limit the spiders’ food source.
Overall, it’s important to appreciate the benefits these spiders provide by keeping other insect populations in check.
Over the years, our website, whatsthatbug.com has received hundreds of letters and some interesting images asking us about these insects. Scroll down to have a look at some of them.
Letter 1 – Writing Spider from Costa Rica
Subject: Has beautiful web pattern
Location: Costa Rica, Limon, Purto Viejo
September 6, 2012 5:41 pm
I have this in my back yard in Costa Rica. Can’t find a match online.
Signature: John L.
Dear John L.,
Writing Spider is our favorite common name for members of the Orbweaving genus Argiope, a name that refers to the elaborate stabilimentum that the Silver Argiope weaves into its web. This type of web is indicative of the immature Silver Argiope and it is distinct from the web of the mature Silver Argiope. We have never quite figured out why the Silver Argiope, Argiope argentata, is so named, until we saw your Costa Rican adolescent female.
Correction: Argiope savignyi
December 15, 2012
We just received a comment from Rose indicating a correction in this identification. The correct species, Argiope savignyi, can be found on Nature Photo as well as on American Arachnology. The Minibeast Wildlife website refers to this species as the Silverback Cross Spider and entomologist Piotr Naskrecki calls it the Tiger Spider.
Letter 2 – Yellow Garden Spider
Hello there! Thanks for the website.. I was able to figure out what we had! You have alot of these on your site, but we capture this picture of the brand new egg sac!
Kevin D. Handley
Irving , TX
Argiope aruantia has numerous common names. In addition to Yellow Garden Spider, it is also called Golden Orb-weaver (California), Yellow Garden Orbweaver, Writing Spider and Black and Yellow Argiope. Now that the females are maturing, reaching their maximum size and laying eggs, they are being noticed, and we expect to be receiving numerous more identification requests for spiders in the genera Argiope and Araneus, the Orb Weavers.
Letter 3 – Writing Spider and Egg Sac
Location: Los Angeles, California
March 8, 2012
I’ve recently been sorting through some old photos and found these two images of a spider and egg sack that I took in my garden this past Fall. My father told me that country people called them “writing spiders” and said that if you saw your name written in their webs you would die. Both the spider and the egg sack were located in the same part of the garden and I assume the egg sack is from this spider. Can you tell me the actual name of this spider and let me know if I should be excited to have more of them in my garden this spring?
Your father is absolutely correct, at least as far as the name goes. Writing Spider is a perfectly acceptable common name for this spider, as are Golden Orbweaver and Yellow Garden Spider, though if you really want to be technical, you would refer to this species as Argiope aurantia to avoid any confusion. The common name Writing Spider arises from the zigzag pattern spun into the web, a structure known as the stabilimentum. We had never heard the lore regarding death being the outcome of seeing your name written in the web. Tell Dr. Lutz we found that bit of trivia perfectly fascinating. The Egg Sac is in fact that of a Writing Spider. Here is a photo from our archives of a female Writing Spider and her Egg Sac. Spiderlings will hatch in the spring and spin a silken thread to catch the wind in order to disperse, a behavior known as ballooning. If you desire more information, you can always search BugGuide.
Letter 4 – Silver Backed Argiope
I noticed the bug of the month and thought you might enjoy this image of what I believe is Argiope trifasciata. This picture was taken early August in a salt marsh in Georgia.
This is not Argiope trifasciata, the Banded Argiope, but Argiope florida, the Silver Backed Argiope. It represents a new species for our site, so if you identified it on our site, please let us know on what spider page and we will make a correction on the previously misidentified specimen.
Letter 5 – Slug Caterpillar and Writing Spider Stabilimentum
Bright Blue Bug!!!
I just came across your site was perusing google, and was blown away by these amazing photos. I have a photo of this incredible bug I saw in Indonesia and am wondering what the heck it is. I have so many pictures of amazing bugs, and also, one picture of this zigzag spider web which I have questions about. ZIGZAG spiderwebs…crazy, what advantage does it provide the spider to have a zigzag web?? I look forward to hearing from you, and please feel free to post for all of those bug lovers out there!!Also, just incase you’re interested, I’m from Vancouver Island on the West Coast of Canada, and someone there has put a camera in a tree, and so right now it’s capturing a LIVE feed of an Eagle sitting on 2 eggs which are expected to hatch at the end of the month!! Enjoy!!!
Thanks for resending with the images. Your Indonesian bug is a Slug Caterpillar in the Family Limacodidae. We have several interesting North American species including the Saddleback Caterpillar and the Stinging Rose Caterpillar. Those spines do contain an irritating chemical that stings. Your spider is some species of Argiope, probably a Silver Argiope, but your photo lacks necessary detail. The zigzag pattern is known as a Stabilimentum and is believed to be a type of camouflage for the spider. These spiders are sometimes called Writing Spiders.
Letter 6 – Two Argiopes: aurantia and trifasciata
what’s this spider?
Here’s a Black-and-yellow Argiope, Argiope aurantia; her prey item is an odonate, probably a male Pacific Forktail (damselfly).
? Now my question: Can you ID this other female, possibly also of genus Argiope? ? These two are common in the Bay Area of N California. I refer to the second as a "Banded-legged Argiope," although it could be in a related genus. Its habits and life cycle are similar to the Black-and- yellow. Curiously, this one has a pattern on the underside of the abdomen that virtually duplicates that on the back of the B&Y.
|Argiope aurantia||Argiope trifasciata|
Common names can sometimes duplicate for different creatures, and they can also vary from locale to locale. Your Black and Yellow Argiope also has other common names like Golden Orb Weaver, Yellow Orb Weaver, and Black and Yellow Garden Spider, but they are all Argiope aurantia. Your Banded Legged Argiope is an Argiope, and is commonly called the Banded Argiope, Argiope trifasciata.
Letter 7 – Unknown Argiope Orb Weaver from Borneo
Found in Borneo, Malaysia near Sandakar
Hi, I have had these 3 pictures for about two years now and always wanted to identify them but with no success. Having come across your website I wondered if you can tell me what they are apart from a spider, grasshopper and a beatle
Your spider is an Orb Weaver in the genus Argiope, but we have had no luck with an exact species.
Letter 8 – Writing Spider from Mexico
Subject: Chiminea Spider
Location: Ajijic, Jalisco, Mexico
May 13, 2016 9:12 pm
Saw this today with a web that covers the entire opening to the chiminea.
Was hoping you could tell me what’s that bug.
This is an Orbweaver in the genus Argiope, possibly a Silver Argiope, Argiope argentata, which you can find on BugGuide. Spiders in the genus Argiope are harmless, and they are frequently called Writing Spiders because of the elaborate patterns woven into the web. We located images of Orbweavers will similar stabilimenta on Nature Photo and National Geographic that are identified as Argiope savignyi, a species found in Central and South America.
Letter 9 – Yellow Garden Spider
July in Alabama
Can you tell me what type of spider this beauty is? The web was so interesting. The spider is about an inch or a little less in size. It’s web was close to the gound in some ivy.
You have sent in a photo of Miranda aurantia, the Yellow Garden Spider. The web is unique. They are orb web builders who place a stabilimentum in the center. It is believed to act as a camoflague for the spider. Your spider has made the lace-like stabilimentum. The spider is widely distributed in the United States and other parts of the world.
Letter 10 – Yellow Garden Spider
Pictures of my friend Gardenia
July 31, 2009
I hope you like the pictures I took in August ’08 of a Female Garden Spider that had made it’s home in my euonymous plant . Once I had identified her, I named her Gardenia, and she became a regular stop on my daily garden tour. I think she is eating a fly in these photos.
Waterdown, Ontario, Canada
Thanks for sending us your photos of Argiope aurantia, a female Yellow Garden Spider or Golden Orb-Weaver as we call them in Los Angeles. We think Gardenia is a very fitting name. One of our gardeners, Raul, has been nicknamed Gardenia by the rest of the crew. Thanks for indicating that your photos were taken last year as we thought it was a bit early to get photos of such a mature spider.