New Find: Joro Spider

Late this summer we discovered a spider that we had never seen before. As is always the case when we find a 'new to us' creature in our garden we dive into research mode and try to figure out what we have. This time we came up empty.


I reached out to one of my favorite ID sites, Bug Guide, to assist in identifying this spider. They did not disappoint. In a few hours we had our answer. We have a Nephila clavata, also known as the Joro spider.  According to Japanese Mythology, this spider is a deceptive shape-shifter (you can read the story at Yoki.com) but I prefer the Korean translation, which means Asian 'Fortune-Teller'.


This is a golden orb weaver that is similar in size to our common black and yellow garden spider (Argiope aurantia); however, the Joro spider is native to East Asia (Japan, China, Korea and Taiwan). How did this lady find her way to our garden? More research was required to unearth her story.

Left: Argiope aurantia (female),    Right: Nephila clavata (female)

According to a 2014 study (*) by Georgia Museum of Natural History at UGA, several Joro specimens were collected in three Northeast Georgia counties (Barrow, Madison and Jackson). These were the first confirmed Nephila clavata in North America and scientists think they arrived as stowaways on cargo ships. Obviously, we are not close to a port but we are located along I-85, a major commercial transportation corridor. It is believed that shipments traveling through our area contained egg sacs, which hatched spiderlings upon arrival. The study sited Braselton Park (in Braselton, GA) as one of the collection locations, where they found a female spider with two male spiders attending her web. This park is about 10 miles away from us and located near a thriving warehouse and distribution district, which deals with overseas freight.




The Joro spider is pretty spectacular looking. The top of the female's abdomen has a wavy black and yellow pattern while the underside is an amazing black and yellow maze with distinct red blotches. The black and yellow striped legs are also prominent. Our spider has gotten rather large over the past two months, approximately 4" wide [including its leg span]. 

top view of abdomen with grayish-black and yellow stripes.

The web of this spider is impressive too. She's set up at our woodland edge between two understory trees and large shrubs spanning a space of at least 5 feet. The web is built in three layers, uncharacteristic of orb spiders. The multilayered structure includes a large orb in the center with an additional front and back layer with irregular threads. The photo below doesn't do it justice, but the golden silk glistens when the morning sun hits the web.


Our spider's web is filled with insects, leaves, and other debris so fortunately it is hard to miss. We definitely wouldn't want to mistakenly walk into this sticky web. When prey is caught in the web the Joro spider immediately bites her victim inserting a potent venom. [Note: The venom is not strong enough to harm a human unless one has an allergic reaction. If bit by a Joro spider, humans typically experience pain, redness and blistering that disappears within 24 hours.]

Male spiders lurk in the outskirts of the web and are significantly smaller and and light brown in color. I have searched assiduously but have been unable to locate a male. Mating season occurs in October, which produces a single egg sac containing 400-500 eggs. The silk cocoon is attached to the bark of trees, on leaves or other human structures. Adults die in the winter leaving the next generation to hatch in spring.

This Asian spider has a North American relative, Nephila clavipes or golden silk spider, which is common in the southeast. The impact this exotic spider will have on our local ecosystem is unknown at this point. Interestingly, there are about 60 species of non-native spiders, mostly originating from Europe and Asia, thriving in North America thanks to international trade. According to Hoebek "there is no indication that the Joro spider will be invasive to the extent that it would be disruptive or economically costly". I wonder how this spider will interact with our native spiders. Will it displace any of our garden spiders or other native spiders? 


It is probable that the Joro spider has established itself in other areas of Georgia and across the country. Apparently this spider can withstand pretty cold temperatures (so be on the lookout northern friends). If you suspect you've discovered a Joro spider contact Hoebeke at rhoebeke@uga.ed. The initial discovery of this spider in our area was because of local residence, which demonstrates just how important citizen scientists are.

(*) study cited Hoebeke ER, Huffmaster W, Freeman BJ. (2015) Nephila clavata L Koch, the Joro Spider of East Asia, newly recorded from North America (Araneae: Nephilidae) PeerJ 3:e763

Comments

  1. Wow, I have not seen this one before...will keep an eye out for it. This time of year I am always walking into webs.

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    1. Yes! There are so many spider webs around the house and garden. I love observing them, they are so fascinating but it definitely isn't fun to walk into a web.

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    2. Tons of this on our property this year. 3-5 webs within just a few feet of each other!!!!!
      Maysville GA:)

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  2. I haven't seen this one here in Nashville, but will be paying attention.

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    1. Yes, do. I am hearing from area residence that once this spider appeared in their garden, our native writing spiders disappeared. I wonder if is any further research is being done on their impact.

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  3. Look at those legs and 4" long! There are some cold areas in Japan, so I'm wondering how far north this species will venture.

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    1. It is a big, fat spider, but with it's large web difficult to miss. Plus the webs are pretty high off the ground. Only time will tell how far these spiders will travel. Down side of international commerce.

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  4. I'm pretty sure that this is the spider that has completely displaced the writing spider that used to live on my property. Thanks for the link. I've been concerned about it but haven't seen much from anyone else who seems to be. I'm in the Southern Piedmont of NC.

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    1. Thanks for commenting. I'm surprised it's made it to your neck of the woods already. I am hearing similar stories of the writing spider disappearing from gardens once this Asian spider established itself. If I find anymore information I will update this post.

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  5. She is a beauty! Yeah, I'm not familiar with this one, but it sounds like it's starting its N.A. infiltration in the south. Hopefully, it won't be a problem--invasive or disruptive.

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    1. Beth, I'm hearing from several local friends that they have lots of these spiders in their garden. It seems to be establishing itself pretty well in a short period of time. That never seems like a good sign to me. Anecdotal stories say that once this Asian spider appears, our native black and yellow spider disappears. Don't know if the Asian spider is outcompeting or just coincidence.

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    2. If you want some they seem to love Fowey Branch Ga with huge strong webs that will have you feeling link you emerged from a haunted house in Oct this year. Kind of spooky how many I've seen

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  6. A very cool spider. Worth appreciating - from a distance! Great pics.

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    1. We've been watching her for about a month now. She is fascinating and we are learning a lot.

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  7. Wow, that is one impressive looking spider! One does wonder though about the native ecosystem with these different insects finding their way over here...

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  8. Hi! I just came across this blog page randomly. My fiance is the one who actually found the first spider in Madison county (in our backyard!) and alerted Dr. Hoebeke at the University of Georgia! It was crazy exciting to find it and take the first pictures with our camera phone and like you, we just had to know more about it. We have found a few here and there since, and it's always a treat. Thank you for this write up and support of citizen science!

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  9. I am pretty sure we stumbled across one and her giant web in our backyard here in Augusta Georgia this evening. She had her web full of other spiders...

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  10. Thank you for sharing! We're in northeast Forsyth County, Georgia. My oldest son just came inside in a panic after finding "a giant black and yellow spider with the biggest web I've ever seen" in our back yard. I was expecting our common garden spider, but I knew it was something else once I looked at it. I'm terrified of spiders, but I think she's beautiful!
    - Melissa

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  11. Came across one of the Joros in Marshalliville, Ga near Perry. I have pretty big hands and this one was nearly the size of my palm.

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  12. Karin - very interesting article. I'm in the Gwinnett part of Hoschton, right next to Braselton. And have 2 of these giants with 3 1/2 ft webs right outside my bedroom window at about a height of 15 feet. My concern is you've labeled them as Joro Spiders but when I google them they say they are poisonous. Do you have any other info on these? They are IDENTICAL to the top picture you have above. Thanks, Carl

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  13. Oh, and I should add that based on the descriptions above, I have a male in the web with her. But MUCH smaller, like the size of my thumb verses the female at about 4 1/2 "front toe to back toe."

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  14. Have two females in large webs, about 6ft above the ground. Did not notice any males, but was not looking close for them as I took my closeup pictures. Location is Gwinnett Co., Lake Lanier about 1 mile Northeast of Lanier Middle School.

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  15. I just spotted three in my yard in different locations. They are absolutely beautiful to watch and to observe everyday. I emailed the above address about it. I live in Gwinnett Co as well. Buford, Georgia.

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  16. Not happy about this at all, there are hundreds of these spiders & they seem to really thrive on the power lines. The other spiders are disappearing & the Joro's have taken over. I have 3 large webs attached to my house next to shrubs. Usually I can observe several males above each female webs just waiting. No more walks in the woods & parks in the Fall for me. Can't stand running into the webs. I live in Hall County, Georgia near Chateau Elan Winery.....

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  17. We have several in our backyard mostly near the house in Jefferson,Georgia. Lots of opinions, but yesterday someone said not to kill them. We have killed several because we run into the webs, did not know what kind of spider they were.



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  19. We live just outside of Jefferson, GA on 1.5 acres of lightly wooded property. Currently there are over 80 male and female Joro spiders on our property and just across the street. At this point, these spiders appear to be extremely invasive. If you watch the power lines around here, there are hundreds of these webs.

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    1. I agree that the rate at which they are multiplying they are considered invasive. I first observed them back in 2017 when I wrote this post. The first year I saw two, the following year we had ten, now we have hundreds on our property. I imagine that they take food from our native spiders. Their webs are large and catch lots of insects. Because of the size and strength of their webs I am concerned that the hummingbirds will get caught in them. They tend to make their webs high in the air. You may want to report your findings at jorospiderga@gmail.com A teacher at UNG is collecting data.

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  23. We have quite the large "JORO" city going on around our house. We had six or seven webs going on here in Cumming. I am about 3 miles from Lanier dam. Enjoying them being here.
    Walker

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  24. Walker, recently saw the first one around my house. Right outside our kitchen window. We are in Sugar Hill about 1.5 miles from Lanier dam. Hate spiders. But this thing is pretty awesome.

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  25. Im in Winder ga I have several Joro spiders

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  26. Our trails to ride the horses on are impossible to go down now with the millions of joro webs and spiders. Jackson county- we were ok this summer but it feels like an explosion of spiders now.

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  27. I found 13 of these spiders on my one acre lot in Winder, near Jefferson. We used to have a lot of writing spiders, but it seems the Joro spiders have taken over.

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  28. I am usually very aware of insects, since I am quite allergic to their bites.
    Until this year, I have never, ever seen a Joro spider but have permanently removed 26 of them in the past week from my house and yard. I've even reached up as high as 25 feet to bring their webs down.
    Any insect this invasive, in such a short period of time, is disconcerting...especially if native spiders are now disappearing.
    I will continue to carry out my duties to remove as many as possible, and thanks for the egg sack info too, Karin. If I find out how to easily spot those, is will certainly let you know!

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    1. The Joro Spiders have multiplied very quickly over the past few years. The numbers are staggering this year. I have been removing them as well. But there are so many that are out of reach. Every little bit helps. I have seen very few native spiders this year. You are right, it is very disconcerting.

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    2. Absolutely! Invasive is putting it mildly. I live SSW below Buford Damn in Forsyth County. I first experienced the Joro last year summer 2020. It was unnerving, as Haw Creek and a good wooded area along it are my back yard. This summer 2021 is like a scifi movie. I destroy dozens each day only for dozens more to replace them the following day. Most webs have the smaller mate (often two) nearby in them. The Joro spiders appear not to have any natural predators - none! The Joro spider's appearance in Georgia is a calamity and I expect no good to come from their invasion of our habitat. I pray for deliverance.

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    3. I totally agree! They completely invaded my place (and my neighborhood) in South Hall County near Friendship Road in 2019. I think I saw a few in 2018 but by 2019 it was stranger than fiction around here! I think they'll cause an ecological disaster because they can catch hummingbirds in their webs and since they arrived I haven't seen a single brown orb weaver and they used to be everywhere. What else will they kill, eat, or chase away?! We need need to deliver ourselves by sending them back to Asia!! 😄

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  29. I didn't realize these spiders made the news until a few days ago but I'm not surprised. I live in South Hall County, GA and these creepy crawlers invaded my place 2 or 3 years ago. I even found one in my bedroom one night! That was a very frightening experience!

    I'd never seen so many huge spider webs in one place until these guys showed up and I used to have the huge (or what I thought was huge) brown garden orb weavers. They spun some pretty impressive webs in the trees than span across my 15ft driveway as well as across my front door. The first year the Joro spiders invaded my area was the first year in over 30 years that I didn't see my brown orb weavers. Not only did I not see the brown orb weavers on my heavily wooded lot but they were also no longer hanging from the bushes at my local Publix where I'd see them every autumn.

    So for those who wonder whether or not the Joro Spider will have an ecological effect on our native spiders, the answer is YES, MOST DEFINITELY!! THEY ALREADY HAVE! I haven't seen a brown orb weaver in over 2 years. I've also read about and seen pictures of hummingbirds getting caught in their webs. When you think of bird-eating spiders, North and Northeast Georgia isn't the place that usually comes to mind but that has changed woth the arrival of this monstrous spider. The Joro Spiders have taken over and crowded my brown or weavers out (or ate them!). There are so many in my yard, I'm terrified to go outside without waving the broom around to knock down webs in the pathway to my car. I have one female Joro in particular at my kitchen bay window whose body appears to be at least as big as my thumb!! I say "appears" because I'm not getting close enough to get exact measurements! LOL!

    Anyway, I enjoyed reading this post and thought I'd share. I really hate to see how many more of these spiders we will have in the years to come. I suppose there's some consolation in that they're not aggressive spiders and they eat yellow jackets which is something I usually have a huge problem with. So... there's that! 😄

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One of my favorite things about blogging is the conversation with readers. Leave a comment and let's get talking. ~Karin

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