They’re big. They’re brightly colored. And they give a lot of people the creeps.
It’s spider season, y’all! Joro spider season, to be specific. Every late fall for the last few years, we’ve seen a massive uptick in the number of Joro spiders in South Carolina. Initially just found in the Upstate, they can now be found in the Piedmont and Sandhill regions, too. This summer and fall have been especially good for spiders due to the weather, which is why it may seem like you’re seeing more spiders than usual (because you are!). These are natural population fluctuations – some years the populations are up, and in other years the populations are down. 2025 happens to be an up year.
Joro spiders, due to their size, propensity to put webs everywhere – including on houses, carports, and landscape plants – and bright color, tend to garner a lot of attention every fall. Let’s dispel some myths and get some answers on some of the most common questions we’re often asked about Joro spiders.
Q: Are they native to the U.S.?
A: No, they are an invasive species from Asia, which likely got here by hitchhiking on a container.
Q: How long have they been here?
A: They were first documented in north Georgia in 2014 but were likely there several years prior – probably since about 2010 based on conversations with local residents.
Q: Are they dangerous to people or pets? More specifically, will they bite me?
A: No, they are not dangerous. They are quite docile, and studies show they would rather not be on you – when held, they typically try to crawl off and drop to the ground. A recent study also found that in order to get a Joro spider to bite you, the spider had to be REALLY antagonized. So long story short, if you get bit by a Joro, you probably brought that on yourself by irritating (e.g., physically pinching or squishing) the spider.
Q: Are they venomous?
A: Yes, all spiders are venomous – that’s how they subdue their prey. However, their venom is not medically relevant to humans, unlike that of black widow or brown recluse spiders (a bite from those will send you to the hospital!).
Q: Are Joro spiders good for the environment?
A: Mostly no. While they will eat some harmful pests (like mosquitoes, or stink bugs), all spiders will do this – not just Joro spiders. And there is mounting evidence that where there are a lot of Joro spiders, the native orbweaver spiders disappear, showing a clear negative impact on the environment.
Q: What should I do if I have a Joro spider on my house? Or porch? Or deck? Or anywhere on my property, really?
A: Probably the easiest thing to do is just ignore the spiders – they don’t want to get in your house, and as already mentioned they aren’t dangerous. But yes, they can be annoying, as their webs can stretch up to 20 feet across! Any physical removal method works great (a stick, a broom, your foot, etc.). There are several sprays labeled for spider control and these are available at any home and garden store. We do not recommend using products that are not labeled for spider control (e.g., machine lubricant) as spraying these substances all over your yard or home may cause unwanted damage to property and impact people or pets in the area.
Find out more about the Joro spider in this video (https://www.youtube.com/watch?v=zhO_bwwg-E4) or on our Clemson Extension HGIC page (https://hgic.clemson.edu/factsheet/the-joro-spider/). If you have Joro spiders on your property, please report them to iNaturalist (https://www.inaturalist.org/) or Joro Watch (https://jorowatch.org/).
Read more about what a bite from a Joro spider feels like: https://academic.oup.com/jme/advance-article/doi/10.1093/jme/tjaf103/8296680?searchresult=1
Learn how to manage Joro spiders on your property: https://academic.oup.com/jee/advance-article/doi/10.1093/jee/toaf225/8296679?searchresult=1
Author
Dave Coyle, Cooperative Extension, Forestry and Wildlife Specialist
Clemson University Cooperative Extension Service offers its programs to people of all ages, regardless of race, color, gender, religion, national origin, disability, political beliefs, sexual orientation, gender identity, marital or family status and is an equal opportunity employer.
