Big, yellow spiders, anyone? South Carolina has them, and as summer heats up, they get more and more noticeable. One of these spiders is the Joro spider, a non-native species first found in northern Georgia in 2014. The Joro spider is now present in the Upstate and parts of the Midlands in South Carolina. These spiders can be nearly 3” across with their legs spread.
Joro spiders overwinter as eggs, which hatch in late spring. Juvenile Joro spiders can be seen beginning in early May, making webs on practically anything: homes, decks, porches, landscape plants, and natural areas. Webs and spiders will get progressively larger until about September, when the large adult females are very noticeable due to their bright coloration. Males are much smaller, drab brown in color, and can often be seen in the webs along with the females.
Because the Joro spider is not native to the United States, we do not know what kind of impact it will have on native fauna. It is unlikely to be dangerous to humans or pets other than being a nuisance in some situations. If Joro spiders are a nuisance and somewhere they need to be removed, simply use a stick to move the web and spider to another location. Pesticides will kill individual spiders, but if you kill one, more are likely to move into that area. We do not recommend using fire (due to safety reasons) as a management tactic.
If you see a Joro spider, please report it to the iNaturalist project “Orb weaving spiders in the Southeastern USA”. iNaturalist is a free online community platform for reporting flora and fauna sightings. Your contributions will help us learn much more about this species.