By: Robyn Stewart
A new spider species has begun to make its way into Northeast Georgia, and you may have seen one yourself this fall. I know that I had one of these arachnids take up residence at my house near my water hose and stay there until we got colder weather. The culprit? Nephila clavata: The East Asian Joro Spider.
The East Asian Joro Spider is not quite as new to Georgia as you may think- they were first spotted in Hoschton in 2013, and genetically confirmed as nephilia clavata in 2015. While we may never know where the spider originally entered Georgia, extension specialists believe they would have gotten here in a shipping container from China or Japan that was brought to the state along Interstate 85. Today, the spiders have been sighted in at least 23 Georgia counties. The spider is widespread in its native habitat of tropical and subtropical regions including Japan, Korea, China, and Taiwan. The spiders mature in early September and die in late November when the temperatures drop.
Joro spiders can be up to 3 inches in size when their legs are fully extended, which makes them a similar size to banana and yellow garden spiders. This species, however, is characterized by yellow and blue-black stripes on their backs and red markings on their undersides. Another unique characteristic of the Joro spider is their large, golden colored webs, which they prefer to make higher off the ground than other species. The spiders are also interesting as they travel by ballooning, a method where the wind carries them on a strand of their web. This is particularly interesting as it is how the male spiders travel to find their mates. In areas with many Joro spiders, the ballooning technique is effective for the males to travel, but in areas with a small population, researchers aren’t quite sure how the males find their mates.
Specialists at UGA have been investigating this species since its arrival in 2013, with a primary goal of understanding how they might impact the local ecosystem. Early observations indicate that the Joro spider can coexist with other orb weaving spiders native to Georgia. A benefit of the new species is that they capture and feed on insects that local spiders do not- mainly the adult brown marmorated stink bug. They also provide habitat in their webs to dewdrop spiders, who are known to steal food from other insects. In return, the Joro spider is a prime target for predators like mud dauber wasps and birds. Fortunately for the public, Joro spiders pose no threat to humans. If you notice a web in an inconvenient location, you can use a broom to shoo away the spider and encourage it to build its home somewhere else. We do not recommend trying to get rid of the spiders permanently, as they are here to stay.
If you need help with insect identification or have entomology questions, we can help! Please send your questions to uge3181@uga.edu or 706-359-3233.
