Golden Silk Spider or Joro Spider?, Vol. 8, No. 18
If you have been watching the news media over the last year or so, you have probably heard about the “giant” Joro spider, Trichonephila clavata, that has invaded north Georgia and parts of other southeastern states. If you spend time outdoors in South Mississippi this summer, you may spot something that looks very much like a Joro spider. Golden silk spiders, Trichonephilia clavipes, have been in the US for more than 100 years and are now common in the southern part of the state. This year, they are more numerous than usual.
Golden silk spiders and Joro spiders look a lot alike. Even their scientific names are similar. Both are colorful, large-bodied spiders with leg spans of mature females ranging from three to four inches. Both are orb weavers that spin large, wagon wheel-shaped webs. Both are capable of catching prey as large as cicadas, and even small lizards, frogs, and young hummingbirds. Neither of these big spiders is to be feared for their bite. Both can bite, but rarely do so unless roughly handled, and bites are not seriously venomous.
How do you know whether you are looking at a golden silk spider or a Joro spider? Look at the legs. Female golden silk spiders have dense tufts of black hairs on their legs. They look a bit like pipe cleaners (see photo). Joro spiders have hairs on their legs, but nothing like this. Also, if you see red markings on the belly, it is a Joro spider. Golden silk spiders are colorful, but no red.
If you spot a Joro spider in Mississippi, we would like to know about it. Please send a photo. They will probably make their way here eventually, and, because Joro spiders are more cold-tolerant, they are expected to thrive in north Mississippi. In fact, it is northeastern Georgia, around Atlanta and Athens and over into Greenville SC, where Joro spiders have recently exploded. Golden silk spiders are more of a tropical and subtropical species. They thrive on the Coast and can be numerous as far north as Jackson following mild winters. In future years, these spiders may have the state divided, golden silk spiders in the south and Joros in the north.
Although golden silk spiders are interesting miniature wildlife, they certainly achieve nuisance pest status when populations are high. Homeowners with a dozen of large spider webs around the front porch and more on the patio often have difficulty appreciating their unique beauty. During years of heavy populations, the cumulative nuisance effect of accidentally walking or riding through spider web after spider web can dampen enjoyment of outside activities. They may not bite, but it is irritating to get one of those webs plastered across your face—for the 5th time that day, and it is alarming to suddenly feel one of these big spiders crawling up the back of your neck. Fortunately, populations tend to wax and wane across years.
See Bug's Eye View No. 31 of 2017 for more information on golden silk spiders.
Here is a link to one of many articles about Joro spiders.
Black and yellow garden spiders are large orb weavers that can be confused with golden silk spiders. But these are native spiders that occur throughout the state and are rarely numerous.
Blake Layton, Extension Entomology Specialist, Mississippi State University Extension Service. The information given here is for educational purposes only. Always read and follow current label directions. Specific commercial products are mentioned as examples only and reference to specific products or trade names is made with the understanding that no discrimination is intended to other products that may also be suitable and appropriately labeled. Mississippi State University is an equal opportunity institution.
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