An invasive species of spider, known as the Joro spider, has been identified in Great Smoky Mountains National Park, according to the National Park Service (NPS). The NPS announced on August 28 that these spiders, which originated in East Asia and first appeared in Georgia, are now spreading northward.
“These large orb-weaving spiders are striking to see, but they pose a challenge: as they move into new areas, populations of native orb weavers have been shown to quickly decline due to competition,” the National Park Service reported. “In Great Smoky Mountains National Park, most sightings have occurred in and around Cades Cove.”
Cades Cove is a popular area within the park, featuring an 11-mile loop road through a valley surrounded by mountains. The park itself covers over half a million acres along the Tennessee and North Carolina border.
The NPS is encouraging visitors to report any sightings of Joro spiders using the iNaturalist app and submit photos. “Observations will provide valuable data to help us better understand and manage this invasive species,” the park says.
Joro spiders are not considered dangerous to humans. According to the North American Invasive Species Management Association, these spiders likely arrived in Georgia by hitching rides on shipping containers and were first documented there in 2014. Since then, their range has expanded into neighboring states.
Adult female Joro spiders can reach more than three inches across when including their legs. They are noted for their bright yellow stripes set against a silver or gray background.
While Joro spiders possess tiny fangs and produce neurotoxic venom for subduing prey, human bites are rare and usually result only in mild symptoms such as redness or blistering unless an allergic reaction occurs. The University of Georgia Extension notes: “They dohave a neurotoxin venom used to immobilize their prey, however it is not very potent and only causes some redness and blistering to people, with exception of allergic reactions.”
“Despite their large size and bright coloring, these spiders cause very little risk to people. The largest nuisance they cause are there very strong webs that they spin on lower hanging tree limbs.”
