The United States has become home to a new arachnid resident: the Joro spider. These large, brightly colored spiders have been the subject of a recent study by Clemson University, which has found that they are swiftly expanding their range beyond the initial sightings in South Carolina. The study utilized advanced modeling to predict that the Joro spider could potentially inhabit a vast portion of the eastern U.S.
The Joro spider, scientifically known as Trichonephila clavata, is native to several East Asian countries and was first reported in the U.S. about a decade ago. It has since established a presence across several states, with sightings as far as Alabama and West Virginia. The females, notable for their size of 3-4 inches and vivid yellow and blue coloring, are significantly larger than the males, which are smaller and brown with less striking markings.
These spiders are part of the golden orb-web weavers group, renowned for their impressive and sturdy webs of gold-colored silk. One of their most fascinating characteristics is their ability to “balloon” – using their silk to catch the wind and disperse to new areas.
Despite their size and venom, Joro spiders are not aggressive towards humans or domestic animals. Their fangs are not capable of penetrating human skin, and they tend to avoid indoor environments, preferring the warmth of the sun. They play a beneficial role in controlling pests such as mosquitoes and flies and are also a food source for birds. The full impact of their presence on local ecosystems in the Southeast is still under investigation.