Researchers from Clemson University in Georgia evaluated how far the Joro spider (Trichonephila clavata) has spread since its arrival in the eastern United States around a decade ago. Despite their imposing size and striking appearance, the creatures are considered harmless to people. This assessment comes from a respected scientific institution.
The invasive species was first identified in Georgia in October 2014. Since then, populations have expanded to North and South Carolina, Tennessee, Alabama, Oklahoma, Maryland, and West Virginia. Current estimates put their habitat range at more than 74,000 square kilometers, signaling a substantial expansion over the years.
Originally native to East Asia, the Joro spider has found climatic conditions across much of North America suitable for establishment. The species shows a remarkable ability to adapt to new environments, particularly in regions that offer warm summers and adequate humidity.
Adult Joro spiders can reach up to about 10 centimeters in diameter when including leg span. They display a yellow-and-black coloration, with females typically larger and more vividly colored than males. A notable trait is their ballooning behavior, which allows young or even adult spiders to travel significant distances by releasing silk and hanging on air currents, effectively dispersing to new habitats.
Biologists emphasize that despite their alien origins, Joro spiders do not pose a threat to humans or to the integrity of local ecosystems under normal conditions. The guidance from researchers suggests that unnecessary killing should be avoided whenever possible. If an individual spider is found in a home or garden and is considered disruptive, relocation with a broom is recommended as a humane option.
Separately, reports from Australia have highlighted concerns about funnel-web spiders, which are known for their venom. This comparison underscores the importance of understanding spider species in different regions and avoiding generalizations about risk levels based solely on appearance or unfamiliar origin. Local authorities and experts advocate informed, cautious handling if encounters occur and encourage education about native versus non-native arachnids.