Study Reveals Jorō Spiders’ Surprising Tolerance for Urban Areas
In a surprising discovery, researchers have found that the Jorō spider, also known as Trichonephila clavata, has a remarkable tolerance for urban areas. Unlike most creatures that find the noise and disturbance of busy roads to be stressful, the Jorō spider seems to thrive in these environments. This new study, published in Arthropoda, sheds light on why these spiders are regularly spotted in urban areas and suggests that they are well-suited to spread throughout the United States.
The Jorō spider, which can grow up to 4 inches in length, was first spotted in the United States around 2013. Since then, it has rapidly spread across the southeastern states. These spiders are classified as orb weavers and catch prey using their giant, three-dimensional webs. They sit in the middle of the web and wait for vibrations that indicate an insect has been caught, allowing them to capture their prey.
To understand how the Jorō spider reacts to the noise and vibrations of busy roads, researchers conducted over 350 tests on spiders across 20 different roads. They used a tuning fork on the spider’s web to simulate prey behavior. Surprisingly, they found that spiders near moderate to heavy traffic roads were only slightly less likely to attack the simulated prey compared to those near low-traffic roads. The spiders near heavy traffic attacked 51% of the time, while those in less busy areas attacked 65% of the time.
Floyd Shockley, collections manager for the Department of Entomology at the Smithsonian National Museum of Natural History, expressed his surprise at the spider’s ability to tolerate being around cars and people. He explained that while most spider species prefer to stick to wooded areas, the Jorō spiders specifically move into urban habitats. They take advantage of easy hunting and access to prey, rather than being interested in humans themselves.
One reason for the Jorō spider’s success in urban areas is its preference for making webs on structures where lights are nearby, such as between buildings or on telephone poles. The light attracts insects that the spiders feed on. The researchers cited past studies that have shown roads to have a negative impact on insect abundance and diversity. However, the Jorō spider and its cousins within the Trichonephila genus seem to be surprisingly tolerant of urban environments and choose to build their homes near busy areas.
The study authors admit that they don’t yet know why these spiders are better suited to city life than others. However, lead study author Andy Davis plans to conduct future studies to investigate the physiology of the Jorō spider and its response to stress. He believes that the species has a unique way of reacting to stress, which allows it to live in a challenging environment. A previous study conducted by Davis in 2023 found that Jorō spiders are rather timid and tend to “freeze” when disturbed. This behavior might help them endure urban settings as freezing could conserve energy.
While the Jorō spider continues to spread in the region, it poses a threat to native species that are beneficial to the environment. However, the spiders do not currently have a negative impact. As they multiply, they could displace native spiders by consuming insects that the native spiders also rely on for food. During their study, the researchers found evidence of Jorō spiders coexisting with native spiders.
It is important to note that the Jorō spider is venomous, but its fangs are incapable of breaking human skin. Therefore, it is advised to leave these spiders alone. They eat both good and bad species for the environment, including the infamous lantern fly.
As researchers continue to study the Jorō spider, they hope to uncover more about its unique adaptations and ability to thrive in urban areas. Understanding these spiders’ behavior and physiology could provide valuable insights into their spread and potential impact on ecosystems.