Big colorful Joro spiders advancing north US

Joro spiders, a brightly colored invasive species, are spreading in the US. Experts say they're not a major threat to humans.

The Joro spider, a large, brightly colored invasive species, is making its way across the United States, with populations growing in the South and East Coast. While some may find these spiders fascinating, experts are more concerned about the impact of invasive species on crops and trees, exacerbated by global trade and climate change.

The Joro spider, a type of orb-weaver native to East Asia, is known for its vibrant yellow and black coloring and can grow up to 8 centimeters in size. Despite their showy appearance, they pose little risk to humans compared to other introduced pests like fruit flies and tree borers that can cause significant damage.

Scientists are still studying the Joro spider's range, with a central population in Atlanta expanding to the Carolinas and southeastern Tennessee. A satellite population has also emerged in Baltimore. While baby Joro spiders can fly using a technique called ballooning, adult spiders do not take flight.

Joro spiders primarily feed on insects that get caught in their webs, potentially competing with native spiders for food. However, their daily catch could also benefit native bird species. While some hope the Joro spiders could help control invasive species like the spotted lanternflies, experts believe they won't make a significant impact on these populations.

In terms of danger to humans, Joro spiders have venom but are not medically relevant. A bite may cause itching or an allergic reaction, but they generally avoid humans. The real concern lies in the ecological damage caused by the introduction of other invasive species that threaten natural resources.

Overall, the spread of the Joro spider serves as a reminder of the broader impact of human activity on the environment. As we continue to see the effects of global trade and climate change, it becomes increasingly important to address the challenges posed by invasive species to protect our ecosystems and biodiversity.