Cornell insect expert breaks down potential impacts of Joro spider

Extension Out Loud

The Joro spider, an arachnid that's been in the United States for years in some southern states, has been trending in the news lately as the next potentially invasive species to land in New York State. Some media hypes giant, venomous, flying spiders, but how concerned should we really be here in New York about their potential arrival? To address these questions Alejandro Calixto, Director of the New York State Integrated Pest Management Program at Cornell University joins this episode of Cornell Cooperative Extension’s ‘Extension Out Loud’ podcast. Calixto discusses the myths surrounding the Joro spider and the impacts of a changing climate on the spread of invasives. While large and venomous like many spiders, the Joro spider does not pose a direct threat to humans. "Every spider has venom, but their venom is primarily for capturing prey and defense, not for attacking humans," said Calixto. One common misconception Calixto addresses is the idea of Joro spiders flying into homes or attacking pets. While they can disperse using a technique called ballooning—where they release silk strands to catch the wind and travel—they do not have wings or parachutes and are not aggressive towards humans or pets. Calixto highlights concerns about the Joro spider potentially outcompeting native species like the golden silk weaver in habitats where they overlap. However, their slow dispersal rate means any effects would likely be gradual and localized. Focusing on more immediate concerns for New Yorkers, Calixto mentions the rise of pests like the spotted lanternfly and the increased activity of ticks due to milder winters. These changes underscore the importance of vigilance and proactive pest management strategies to mitigate potential impacts on agriculture and public health. To learn more about the Joro Spider and other invasive pests in New York State visit the NYS Integrated Pest Management website.