Why you shouldn't worry about invasive Joro spiders

Joro spiders are starting to spread across the East Coast. They are an invasive species that likely arrived in Altanta, Ga through shipping containers from eastern Asia. The city now has a large population of the arachnid. Their success in the U.S. may be due to the similarities between the southeastern climate and their native habitat.

Joro spiders are orb weavers, like Charlotte in the beloved children's book Charlotte's Web. and have patterns like native garden spiders. However, their arrival in the U.S. has alarmed people because of their appearance: Female Joro spiders can grow up to four inches long and their coloration is black and electric yellow — a combination that often indicates danger.

Although they look like something out of a Tim Burton movie, these spiders rarely bite. Even if they did, their fangs are so small that they would have difficulty breaking human skin. Besides, on the rare occasion they do, the bite is less painful than a bee sting and doesn't need special treatment.

Human impact aside, invasive species often affect the broader ecology of an area.

The number invasive species has increased — a trend that is expected to continue thanks to global warming and increased trade. Warmer winters allow insect population to thrive, creating longer breeding seasons and an increase it habitable areas. "We also open up new shipping lanes and longer durations of shipping. And so you can actually ship things more easily and more cheaply from places where you might not have been able to get them from before," says Hannah Burrack, an entomologist at Michigan State University.

Researchers don't yet know when Joro spiders will reach the northeastern U.S. and more research is needed to determine how they will affect the environment.

In the meantime, you can help contribute to research efforts. If you've see one of these spiders, you can log the sighting at Joro Watch and iNaturalist's Project Joro.

Unrelated, we're hard at work on an upcoming episode about Pluto. As part of that, we would love for you to send a voice memo with your name, where you live, what your favorite planet is and why to us at shortwave@npr.org. We might include it in that episode!

Listen to Short Wave on Spotify, Apple Podcasts and Google Podcasts.

Listen to every episode of Short Wave sponsor-free and support our work at NPR by signing up for Short Wave+ at plus.npr.org/shortwave.

What science story do you want to hear next on Short Wave? Email us at shortwave@npr.org.

This story was produced by Berly McCoy and Gus Contreras, edited by Rebecca Ramirez and fact-checked by Regina G. Barber and Rachel Carlson. Josh Newell and Neil Tevault were the audio engineers.