Are 'giant, flying' joro spiders really taking over the U.S.?

🌈 Abstract

The article discusses the arrival and spread of Joro spiders in the United States, addressing the sensationalized media coverage and providing a more balanced perspective from experts on the actual threat and characteristics of these spiders.

🙋 Q&A

[01] Joro Spiders in the News

1. What are some of the sensationalized claims made in the media about Joro spiders?

• The media has described Joro spiders as "giant venomous flying spiders" that are "heading to the New York area" and capable of a "palm-sized" size with "venomous" bites.
• These descriptions are considered misleading by experts, who say the spiders are not as large or dangerous as portrayed.

2. How have experts responded to the media coverage?

• Entomologist Floyd Shockley says he is "mortified" by the sensationalist headlines, as there is no evidence the spiders have made it to New York.
• Experts like David Coyle and Andy Davis say the spiders are relatively harmless, shy, and unlikely to pose a significant threat to humans.

3. What is the current status of Joro spider populations in the U.S.?

• Joro spiders arrived in Georgia in 2014 and have since spread to a few other southeastern states, but their colonization of the entire East Coast is not imminent.
• The spiders are currently only found in small, localized populations in states like Georgia, the Carolinas, Tennessee, and Oklahoma.

[02] Joro Spider Characteristics and Behavior

1. How large do Joro spiders actually get?

• Experts say the claims about Joro spiders having bodies up to 4 inches long and leg spans of 6-8 inches are "completely ridiculous" exaggerations.
• In reality, the largest adult Joro spiders are no bigger than a grain of rice, as they die off each winter and hatch anew in the spring.

2. Are Joro spiders capable of flying?

• While Joro spiders cannot fly as adults, the young spiderlings can engage in a dispersal process called "ballooning" where they release silk strands and get carried by the wind.
• This allows the small spiderlings to spread to new areas, but does not constitute true "flying" as portrayed in some media reports.

3. How venomous are Joro spiders, and what is the risk to humans?

• Nearly all spiders are venomous to some degree, as venom is used to capture prey.
• However, Joro spider venom is not toxic to humans, and bites are only reported to cause minor irritation similar to a mosquito bite or bee sting.
• Experts say Joro spiders are generally docile and unlikely to bite humans unless provoked.

4. How do Joro spiders compare to native spider species in terms of behavior?

• Studies have found Joro spiders to be much more timid and less aggressive than native spider species when threatened.
• Researchers have observed Joro spiders remaining motionless for over an hour when exposed to a puff of air, much longer than the 96-second freeze response of native spiders.

[03] The Future of Joro Spiders in the U.S.

1. What is the expert perspective on dealing with the spread of Joro spiders?

• Some experts, like Andy Davis, suggest it may be better for people to learn to "live with" Joro spiders, as their spread is now considered "exponential" with millions present.
• David Coyle says killing individual Joro spiders is unlikely to have any meaningful impact on the overall population.

2. What are the potential environmental impacts of Joro spiders?

• Joro spiders may have a mixed impact, as they eat other invasive species like stink bugs and spotted lanternflies, but they also outcompete some native spider species.
• Overall, the long-term ecological effects of Joro spiders in the U.S. are still not fully understood by experts.