Butt-less Cicadas

  • By Anna Rothschild
  • Posted 07.23.15
  • NOVA

The fungus Massospora cicadina makes periodical cicadas’ butts fall off. Learn more in this episode of Gross Science.

Running Time: 02:26


Butt-less Cicadas

Posted: July 2, 2015

Imagine if after a lifetime underground, you only had a few glorious weeks to live in the sun, eat, and mate… and then your butt fell off.

I’m Anna Rothschild, and this is Gross Science.

If you’ve ever been to the countryside in the eastern half of the US, you might have heard the buzz of cicadas in the air. And if you’ve seen my buddy Joe’s video over at It’s OK To Be Smart, you know that some of these gossamer-winged, singing insects called periodical cicadas are elusive—they only appear every 13 or 17 years, depending on the species.

Baby cicadas spend their long childhoods deep underground. If they’re lucky, they emerge after 13 or 17 years to spend their month-long adult lives drinking sap and procreating. But if they’re unlucky, they could spend those precious days sharing their body with a fungus that eats them from the inside out.

The fungus is called Massospora cicadina, and it specifically infects periodical cicadas. Its spores lie dormant near the surface of the soil, waiting for cicadas to start tunneling out of the ground. Then the spores invade the emerging cicadas’ abdomens and begin replicating. And when the insects start looking for love a few days later, they spread the fungus from cicada to cicada during their hour-long copulation sessions. Eventually, the fungus expands to such an extent that it splits the cicada’s abdomen open, causing its butt to fall right off.

Surprisingly, the cicadas don’t seem to mind. They carry on as they were, flying around and attempting to mate—which allows them to spread the fungus far and wide. One student who wrote a great article about this called these Massospora-infected cicadas “flying salt shakers of death.” Wherever they go, they sprinkle the soil underneath them with infected spores. And there, the fungus lies dormant—waiting for the next brood to emerge, 13 or 17 years later.

Now, just to be clear, there isn’t a rampant butt-exploding epidemic killing off periodical cicadas. Far more of them die from predation, and habitat disruption is a much bigger concern for these species. But every time these elusive creatures emerge, some of them fly around butt-less.




Host, Animator, Editor
Anna Rothschild
Writer, DP, Sound
Rachel Becker
Many thanks to Dr. Chris Simon, Dr. Michael J. Raupp, and Dr. Kimberly G. Smith.
Rag Tag Rag
Music Provided by APM


Cicada photographs and footage
Courtesy Michael J. Raupp, Professor at University of Maryland College Park
Magicicada young
Wikimedia Commons/Arthur D. Guilani


(used with permission from author)
Squeak Pack/squeak_10
A Magicicada chorus containing M. septendecim, M. cassini, and M. septendecula.
Wikimedia Commons/Audio S4 from Fontaine K, Cooley J, Simon C (2007). “Evidence for Paternal Leakage in Hybrid Periodical Cicadas (Hemiptera: Magicicada spp.)” PLoS ONE.
Produced by WGBH for PBS Digital Studios


(main image: Massospora-infected cicada)
Courtesy Michael J. Raupp


Want more info?

Angie Macias's “Flying Salt Shakers of Death” article, from the Cornell Mushroom Blog:

Massosspora Cicadina as a cicaca STD, from University of Maryland College Park Professor Michael Raupp:

An excellent review of all thing periodical cicada, fungal details on page 279:

And here are some details about how these insects die:

Related Links