As the temperatures rise and spring arrives in the eastern United States, the ground comes alive with the emergence of periodical 17-year cicadas from Brood XIV. These fascinating insects, found only in North America, begin their journey from underground burrows to the surface. Last seen in 2008, these cicadas will make a grand appearance in billions across twelve states from May to June.
The transformation of flightless cicada nymphs into black-bodied, winged adults marks the beginning of a month-long celebration of song and reproduction. However, a sinister presence lurks among these creatures in the form of the deadly fungus Massospora cicadina. This fungus infects only 13-year and 17-year cicadas, turning their mating rituals into a gruesome display of zombification.
Infected cicadas, despite having their genitals consumed by the fungus, continue to engage in mating behaviors. The fungus manipulates male cicadas to flick their wings like females, leading to further infections as healthy males attempt to mate with the infected individuals. Additionally, the fungus floods the cicadas with cathinone, a stimulant that enhances hypersexualized behavior.
John Cooley, an evolutionary biologist at the University of Connecticut, describes this phenomenon as “sex, drugs, and zombies,” highlighting the bizarre nature of these interactions in the natural world. The relationship between the fungus and the cicadas dates back millions of years, providing scientists with valuable insights into evolutionary processes that cannot be replicated in a laboratory setting.
Matt Kasson, a mycologist at West Virginia University, explains that each emergence of Brood XIV offers a unique opportunity to study the complex interactions between the fungus and the cicadas. The fungus produces resting spores that infect other nymphs, but the exact mechanisms of infection remain a mystery. With the discovery of the largest genome in the fungus kingdom, researchers speculate that Massospora cicadina may possess a complex reproductive cycle involving multiple spore varieties.
Periodical cicadas, with their extended nymph stage, lack specialized predators, except for Massospora cicadina. This fungus’s ability to wait out underground for years aligns perfectly with the cicadas’ long life cycle. The impact of the fungus on cicada populations and distribution adds another layer to the intricate puzzle of periodical cicadas.
As Brood XIV emerges, researchers like Cooley are eager to study the dynamics of species distribution and population shifts. Climate change and human activities have reshaped cicada habitats over time, leading to fluctuations in populations and the disappearance of certain broods. The emergence of three periodical cicada species within Brood XIV will shed light on how species interact and find mates within their own kind.
The abundance of cicadas in Kentucky and Tennessee during this emergence is expected to correlate with higher instances of Massospora infections. By leveraging citizen science platforms like iNaturalist, researchers can track and monitor the spread of the fungus among cicada populations. This collaborative effort allows individuals to contribute valuable data to ongoing research on Massospora cicadina.
Witnessing the emergence of Brood XIV cicadas, with predictions of millions of insects per square acre, is a spectacle to behold. Whether spotting a zombified cicada or marveling at the sheer numbers of these fascinating creatures, this year’s emergence is bound to leave a lasting impression on observers. The intricate dance between cicadas and the fungus that manipulates them serves as a reminder of the complexities of nature and the mysteries that continue to unfold in the world around us.
