Episode Summary
Executive Summary: The episode explains the coming emergence of Brood X cicadas: billions of insects that have lived underground for 17 years and will surface to mate, sing, and die within weeks. It breaks down their biology, the surprisingly limited damage they cause, the parasitic fungus that hijacks some cicadas, the mystery of how they time their emergence, and the ecological benefit their carcasses provide to forests.
Main Topics: Brood X emergence and public spectacle (Priority: 5/5): The episode frames the cicada event as an enormous, noisy, once-in-17-years natural spectacle expected across a large swath of the eastern U.S. 17-year life cycle and synchronized emergence (Priority: 5/5): Cicada nymphs spend 17 years underground feeding on tree roots, then emerge together under the right weather conditions to begin a short above-ground adult phase. Mating behavior and the source of the soundscape (Priority: 4/5): Male cicadas compete and sing to attract females, while females respond with wing flicks; the combined songs of three species create the famous chorus. Why cicadas are not like locusts (Priority: 4/5): The show clarifies that cicadas do not destroy crops because their mouthparts are for sucking root fluids, not chewing plants, though egg-laying can damage small branches. Cicada-killing fungus and behavioral manipulation (Priority: 5/5): A fungus called Massospora infects cicadas, destroys their rear ends, spreads spores, and appears to alter behavior using chemicals including cathinone, an amphetamine. Ecological timing and survival strategy (Priority: 4/5): Scientists think periodic emergence helps cicadas avoid predators through safety in numbers, and their synchronized timing may be tracked through changes in tree chemistry. Nutrient cycling and forest benefits (Priority: 3/5): Dead cicadas decompose into nitrogen-rich fertilizer that can help trees grow, showing the insects are not just pests but part of a forest nutrient cycle.
Key Arguments: Brood X is a massive periodic emergence that will likely produce billions of cicadas across roughly a third of U.S. states. Cicadas are loud and abundant, but they are not locusts and are not expected to cause major agricultural damage because they cannot chew crops. Female cicadas can harm young trees by slicing branches to lay eggs, but mature trees usually tolerate the damage. The famous chorus is not one sound but a mix of calls and wing flicks from three cicada species. The fungus Massospora turns infected cicadas into spore-spreading vectors and may increase their sexual behavior by producing amphetamine-like compounds. Cicadas likely emerge in coordinated waves to reduce predation, with scientists proposing they track time through tree-root feeding and chemical cues. After mass die-off, cicadas can enrich soil and improve tree growth by adding nitrogen back into the ecosystem.
Data Points: Underground development period: 17 years - Cicada nymphs feed on tree roots underground before emerging. Adult lifespan: Less than 6 weeks - Most cicadas die within weeks after surfacing to mate. Geographic reach: Almost a third of U.S. states - Brood X is expected to emerge from Georgia north to New York and Michigan. Eggs laid per female: Up to 600 - Female cicadas deposit eggs in tree branches after mating. Recorded mating duration: 96 hours - Longest sex act recorded by the researchers cited in the episode. Trees in experiment: Average 5% taller - Sycamore trees littered with cicada carcasses grew taller over three years. Tree trunk growth: 10% wider - Same experiment showed thicker trunks from nutrient-rich cicada remains. Cicada carcass count in experiment: Dead cicada carcasses - Used as natural fertilizer in Louis Yang’s sycamore study. Episode citations: 116 - The show notes mention 116 citations supporting the episode. Potential fungal chemical: Cathinone (an amphetamine) - Detected in Massospora-infected cicadas and linked to increased activity/horniness.
Pivotal Quotes: "It’s going to be a mind-blowingly big number of cicadas. You can’t possibly ignore this." — John Cooley: Describing the scale of Brood X emergence. "They’re going to be a drug-fueled orgy complete with sexy music, crazy competition and to finish us off, billions of dead carcasses." — Wendy Zuckerman: A vivid summary of the cicadas’ mating cycle and aftermath. "We call them the flying salt shakers of death." — Matt Casson: Describing fungus-infected cicadas spreading fungal spores as they fly.
Implications: Listeners are encouraged to see Brood X as a rare natural spectacle rather than a threat. The episode also highlights citizen science opportunities and shows how insects can shape ecosystems, from mating dynamics to forest fertilization.
About Science Vs
There are a lot of fads, blogs and strong opinions, but then there’s SCIENCE. Science Vs is the show from Spotify Studios that finds out what’s fact, what’s not, and what’s somewhere in between. We do the hard work of sifting through all the science so you don't have to and cover everything from 5G and ADHD, to Fluoride and Fasting Diets.