Most cicadas live between 2 and 17 years in total, but the vast majority of that time is spent underground as nymphs. The adult stage, the noisy, flying phase most people associate with cicadas, lasts only a few weeks. The answer depends on which type of cicada you’re talking about, because there are two broad categories with very different timelines.
Annual vs. Periodical Cicadas
Annual cicadas, the kind you hear buzzing every summer across much of the world, have a total lifespan of roughly 2 to 5 years. They’re called “annual” not because each individual lives one year, but because their broods overlap enough that some adults emerge every summer without fail.
Periodical cicadas are a different story entirely. Found only in eastern North America, these species in the genus Magicicada spend either 13 or 17 years developing underground before emerging in enormous synchronized broods. They hold the record for the longest life cycle of any cicada, and among the longest of any insect. No other cicada species anywhere in the world matches their timeline.
What Happens Underground
A cicada’s life begins as an egg tucked into a slit in the bark of a young twig. The female carves a groove into the wood and deposits her eggs there. After 6 to 10 weeks, the eggs hatch and tiny nymphs drop to the ground, burrowing about two feet into the soil. This is where they’ll spend nearly their entire lives.
Underground, nymphs build a network of tunnels near tree roots and feed by drinking xylem fluid, the same watery sap that flows through tree trunks. They go through either four or five molting stages (sources vary slightly), shedding their exoskeleton and growing larger each time. Despite spending years attached to roots, their feeding doesn’t cause meaningful damage to the host trees.
For annual cicadas, this underground phase lasts 2 to 5 years. For periodical cicadas, it stretches to essentially the full 13 or 17 years, with nymphs going dormant through each winter and resuming feeding in warmer months. That’s a lot of winters spent in the dark, drinking tree sap.
What Triggers Emergence
Periodical cicada nymphs don’t simply count the years. They respond to a soil temperature threshold: when the ground at a depth of 8 inches warms past 64°F (18°C), typically from late April to early June, the final-stage nymphs tunnel to the surface. Annual cicadas follow a similar temperature-driven cue, though their emergence is spread across the summer rather than concentrated into a single dramatic event.
Once above ground, nymphs climb the nearest vertical surface, split their exoskeleton one last time, and emerge as winged adults. The hollow brown shells left clinging to tree trunks and fence posts are what most people find in their yards.
The Brief Adult Stage
After spending years underground, adult cicadas get remarkably little time in the open air. Periodical cicadas live about 3 to 6 weeks as adults, depending on the source and conditions. Annual cicadas have a similar adult window. During this time, males produce their loud buzzing calls to attract mates, pairs breed, and females lay eggs. A single female periodical cicada can deposit 400 to 600 eggs across multiple twigs before she dies.
Both males and females die shortly after reproduction is complete. There’s no second act. The entire purpose of the adult stage is mating and egg-laying, and once that’s done, the generation is finished.
Why Periodical Cicadas Emerge All at Once
The mass emergence strategy is a survival tactic called predator satiation. When millions or even billions of cicadas surface simultaneously, birds, squirrels, and other predators gorge themselves but physically cannot eat enough to make a dent in the population. The sheer numbers ensure that the vast majority survive long enough to reproduce.
This strategy is so important that cicadas emerging out of sync, a few weeks early or late, rarely survive. They’re not numerous enough to overwhelm predators, and most get eaten before they can mate. The timing pressure keeps the broods tightly synchronized across generations.
What Kills Adult Cicadas
Predation is the most obvious threat. Nearly everything eats cicadas: birds, mammals, reptiles, fish, even dogs and cats. Their large size and clumsy flight make them easy targets, which is exactly why emerging in overwhelming numbers matters so much.
Cicadas also face a specialized fungal parasite that replaces their abdomen with a mass of fungal spores. This pathogen is considered the only natural enemy that’s synchronized to periodical cicada broods. In natural conditions, infection rates tend to stay low, under 1% in some observed emergences. But when spore concentrations are higher, infection rates can climb above 10%. Infected cicadas continue flying and attempting to mate, which spreads the fungus further.
Beyond predators and parasites, simple exhaustion and energy depletion end the adult phase. Cicadas feed minimally as adults, and their bodies are essentially running on a timer once they surface.
Total Lifespan at a Glance
- Annual cicadas: 2 to 5 years total (nearly all underground), with 2 to 6 weeks as adults
- 13-year periodical cicadas: roughly 13 years total, with 4 to 6 weeks as adults
- 17-year periodical cicadas: roughly 17 years total, with 4 to 6 weeks as adults
No matter the species, the pattern is the same: a long, quiet life underground drinking from tree roots, followed by a few frantic weeks of noise, mating, and death. The buzzing chorus that fills the trees each summer, or erupts in spectacular broods every 13 or 17 years, represents the very end of lives that began years earlier in the soil.