This spring and summer, millions of periodical cicadas are set to emerge in a natural event not seen since the early 1800s. Two distinct broods—one on a 13-year cycle and the other on a 17-year cycle—will rise together across parts of the Midwest, giving scientists and nature lovers alike a front-row seat to a biological marvel.
Nature’s Timekeepers
“While there are probably 5,000 to 6,000 species of cicadas, fewer than 10 are periodical,” says Dr. John Cooley of the University of Connecticut. Brood XIII and Brood XIX will both appear this year, spanning up to 18 states.
Although their ranges don’t overlap, their simultaneous arrival offers a rare chance to study evolution in real time.
Science in the Field
For researchers like Dr. Catherine Dana of the Illinois Natural History Survey, this is a once-in-a-career opportunity. “The research opportunities are boundless,” she says. The samples gathered this season could serve future scientists for generations.
Illinois sits at the heart of the emergence, with one brood in the north and the other in the south, making it a research epicenter.
Tracking Cicadas Through Time
The history of cicada tracking dates back to the 1840s, when early naturalists gathered reports through newspapers. Today, citizen scientists contribute through modern technology.
Dr. Gene Kritsky’s popular app, Cicada Safari, received over 200,000 downloads during the 2021 emergence. This year, artificial intelligence will help analyze user photos, accelerating identification while maintaining expert verification.
Busting the “Cicada Armageddon” Myth
Despite some viral headlines, experts say this dual emergence won’t be overwhelming. “We’re not expecting a cicada Armageddon,” says Kritsky. The overlap zone between the two broods is minimal, and their life cycles are staggered by geography and climate. Southern populations may appear weeks earlier than their northern cousins, spreading out the spectacle over time.
The Joy of Cicada Watching
For many, observing cicadas offers a simple way to reconnect with nature. Dana recommends visiting older parks or wooded areas where the soil hasn’t been disturbed. “It’s a fun, family-friendly adventure,” she says.
During the pandemic, cicada-watching became a beloved outdoor activity—“a gateway drug to getting kids into science,” as Kritsky puts it.
Climate Change and Timing Shifts
Cicadas emerge when soil temperatures reach about 64°F eight inches underground. Warmer winters and earlier springs are shifting those patterns. “We’re seeing them emerge weeks earlier than they did a century ago,” says Kritsky.
The 2021 Brood X emergence happened nearly two weeks ahead of schedule, a sign that climate change is influencing their ancient biological clocks.
Ecosystem Engineers
Though their numbers can seem overwhelming, cicadas provide major ecological benefits. When they dig upward, their tunnels aerate the soil, improving water flow to tree roots. Their short-lived life cycle also enriches forests—fallen cicadas decompose into nutrient-rich fertilizer.
Even their egg-laying, which sometimes damages branches, acts as a natural pruning process for trees.
A Feast for Wildlife
From birds and raccoons to fish and snakes, nearly every predator indulges in the cicada buffet. This surge of food boosts reproductive success for many species.
“Everything eats them,” says Kritsky. Studies even show male turkeys grow larger in cicada years. These periodic pulses of protein ripple through ecosystems, rejuvenating wildlife populations.
Lessons from a Timeless Cycle
Cicadas have survived ice ages and continental shifts, their synchronized emergence reflecting both resilience and mystery. “Cicadas are bugs of history,” says Kritsky.
As scientists probe how climate shifts affect their timing and survival, these humble insects may hold clues to broader ecological changes. “The question,” Kritsky adds, “is whether we’re smart enough to interpret them.”
Reflecting on Nature’s Clock
Dr. Cooley encourages people to think beyond the noise. “Where were you 13 or 17 years ago? Where will you be when they return?” he asks.
The cicadas’ song is more than a summer soundtrack—it’s a reminder of time’s rhythm, nature’s balance, and the interconnectedness of every living thing on Earth.
FAQs
When will the 2024 cicadas emerge?
The 2024 cicadas—Brood XIII and Brood XIX—are expected to start emerging in early May, beginning in southern states like Tennessee and moving north through June. Each local emergence typically lasts about six weeks, as cicadas live roughly one month after surfacing.
Where can I see the cicadas this year?
The dual cicada emergence will occur across up to 18 states, mainly in the Midwest. Illinois will be at the center of the action, with Brood XIII appearing in the north and Brood XIX in the south. Look for older forests, city parks, and areas with undisturbed soil for the best viewing.
Are cicadas dangerous to people or pets?
No, cicadas are harmless. They don’t bite or sting, and they pose no threat to pets. However, some curious dogs or cats may eat them—doing so in moderation is generally fine, but overeating can upset their stomachs.
Why do cicadas emerge in cycles of 13 and 17 years?
Scientists believe cicadas evolved prime-numbered life cycles—13 and 17 years—to avoid syncing with predators’ reproductive cycles. This timing helps them survive by overwhelming predators through sheer numbers during each rare emergence.
How is climate change affecting cicada emergence?
Rising temperatures are causing cicadas to appear earlier than in past decades. Warmer soil speeds up their underground development, leading to premature emergences in some regions. Researchers are studying these changes to understand how climate patterns impact cicada populations.
