Periodical Cicadas: Nature's Timekeeping Wonders
Every 13 or 17 years, parts of the Eastern and Midwestern United States witness an incredible natural spectacle. Billions of periodical cicadas simultaneously emerge from underground, their mass chorus of buzzing and clicking erupting on the landscape for the first time since the last turn of the century. This cyclical phenomenon represents nature at its most precise and intriguing.
These special cicadas, known as broods, are not your average backyard insect fare. Their remarkably synchronized, decade-plus-long life cycles and massive swarms inspire awe in even the most jaded of observers. While loud and perhaps unsightly to some, periodical cicadas play a valuable role in their native habitats. Learning about their unique life histories reveals an appreciation for these insects as harbingers of seasonal change and ecological health.
The Life of Periodical Cicadas
Periodical cicadas begin life as rice-sized eggs deposited in the branches of deciduous trees like oaks, maples and hickories. Upon hatching, the tiny nymphs drop to the ground where they immediately start burrowing tunnels. Using their sucking mouthparts, the developing cicadas feed on sap from tree roots underground for nourishment.
As the nymphs grow through five juvenile instar stages over 13 or 17 years, they track the passing seasons using biological signals and responses tuned to their specific brood’s schedule. Their internal clocks count down the years until the next mass emergence event for their brood. Different species occupy different regions based on their cycle length. When the 13th or 17th year finally arrives, the cicadas all tunnel en masse back to the surface within a few weeks of each other.
Once above ground, the cicadas quickly shed their previous exoskeletons and unfurl wings, taking just hours to shift into their adult form. Now airborne, the main objective becomes reproduction. Male cicadas court females through chorus calls, vibrating loud tymbal organs to amplify their species-specific songs. Some broods even synchronize to alternate their calls between 13- and 17-year groups. After mating, females lay eggs in branches, starting the generation cycle anew. Adult cicadas perish within 2 to 6 weeks.
Impacts on Ecosystems
The sudden presence of billions of adult cicadas represents a major food source for all kinds of predators. Birds gorge on the protein-rich, abundant insects to fuel migration and feed chicks. Other animals like squirrels, foxes, snakes and raccoons also benefit from the movable feast. When the cicadas die off en masse, their decaying bodies return key nutrients to forest soil.
Underground as nymphs, periodical cicadas play the long game in enhancing their native ecosystems. As they feed on sap, their constant burrowing and tunneling aerates soil and prunes tree roots for new growth. Mature trees weather the brief adult feeding frenzy well, only suffering light cosmetic damage. The cicadas avoid harming young trees and plants. Overall, forests renewed by cicada activity tend to show increased vigor after an emergence event.
Appreciating the Cicada Symphony
The most obvious sign announcing a cicada brood’s arrival is their sheer noise. Up close, the shrill chorus can exceed 100 decibels, on par with motorcycles or lawnmowers. This steady droning emanates from the cicadas rapidly vibrating tymbal organs to amplify their calls over distance in search of mates. Combined, the accumulated sounds of billions of individuals can carry for miles.
While admittedly an assault on the eardrums for humans, each species contributes distinctive songs like the scattered clicks of 13-year Decim broods or the oscillating whine of 17-year Magicicada septendecim. Some broods even tune their calls to alternate back and forth. The resulting cacophony forms a kind of natural symphony, chaotic yet awe-inspiring in its synchronicity.
Witnessing an emergence in person multiplies the impact. Seeing countless cicada husks left behind on trees brings home their massive numbers. Observing their bulbous black bodies and striking red eyes invites new admiration for their otherworldly appearance. And feeling the unrelenting background roar as daylight wanes recalls the pulse of nature’s endless cycles. The experience leaves a powerful impression for years afterward.
A Once-in-a-Lifetime Event
No two cicada emergences are exactly alike. Weather, food sources and predators influence survival rates, leading to fluctuations in brood sizes over their extended underground development. For people lucky to experience multiple emergences across different life stages, each event carries its own significance. Young children may react with delight at witnessing the novelty. Teenagers might find the insect horde gross yet fascinating. Adults likely appreciate the rarity of the cyclical occurrence.
With continued climate change and habitat loss, some experts worry future cicada broods may struggle to maintain their numbers. This lends extra impetus to appreciate each emergence as potentially the last of its scale. Traditionally occurring like clockwork, a failure of periodical cicadas to re-emerge on schedule due to environmental factors would signal deeper ecological imbalances. Their timekeeping reflects the health of local ecosystems.
In recent years, Brood X cicadas last surfaced in 2004 across much of the Eastern seaboard while Brood XIII emerged across the Midwest in 2007. Now in 2021, both broods ranging from Virginia to Illinois will again arise simultaneously for a rare overlapping mega-emergence. For anyone within their range, the event represents a unique chance to experience one of nature’s great shows.
Observing and Interacting Safely
For those excited to observe periodical cicadas up close, a few tips can enhance the experience while avoiding potential downsides:
- Plant protective netting around young trees and vegetation to limit damage. Prioritize more mature plants when checking for signs like small flag cuts on branches.
- Consider wearing earplugs if spending extended time outdoors near dense broods, as their accumulated calls can cause headaches or drown out conversation.
- Keep pets on leashes and supervise young children during peak activity to avoid cicada consumption. The insects are non-toxic but can pose a choking hazard.
- Clean up and dispose of dead cicadas to limit mess. A shop vac is perfect for clearing piles from walkways, porches and outdoor furniture. Their crushed bodies act as natural fertilizers.
- Capture the moment! Photograph or video record the emergence spectacle, or simply sit and soak in the sights and sounds of this incredible natural event.
A Welcome Sight
Rather than recoil in horror, the return of periodical cicadas should be welcomed as a positive omen. Their very existence points to established forests with deep tree roots and healthy soils. A thriving cicada brood indicates well-balanced regional ecosystems able to sustain such an immense influx of temporary life.
Of course, the reality of finding the insects everywhere overnight takes adjustment. However adopting a broad ecological perspective puts their startling presence into illuminating context. If anything, an emergence should inspire local communities to protect the old-growth woodlands and robust natural spaces that make such phenomena possible.
Our human lifespans struggle to fathom decade-plus cycles playing out endlessly through the centuries, as generation after generation of cicadas instinctively keeps schedule to perpetuate their species. Taking time to purposefully observe, listen and reflect during a regional emergence connects us to deeper powers at work across the natural world. There are mysteries in even the humblest backyard bug worth celebrating.
So next time periodical cicadas arise, set aside reflexive irritation and lean in with open curiosity. Witnessing nature’s timekeepers in action is a privilege, not a burden. Let their spirited cacophony remind you of untamed rhythms that have cycled long before us and will continue echoing long after we are gone. Thanks for listening to Quiet Please. Remember to like and share wherever you get your podcasts. And Hey! History buffs, buckle up! Talking Time Machine isn't your dusty textbook lecture. It's where cutting-edge AI throws wild interview parties with history's iconic figures. In the Talking Time Machine podcast: History Gets a High-Tech Twist, Imagine: Napoleon Bonaparte talking French Politics with Louis the 14th! This podcast is futuristically insightful. Our AI host grills historical legends with questions based on real historical context, leading to surprising, thought-provoking, and often mind-blowing answers. Whether you're a history geek, a tech junkie, or just love a good interview, Talking Time Machine has something for you. Talking Time Machine: search, subscribe and (Listen Now!)