By Bill Napper
Explore the incredible phenomenon of Brood XIV periodical cicadas in this first installment of this three-part series.
A Rare Natural Spectacle
Every 17 years, the forests around Bullitt County, particularly Bernheim Forest, resonate with a remarkable, almost otherworldly symphony. This awe-inspiring performance comes courtesy of the fascinating periodical cicadas, specifically Brood XIV. Also known as the “Bourbon Brood,” this group last emerged 17 years ago, in 2008. In the coming weeks, likely around mid-May when soil temperatures reach the mid-60s Fahrenheit, our entire area will be “buzzing”—both literally and figuratively—with this event!
Periodical vs. Annual Cicadas: Nature’s Different Drummers
While periodical cicada of Brood XIV creates an extraordinary spectacle every 17 years, Kentucky is also home to the more common annual cicadas (often called “dog-day cicadas”). These appear every summer, typically from July through September, albeit in much smaller numbers. These annual visitors, with their greenish bodies and dark eyes, blend into the foliage while producing a steady, high-pitched buzzing that forms the familiar soundtrack of late summer.
In contrast, periodical cicadas emerge in spectacular synchronized waves, boasting striking black bodies, brilliant red eyes, and orange-veined wings. Annual cicadas complete their lifecycle in just 2-5 years with staggered development, ensuring some mature each year.
Periodical cicadas, however, represent one of the longest-lived insect species with their synchronized 17-year underground development, making their mass emergence at Bernheim a biological phenomenon witnessed only a handful of times in a human lifetime. Once the emergence begins, the adult cicadas will remain active for several weeks before the next generation returns underground, not to be seen again until 2042!
For the naturalist-minded, there are potentially three species of 17-year cicada within Brood XIV: Magicicada cassini, Magicicada septendecim, and Magicicada septendecula.
The Cicada Lifecycle: Nature’s Marvel
Imagine a hidden world beneath our feet where life unfolds at an almost geological pace. For an incredible 17 years, periodical cicadas exist in this silent, subterranean realm, patiently drawing sustenance from tree roots, counting down unseen years until a signal known only to them.
Then, the magic happens. Triggered by warming spring soils, a biological clock perfected over millennia summons them to the surface. Not one by one, but in a breathtaking, synchronized wave, millions upon millions ascend, transforming quiet woodlands into bustling arenas of life seemingly overnight. This isn’t just emergence; it’s a calculated evolutionary spectacle – a strategy of overwhelming predators by sheer, astonishing numbers, ensuring the continuation of their ancient lineage. The air soon vibrates with their iconic chorus, a soundscape unlike any other in nature.
For the fortunate observer, the wonder becomes deeply personal. Find a cicada nymph climbing a tree, and witness a moment of profound transformation. Over roughly 90 minutes, you can watch it shed its earthy nymphal shell—a relic of its long underground life—and unfurl its delicate, new wings. This vulnerable, almost ethereal moment of complete metamorphosis, unfolding right before your eyes, is more captivating than any screen could convey. It truly is, as some have said, like stepping into a live David Attenborough documentary playing out in your own backyard – a rare and wondrous glimpse into one of nature’s most patient and spectacular performances.
Cicadas: Harmless and Fascinating
Rest assured—cicadas are entirely harmless. They do not bite, sting, or spread diseases. They exist peacefully, focused solely on their life cycle and reproduction. Furthermore, if your pet happens to eat one, don’t worry – cicadas are actually nutritious!
While the sudden sight and noise might seem overwhelming, knowing their peaceful nature helps transform potential fear into fascination.
A Century of Cicadas at Bernheim Forest
For nearly a century, Bernheim Forest has hosted the remarkable return of Brood XIV periodical cicadas. Since the forest’s founding in 1929, these insects have faithfully emerged on their 17-year cycle, with documented
appearances in 1940, 1957, 1974, 1991, and 2008.
Including the current emergence expected in mid-May 2025, Bernheim has witnessed six of these fascinating broods since its establishment. Looking ahead, based on their consistent 17-year interval, we can anticipate their return around 2042, 2059, and 2076.
To truly grasp how infrequently these cicadas appear, consider the span of major historical events:
- Since Abraham Lincoln was president (1861-1865), this specific brood of cicadas has completed its 17-year underground lifecycle and emerged only 10 times (including the current 2025 emergence).
- Since the Wright Brothers achieved the first powered flight in 1903, we have seen only 8 emergences of Brood XIV.
- Since humans first walked on the Moon in 1969, Brood XIV has only emerged 4 times.
These comparisons highlight the incredible patience of the cicadas’ lifecycle and make their rare appearances truly significant events in the natural world.
Heads Up: Look for the Opening Act!
In the next few days, keep your eyes peeled for little emergence holes suddenly appearing in the ground – think of them as tiny escape hatches. These are your first clue that the cicadas have arrived! Give them about a week after their grand entrance, and then the real show – the non-stop singing – begins.
