Definitions Deconstructed
Cicadas
S. G. Lacey
Definition:
Any large homopterous insect of the family Cicadidae, the male of which produces a shrill sound by means of vibrating membranes on the underside of the abdomen. [REF]
Deconstruction:
How can something so tiny, make such an impressive racket?
These small insects, ranging from 2 to 5 cm in length, with black, brown, or green body coloration, and wispy, iridescent, wings, are found throughout the world. When they materialize from their subterranean hibernation, that is. Don’t worry, you’ll know, based on their raucous noise, and impressive abundance.
Cicadas are quite common, with over 3,000 unique species distributed globally. Many of these critters are located in the heat of the tropics, with a gestation period of 2 to 5 years, molting timeline dictated by climate factors.
For a flying insect, cicadas spend an impressive amount of their life underground. With eggs typically laid in nutrient rich plant material, over the subsequent seasons, larvae will molt up to 5 times, transitioning to nymphs during these instars, allowing for continued growth in the moist, dark, ground.
However, eventually, they return to the air, aspiring to sing, mate, and lay eggs. It’s like if the local karaoke bar was only accessible once every few years. Fortunately, for each species, their innate senses tell them exactly when the “Open” sign lights up, and the booze starts flowing.
When your adult life is condensed into the period of 4 weeks, may as well live it up. In fact, this drive to enjoy life, and reproduce, once cicadas take flight, is so acute that adults rarely eat during their brief stint above ground. That’s quite a bender.
Predictably, like most bars, the male cicadas are the loud ones. Using their tymbal organ, a muscle in the first segment of their abdomen, the gentlemen activate thin membranes at up to 500 cycles per second, with amplification from supplemental air sacs.
This unique anatomical skill can create all manner of buzzing, ticking, or humming noises. The ladies simply sit back and listen in silent amusement; thus, completing the bad karaoke bar analogy.
Impressively, each species of cicada has its own unique sound, some of which exceed 100 dB, allowing them to be heard from over a mile away. This makes them one of the loudest insects in existence.
The most interesting species, which many U.S citizens are intimately familiar with, are the periodic cicadas. In North America, there are 13-year and 17-year versions of these critters, which captivate both local communities, and national tabloids, when they emerge.
How do they survive over these long periods of seclusion? What cues the next batch to rise from the earth?
First, it’s important to differentiate friendly cicada appearances from the invasive hordes of locusts, with which they are often confused. The former follows a calculated growth regimen, in order to optimize their chance of survival. The latter is an overbreeding pest, who’s rampant eating habits can have devastating effects on local vegetation. Think miniature bald eagles vs. tiny flying rabbits.
Despite the seeming randomness of appearance, scientists have been able to establish very defined timelines to track and document each specific cicada genre. Affectionately labelled broods, which elicits memories of “Tremors” or “Gremlins” movies, the location and timing of hatching cycles throughout the world is now very well defined.
The duration of cicada hibernation is another of nature’s many miracles. The numbers 13 and 17 have something in common. They are both prime numbers; which is likely not a coincidence.
While trends in predators, precipitation, and policy typically vary on a yearly cadence, the randomized appearance of the cicadas allows at least some portion of their population to survive to the next long cycle.
Since cicadas emerge from the earth for just a few weeks per decade, with their singular focus on mating, they have understandably not adapted any beneficial elements to promote protection. As a result, the main defense of the periodic species is their randomness of arrival, and subsequent disappearance.
In our digital era, where humans operate on even annual, decade, and century timelines, other events in the natural world, while still repeatable, are not constrained by the traditional base ten format.
Halley’s Comet, which cruises past Earth every 76 years, close enough for naked eye observation, before disappearing back into the darkness of space for decades.
Bioluminescent plankton, causing red tides during the day, and glowing blue oceans at night, occurs so sporadically that scientists still don’t know the factors which drive this phenomenon.
Total solar eclipse events, which happen every few years, along random arcing paths around the globe, on account of the complex orbits of the multiple celestial bodies involved.
Considering the unique, seemingly random, appearance of cicadas, they have been the fascination of people for centuries, ranging from Native Americans, to Chinese lore.
Like many unique insects globally, cicadas have drawn the attention of adventurous, hungry, individuals. Many cultures, especially in Asia, have embraced the medicinal benefits of cicadas. If your inclined, there’s a few establishments in the United States offering up some tasty selections, albeit with oil, chocolate, and spices to improve the flavor.
Rumor has it, the teneral phase, before the cicadas have donned their final exoskeleton, represents the best chance for a tasty, tender, morsel. Extra salt please.
Unfortunately, even while seemingly safely buried, cicadas have an underground enemy in the form of a parasitic fungus. This mushroom affliction has adapted its own cadence to match that of the cicada host, waiting until the bugs have arisen to activate. The impact of this fungus is terrifying, and devastating, inflicting the male genitalia. This condition might be a deal breaker for those interested in experimenting with cicadas as snacks, and definitely doesn’t help promote procreation of the species.
One ancillary benefit of the cicadas’ long gestation period, and deep connection to the environment, is that they provide a valuable yardstick for monitoring climate change. Several of the 17-year periodic variety have emerged 4 years ahead of schedule in recent years, suggesting some, yet undetermined, factors are influencing their natural cycle.
Long a fascination of scientists, engineers are becoming increasingly intrigued with one feature of cicadas. Their wings, which display antibacterial, self-cleaning, and water repellant, properties. These traits could be valuable for all manner of product applications, from sunglasses to solar panels, medical gloves to microfiber gear.
The key seems to be the nanopillar, which represent the fundamental building block of the delicate wings. However, research is still in the infancy, with hypotheses on functionality ranging from panel geometry, to cellular secretions. When the subject of your research only appears every few years, it can be difficult to validate conclusions.
The summer of 2021 is welcoming in Brood X of the periodic cicadas to the Eastern United States. Hatching started in early May, trigged when the warming earth surpassed 60°F; these insects are now appearing in droves from a 17-year hibernation. These specific larvae went into their underground holes way back in 2004, having lived off tree root nutrients ever since, and are now fully grown nymphs.
Once emerging from the ground, the nymph’s immediately climb the nearest vertical structure, be it natural or manmade, then shed their outer shell. A new exoskeleton grows over the next week, transitioning the body from white and soft, to hard and black. Having donned this new outfit, each classy cicada is now ready to mate. That’s when the noise begins.
The cicada’s range in 2021 will stretch vertically from Michigan to Georgia, and horizontally from Illinois to New Jersey. Brood X has bright red eyes and legs, connected to a black head, with large, translucent wings.
If you live in this region of the country, get outside and check out a truly unique natural phenomenon. If you miss this year’s crop, never fear, there’s a new brood, appearing in a new location, per the map below, every summer over the next few decades. [REF]
Considering the impressive timeline and geographic randomness of the periodic cicadas, they have certainly earned their given scientific name. Magicicada.
Details: