The Cicadas Story
In the spring of 2014, one of nature’s most unusual pageants is taking place in the lower Mississippi Valley. Somewhere north of 30 billion 13-year cicadas, or Magicicada tredecim, will emerge from dime-sized holes in the ground. The nymphs crawl up into trees and spend six weeks molting, chirping, mating, laying eggs, and dying. Their droning mating call, made by males rubbing together drum-like organs called tymbals, can reach 95 decibels, as loud as a rock concert. It will be the first such “swarmageddon” in the region since 2001, and the last until 2027.
In late May the show continues when the 17-year cicadas, or Magicicada septendecim, emerge in Iowa and northwestern Illinois. If the 17-year cicada immigration along the Eastern Seaboard in 2013 is any indication, the precisely timed mass-emergence and active chorus will produce quite a show for anyone in cicada habitat.
When cicada nymphs crawl from the ground at sunset, the insects are unremarkable, except for their huge numbers. Researchers estimate there may be as many as 1.5 million cicadas per acre. After resting a few days, the cicadas molt and spend about six days resting before their exoskeletons completely harden. This is when the magic begins. Magicicada adults have black bodies, striking red eyes, and orange wing veins, with a black “W” near the tips of the forewings. The bugs take to the air in massive swarms and the males begin their love songs as individuals and in choruses.
The cicadas have no protection from predators and become
protein-rich happy meals for birds, frogs, turtles, snakes, mice, and
even dogs and cats. However, there are so many cicadas they cannot all
be eaten, a situation called “predator satiation.” In other words, the
predators have had their fill of cicada.
After the females breed, they carve countless y-shaped eggnests in twigs and branches. Each female lays a total of around 600 rice-shaped eggs, each the size of a grain of rice, depositing about 20 in each nest. With their role in life fulfilled, the great cicada die-off begins. Trails, roads, backyards, and the floors of forests become massive graveyards filled with countless crunchy cicada corpses.
The eggs hatch into nymphs within 6 to 10 weeks, long after the adults are dead. They instinctively drop down from their eggnests and begin burrowing into the ground. For 13 or 17 years, they patiently suck sap from tree roots until it is time to begin the process again. Awakened en masse, they tunnel to the surface to do what their parents did so many years before.
There are 150 species of non-periodic cicadas in North America, those that emerge every year. But there are only 7 species with 13- or 17-year lifecycles. While they only emerge periodically, they do so in different regions every year. In 2015, the 17-year cicada show will take place in Kansas, Missouri, Nebraska, and Texas. In 2016, Magicicada septendecim will emerge in western New York, Ohio, Pennsylvania, and West Virginia. And so it goes year after year as the cicada story continues unabated.