Their parents passed away thirteen, or maybe seventeen, years ago. They grow up alone, hidden in tunnels of their own making, nursing from the rootlets of trees. In those narrow tunnels, they go through five molts, each time emerging from their shed exoskeleton larger than they were before, until somehow, they know. After thirteen, or maybe seventeen, years of subterranean night, they will, finally, dig toward the air. A little chimney of displaced dirt will announce them. When they surface, they are pale nymphs and they climb their home trees. They cast off their exoskeletons like heavy capes and soon enough their pallor blushes to a bright attractive green. The males start to sing. The females dance, subtly, with their wings. And there are so many of them! They have around five weeks to meet, mate, and hope not to be eaten before their clamorous carnival ends, and they die off, leaving behind their remains, as numerous as leaves in the fall. The scent of their decay is not unrelated to that of old beer.
For some people, the whole romantic cycle is, understandably, a nightmare: billions of toe-sized insects, as many as a million per acre, on lawns and on wooden fences and on your pants. They evince no fear; their pace is that of zombies and, yet, the collective song of these slow-moving hordes is as loud as roadwork, or advancing artillery. Some of them even have red eyes.
The time of the periodical cicadas is nigh. Again. And, this time, it’s people in the Midwest and the Southeast who will be their witnesses. The cicadas will arrive in seventeen states in mid-May and stay until late June, more or less. Periodical cicadas are unique to the United States, in the way that wallabies exist only in and near Australia. This year, two broods will emerge simultaneously. One is Brood XIII, which comes out every seventeen years, and the other is Brood XIX, which comes out every thirteen years. “Brood” is a more phenomenological classification than “species” is. A cicada brood is defined as all the cicadas of the same life-cycle length that come out in the same year and region. (There can be more than one species within a brood, and there usually are. To further confuse you, I’ll also note that only seven of the three thousand or so species of cicada are periodical cicadas.) Broods XIII and XIX will next coincide in 2245. There are, however, other broods to hang out with in the meantime: another twelve broods are on a seventeen-year cycle, and another three on a thirteen-year cycle. Each species of cicada sings its own distinctive song.
Periodical cicadas are not locusts, though they have often been called that. Locusts are less noisy but more fearsome. Locusts travel in swarms, in an aggregate, moving together like a battalion. They devastate acres of crops, quickly. Periodical cicadas don’t do that, and they’re more uniformly spread out, and their collective song can be as loud as people shouting.
In March, I went to visit the entomologist Jessica Ware at the American Museum of Natural History. I saw the wasp-nest collection of the sexologist Alfred Kinsey and part of the butterfly collection of Vladimir Nabokov, and eventually I arrived at Ware’s spacious trapezoidal office. The armchairs and rugs looked Victorian, as did the cluttered curiosity cabinets; the file folders and piled papers and nets on poles of varied lengths looked like they belonged in a pre-Internet laboratory. A dazzle of fireflies—firefly sculptures, posters, road signs, drawings—provided the dominant spirit. Fireflies are central to Ware’s research interests. Ware, forty-eight, wearing a patterned dress, looks like everyone’s idea of a cool professor.
“They really only have one thing to do,” Ware said, of cicadas when they emerge. “And that’s to mate.” She explained that it takes a week or so for the débutante cicadas to “sclerotize,” or stiffen up. Male cicadas don’t produce song until that hardening has happened; they need to vibrate a tymbal—a rigid exoskeleton connected to their abdomen—in order to make their characteristic drone. Notes are sounded by the flexing and releasing of abdominal muscles, a system somewhat analogous to the one used by a steel-drum set.
“Certain songs are particularly impressive to the ladies,” Ware said. “Longer calls are better, because it usually means you have more energy.” The ones that can keep singing in the heat of day are also considered, well, hot. “If they’re able to withstand doing this very energetically expensive thing, in really hot temperatures”—that suggests good health. Singing louder is another way to trumpet one’s qualities as a mate. Cicadas sing for weeks, and their song can be as loud as a hundred decibels—the same as when you run a blender. Many cicada songs have been recorded, should one be curious, and some human songs exist that imitate them.
The public will undoubtedly experience the cicadas as an innumerable nuisance, but entomologists will be looking at how this year’s numbers compare with previous years’. “With insects, there’s a big difference between billions and trillions,” Ware said. Insects have been around for eons longer than we have, but in the past forty years their populations seem to have decreased by nearly half. In the case of periodical cicadas, studying a phenomenon that occurs less than even once in a blue moon has challenges distinct from studying, say, a colony of ants. “But there’s more data on emergences now, because of cell phones,” Ware said. The entomologist Gene Kritsky, of Mount St. Joseph University, worked with colleagues in the Center for IT Engagement to develop an app, called Cicada Safari, that uses photographs submitted by amateurs to help map the emergence.
Toward the end of June, after mating, females will make slits in small tree branches and lay their eggs; an individual female may lay as many as six hundred eggs, leaving ten or so in each slit. The branches will droop from the weight. (The weaker branches tend to break off, incidentally pruning the tree. In the year following a cicada emergence, there are often more cherry blossoms, more peaches—more of anything that blooms or fruits.) The singing will begin to subside. A few female cicadas will still be seen in the songless coda, as they make their final nests. “And then they’re just going to die,” Ware added, of the male and female cicadas alike.
Many animals are pleased with the abundance of periodical cicadas—as a meal. In 1859, the journalist Peter Lund Simmonds observed that immense numbers of the insects “are destroyed by hogs before they emerge from the ground,” and that “they are also, when in their perfect state, eagerly devoured by chickens, squirrels and many of the larger birds.” In 1715, the Philadelphia-based Lutheran pastor Andreas Sandel noted, of a cicada emergence, “Swine and poultry ate them, but what was more astonishing, when they first appeared some of the people split them open and eat them, holding them to be of the same kind as those said to have been eaten by John the Baptist.” The taste of cicada when they are still pale is described by Cicada Safari as being like “cold canned asparagus.” During a previous brood emergence, Ware had her lab over for a barbecue; cicada sauteed with garlic and onion was served with burgers. “They’re very crunchy,” she said. “If you like to add that texture.” Ware has also gone out cicada gathering with the chef Joseph Yoon, whose recipe for a Forbidden Rice Bowl includes stir-fried cicadas and a cricket-ramp kimchi.
But what is life like for the cicada? “I have never seen any animals more entirely stupid than the seventeen year locusts,” the naturalist John Cassin wrote, in his report on periodical cicadas, published in the Proceedings of the Academy of Natural Sciences of Philadelphia, in 1851. “They make no effort to escape, but allow themselves to be captured with perfect passiveness, thus reminding one of the tameness of animals in countries where they are not molested by enemies.” (Again, like wallabies.)
The cicadas’ near-total unguardedness is counterbalanced by their plenitude. There are simply so many of them. “If there’s millions of you—or, in some broods, trillions of you—then you’re less likely to be on the plate for supper,” Ware said. Their curiously long life cycle also protects them. By arriving so infrequently, and at such odd intervals—prime numbers!—no predator can expect to depend on the plenty. “Prime” life cycles are also thought to be a means of evading fungi, parasites, and pathogens that rely on regular intervals around which their own life cycles can be built.
There is, however, one single-minded enemy in successful pursuit. Massospora cicadina, a parasitic fungus, infects only periodical cicadas, and its mechanisms make Ebola seem mild-mannered. First, the fungi invade the cicada’s abdomen. During the first week of the invasion, the infected cicada still looks normal, and can infect other cicadas through copulation. But eventually the infected abdomen begins to degrade; as Ware said, “their bums fall off.” The lower halves of the periodical cicadas get replaced by a plug of fungus. A male cicada infected with Massospora cicadina can still sing, but its sound will be altered by the spores that populate the cavern of the abdomen. The fungi-carrying insect then sprinkles the invader’s spores around like, as Ware put it, “a salt shaker.” A mystery is that Massospora is as ancient as the periodical cicadas they wreck—they have coexisted in this gruesome way for millennia.
The self-taught nineteenth-century French entomologist Jean-Henri Fabre grew up in poverty. His father ran a series of failing cafés; his grandmother told him that learning the alphabet ruins one’s eyesight. He became a schoolteacher, and spent his first month’s salary on an illustrated book of insects. Eventually, he wrote thousands of pages himself, almost all on insects (with some on mushrooms and lichen). When he was in his seventies, his work was championed by the poet and critic Stéphane Mallarmé; Darwin called him “the Homer of Insects,” and for a time his work was regularly taught to French schoolchildren. In 1900, in a letter to his brother, Fabre wrote that he would have long ago given up on life “had I not for my encouragement the consciousness of being engaged in the continual search for truth in the little world of which I had made myself the historian.”
In a ten-volume work, “Souvenirs Entomologiques,” published between 1879 and 1909, Fabre writes that cicadas have been maligned. (He is not speaking about periodical cicadas, specifically, which don’t exist outside North America.) He says that La Fontaine’s “The Ant and the Cicada”—which he notes is usually translated into English as “The Ant and the Grasshopper”—is a slander. This is the tale, also found in Aesop, of the insect that sings away the summer while the ant works to prepare for the winter. In some versions, when the cicada shows up in the winter begging for food from the ant, the ant says O.K., and in other versions the ant says no.
Fabre writes, in response to this tale, that his village “does not contain a peasant so ignorant as to imagine the Cicada ever exists in winter. . . . A thousand times he has seen the grub leave the ground through a round hole of its own making, fasten itself to a twig, split its own back, take off its skin, and turn into a Cicada.” (Presumably the earlier stages underground are seen as separate from the brief summer life of the insect in its more mature form.) Of the cicada’s song, he says, “The Cicada is no beggar, though it is true that he demands a good deal of attention from his neighbors. . . . He tortures my head with the rasping of his harsh music.” The tale has the dynamic backward, Fabre argues: “The Cicada is never dependent on others for his living. At no time does he go crying famine at the doors of the ant-hills.” Instead, it is the industrious ant who comes to feed on the tree sap made available by holes drilled by the droning insects, and who even sometimes eats the nearly defenseless musician, the cicada. ♦
