Male cicadas produce loud calls to attract females, females respond with wing flicks, and the two engage in a back-and-forth duet that ends in mating lasting about 35 minutes. But the full process, from underground emergence to egg-laying, involves a surprisingly elaborate sequence of signals, competition, and timing.
How Males Produce Their Calls
Only male cicadas sing. They produce sound using a pair of ribbed, hardened membranes called tymbals, located on the sides of the first abdominal segment. Rapid buckling and unbuckling of these membranes generates the loud, buzzing calls that can carry over long distances. The sound serves several purposes: attracting females, coordinating with other males, and even deterring predators.
Periodical cicadas (the 13- and 17-year species) take this a step further by forming dense choruses where large numbers of males synchronize their songs. Annual cicadas, the ones you hear every summer during the dog days, tend to call individually rather than in coordinated groups. In both cases, the male’s song is the opening move in the mating process.
The Female Wing-Flick Response
Females don’t sing. Instead, they respond to a male’s call with a quick flick of their wings that produces a sound ranging from a soft rustle to a sharp pop. The timing of this wing flick relative to the male’s call is species-specific, meaning different cicada species use different rhythms. This prevents cross-species mating attempts and helps males zero in on the right partner.
Males can detect both the visual motion and the sound of the wing flick. When a chorusing male perceives a female’s response, he increases the frequency of his calls relative to how far he moves, essentially slowing down and calling more to draw out additional responses. If he gets multiple replies, he stops his fly-and-sing routine and switches to courtship mode, beginning a signaling duet with the female to locate her precisely.
Courtship and Competition
Periodical cicadas use at least three distinct courtship calls, each deployed at a different stage. The first call initiates a duet with the female. Between calls, the male walks toward her. As he gets closer, he shifts to a second call. After making physical contact or preparing to mount, he switches to a third call that continues through copulation.
Competition between males is intense and surprisingly strategic. Males engaged in duets will sometimes acoustically obscure the calls of nearby rivals, essentially jamming the signal so the female is less likely to respond to a competitor. This increases the odds that the rival will give up and move on to search elsewhere. Females, for their part, evaluate males based on both their long-range calling songs and their close-range courtship songs, choosing mates using the quality of both signals.
The Physical Act of Mating
Once the male reaches the female and mounts her, the pair connects at the abdomen. Their bodies initially form an angle, then gradually align into a straight line with wings overlapping. Mating lasts an average of about 35 minutes, though individual pairs can vary by several minutes in either direction. After separation, both insects go their separate ways: the male may attempt to find additional mates, and the female begins the work of laying eggs.
Egg-Laying and the Next Generation
Mated females use a sharp, blade-like structure called an ovipositor to cut into the twigs of trees and shrubs. They carve out small Y-shaped nests in the living wood and deposit up to 20 eggs in each one. A single female can lay as many as 600 eggs across many different twigs, leaving visible scars on the branches.
About six to seven weeks later, the eggs hatch. Tiny nymphs, barely visible, drop from the twigs to the ground and immediately burrow into the soil, digging 18 to 24 inches deep in wooded areas. For annual cicadas, the nymphs spend two to three years underground feeding on root fluids. For periodical cicadas, that underground phase lasts 13 or 17 years depending on the species.
What Triggers the Whole Cycle
The mating season begins with emergence from the soil, and that emergence is temperature-driven. Cicadas crawl up and out when the soil a few inches below the surface reaches 64 degrees Fahrenheit. For periodical cicadas, this happens in spring. For annual cicadas, it happens during the heat of summer, and because their generations overlap, some adults appear every year.
Once above ground, adults live only about four to six weeks, with weather conditions affecting that window. Everything about their aboveground life is compressed into this short period: molting into winged adults, calling, mating, and laying eggs. After the females finish depositing their eggs, both sexes die.
Safety in Overwhelming Numbers
Periodical cicadas rely on a survival strategy called predator satiation. They emerge in such enormous densities, sometimes millions per acre, that predators simply cannot eat them all. Birds, mammals, and other animals gorge themselves, but the sheer volume of cicadas ensures that plenty survive long enough to mate and lay eggs. The strategy works in part because the cicadas vanish for so long between emergences that predator populations can’t build up in anticipation. For this to function, a critical mass of cicadas must emerge together on the same schedule. Stragglers that emerge a year early or late face predators without the protection of the crowd and rarely survive to reproduce.