Northern Dog-Day Cicada

Fascinating facts about the Northern Dog-Day Cicada

• A male northern dog-day cicada produces sound at 120 decibels—as loud as a rock concert or chainsaw—using a pair of drum-like organs called tymbals that vibrate up to 4,400 times per second. The sound travels through hollow chambers in their abdomen that act as biological amplifiers. Each species sings a different song; a human ear can distinguish them in a dense forest as easily as picking out a voice in a crowd.
• Underground for 2 to 5 years, a cicada nymph pierces tree roots with a needle-like mouth and drinks sap, barely moving, counting the days through molecular clocks that track soil temperature and light penetration. When the soil hits exactly 64°C at the surface over consecutive years, something in their body flips a switch. They crawl upward on a single night in late summer, split open their skin, and climb into the air they'll inhabit for only 4 to 6 weeks.
• The northern dog-day cicada emerges in August on the hottest days of the year—the Romans called this cicada season 'canicularis' (dog days) because it coincided with the heliacal rising of Sirius, the Dog Star. Their August-September appearance is so reliable that early American farmers used their arrival as a calendar; the sound meant harvest time was near. Warming springs are now pushing emergence earlier, a shift biologists are tracking as a bellwether of climate change.
• A male's ear is located not on his head but in his abdomen—a tympanum that can hear frequencies up to 40,000 Hz, far sharper than human hearing. This lets him detect rival males' songs from hundreds of metres away and home in on receptive females. The system is so sensitive that even the insect's own deafening song, ricocheting off his body, feeds back into this ear; his nervous system filters it out like noise-cancelling headphones.
• When a female is ready to breed, she doesn't answer with sound—she signals by flicking her wings in response to a male's song. The male locks onto that tiny acoustic signature and flies toward her. Once paired, they mate in seconds. Then she uses her blade-like ovipositor to slice into tree bark and lay hundreds of eggs in a thin line along the branch. Those eggs hatch into nymphs that will drop to the soil and vanish underground for years, restarting the cycle.

At a glance

About the Northern Dog-Day Cicada

In the sweltering heat of a summer's day, the Northern Dog-Day Cicada emerges, its tawny wings beating in a slow, languid rhythm as it rises from the verdant underbrush to claim its place in the sun-drenched canopy above. With a call that is at once a primal scream and a haunting melody, this cicada weaves its song into the fabric of the forest, a mesmerizing serenade that echoes through the trees as it moves with deliberate, almost sensual, abandon. As it sings, its very existence seems to embody the languorous, sun-kissed essence of a long, lazy summer's day.

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