Every 17 years, and when the weather warms, periodical cicadas become a news event. East of the Great Plains in the northern U.S., millions burst forth from the ground. Using specially adapted forelegs, the mature nymphs dig themselves out of the soil where they’ve been feeding on fluids in tree roots. They climb up trees, split out of their skins into winged adults, then eat and mate. During the day, you’ll hear a chorus of wailing males calling out to females, who click in response.

Mass emergence is an effective adaptation that allows these insects to overwhelm potential predators. But sheer numbers shouldn’t lull cicada fans into complacency, for the insects do face stressors, particularly ongoing forest habitat destruction and pesticides. Land clearing and development may destroy the underground nymphs before they can emerge and reproduce. And pesticides applied to lawns, golf courses and parks seep into the ground where the nymphs feed. For now, research into the actual numbers and population dynamics of periodical cicadas is more important than ever.

Seventeen-year cicada
Magicicada septendecim
About 1.4–2 inches (36–50 mm)
Threatened (iucn); secure (natureserve)
Ecological Role
AMNH Specimen Number
AMNH_IZC 00131214
Pennsylvania, U.S.