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Periodical Cicadas: A Resource Guide

This guide presents researchers with resources on the life cycle of the 13 and 17 year periodical cicada.


Photograph of " Cicadas."
Cicadas 2004. USDA Agricultural Research Service. U.S. Department of Agriculture

Certain summers hundreds of millions of large, winged, red-eyed, noisy insects will emerge from the ground and blanket large portions of the United States in a buggy mess. These groups of periodical cicadas emerge in 13 or 17 year cycles and differ from annual cicadas that emerge every year in late summer to early fall.

Periodic cicadas are part of the genus Magicicada and they will range from northern Georgia to New York, then west to the Mississippi River and the Midwest. There can be as many as 1.5 million cicadas per acre, and even though they look very creepy, they do not bite and will not harm you or your pets.

Life Cycle

The cicada has one of the longest life cycles of any insect. These 13- or 17-year life cycle cicadas have lived underground in a wingless nymph form since when the last Brood of their number emerged and laid their eggs. All this time they have been living about a foot or two underground, feeding on the sap of tree roots and growing. When ground temperature reaches 64 degrees Fahrenheit at a soil depth of 8 inches, the nymphs will emerge and metamorphose into winged adults. The dried husks you will find all over the place this summer are the remnants of the metamorphosis process.

Newly metamorphosed adult cicadas are white in color, very fragile and in danger for hours or even a days after to they emerge until their new exoskeletons harden. In this transitioning stage they are easier to spot and be caught by predators. Once mature, they spend 2 to 4 weeks flying around making tons of noise, mating, and serving as food for many different species of animals.

The surviving adults will then lay their eggs in trees and the eggs, and the eggs will hatch as larvae 4 to 6 weeks later. These larvae will then make their way to the ground, burrow down and wait 13 or 17 years to emerge and start the cycle again. 


Usually only one Brood will emerge at the same time but some years like 2024 two different broods one 13 year and one 17 year will emerge at the same time like this summer when Broods XIX and XIII co-emerge for the first time since 1803.

Table of upcoming co-emergences

13-year brood 17-year brood Year
XIX IX 2037
XIX V 2050
XIX I 2063
XXII IV 2066
XXIII V 2067
XIX XIV 2076

Learn More About Cicadas!

  • Periodical cicadas average 1 to 2 inches long and have a wing span of 3-4 inches. They have black bodies, long wings laced with orange veins, red legs and bright red eyes.
  • The males of the all cicada species make the loud noise that you hear, which is their mating call to attract females. Their mating call ranges between 90 to 100 decibels which is equivalent to the sound of a lawn mower. You can check out what they will sound like by listening to the  National Park Service audio recording- Grand Canyon National Park Cicadas.
  • Almost all periodical cicadas grow and mature into adults at the same time, which is why we witness such large groups every 13 or 17 years. With numbers in the billions, the cicadas have an advantage over the predators trying to feast on them, known as predator satiation. The cicadas will emerge in such a small time frame and in such great numbers that even though a large percentage will get eaten by predators, enough will survive to produce the next generation.

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