Periodical Cicada

Figure 1 Ward Upham, Kansas State University, Figure 1. Brood X periodical cicada.

Photo Credit: Ward Upham, Kansas State University,

Periodical cicadas are native to the eastern United States and emerge once every 13 or 17 years making them a rare sight to see! Maryland is home to three 17-year species Magicicada septendecim, Magicicada cassini, and Magicicada septendecula. (Cicada Mania)

Periodical cicadas are grouped into broods based on their geographical region and year adults emerge. There are 15 broods of 17-year cicadas still in existence.

Brood X Emergence

Mid-Atlantic Brood Map. Photo Credit Cicada.Info.jpg Figure 2. Mid-Atlantic Brood Map.

Photo Credit: Cicadas.Info

The Brood X cicada emergence is the largest of all broods, with many billions emerging at the same time. Numbers vary from place to place. 

Based on the last Brood X emergence in Maryland, they will likely appear in the following counties: Allegany, Anne Arundel, Baltimore, Carroll, Cecil, Frederick, eastern Garrett, Harford, Howard, Montgomery, Prince George’s, and Washington. 

Brood X cicadas synchronously emerge in large numbers as part of a predator satiation strategy. By coordinating their emergence, the sheer number of cicadas will allow for many to be eaten by predators while some of the population survives to procreate. Cicada predators include some birds, reptiles, amphibians, mammals, and other insects. (Cicada Crew UMD)

Maryland Department of Agriculture-Brood X-Periodical Cicada-Brown Nymph.jpg
Figure 3. Brown periodical cicada nymph.

Photo credit: Maryland Department of Agriculture

Figure 2. Michael J. Raupp, UMD UME.jpg
Figure 4. Previous Brood X emergence.

Photo Credit: Michael J. Raupp, Ph.D., Professor Emeritus of Entomology and Extension Specialist at the University of Maryland Extension

In Maryland, Brood X will begin to emerge in early May 2021 and will die off by the end of June. Adult periodical cicadas live for just a few weeks. During this short adult lifespan, they shed their nymphal exoskeletons, grow wings, fly, mate, lay eggs in trees, and then die. 

The last Brood X emergence was in spring 2004 and after this year, we will not see them again until 2038.


In early May, when soil temperatures reach around 64 degrees Fahrenheit, Brood X cicada nymphs will dig their way up from the soil where they have been living a couple of feet below the surface, feeding on sap from tree roots for the past 17 years. Where Brood X cicadas emerge, expect to see many exit holes in the ground, about 1/2-inch in diameter. (University of Maryland Extension)

Figure 3. Michael J. Raupp, UMD UME.jpg 
Figure 5. Exit holes from a previous Brood X emergence. Photo Credit: Michael J. Raupp, Ph.D., Professor Emeritus of Entomology and Extension Specialist at the University of Maryland Extension

After emerging from the ground, they will climb up trees, weeds, and any other vertical surfaces. They then molt out of their brown exoskeletons, revealing fragile, crumpled white wings that slowly expand and darken over the next few hours, transforming into the well-known adult appearance. Periodical cicadas are lousy fliers and tend to bump into many objects. This makes them easy targets for predators.

Figure 5 Maryland Department of Agriculture Cropped.jpg
Figure 6. Newly molted adult with fragile wings fully expanded before exoskeleton hardens.

Photo Credit: Maryland Department of Agriculture

Once they are fully grown, male cicadas “sing” their mating call to attract females, making a loud chorus that can reach a volume as high as 105 decibels! (Cicada Crew) This is comparable to a lawn mower, leaf blower, or chainsaw. These sounds will usually last from late-May to late-June.

Approximately 10 days after emergence, cicadas mate, and females lay eggs in thin tree branches. They cut deep slits into the twigs and deposit tiny eggs in rows, around 2-3 inches long and about a pencil-width in diameter. A female can deposit anywhere from 400-600 eggs in her lifetime. Adult periodical cicadas will be active above ground for about six weeks.

 Figure 5. Pennsylvania Department of Conservation and Natural Resources Rotated.jpg
Figure 7. An adult female periodical cicada laying eggs in small rows. Photo Credit: Pennsylvania Department of Conservation and Natural Resources - Forestry,

 Figure 6 Maryland Department of Agriculture CROPPED.jpg

 Figure 8. The next generation of eggs about to hatch in a twig. Photo Credit: Maryland Department of Agriculture

In late July-early August, about six weeks after the eggs are laid, they will hatch. Tiny white nymphs, that look similar to ants, fall from the trees and immediately begin to burrow underground where they will live again for another 17 years before the cycle repeats itself.​​

Maryland Department of Agriculture-Brood X-Periodical Cicada-Hatch.jpg Figure 9. Tiny white nymphs after hatching.

Photo Credit: Maryland Department of Agriculture

To see this lifecycle in action, watch “Return of the Cicadas” made by Motionkicker on Vimeo.


The Brood X adult is 1-1.5 inches long and has a wingspan of 2-3 inches. Its body is mostly black with stunning red eyes and orange-veined transparent wings. The three species of 17-year periodical cicada found in Maryland differ slightly in appearance, size, and sound. 

Watch this Cicada Mania video to see and hear the difference among Magicicada species.

Periodical cicadas are commonly confused with annual cicadas. Most annual cicadas are larger with silver underbellies, green and black bodies, and green-veined clear wings. The annual cicadas also emerge later, appearing from July through September.

Figure 8 and 9  Bugwood.png

Figure 10. Periodical cicada. Photo Credit: Jon Yuschock, (left)

Figure 11. Annual cicada. Photo Credit: David Cappaert, (right)

Are they harmful to...

Figure 9 Maryland Department of Agriculture.JPG 
​Figure 12. Adult Brood X cicada sitting on a hand.
Photo Credit: Maryland Department of Agriculture

  • Humans - NO. Cicadas do not bite or sting. Humans can even eat cicadas! 
  • Animals - NO. Again, cicadas do not bite or sting. If your animal or pet consumes a few cicadas they should be ok, but consuming a large amount may upset an animal's stomach. Try your best to limit the number of cicadas your animal or pet ingests. (Cicada Crew)
  • Crops/Most Plants - NO. Cicadas do not chew on plants. They feed off of sap from woo​dy plants.
  • Small, young woody plants - MAYBE. Small twigs can be damaged by deep slits cut by the female as she deposits her long rows of eggs. Very small woody stock, 1-3 years of age, can be severely damaged by large numbers of egg sites. Most mature, large trees are able to tolerate cicada damage.

What can be done?

Figure 10 James B. Hanson, USDA Forest Service,
Figure 13. Tree netting used to control cicada populations. Photo Credit: 
James B. Hanson, USDA Forest Service,

  • Delay pruning of landscape materials until after egg-laying stops in June and adult periodical cicadas have died off.
  • Wait to plant
    new saplings outdoors until after cicadas are gone in June. 
  • Cover Trees. The University of Maryland Extension recommends covering small trees, shrubs, and fruit trees with insect netting that has openings ranging from 1/4-inch to 3/8-inch or other breathable fabrics like tulle. Remove netting after adult periodical cicadas are gone. UMD's Cicada Crew has a great demonstration video on how to correctly cover your small trees in netting on their YouTube

  • Do not use insecticides.
    Insecticides will not be helpful in controlling populations or damage. Using insecticides also poses a threat of harming other helpful, beneficial insects.
  • Compost.
    Add cicada carcasses to your compost pile. 
  • Download the Cicada Safari App.
    Use Cicada Safari to identify 17-year periodical cicadas, share photos, map your finds, and compete with other users for most cicadas found. This app was created by Mount St. Joseph University and will help scientists use data to track Brood X populations. More information about the app on Cicada Mania.
  • Enjoy!
    Sit back and watch this amazing natural phenomenon that happens nowhere else in the world! Have fun and take the time to appreciate their incredible life cycle

    – they'll be gone again before you know it.​


Contact the department’s Plant Protection and Weed Management Section at

Media Contacts

Jason Schellhardt 

Director of Communications 

Phone: (410) 841-5888

Megan Guilfoyle 

Public Information Officer 

Phone: (410) 841-5889

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