Question Sheet: Prime Time for Cicadas


Before reading:

  1. Do you live in an area that has cicadas? Where and when do you find cicadas? 
  2. Can you think of an animal that travels or gathers in large groups? What advantages does such a herd or swarm have?

During reading:

  1. Describe the cicada life cycle. 
  2. How do annual cicadas differ from periodical cicadas? 
  3. How often do periodical cicadas emerge? 
  4. When did periodical cicadas first appear on Earth? 
  5. How does cold affect a cicada? 
  6. What is a prime number? 
  7. How did the experiment at the University of California, Davis affect periodical cicadas? What do the results suggest about the behavior of cicadas?

After reading:

  1. Predict what will happen with the cicada babies that are a cross between the 13-year species and the 17-year species. Explain your prediction. 
  2. Compare and contrast the evolutionary advantages of staggered maturation versus periodical mass maturation. 
  3. Why do you think more animals don’t hibernate or wait long periods before appearing in the world? 
  4. What do cicadas teach scientists about evolution? 
  5. Design an experiment related to periodical cicadas. Include your hypothesis and the tools and materials you would need for the experiment.


  1. Different broods of 17-year periodical cicadas appear at different times in different parts of the United States. You’ll find a table listing different broods at of Michigan Museum of Zoology). Select one brood and make a map showing where these periodical cicadas live in the United States. 
  2. Select a state and make a list of when different broods of periodical cicadas are scheduled to appear in this state. 
  3. Imagine that you have a friend from another country who is not familiar with the United States or periodical cicadas. Describe what kind of environment cicadas live in. Where is this area in the U.S.? What is the weather like? What are the main plants in this region? 
  4. Find out which old newspapers your local library has. If you find newspapers from cities where periodical cicadas appeared in 1987 (for example, Washington, D.C., Detroit, or Cincinnati), check the issues for May of that year. Were there articles about cicadas? What were the articles about?


  1. When unusual or important natural events occur, people often create festivals or holidays to celebrate or commemorate them (for example, events celebrating the winter solstice or harvest time). Create a cicada festival. What sort of entertainment would you have? What sort of food? What would the games be like? Invent a game related to the bugs that people might enjoy playing. For information on a cicada festival, see Earth Center). 
  2. If you live in an area where periodical cicadas are due to emerge, keep a daily journal of their appearance, the number you see, and how people react to the bugs. 
  3. If you don’t live in an area where cicadas are due to appear, write a letter to a park ranger stationed where the bugs are numerous. Come up with at least four questions to ask him or her about the experience.


  1. If the cicada cycle continues every 17 years and cicadas appeared in 2004, when is their next appearance? 
  2. Use a timeline to show why 13-year and 17-year cicadas will emerge at the same time only once every 221 years.