17-Year Cicada Swarm

Brood III of the periodical cicadas emerged in Iowa in 2014 after 17 years underground. They are found primarily in central, south-central, and southeastern Iowa. The cicada spends all but a few weeks of its life underground, emerging to mate and reproduce, only then to continue the 17 year cycle over again. Female cicadas lay eggs and those eggs hatch into nymphs which fall to the ground and burrow themselves into the dirt and attach to tree roots. They stay there feeding on sap from the tree root for 17 years before digging their way up to the surface. The insect then goes through metamorphosis where it  forms a crack down on its back, opening the cicada shell, allowing the insect to crawl out of its own skin. The males sing with a drum on the side of their abdomen which attracts females. Once the female is mated she lays eggs and the cycle starts over. There can be as many as 40,000 cicadas in a single tree. 

(Varying species): There are other broods of cicadas that emerge in other years and there are annual cicadas we see and hear every year. The periodical cicadas are related but are a different species than the annual cicadas. The periodical cicadas look different and are on a different schedule than the annual cicadas. The periodical cicadas are here in June and July and sing during the day time. The annual cicadas are here in July until frost and sing during the evening. 

• How does the cicada “sing”?

• How might the female detect the “singing”?
• What other organisms use vocalizations (i.e. “singing”) to increase the probability of successful reproduction?
• How does the male’s singing compare to the mating calls of other organisms?

Students could:

• Examine behaviors of an organism that are useful for reproduction.
• Examine specialized plant structures that are useful for reproduction.
• Formulate a claim that an organism's characteristic behaviors or specialized structures affect the probability of successful reproduction. Support the claim with evidence (specific behaviors or structures) and reasoning (scientific explanation that connects the claim to the evidence).
• Discuss the cause-and-effect relationships between animal behaviors and probability of reproduction.
• Discuss the cause-and-effect relationships between plant structures and probability of reproduction.
• Brainstorm scenarios when animal behavior may impact successful plant reproduction.

• Entomology Today | Periodical Cicadas in Iowa: Read about an Iowan entomologist’s view of the periodical cicada event of 2014.
• Iowa State University Extension | 2024 Periodical Cicada Emergence: What Should You Expect?: Article includes maps and videos of the 2024 cicada emergence.
• Cicada Mania | The Brood Chart: This resource features the names of the broods, their life cycle length, when they will emerge next, which states they'll emerge in, links to Maps, the species that will emerge, photos of cicada’s physical characteristics and other information.
• Lang Elliot Music of Nature | Periodical Cicadas – Brood V: Article and recordings of Periodical cicada.