page_title: Periodical cicadas
section_title: Broods
hierarchical_section_title: Periodical cicadas / Broods
caption_attribution_description: English: Brood XIII Magicicada septendecim 17-year cicada nymph instar, from the south suburbs of Chicago.
context_page_description: Magicicada is the genus of the 13-year and 17-year periodical cicadas of eastern North America, consisting of seven species. Although they are sometimes called "locusts", this is a misnomer, as cicadas belong to the taxonomic order Hemiptera, suborder Auchenorrhyncha, while locusts are grasshoppers belonging to the order Orthoptera. Magicicada belongs to the cicada tribe Lamotialnini, a group of genera with representatives in Australia, Africa, and Asia, as well as the Americas.
  Magicicada species spend almost the full length of their long lives underground feeding on xylem fluids from the roots of deciduous forest trees in the eastern United States. In the spring of their 13th or 17th year, mature cicada nymphs emerge in the springtime at any given locality, synchronously and in tremendous numbers. After the prolonged developmental phase, the adults are active for only about 4 to 6 weeks. The males aggregate into chorus centers and attract mates. Mated females lay eggs in the stems of woody plants. Within two months of the original emergence, the lifecycle is complete and the adult cicadas disappear for another 13 or 17 years.
context_section_description: Periodical cicadas are grouped into geographic broods based on the calendar year when they emerge. For example, in 2014, the 13-year brood XXII emerged in Louisiana and the 17-year brood III emerged in western Illinois and eastern Iowa.
  In 1898, entomologist C. L. Marlatt assigned Roman numerals to 30 different broods of periodical cicadas: 17 distinct broods with a 17-year lifecycle, to which he assigned brood numbers I through XVII (with emerging years 1893 through 1909); plus 13 broods with a 13-year cycle, to which he assigned brood numbers XVIII through XXX (1893 through 1905).
  Many of these hypothetical 30 broods, however, have not been observed. Furthermore, two of the brood numbers assigned by Marlatt (broods XI and XXI) existed at one time, but have become extinct. The Marlatt numbering scheme has been retained for convenience (and because it clearly separates 13- and 17-year lifecycles), although today only 15 broods are known to survive.
caption: Cicada nymph prior to final molt
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