Decim periodical cicadas

Decim periodical cicadas is a term used to group three closely related species of periodical cicadas: Magicicada septendecim, Magicicada tredecim, and Magicicada neotredecim. M. septendecim, first described by Carl Linnaeus, has a 17-year life cycle; the name septendecim is Latin for 17. M. tredecim, first described in 1868, has a similar call and appearance but a 13-year life cycle; tredecim is Latin for 13. M. neotredecim, first described in 2000 by Marshall and Cooley in an article in the journal Evolution, is a 13-year species but otherwise much more similar to M. septendecim than to M. tredecim as shown by studies of DNA and abdominal color variation by Chris Simon and colleagues in a companion article in the same journal issue.

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