General periodical cicada informationPeriodical cicadas are unique in their combination of long, prime-numbered life cycles (13 or 17 years), precisely timed mass emergences, and active choruses.Periodical cicadas are found only in eastern North America. There are seven species -- four with 13-year life cycles and three with 17-year cycles. The three 17-year species are generally northern in distribution, while the 13-year species are generally southern and midwestern.http://www.magicicada.org/magicicada_2015.php