In contrast to annual cicadas, which emerge as adults after a year long development under ground, periodical cicadas spend 13 or 17 years developing prior to emergence. Brood X (i.e. group 10 of 15 periodical cicada groups in the Eastern US) includes species Magicicada septendecim, Magicicada cassini and Magicicada septendecula. Millions of cicadas in this group are set to emerge sometime soon in a geographic range covering up to 15 Eastern states.

Sketch by Cassidy Cooper. Fact contributed by Adrian Perez.

[Edited by Adrian Perez]

Source: Cooley, J., Kritsky, G., Edwards, M., Zyla, J., Marshall, D., Hill, K., & Simon, C. (2009). The distribution of periodical cicada. American Entomologist, 55(2), 107.