Magicicada

Magicicada is the genus of the 13- and 17- year periodical cicadas of eastern North America.

Periodical cicadas are grouped into 30 broods, based on the year they emerge.
Broods are numbered using Roman numerals; broods I–XVII are the seventeen-year cicadas,
while Broods XVIII–XXX are the thirteen-year cicadas. Brood XIV is emerging in 2008.

See http://en.wikipedia.org/wiki/Magicicada