periodical cicada

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun Any of several cicadas of the genus Magicicada of the eastern United States that have a 17-year or 13-year life cycle and spend most of their lives underground as nymphs. Broods of periodical cicadas in a given region emerge synchronously in large numbers, metamorphosing into winged adults that mate, lay eggs, and die shortly thereafter.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun North American cicada; appears in great numbers at infrequent intervals because the nymphs take 13 to 17 years to mature