Brood II

Every 17 years, Brood II tunnels en masse to the surface of the ground, mates, lays eggs, and then dies off over the span of several weeks.

Although entomologist C. L. Marlatt published an account in 1907 in which he argued for the existence of 30 broods, over the years a number have been consolidated and only 15 are recognized today as being distinct.

Once they emerge, they spend their short, two-week adult lives climbing trees, shedding their crunchy skins and reproducing.

In 2013, to aid in accurately mapping the geographic range of Brood II, National Public Radio's science show Radiolab created the Cicada Tracker project.

It encouraged listeners to use a mix of Arduino-based tools to report the underground soil temperature so as to predict when the cicadas would appear.