Periodical cicadas emerge after 17 Years

Screen shot 2013-05-09 at 17.08.55

Timescales and evolution. Differing ratios of life periods.

The adult males are snapping rigid plates on their abdomens to produce their courtship song. The females are clicking their wings to signal approval.

Marvels and a Few Mysteries in Cicadas’ 17 Years – NYTimes.com.

NYT_Cicadas_1894 [PDF] Details of how the dissemination of moles and birds and other insect predators have led to these large swarms of insects being able to live uneaten and then hatch en masse. From over 100 years before – very early environmentalism in the New York Times.