It is late June and the final few weeks of Brood XIII, a boisterous batch of 17-year cicadas whose loud-partying ways seem to put everything else in perspective. Like the Northern Lights, or an ocean horizon, or fossils from ancient swamps now embedded in mountaintops, the emergence of trillions of the cicadas speaks of time beyond the limits of human understanding and the hubris of human control. To these Rip Van Winkles of the insect world so intent upon their mission of love, the changing scenery above-ground barely seems to register. Mammoth to Man to we’ll see who’s next.

Although no one really knows for sure what’s behind the periodic cicadas’ unique prime number cycle (there are also 13 year cicadas), it surely isn’t to outfox predators. Cicada predators – birds, raccoons, possums, squirrels, reptiles – live at most 4 or 5 years. A 17-year cycle isn’t a survival strategy. It’s a quirk.

My personal favorite  theory -- and the most poetic -- is that periodic cicadas are a literal echo of the last Ice Age. They are found, after all, only in areas that were on the edges of North American Pleistocene glaciers, and only emerge when the ground temperature is about 64 degrees. Perhaps 10,000 years ago, this brood, spreading into newly warming territory, got caught in a time warp caused by cold springs and summers. They stayed submerged for years on end, which somehow reset their internal clocks in a way that could be passed down through generations. Anatomically, there is little difference between periodic cicadas and their annual cousins. But while annual cicadas sing of the languorous days of late summer, these cicadas sing of summer’s beginning, and of the deep past and the promise of a future, only 17 years away. 

(See also “The Motors of August Cicadas”)