May 22 2007
Cicada invasion
The 17-year invasion of cicadas is coming this week.
According to the National Geographic:
Cicadas—insects that spend most of their lives as nymphs, burrowed underground and sucking sap from tree roots—emerge once every 17 years. Living fast and dying young, the shrimp-size, red-eyed insects transform into adults, reproduce, and die, all the while buzzing to beat the band.
Within each 17-year cycle there are subsets, or “broods”. The one coming is Brood XIII, which sounds particularly sinister.
Each brood of 17-year cicadas actually consists of three different species, and they all emerge together. The species look different from one another, and each one has its own song. Listen carefully and you should be able to distinguish the different choruses, according to experts. The three songs have been described as sounding like the word “pharaoh,” a sizzling skillet, and a rotary lawn sprinkler. The different species sing at different times of the day—one favors the early part of the day, another prefers midday, and the third takes the late-afternoon shift.