July 14, 2000

     Cicadas

This week we have had temperatures in the 80s and 90s, and the male cicadas have sung loudly.  One wonders what they sounded like on this date in 1936, at 108 degrees the hottest day in the Twin Cities since records were begun in August 1918.  Their powerful, pulsating buzzing intensifies with warmth, but possibly 108 degrees Fahrenheit was even too warm for cicadas.

Cicadas are common insects, more often heard than seen since the majority are aboreal.  The sounds are produced by the males, with each species having a characteristic song.  The buzzing sound is made by vibrating membranes stretched over a pair of sound chambers, situated one on each side of the abdomen.

There are more than 75 species of cicadas in North America.  Most are large, black insects, about 2 inches long, with green markings and clear wings.  The species we are now hearing is the annual cicada.