Thursday, August 16, 2012

Crickets

I spotted a one-inch long black cricket in our garage this week. My best guess is a northern fall field cricket (Gryllus pennsylvanicus). This is the common cricket that you hear chirping at night in late summer. The male cricket raises its wings over its body and rubs one against the other. Its thin, papery wings vibrate, amplifying the sound. If you try to find a chirping cricket it quickly goes silent as you approach.
During the past week I've noticed more crickets--in our garden, at New Roots Farm in the high tunnels, along meadow paths. Earlier this summer a friend said she noted a lack of crickets in her yard the past few years. I wonder if her free ranging chickens are the culprit. Although crickets are most active at night, when the chickens are safely tucked away in their coop, I assume chickens can search out and eat crickets during the day. And crickets do start chirping on warm summer afternoons, just when chickens are out scratching around in the barnyard.

As I was reading about crickets on the Internet, I discovered the website, Singing Insects of North America. The website mentions a book, Guide to Night-Singing Insects of the Northeast by John Himmelman, that sounds (yes a CD comes with it) intriguing. I might add that one to my bookshelf.

In his delightful book, Crickets and Katydids, Concerts and Solos, Vincent Dethier wrote this about a chirping cricket:

"The instrument of this indefatigable musician is his interlocking front wings, the stiff parchment-like covers for his membranous hind wings. As the bow of a violin is drawn across the strings and sets them vibrating and as the body of the violin is set resonating by transmission of the vibrations through the bridge, so the cricket draws a scraper across a file of small teeth and sets the wing covers to resonating. The wing covers are raised in song at an angle of about forty-five degrees and brought together periodically. With this closing motion, a ridge on the upper wing cover scrapes across a file on the lower wing cover and generates a high-pitched sound lasting about one-hundredth of a second. Each chirp consists of a group of three or more of these sound pulses. They are executed so rapidly that the human ear cannot resolve the pattern. We hear only the chirp."

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