They produce sound by raking a file on the base of their left forewing with a scraper on right forewing. The file is a modified vein with file-like teeth. As the insect closes its wings the scraper is raked over the file. The frequency of their sound increases as the scraper more rapidly rakes the file. When necessary, they can increase the volume by slightly raising their forewings, forming a small cavity in which the sound resonates and is amplified. Our hearing is not sensitive enough to hear their entire melody because their ultrasonic range extends above the 20 kHz upper limit of our hearing! They apparently achieve these high frequencies by straining the scraper against the file in such a fashion that when it breaks loose and glides down the file it is under greater pressure and moving significantly faster. http://msucares.com/newsletters/pests/gloworm/2008/glow0508.pdf
1 comment:
Greetings!
Thanks for following my Blog. Is greatly appreciated. I noticed that you are from Kingsport, TN. Have been to TN quite a number of times in my past. Used to go to a town named Greenville, TN. I have many memories of that ole' Town.
The Katydid. I haven't seen one of these wonderful bugs in a long time. They used to be around our area, but I haven't seen or heard any. Don't know why. You can always tell what they are by their distinctive sound. They area great to hear. My Wife is afraid of them!
Stay Well! - Les
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