Tettigonia cantans

The loud, sibilant calling song is produced both during the day (especially afternoon) and at night, and is much influenced by temperature. In warm, sunny weather the song usually consists of echemes lasting about 1-7 s, with a marked crescendo in the early part of each echeme (Figs 209, 210). As the temperature falls in the late afternoon the echemes become longer, and the nocturnal song (Figs 211, 212) often continues without interruption for several minutes. In warm daytime conditions the syllable repetition rate is usually more than 35/s and can be as high as 55/s in hot sunny weather; on cool nights the rate drops to below 20/s and can be as low as 10/s (rarely 6/s) in cold conditions (c 10°C).

OScillographic analysis shows that the sound is almost always produced only by the closing strokes of the forewings. In warm conditions the closing hemisyllables last about 12-20ms, but become longer at lower temperatures,lastingup to 70 ms or more on cool nights. The intervals between successive hemisyllables are also temperature-dependant, ranging from about 5-10 ms at high temperatures to about 30-40 ms in cool conditions. [1]

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