Eurycorypha flexata, Hemp, 2017

Heller, Klaus-Gerhard & Hemp, Claudia, 2020, Hyperdiverse songs, duetting, and the roles of intra- and intersexual selection in the acoustic communication of the genus Eurycorypha (Orthoptera: Tettigonioidea, Phaneropterinae), Organisms Diversity & Evolution (New York, N. Y.) 20 (4), pp. 597-617 : 604

Eurycorypha flexata ( Figs. 3 , 4a , and 6 )

The basic unit of the calling song of E. flexata consists of a pair of syllables, followed after an interval of nearly 1 s (0.8 ± 0.3 s; n = 41; range, 0.4– 1.3 s) by a single syllable ( Fig. 4a ). The syllables in the pair were produced at a rate of around 15 Hz (syllable period, 70 ± 7 ms; n = 42). The duration of the syllables was relatively variable, but the means increased from 11.9 ± 5.3 ms in the first, 16.5 ± 7.4 ms in the second to 27.1 ± 5.9 ms in the third (n = 32–33). The song units were heard at intervals of a few to many seconds, with short close series separated by longer gaps.

If a female responded, she did so always after the third syllable (trigger syllable) with a latency of 349 ± 34 ms (n = 40) ( Fig. 5 ). The female response consisted mostly of several loud impulses (2.7 ± 1.8; n = 38: range, 1–6) often combined with irregular soft sounds. Having heard a female’ s reply, the male often modified its song and omitted the pair of syllables in the next song. It produced even several of these monosyllabic songs (2.8 ± 1.8; n = 23) in a series, starting after a first interval of 2.5 ± 0.4 s (n = 24) after the responded syllable. Occasionally, the females responded to these isolated syllables with single impulses. A female deprived of any male contacts for a long time sang spontaneously with several (3–5) impulses in a fast sequence (60–70 ms periods).

Figures

Fig. 3 Power spectra of male calling song of Eurycorypha species. In species with restricted frequency range, short black lines mark its end. Blue lines indicate power spectra of female responses

Fig. 4 a, b Oscillograms of male calling songs, overview (10 s sections)

Fig. 6 Oscillograms of male- female duets, overview (10 s sections)

Fig. 5 Oscillograms of male calling songs, details (1.5 s sections)