Eurycorypha elongata, 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 elongata ( Figs. 3 , 4a , and 5 )

The calling song of E. elongata consisted nearly always of short, mostly disyllabic echemes ( Fig. 4a ; 1.9 ± 0.7; n = 104; range, 1–5) with a syllable repetition rate of around 25 Hz (syllable period, 41 ± 3 ms; n = 47). These echemes followed each other in quite variable intervals (echeme period, 4.2 ± 6.3 s; n = 92; range, 0.1–32 s). In the first syllable of the recorded type specimen, always a very weak opening hemisyllable was observed and an abrupt beginning of the closing hemisyllable.

While singing in the afternoon, the paratype from Amani produced a very different song, consisting of pairs of two various echemes ( Fig. 5 ). The first echeme was made by a series of six to seven syllables, with the last the loudest and the penultimate the softest. Here, the syllable repetition rate was about 30 Hz (syllable period, 37 ± 3 ms; n = 11), while in the second echeme the much shorter syllables were produced at a rate of about 15 Hz (syllable number, 5.4 ± 0.9; syllable period, 62 ± 6 ms; n = 8).

In a series of recordings, a female was caged together with a male. Here, after disyllable echemes of the male sometimes soft impulses were registered which may be considered as female responses (at intervals of about 400 ms). However, they differed only very little in spectrum from the male song so they may also be female imitations by the male (see Discussion).

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

Fig. 1 Habitus of a male and b female Eurycorypha curviflava