Eurycorypha kenyensis, Massa, 2016

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 : 605

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

In the calling song of E. kenyensis , two different elements were observed, both of them produced for quite long times without alternating between them ( Fig. 4a ). The first element was a simple echeme with four syllables (syllable period, 32 ± 3 ms; SRR, 31 Hz; n = 10; T = 26 °C). It was heard continuously for more than 2 h produced at an echeme repetition rate of 1.3/min (in another recording, 0.8/min for 60 min). The second element was produced at intervals of some seconds in series lasting a few minutes and separated by intervals often larger than 10 min. It was relatively variable in structure and can be described in its most typical form as a group of two echemes ( Fig. 5 ). At the beginning of a series, the first echeme consisted of about 20 syllables (20.4 ± 1.6; n = 10), starting with a SRR of about 50 Hz (syllable period, 21.3 ± 1.5 ms) and slowing down to 30 Hz (syllable period, 34.0 ± 2.0 ms). The first syllables were very short but increased more or less continuously in duration. After a relatively variable interval (78 ± 27 ms), the second echeme followed. It was quite similar to the first element, containing three to four syllables (3.6 ± 0.5) with a syllable period of 40 ± 3 ms. The amplitude modulation of the second element was quite characteristically v-shaped, with a loud beginning and end. Within a series, very soon the fourth or fifth syllable of the first echeme became longer without any other changes. However, after some complete echemes, the male often shortened the element by finishing the first echeme after a very long fourth or fifth syllable after some crescendoing short syllables. In the following, it may produce several of these shortened elements. Sometimes even the first echeme occurred as an isolated syllable group. Also, the second echeme was sometimes shortened or enlarged. In addition, isolated impulses were sporadically observed after the second element.

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)