Bioacoustics of Eurycorypha paraspicula

Diagnosis . — Males of E. paraspicula are characterized by an unusually roundish habitus, which is uncommon within the genus. This species is morphologically most similar to E. spicula from the Nguru Mountains, but can be distinguished by the more rounded shape of the male body, longer paired spines on the posterior margin of the tenth abdominal tergite, and notably thicker cerci. The male cerci of E. paraspicula are robust and terminate in a distinct sclerotized ridge, whereas in E. spicula they are more slender with narrower tips. Most significantly, the acoustic signals of E. paraspicula differ from those of E. spicula , providing a reliable means of species recognition. The female of E. paraspicula is currently unknown.

Bioacoustics . — The male song consists of groups of polysyllabic, crescendoing echemes (Figs 8 A , 9 A ). An echeme contains 7.7 ± 0.5 syllables ( 4 males ; 68 measurements; range 5–9), produced at an SRR of 41 Hz corresponding to a syllable period 24.4 ± 0.8 ms (range 20–28 ms; T = 24–25 ° C). One group of echemes typically contains 1.9 ± 0.3 elements ( 4 males ; 35 measurements; range 1–3), repeated at periods of 1.56 ± 0.56 s ( 4 males ; 37 measurements; range 1.2–2.4). These groups are separated by intervals of 8.7 ± 1.6 s ( 4 males ; 32 measurements; range 4.6–24.2) from the next. The spectrum of the song shows a relatively narrow peak around 13 kHz (Fig. 11 ; see Table 1 for other details). Stridulatory file, tooth number, and tooth intervals are in the range typical for Eurycorypha (Table 1 ; for comparison, see Heller and Hemp 2020 ). Species File length (mm) Tooth number Tooth spacing in middle (μm) Peak frequency m / f (kHz) Bandwidth 10 dB below peak m / f (kHz) E. paraspicula 2.2 (n = 4) 90 (n = 1) 32 12.8 / n. a. - (n = 4) 4.1 / n. a. - (n = 4) E. spicula 1.8 (1.7–2.5; n = 6) 75 (n = 1) 25 13.3 / 11.6 (n = 3) 8.2 / 9.3 (n = 3) E. willschi 2.0 (n = 1) 97 (n = 1) 21 16.5 / 14.5 (n = 3) 6.8 / 12.6 (n = 3) E. binasuta 1.8 * 110 * 22 * 10.9; 10.5 $ / 11 (n = 1) 6.2; 2 $ / 1.9 (n = 1) * from Heller and Hemp 2020 ; $ groups of syllables; pulse-like syllables; n. a. not available.