Bioacoustics of Typophyllum onkiosternum

Description. As in the two preceding species the internal tympanal chamber walls are not extending beyond the dorsal surface of the fore tibia, and the hind tibiae are developed normally, so this species also belongs to Vignon’s first group. As in the other species the tegmina shapes of male and female are very different ( Figs. 8 , 10 ). The speculum of the right tegmen in males is fairly small and transparent. This species has unique black hooklike spines on the meso- and especially the metasterum, described for no other Typophyllum species ( Fig. 8 C,D). The prosternum has very small, short and obtuse processes. On the margins of the mesosternum sit delicate, almost straight and obtuse spines that diverge laterally about 45 degrees. The metasternum is equipped with curved and strongly laterally diverging spines that are longer and reach 1 mm in the male. Upon this character was established the conspecificity of the single male, the very dissimilar female, as well as the two nymphs. Coloration. The only known male is light brown with greyish and yellowish hues ( Figs. 10 A,D and 11B). Its abdominal tergites have black lateral spots and the sternum is blackened. The only female is light green with dark brown legs and reddish brown ovipositor ( Figs. 10 B,C and 11A). Measurements. Tegmen length in male 15 mm and in female 23 mm , hind femora in males 14 mm and in females 18 mm . Acoustic behaviour. The single recorded male produced series of pulse pairs ( Fig. 19 B). At 18ºC the pulse length is 20–30 ms (without the soft hemisyllables corresponding to the opening strokes), and the interval about 50 ms. On a field recording of an untraceable male at 13ºC pulse length is 40 ms and interval 70 ms. These series can consist of 10–15 such pulse pairs, separated by 2–5 seconds respectively. The pulses are broken up into not completely fused impulses, and the spectrogram shows a fairly narrow peak between 20 and 22 kHz.