Poecilimon (Poecilimon) sanctipauli Brunner von Wattenwyl, 1878

The calling song of the male consists of isolated syllables produced at intervals of several seconds. Each syllable consists of two separate impulse groups. The first long and crescending syllable results from the slow closing movement of the tegmina at the beginning, the second much shorter one from the fast final closure at the end of the movement cycle (Fig. 8; see also Heller & Helversen, 1986; Heller, 1988). From the knowledge of the stridulatory movement and the structure of the stridu- latory file it is possible to predict the process of sound production. During the first part of the syllable the scraper moves along the long outer part of the file, then probably stops at the bulge (Fig. 5), and finally moves along the short proximal part of the file. Since the song is difficult to characterise by measurements, an example of the intra-population variability in amplitude modulation is shown in Fig. 9. In the recordings of 15 animals the two- part syllable structure is easily recognised. The duration of the syllable depends on temperature and is about 500 ms at 25°C. In the course of the afternoon the syllables become longer and of the morning shorter (Fig. 9).

A female responds to male song by abruptly closing her tegmina, producing one or a few impulses (Heller & Helversen, 1986). A schematic figure of the position of the non-homologous stridulatory organs in males and females of P. sanctipauli can be found in Heller & Helversen (1986).

The frequency spectrum of the song (analysed up to 70 kHz) has a distinct maximum in the high audio range between 10 and 20 kHz (Heller & Helversen, 1986; Heller, 1988). [1]

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