ON SOME SONG CHARACTERISTICS IN EPHIPPIGER (ORTHOPTERA, TETTIGONIOIDEA) AND THEIR GEOGRAPHIC-VARIATION

Some characteristics of the song of a number of Ephippiger (sub) species are compared, in particular the number of syllables in the chirp. Syllable duration appears comparable in all forms studied. In E. terrestris (with E. t. bormansi and E. t. caprai included) all chirps are monosyllabic, in E. discoidalis 3-(2/5)-syllabic, in E. perforatus 5/6-syllabic and in E. provincialis the chirps are predominantly 3/5-syllabic. In the E. ephippiger diurmus complex a clinal variation exists: in northern locations monosyllabic chirps prevail, in the south of France (Pyr. orient., Aude, Herault) polysyllabic ones (Fig. 3). Just as in morphometric and allozymic characters, there are continuous transitions between populations from 1/2-syllabic to 5/6/7-syllabic chirps. None of these characters, however, vary along the same geographical lines. Therefore, neither the song structure nor other known parameters can be used to distinguish taxa within the E. ephippiger diurnus complex. E. e. vicheti generally produces polysyllabic chirps, but in this case no clinical variation is apparent. The available data are discussed in the perspective of the function and the phylogeny of the song in the Ephippigerinae.