New data on bioacoustics and courtship behaviour in grasshoppers (Orthoptera, Acrididae, Gomphocerinae) from Russia and adjacent countries

Abstract

The songs of seven grasshopper species of subfamily Gomphocerinae from Russia, Ukraine, Georgia, and Kazakhstan were studied. We analysed not only the sound, but also the stridulatory movements of the hind legs to more entirely describe the songs. In Mesasippus kozhevnikovi, Chorthippus macrocerus, and C. hammarstroemi, the legs are moved in a relatively simple pattern; four other species, Myrmeleotettix palpalis, Stenobothrus newskii, C. pullus, and Megaulacobothrus aethalinus demonstrate more complex leg movements. In six of the seven species studied, the courtship songs contain more sound elements than the calling songs. The highest number of courtship sound elements was found in M. palpalis and M. aethalinus. The different parts of a remarkably long stridulatory file in M. aethalinus are thought to participate in the production of different sound elements. The songs in S. newskii are shown for the first time. This species produces sound not only by common stridulation but also by wing beats. A relationship of S. newskii to some other species of the genus Stenobothrus, which are able to crepitate, is discussed. We also analyse the frequency spectra of the songs. A maximum energy of the song power spectra in six species studied lies in ultrasound range (higher than 20 kHz). In only M. aethalinus, the main peaks in the song power spectra lie lower than 20 kHz. The courtship behaviour in M. palpalis, C. macrocerus, and C. hammarstroemi was shown to include conspicuous visual display (movements of antennae, palps and the whole body).