Chorthippus karelini (Uvarov, 1910)

Vedenina, Varvara, Sevastianov, Nikita & Tarasova, Tatiana, 2020, Contributions to the study of the grasshopper (Orthoptera: Acrididae Gomphocerinae) courtship songs from Kazakhstan and adjacent territories, Zootaxa 4895 (4), pp. 505-527 : 520-523

Chorthippus karelini (Uvarov, 1910)

Distribution. North-eastern part of Asia Minor, very locally in Ukraine (Askania-Nova), south-eastern part of European Russia, Transcaucasia, Kazakhstan, Siberia eastwards to Irkutsk region.

Material. Kazakhstan: 1. 10 SE of Aktobe, near Aktjubinsk reservoir, 50°09.6’ N, 57°18.8’ E, 25.06.2018, song recordings in 4 ³; 6. Pavlodar reg., ab . 44 km SW of Pavlodar, environs of Pogranichnoe, 52° 05.4’ N, 76°24.9’ E, 04.07.2019, song recording in 1 ³; 7. Pavlodar region , between Terenkol’ and Beregovoe, near Irtysh river , 53° 05.1’ N, 75°56.6’ E, 05.07.2019, song recordings in 2 ³; 10. Almaty region, ab . 60 km NE of Taldykorgan, near Kapal , 43° 08.4’ N, 79° 01.3’ E, 1220 m a.s.l., 01.07.2016, song recordings in 2 ³ .

References to song. Helversen, 1986: recordings from Asia Minor, calling and courtship songs; Vedenina & Bukhvalova, 2001: recordings from Russia (Altai and Tyva), calling song; Benediktov, 2005: recordings from southern Siberia, calling and courtship songs; Savitsky & Lekarev, 2007: recordings from Russia (Volgograd and Astrakhan’ regions), calling and courtship songs; Bukhvalova & Tishechkin, 2009: recordings from Russia (Irkutsk region), calling song; Savitsky, 2009: recordings from Russia (Volgograd region), calling song; Vedenina & Helversen, 2009: recordings from Ukraine (Kherson region), Russia (Volgograd region), Turkey and Italy, calling and courtship songs; Vedenina, 2015: recordings from Ukraine (Kherson region) and Russia (Saratov, Samara and Orenburg regions), courtship song.

Song. The courtship song ( Fig. 13 ) starts with alternation of two elements, which are repeated with the period of about 1 s ( Fig. 13 C ). When producing the element 1, the legs vibrate synchronously at the rate of about 10–11/s. When producing the element 2, the two hind legs vibrate with a phase shift at the rate of about 26–32/s in a complex pattern: every two up and down leg movements are coupled in a characteristic way. Oscillographic analysis shows that the syllables of the element 1 consist of the well pronounced pulses repeated at the rate of 21–24/s, whereas the syllables of the element 2 contain much more dense pulses following almost without gaps. The alternations of these two elements can last up to 2–3 min, followed by a complex of three more elements. The element 3 of the Ch. karelini song is similar to the element 2, but is remarkably longer, reaching 4–8 s in duration; the pulses of the element 3 are separated by gaps and repeated at the rate of about 98–103/s ( Fig. 13 F ). Then comes a rather short (200–400 ms), element 4; sometimes, one can distinguish in it the distinct pulses. The element 4 is produced by almost synchronous leg vibrations at the rate of about 40–53/s. A subsequent element 5 is accompanied by two fast strokes of the legs ( Fig. 13 D–F). During a first stroke, a short (about 100 ms) noisy sound is generated; this is followed by high-frequency leg vibrations that also produce a noisy sound lasting for 100–200 ms. A second stroke is accompanied with lifting of abdomen and produced with the tibiae; the maximal angle between tibia and femur is 30°. Both strokes are produced with synchronous movements of the two legs, but most of the element 5 is generated by alternate leg movements ( Fig. 13 F ). During the second stroke, a short loud pulse is produced, followed by a quieter syllable of distinct pulses lasting for 200–300 ms. The element 5 reminds the calling song of Ch. karelini ; however, both strokes in the element 5 are of higher amplitude and of shorter duration than in the calling song ( Vedenina & Helversen, 2009). The complex of the elements 3, 4 and 5 is usually repeated 2–3 times, and then again followed by the alternation of the elements 1 and 2. A male tries to copulate with a female after the element 5. The frequency spectra of elements 3 and 4 are much more narrow (10–20 kHz) than the spectra of the element 5 (5–40 kHz) ( Fig. 13 G–J).

Comparative remarks. The recordings of courtship song in Ch. karelini from Kazakhstan do not differ from the recordings from Asia Minor, Ukraine and south-east of European Russia ( Vedenina & Helversen, 2009; Vedenina, 2015). Our recordings, however, slightly differ in the relative amplitude of the elements 3, 4 and 5 from those made by Benediktov (2005) and Savitsky & Lekarev (2007). The differences may arise from the distortions of the relative amplitude in various elements, similarly to those shown in M. pallidus . The recordings of Benediktov (2005) and Savitsky & Lekarev (2007) were made with the filed cassette recorders with the upper frequency limit not exceeding 15 kHz. Thus, the elements that have broader frequency spectra extending to the ultrasound band have smaller amplitude than the elements with the frequency spectra that lie below 20 kHz.

Figures

FIGURE 13. Oscillograms and frequency spectrum of the courtship songs of two males of Chorthippus karelini from Almaty region (A) and Aktobe region (B). Song recordings are presented at three different speeds (faster oscillograms of the indicated parts of the songs shown in C–F). In all oscillograms the two upper lines are recordings of hind leg movements and the lower line is the sound recording. Different elements of the courtship song are indicated by numbers 1–5, drawings show different positions of the hind legs and abdomen at the corresponding moments of the song. Frequency spectra shown for the element 3 (G), the element 4 (H), the element 5 (I–J).