Chorthippus Chorthippus oschei pusztaensis

Calling song (Figs 24–27, 30–33) The calling song of Chorthippus oschei pusztaensis is different from the albomarginatus song by a higher rate of the leg movements (50/s) and a higher pulse rate (90–110/s). The legs in the nominate subspe- cies move even more frequently, at a rate of 60–65/s, and besides, these movements are modulated by a lower frequency of about 8/s. Oscillographic anal- ysis shows that the gaps between pulses are some- times distinct in the songs of pusztaensis , however, these gaps are completely absent from the songs of the nominate subspecies. In the latter subspecies, the sound is sometimes modulated in the ampli- tude. Other parameters of the calling song, like the number and duration of songs, are similar to those in albomarginatus .

Courtship song (Figs 56–59, App. 2) Similarly to Ch. albomarginatus , the courtship song of oschei also starts with alternation of A and B ele- ments. The rate of the leg vibrations during A and B elements, as well as the leg-movement pattern producing A elements, in oschei are quite similar to that in albomarginatus . However, the leg movement pattern producing B elements is more complex than in albomarginatus . The rate of sound pulses in A and B elements is similar to that in Ch. albomarginatus : about 59–62/s in the A element and about 22–24/s in the B element. However in Ch. oschei , B elements are always of a higher intensity than A elements. After about 20–30 alternations of A/B pairs, a complex of B1-A1-C elements follows. In Ch. o. pusztaensis , an amplitude of the leg movements during the B1 element gradually increases and the sound loud- ness essentially increases as well (3–4 times higher in comparison to the loudness of B element). The B1 element lasts for 2 s on average. During the up movement, the legs produce a low-amplitude pulse, during the down movement – a high amplitude pulse. The high amplitude pulses of the B1 element follow each other rather regularly at a rate of about 20–30/s. After that, a rapid leg vibration at a rate of about 75–80/s produces a very short (about 0.18 s) element A1 that contains the pulses following at the same rate. The complex element C starts with lifting of the abdomen at a maximal angle of 50°, accompa- nied with a fast movement of the legs into an extra- high position and a very characteristic stroke with the tibiae. The maximal angle between the tibia and femur is 100–130°; the tibial stroke lasts for 0.2–0.4 s. During the up-stroke, the C1 element is produced. Then the tibiae come again to their normal position and the legs vibrate in a complex pattern. In two sub- species, B1 and C elements are different. In the B1 element of the nominate subspecies, the pulses fol- low regularly only in the first third of the duration of B1 element; then the pulse rate starts abruptly to be very low (5/s). The B1 element is shorter, lasting for 0.8–1 s. When producing the C element, after fin- ishing the tibiae stroke, the legs vibrate in a different pattern in the two subspecies. In Ch. o. pusztaensis the legs vibrate at a rate of 60–70/s modulated by the frequency of 15–20/s, whereas in Ch. o. oschei they vibrate at a similar rate of 55–60/s, however, this vibration rate is modulated by much lower frequency of 4–5/s. As a result, an amplitude-modulated hissing sound is produced in the nominate subspecies and a quieter sound without modulation of an amplitude is generated by Ch. o. pusztaensis. [1]

References