Conocephalus (Conocephalus) conocephalus (Linnaeus, 1767)

Korsunovskaya, O. S., 2024, New for Russia bush crickets (Orthoptera: Tettigoniidae) from Crimea and Caucasus, Far Eastern Entomologist 495, pp. 17-21 : 18-20

Conocephalus (Conocephalus) conocephalus (Linnaeus, 1767)

Figs 1-5 , 11–15

MATERIAL EXAMINED. Russia: Krasnodarsky krai, vicinity of Adler, vill. Sirius,

43.39º N, 39.98º E, 30 IX. 2023, 3 ♂, 3 ♀ (Korsunovskaya).

DISTRIBUTION. Russia (new record). North Africa, Europe from Iberian Peninsula to southwestern Balkans, Greece, and Turkey ( Harz, 1969; Massa, 2009; Hemp, 2013; Massa et al., 2012; Bazelet & Nasckrecki, 2014).

REMARKS. The main morphological characters of studied specimens ( Figs 1–5 ) well agree with those of European ( Harz, 1969; Willemse et al., 2018) and African ones (Naskrecki & Guta, 2019; Hemp, 2021). In Krasnodarsy krai these bush crickets were caught in an area of about 500 m 2 overgrown with cereals. The population density was quite high: from one to three individuals could be found per 1 m 2. During the daytime, high acoustic activity of males was observed. The captured insects were just as active in the laboratory and cages, as in the wild environment. Males constantly produce songs, and at night their signals became long, similar to trills. These songs are not different from those previously recorded for European ( Ragge & Reynolds, 1998) and African specimens ( Heller, 2019). A distinctive feature of the songs is the periodic change in the syllable amplitude ( Fig. 11 ), which is less frequent, however, at night ( Fig. 12 ). The structure of soft ( Fig. 13 ) and loud ( Fig. 14 ) syllables is similar. At 22 oC, the mean duration of soft closing hemisyllables in short series is 87 ms (SD=8 ms); mean duration of loud closing hemisyllables – 81 ms (SD=6 ms). Syllable repetition rate in daytime songs is 7–8 s-1, in nocturnal signals up to 10 s-1. The frequency spectra of diurnal and nocturnal songs are also similar. They occupy the 15–100 kHz band. Several maxima can be distinguished in the spectra. The dominant one is located in the range of either 40–50 or 50–60 kHz ( Fig. 15 ). Comparison of acoustic signals of C. conocephalus from populations separated by thousands of km indicates the extreme stability of their temporal pattern and frequency characteristics (see, e. g. Heller, 2019). This phenomenon can obviously be explained by similar living conditions (in dense grass, with a high population density). Thus, the signals with similar parameters were formed, ensuring both optimal sound propagation in the biotope and successful recognition of sounds by conspecific specimens.

Subfamily Tettigoniinae

Tribe Platycleidini

Figures

Figs 1–10. Tettigoniidae. 1–5 – Conocephalus conocephalus: 1 – anterior part of male body, dorsal view; 2 – male apex of abdomen, dorsal view; 3 – male subgenital plate, ventral view; 4 – right titillator, dorsal view; 5 – female, lateral view; 6–9 – Incertana incerta: 6 – right titillator, dorsal view; 7 – male, lateral view; 8 – male apex of abdomen, lateral view; 9 – female apex of abdomen and ovipositor, lateral view; 10 – Parapholidoptera georgiae, titillators of specimen from Grozny, dorsal view. Scale bars: 1, 8, 9, 10 = 1 mm; 2-4, 6 = 0.5 mm; 5, 7 = 5 mm. 18

Figs 11–15. Acoustic signals of Conocephalus conocephalus from Adler at 22 oC: 11, 13, 14 – oscillograms of diurnal song, 12 – nocturnal song, 15 – frequency spectrum of the song in linear scale. Lines below the oscillograms are fragments with a higher speed of the song shown in Figures 13 and 14.