Figs. 6–10, 21–28, 40–49
A. bicinctus centrorossicus Zakhvatkin, 1953: 218
Material examined. Kyrgyzstan, West Tien Shan Mts., Chatkal Mtn. Range, Sary-Chelek Nature Reserve, fruitwalnut forest North of Arkyt Village, 17. VII. 2008, signals of 3 m # recorded on disk at 22–23 o C (Figs. 40, 44 and 49); South Siberia, Altai Mts., Southern end of Teletskoe Lake, meadows on the bank slope, 15. VII. 1999, signals of 1 m # recorded on tape at 22 o C (Figs. 41 and 45); South Siberia, South Tyva, environs of Erzin Village, meadows in the floodplain of Tes-Khem River, from herbaceous Fabaceae, 1. VIII. 1 989, signals of 1 m # recorded on tape at 22 o C (Figs. 42 and 46); South Sakhalin, (1) ca. 5 km North of Starodubskoe, dry meadow, 31. VII. 2015, signals of 1 m # recorded on disk at 25 o C; (2) the shore of Aniva Bay in the environs of Ozerskiy Village, 14. VIII. 2015, signals of 2 m # recorded on disk at 25 o C (Figs. 43 and 47); (3) environs of Sokol Town, dry meadow on the bank of Maly Takoy River, Trifolium sp., 8. VIII. 2 0 15, signals of 1 m # recorded on disk at 21–22 o C (Figs. 48). Additional material (no signal recordings). Kazakhstan, environs of Almaty, from herbaceous Fabaceae; Kyrgyzstan, West Tien Shan Mts., Chatkal Mtn. Range, Sary-Chelek Nature Reserve, many specimens of both sexes from the fruit-walnut forest zone and from subalpine meadows including one male from the thickets of grasses and nettle under the canopy of walnut forest; Kyrgyzstan, Alay Mtn. Range, meadow on the bank of Kurshab River 10 km North of Gul’cha Town; West Siberia, Tomsk Area, Kolpashevo Town; West Siberia, Krasnoyarsk Province, (1) Turukhansk District, Mirnoe; (2) Ermakhovsk District, Bol’shie Ury River 24 km from the mouth.
Morphology. Coloration typical for the group but more contrasting than in A. bicincta, longitudinal veins on both sides of claval suture usually white, distinctly lighter than surrounding areas, middle part of inner claval vein as a rule is also marked with white (Figs. 6–9).
Body length (including tegmina) in males from Central Asia, Siberia, and the Russian Far East 4.8 –5.6 mm, penis length 0.94–1.00 mm; thus, in both parameters they are somewhat larger, than males from Western Europe (Bluemel et al., 2014). However, in ratio of body length to penis length European and East-Palaearctic populations are indistinguishable (4.98–5.90 in European males, 5.10–5.64 in East-Palaearctic ones).
Penis stem is almost straight, as a rule is slightly more slender than in A. bicincta. The ends of the upper spines only rarely reach the bases of the lower ones and never extend beyond them (Figs. 21–28).
Male calling signals. Calling signal is a single or regularly repeated phrase. As a rule it consists of several syllables with elaborate temporal pattern (Figs. 40–41 and 43); occasionally the male produces single syllables with irregular intervals up to 10–15 minutes and more (Fig. 42). Each syllable begins with a prolonged succession of variable pulses; occasionally its temporal pattern is irregular. In the initial syllable of a phrase this succession is about 3–6 times longer than in the next ones (Figs. 40–41 and 43). Then follows a more constant part of the syllable consisting of one rather long pure-tone pulse and a train of very short pulses with noise frequency spectra; this train begins quietly and reaches maximum intensity in the second half or in the end (Figs. 44–49). Difference in frequency spectra between pure-tone and noise pulses is clearly visible on the sonogram (Fig. 49). Relative amplitude of different components of a syllable can vary to a great extent (Figs. 47–48). No distinct differences were revealed between the signals of males from different localities even situated at a distance of several thousand kilometres (Figs. 44–48).
Remarks. A. diminuta was originally described as a subspecies of A. bicincta based on differences in body size and penis shape (Ribaut, 1952; Figs. 20–21). The original description of A. centrorossica was published after the death of Zakhvatkin in the collection of unfinished manuscripts some of which apparently were not intended for print in the present form; for this reason some taxa were described in these articles in insufficient detail (Zakhvatkin, 1953). Bluemel et al. (2014) treated A. centrorossica as a junior synonym of A. diminuta without any explanation. Based on original descriptions of both forms and on comparison of morphological and acoustic data on West-European populations from Bluemel et al. (2014) with our material we share the opinion that A. diminuta = A. centrorossica.