Pseudochorthippus iliensis, Tishechkin & Vedenina, 2025

Pseudochorthippus iliensis View in CoL sp. nov.

Figs 1 View FIGURE 1 , 27–48 View FIGURES 27–40 View FIGURES 41–58

Material examined ( Fig. 1 View FIGURE 1 ). Holotype, ♂, southeastern Kazakhstan, meadow on the western bank of the Ili River ca. 45 km downstream from Bakanas, environs of Akzhar Village, 44.960 N, 75.787 E, 20. VI GoogleMaps . 2024, D. Tishechkin, songs recorded at 32–35 oC. Paratypes: 8 ♂, 2 ♀, same data, songs of GoogleMaps 4 ♂ recorded at 32–35 oC; 3 ♂, same locality, 15. VI GoogleMaps . 2017, songs of several males from this locality recorded on this date at 25–27 oC (recorded males were not collected); 1 ♂, 1 ♀, southeastern Kazakhstan, the Lower Ili River basin, environs of Topar Village, meadow on the shore of a small lake, 44.995 N, 75.011 E, 18. VI GoogleMaps . 2024, D. Tishechkin, the male song recorded at 30–35 oC; 1 ♂, southeastern Kazakhstan, the Charyn River Valley , ca 20 km north of Chundzha (= Shinzha), marshy meadow, 43.716 N, 79.418 E, 25. VI GoogleMaps . 2024, songs recorded at 27 °C. The type series is deposited in ZMMU .

Description. Head from above shorter than pronotum; face slightly oblique in lateral view ( Figs 27–31, 33 View FIGURES 27–40 ). Foveolae with distinctly curved upwards or almost straight parallel margins ( Fig. 34 View FIGURES 27–40 ), 2.5–3.0 times as long as their maximum width. Vertical diameter of eye 1.6–2.0 times greater than subocular furrow in male ( Fig. 33 View FIGURES 27–40 ) and 1.3 times greater than subocular furrow in female. Antennae filiform, 10 th –12 th segments in male, respectively, 2.4–2.8, 2.4–2.9, and 2.2–2.9 times as long as their width in broadest aspect, in female, respectively, 2.5–2.8, 2.3–2.9, and 2.4–2.5 times as long as their width. Anterior margin of prozona rounded; posterior margins of metazona almost straight, projecting backwards at an obtuse angle. Lateral carinae concave in prozona, slightly divergent or almost parallel in back part of metazona. Ratio of maximum/minimum widths of pronotum 1.4–1.8; prozona nearly as long as metazona. Length of lateral lobes of pronotum measured along lateral carina exceeds their maximum width by 1.2–1.4 times in male ( Fig. 33 View FIGURES 27–40 ) and by 1.1–1.2 times in female. Mesosternal lobes are 1.5–1.8 times as wide as mesosternal interspace in both sexes, mesosternal interspace trapezoidal. In brachypterous male, tegmina not reach apices of hind femora, only sometimes almost reach bases of dark-colored distal parts of hind femora, with narrowly rounded apices, hind wings shortened, about half or third shorter than tegmina ( Fig. 27 View FIGURES 27–40 ). In brachypterous female, tegmina strongly shortened, do not reach middle of hind femora ( Figs 30–31 View FIGURES 27–40 ). In macropterous male and female, tegmina distinctly exceed apices of hind femora, with wider apices, hind wings only slightly shorter than tegmina ( Fig. 28 View FIGURES 27–40 ). Stigma usually more or less distinctive both in brachypterous and macropterous individuals ( Figs 27–28, 32 View FIGURES 27–40 ). Radial vein of tegmen almost straight. Ratio width of C/Sc areas of tegmen 1.7–2.4 in both macropterous and brachypterous males and 2.8 in macropterous female. Ratio width of C+Sc/R areas of tegmen 1.8–2.8 in both macropterous and brachypterous males and 1.7 in macropterous female. Hind femora in both sexes 4.6–5.0 times longer than their maximum width. In male, stridulatory file consists of 112–131 pegs arranged in single row. Hind tibiae with 12–14 outer and 11–14 inner dorsal spines. Length of arolium is approximately equal to half length of claws, length of 1 st hind tarsomere equal to length of 3 rd tarsomere without claws. Tympanum wide, oval. Cerci conical, 2.0–2.5 times as long as their width at base ( Fig. 35 View FIGURES 27–40 ). In shape of male genitalia similar to P. turanicus ( Figs 36–40 View FIGURES 27–40 ).

In dorsal view, body brown or yellowish brown, usually, with variable irregular dark pattern on head and pronotum, ventrally, lighter, yellowish brown. Hind femora brown with yellowish ventral and inner parts and dark brown or black knees. Hind tibiae yellowish or reddish, darkened distally, dorsal spines with black apices.

In coloration and most morphometric characters indistinguishable from P. turanicus . Differs from it in the mean of proportions of the middle segments of antennae, although the extreme values in both species overlap. In male of P. iliensis sp. nov., length to width ratio of 10 th –12 th segments are, respectively, 2.6±0.1 (2.4–2.8), 2.6±0.2 (2.4–2.9), and 2.5±0.2 (2.2–2.9) (mean±standard deviation (range); n=13) vs 2.8±0.1 (2.5–3.1), 2.8±0.2 (2.4–3.3), and 2,7±0.2 (2.4–3.0) (n=16) in P. turanicus . For female of P. iliensis sp. nov., these values are 2.7±0.1 (2,5–2,8), 2.7±0.2 (2,3–2,9), and 2.5±0.0 (2,4–2,5) (n=3) vs 2.4±0.3 (2.0–2.7), 2.4±0.1 (2.2–2.6), and 2.4±0.3 (2.1–2.9) (n=5) in P. turanicus . However, since the number of females examined was very small, it is impossible to determine whether differences in antennal segment proportions between these species are significant. In female of P. iliensis sp. nov., vertical diameter of eye 1.3 times greater than subocular furrow, whereas in P. turanicus this ratio is 1.4–1.5; males of these species are indistinguishable in this character. Also, among P. turanicus , individuals with poorly or completely undeveloped stigma are more common.

Measurements (mm). Length of head in dorsal view: ♂, 2.5–3.0, ♀, 2.8–3.6; length of pronotum: ♂, 3.6–4.2, ♀, 4.9–5.1; length of tegmina: brachypterous ♂, 10.5–12.1, macropterous ♂, 17.0–17.3, brachypterous ♀, 9.4–9.6, macropterous ♀, 17.6; width of tegmina: brachypterous ♂, 2.7–3.2, macropterous ♂, 4.0–4.1, macropterous ♀, 3.9; length of hind femora: ♂, 10.9–12.3, ♀, 13.4–13.7; width of hind femora: ♂, 2.3–2.5, ♀, 2.7–2.8.

Song. The calling song is a sequence of several (usually, 2–4) echemes separated by irregular intervals of about 3–10 s ( Fig. 41 View FIGURES 41–58 ). Each echeme consists of 3–11 (as a rule, 6–10) syllables following each other with a period from 110–120 to 150–180 ms ( Figs 42–48 View FIGURES 41–58 ). The first 1–3 syllables contain numerous distinct gaps; in the subsequent syllables the number and duration of gaps usually decreases; sometimes they are completely reduced ( Figs 43–44 View FIGURES 41–58 ).

The song temporal pattern is somewhat variable, but the songs of macropterous and brachypterous males do not have significant differences.

Habitats. Meadows with mesophilic vegetation and swamps along the banks of rivers and small lakes in the desert zone. Often is strictly sympatric with P. turanicus .

Distribution. So far was found only in the Ili River basin in Kazakhstan ( Fig. 1 View FIGURE 1 ); most likely, also occurs in the adjacent territories of China.

Etymology. The name of the new species derives from the name of the Ili River.