Idiocerus bilituratus Dubovskiy, 1966

Tishechkin, Dmitri Yu., 2018, Contributions to the study of Idiocerinae (Homoptera: Auchenorrhyncha: Cicadellidae) of Central Asia with notes on synonymy, Zootaxa 4446 (4), pp. 541-554 : 549-553

Idiocerus bilituratus Dubovskiy, 1966

Figs. 9–13 , 44–47 , 86–105

Idiocerus bilituratus DubOvskiy, 1966: 116

Idiocerus bipustulatus Mityaev, 1967: 718 . Syn. n.

Material examined. 1. Russia, the Lower Volga Region, Astrakhan Oblast, Dosang Railway Station 60 km N of Astrakhan, from cultivated Populus (Turanga) pruinosa , 3. VII. 2000, 1 ♂, 4 ♀ ; 6. VII. 2005, 3 ♂ (locality No. 1 on Fig. 1 ). All specimens were collected from the same clump of trees.

2. Southern Kazakhstan, western bank of the Ili River ca. 45 km downstream from Bakanas, environs of Akzhar Village, 15. VI. 2017, from Populus (Turanga) sp., 5 ♂; calling signals of 3 ♂ recorded on flash-card at 35 o C (locality No. 3 on Fig. 1 ). All specimens were collected from the same clump of trees.

3. Kyrgyzstan, foothills of Ferghana Mtn. Range, the Aksu River ( Shin-Say Gorge ) on the left bank of the Lower Naryn River Valley opposite to Tash-Kumyr Town, from P. (T.) pruinosa , 3. VII. 2014, 1 ♀ ; 20. VI. 2016, 2 ♀ (locality No. 8 on Fig. 2 ).

Taxonomic notes and description. I. bilituratus was described from Ferghana Valley (territory of Uzbekistan and Tajikistan) based on a series of more than 100 specimens collected from Populus (Turanga) sp. According to the original description, “in the shape of male genitalia this species is closely related to the species intended to be described by I.D. Mityaev from the lower reaches of the Ili River. But it differs by inflated aedeagus stem, more massive and less bent styles, etc.” ( Dubovskiy, 1966: 116; figures from the original description are reproduced as Figs. 86–88).

I. bipustulatus was described one year later based on one male and four females collected from P. pruinosa in the Lower Ili River Valley ( Mityaev, 1967: 718; figures from the original description are reproduced as Figs. 89– 91). The type locality is referred to as “urochishche Kara-Turanga”. The Russian obsolete word “urochishche” does not have strict analogues in English and means a part of terrain that is clearly different from the surrounding landscape; also we have found another name of this place, “the grove Kara-Turanga”. However, it cannot be found on any modern maps, so we can only conclude that the type locality is situated in the valley of the Lower Ili River.

Since then it was believed that I. bipustulatus lives on desert poplar in the deserts South of the Balkhash Lake and in the Kazakh part of the Syr-Darya River Valley ( Mityaev, 2002); it was never recorded from the territories outside Southern Kazakhstan. I. bilituratus was also found in the Syr-Darya Basin, but only in Ferghana Valley within the territories of Uzbekistan and Tajikistan. Since riparian forests (called “tugai” in Central Asia) grow throughout the course of the river, such a replacement of one species by another seems very strange.

In external appearance, specimens from different localities are similar to each other: face with two round black spots between eyes; ocelli often marked with black ( Fig. 9 ). Body pale greenish or pale yellowish, females are usually paler than males ( Figs. 10–13 ). In males, two dark dots sometimes present on fore margin of pronotum ( Fig. 11 ). Ovipositor black (visible on Fig. 13 ).

Body length (including tegmina): ♂, 3.5–3.9 mm; ♀, 4.2–4.5 mm.

The material studied by us is not abundant, but even in our samples from the Lower Ili River Valley, Kazakhstan and from Astrakhan Oblast, Russia males corresponding to the descriptions of either of the two taxa can be found.

For example, in one male from Dosang, Astrakhan Oblast the inner margin of the penis stem in side view is convex (Fig. 93), whereas in another male it is concave (Fig. 96). On the other hand, a penis with a convex inner margin is somewhat narrower in hind view (Fig. 92), than a penis with a concave inner margin (Fig. 95). A similar situation occurs in males from the Lower Ili Valley, collected not far from the type locality (Figs. 98–99 and 101– 102). Males with styles gradually tapering to the apices (Figs. 94 and 100) prevail in our material, but males with rather wide styles rounded on the apices (Figs. 97 and 103) also present.

Moreover, occasionally traits characteristic of different taxa can be found in the same male. For example, in males with a convex inner margin of the penis stem as in I. bipustulatus (Fig. 96), styles are rather wide with rounded apices as in I. bilituratus (Fig. 97) and vice versa (Figs. 93 and 94).

FIGURES 57–85. Sahlbergotettix salicicola . 57, 61, 64, 70, 73, 79, and 81―penis, back vieW; 58, 62, 65, 67, 71, 74–76, 80, and 82―same, lateral view; 59, 63, 66, 68, 72, and 85―style; 60, 69, 77–78, and 83–84―same, apical part. 57–60―eurOpean male, after Anufriev (1978); 61–63―same, after Ossiannilsson (1981); 64–66― Idiocerus fulvius , after DlabOla (1967); 67– 69―same, after Anufriev & EmeljanOv (1988); 70–72― Sahlbergotettix mesasiaticus , after DubOvskiy (1966); 73–78―males frOm Chatkal Mtn. Range (73 and 75–78―Arkyt, loc. 6 on Fig. 2 ; 74―Ala-Buka, loc. 5 on Fig. 2 ); 79–85―males from the Ili Valley, SOuthern Kazakhstan (lOc. 3 On Fig. 1 ), 81–83 and 85―the male WhOse signals Were recOrded.

FIGURES 86–105. Idiocerus bilituratus . 86, 89, 92, 95, 98, and 101―penis, back vieW; 87, 90, 93, 96, 99, and 102―same, lateral view; 88, 91, 94, 97, 100, and 103―style; 104―1 st and 2nd abdOminal sterna, 105―2nd and 3rd abdOminal terga. 86– 88― I. bilituratus, after DubOvskiy (1966); 89– 91― I. bupustulatus, hOlOtype, after Mityaev (1967); 92–97―tWO males frOm the same clump Of trees frOm Astrakhan Oblast (lOc. 1 On Fig. 1 ); 98–105―tWO males frOm the same clump Of trees frOm the Ili Valley nOt far frOm type lOcality (lOc. 3 On Fig. 1 ), 98–100 and 104–105―One Of the males WhOse signals Were recOrded.

For this reason we establish the synonymy Idiocerus bilituratus Dubovskiy, 1966 = Idiocerus bipustulatus Mityaev, 1967 , syn. n. The shared host plant and records of both forms from the same river basin are additional evidence supporting the synonymy.

Calling signals. Calling signal is a phrase consisting of several syllables ( Fig. 44 ); their amplitude increases towards the end of a phrase. Temporal pattern of syllables is somewhat variable ( Figs. 44–47 ). Occasionally several males occurring on the same twig alternately produce short signals consisting of only 1–3 syllables ( Fig. 45 ).

Distribution. River valleys in the plains and foothills of Southern Kazakhstan, Uzbekistan, and Tajikistan within the range of desert poplar ( Populus from the subgenus Turanga ). Also found in Kyrgyzstan on the boundary of Ferghana Valley and on cultivated P. (T.) pruinosa in semideserts of the Lower Volga Region, Russia (new records).

Remarks. The species was described in the genus Idiocerus sensu lato and attributed to this genus thereafter. Possibly, it should be excluded from Idiocerus sensu stricto.

Figures

FIGURES 3–13. IdiOcerinae, dOrsal vieW (3–8 and 10–13) and face (9). 3–5―Populicerus ambigenus (3–4―male, 5―female); 6–8―Sahlbergotettix salicicola (6―male, 7–8―female); 10–13―Idiocerus bilituratus (9–11―male, 12– 13―female).

FIGURES 36–47. OscillOgrams Of male calling signals Of IdiOcerinae. 36–41―Populicerus ambigenus; 42– 43―Sahlbergotettix salicicola; 44–47―Idiocerus bilituratus. Faster OscillOgrams Of the parts Of signals indicated as “38–41”, “43”, and “46–47” are given under the same numbers.

FIGURES 1–2. Maps Of lOcalities in Russia and Kazakhstan (1) and in Kyrgyzstan (2), Where the materials Were cOllected. 1―Russia, Dosang Railway Station 60 km North of Astrakhan; 2―Kazakhstan, southern part of the Syrdarya Karatau Mtn. Range, the mouth of Sayasay Gorge; 3―Kazakhstan, western bank of the Ili River ca. 45 km downstream from Bakanas, environs of Akzhar Village; 4―Kazakhstan, ca. 45 km NE of Sarkand Village, the Lepsy River at the exit from the gorge to the plain; 5―Kyrgyzstan, foothills of Chatkal Mtn. Range, environs of Ala-Buka Village; 6―Kyrgyzstan, Chatkal Mtn. Range, Sary-Chelek Biosphere Nature Reserve, environs of Arkyt Village; 7―Kyrgyzstan, foothills of Chatkal Mtn. Range, environs of Ak-Jol village 25 km N of Tash-Kumyr; 8―Kyrgyzstan, foothills of Ferghana Mtn. Range, the Aksu River Gorge on the left bank of the Lower Naryn River opposite to Tash-Kumyr Town; 9―Kyrgyzstan, basin of the Lower Naryn River, the Kara-Suu River 15–20 km upstream from Kara-Kul Town; 10―Kyrgyzstan, foothills of Ferghana Mtn. Range, the Kara-Unkur River Valley in the environs of Kyrghyz-Gava Village; 11―Kyrgyzstan, northern slopes of Turkestan Mtn. Range, the Layli-Mazar River Valley 2–3 km upstream from the source of the Laylyak River; 12―Kyrgyzstan, Alay Mtn. Range, ca. 25 km SE of Kyzyl-Kiya, Abshirsay Gorge; 13―Kyrgyzstan, Alay Mtn. Range, the Kurshab River Valley ca. 10 km NW of Gul’cha Town; 14―Kyrgyzstan, Central Tien Shan, the Dzhumgal River Valley E of Chaek; 15―Kyrgyzstan, the Chu River near the western extremity Of the Issyk-Kul Lake (ca. 6 km w Of Balykchi TOWn).