Kybos oshanini Zachvatkin, 1953

Tishechkin, Dmitri Yu., 2024, Leafhoppers of the genus Kybos Fieber, 1866 (Hemiptera: Cicadellidae: Typhlocybinae: Empoascini) in Kyrgyzstan, Zootaxa 5496 (1), pp. 89-100 : 90-93

Kybos oshanini Zachvatkin, 1953

Figs 5–8 , 17–32 , 40–41, 53, 59 , 70–73

Kybos mesasiaticus Zachvatkin, 1953: 237–239 (synonymy by Tishechkin, 2002: 1401)

Kybos oshanini mesasiaticus Zachvatkin, 1953: 208 , syn. n.

Kybos mesasiaticus iliensis Mitjaev, 1971 ; 122–123, syn. n.

Empoasca (Kybos) iliensis (Mitjaev, 1971) (in Dworakowska, 1976: 446–447), syn. n.

Description. Bright green with lighter spots in fore part of body, old dry specimens slightly yellowish. In darker specimens, forewings sometimes slightly smoky in apical parts, veins of hindwings darker than membrane and visible through folded forewings. Dorsal side of abdomen green ( Figs 5–8 ).

Length of dorsal apodemes same or slightly greater than their width at base, their inner margins parallel or slightly divergent, usually separated by rather narrow notch ( Figs 17–24 ). Ventral apodemes 1.8–2.5 times longer than their width at base, parallel-sided, touching with inner margins or separated by narrow notch ( Figs 25–32 ). Aedeagus without lateral processes ( Figs 40–41 ). Style same as in K. montanus , with numerous long setae and serrated falcate apical part. Pygofer appendages narrow ( Fig. 53 ). Anal collar appendages narrow, falcate ( Fig. 59 ).

Males with very long ventral apodemes ( Figs 25–27 ) were found only in a population on the northern edge of Fergana Valley near Shekaftar (=Shakaptar) Village, 45 km southwest from Kerben. However, in the same locality on the same group of trees, males with the same coloration but with shorter apodemes were found ( Fig. 28 ). It is likely, that males with different lengths of apodemes may predominate in different populations; this was the reason for the description of the form with shorter apodemes as a subspecies, K. mesasiaticus iliensis ( Figs 23, 31 ). However, since both forms are sometimes found in the same sample, it is clear that such differences are the result of intrapopulation variability.

Hosts. We collected K. oshanini from different species of Salix from the section Helix in Kyrgyzstan, Zachvatkin (1953a, b) collected it from S. songorica in Uzbekistan and from S. viminalis in Moscow Oblast.

Calling signal. Signals of five males from Kyrgyzstan (the bank of the Taldy-Sai River 3 km down from Shekaftar (=Shakaptar) Village, 45 km southwest from Kerben Town, on Salix sect. Helix , 7. VII. 2023, recording at 22 oC) were investigated.

Calling signal is a phrase consisting of 2–5 syllables, following each other with a period of 360–760 ms; syllable repetition period usually increases towards the end of a phrase ( Figs 70–71 ). Each syllable consists of several low-amplitude pulses following with a period of 80–140 ms, and one higher-amplitude pulse ( Fig. 72 ). Occasionally, low-amplitude pulses are divided in two and an additional low-amplitude short pulse follows immediately before the high-amplitude one ( Fig. 73 ).

The signal K. oshanini is very similar to the calling signal of K. montanus . The most noticeable difference is that low-amplitude pulses in the beginning of the syllable are always present in the signals of K. oshanini , whereas in the signals of K. montanus they are fully or partially reduced. Also, the higher-amplitude component of syllable in the signal of K. montanus is longer, has a flat leading edge, and sometimes consists of several partially merged pulses. In K. oshanini it is shorter, with a steep leading edge, and consists of only one or two pulses.

Distribution. Widely distributed on the plains and arid low mountains of Central Asia along rivers and in oases; does not penetrate into the mountains above the zone of arid shrubs. In European Russia it is known only in the enclave of steppe vegetation in the Oka River Valley, Moscow Oblast, Serpukhov Region, where a significant number of steppe insect species are found that do not penetrate farther to the north and west.

Remarks. The description of K. oshanini is based on specimens collected in the environs of Luzhki Village, Serpukhov Region, Moscow Oblast from Salix viminalis ( Zachvatkin, 1953a) . It is indicated that this species is widespread and forms several races, one of which, K. oshanini mesasiaticus , is common in the oasis regions of Central Asia on willows and differs from the nominotypical one in its brighter coloration and somewhat smaller size. Type specimens are absent in the collection of the Zoological Museum of Moscow University. However, in the materials collected by Zachvatkin and his students, a series of specimens with the label “ Moscow Oblast, Prioksko-Terrasny Nature Reserve, 10. VII. 1946, Salix viminalis ” was found. Since these specimens fully correspond to the original description, and Luzhki Village is located on the bank of the Oka River close to the Prioksko-Terrasny Nature Reserve boundary, we previously suggested that they represent topotypes of this species ( Tishechkin, 2002). It should be added that Salix viminalis grows in this area only on alluvial sands on the banks of the Oka River, so these specimens cannot be collected in other parts of the reserve, where forest communities predominate. Thus, identification of K. oshanini from European Russia is based on these specimens, which are illustrated in Tishechkin (2002) and shown on Figs 8 , 24, 32 .

In another article from the same collection, Zachvatkin (1953b) described K. mesasiaticus from Yargak Village, Khatyrchi Region, Navoi Oblast (later belonged to Samarkand Oblast), Uzbekistan based on the large series, collected at July 1928; in the original description, it is stated that this species is widespread in the oasis regions of Central Asia ( Zachvatkin, 1953b). Only a series of 21 females with labels “Bukhara Oblast (sic!), env. Khatyrchi, Yargak, 14. VIII. 1928, Zachvatkin”, which are topotypes of this taxon ( Fig. 5 ) was found in the collection of the Zoological Museum of Moscow University. Our specimens from Kyrgyzstan do not differ from them in appearance; in the shape of genitalia and apodemes they are similar to the specimen of K. mesasiaticus from Afghanistan illustrated by Dworakowska (1976: 445, figs 308–313). As a result, our specimens from Kyrgyzstan can be confidently identified as K. mesasiaticus sensu Zachvatkin (1953b) .

Comparison of specimens from Central Asia ( Figs 5–7 , 17–23, 25–31 ) and Moscow Oblast ( Figs 8 , 24, 32 ) showed, that they belong to the same species. Certain differences in the shape of the abdominal apodemes, as mentioned above, are the result of intrapopulation variability. The description of K. mesasiaticus indicates a body length of 3.78–4.22 mm for females (data on males are not given; Zachvatkin, 1953b), while the description of K. oshanini indicates a body length of 3.79–4.22 mm (sex is not specified; Zachvatkin, 1953a). This contradicts the statement in Zachvatkin (1953a) that these taxa differ in size. Such inconsistencies in these articles are due to the fact that they were published after the death of Prof. Zachvatkin in a collection of works, the manuscripts of which, in an unfinished form, were found in his archive.

Previously, as a first reviser, we chose for this species the valid name K. oshanini and, following Zachvatkin (1953a), left the Central Asian taxon in a subspecies rank, K. oshanini mesasiaticus ( Tishechkin, 2002) . Despite this, afterwards, K. mesasiaticus and K. oshanini were considered as separate species by Mitjaev (2002, 2015) and Dmitriev et al. (2022 onward). Presently, after studying additional materials from different regions of Kazakhstan and Kyrgyzstan, we found no significant differences between the European and Central Asian taxa. In this regard, we establish synonymy K. oshanini oshanini = K. oshanini mesasiaticus , syn. n.

K. mesasiaticus iliensis was briefly described in a key (Mitjaev, 1971) from the region south of the Balkhash Lake and from the middle part of the Ili River valley. According to the drawings, it differs from the nominotypical subspecies in having shorter abdominal apodemes. Indeed, the male we collected in the Charyn River valley near the confluence with the Ili has short apodemes and fully corresponds to the drawings in Mitjaev (1971) ( Figs 7 , 23, 31 ). Apparently, based on these differences, Dworakowska (1976) raised this taxon to the species rank, Empoasca (Kybos) iliensis . However, since the shape of apodemes in K. oshanini can vary within the same population, we establish the synonymy K. oshanini = K. mesasiaticus iliensis , syn. n. = Empoasca (Kybos) iliensis , syn. n.

Figures

FIGURES 1–12. Kybos spp., dorsal habitus. 1–4—K. montanus (1–2—specimens from Inner Tien Shan, 3—specimen from West Tien Shan, 4—specimen from Alai Range); 5–8—K. oshanini (5—specimen from the type locality of K. mesasiatica in Uzbekistan, 6—specimen from Shekaftar, the northern edge of the Fergana Valley, 7—specimen from the Ili River basin, Kazakhstan, 8—specimen from the type locality of K. oshanini in Moscow Oblast); 9—K. niveicolor; 10—K. auricillatus; 11—K. populi; 12—K. virgator.

FIGURES 13–37. Kybos spp., abdominal apodemes. 13–16—K. montanus (13–14—dorsal apodemes, 15–16—ventral apodemes); 17–32—K. oshanini (17–24—dorsal apodemes, 25–32—ventral apodemes; 17–20, 25–28—specimens from Shekaftar, the northern edge of the Fergana Valley, 21–22, 29–30—specimens from the same locality in West Tien Shan, 23, 31—specimen from the Ili River basin, Kazakhstan, 24, 32—specimen from the type locality of K. oshanini in Moscow Oblast); 33—K. niveicolor, dorsal and ventral apodemes; 34–35—K. auricillatus (34—dorsal apodemes, 35—ventral apodemes); 36— K. populi, dorsal and ventral apodemes; 37—K. virgator, same.

FIGURES 38–63. Kybos spp., male genitalia. 38–39, 50, 52, 58—K. montanus; 40–41, 53, 59—K. oshanini; 42–43, 51, 54, 60—K. niveicolor; 44–45, 55, 61—K. auricillatus; 46–47, 56, 62—K. populi; 48–49, 57, 63—K. virgator. 38, 40, 42, 44, 46, 48—aedeagus, lateral view, 39, 41, 43, 45, 47, 49—same, dorsal view, 50–51—style, 52–57—pygofer appendage, 58–63—anal collar appendage.

FIGURES 64–78. Oscillograms of male calling signals of Kybos spp. 64–69—K. montanus; 70–73—K. oshanini; 74–76—K. niveicolor; 77–78—K. populi. Faster oscillograms of the parts of signals indicated as “66”, “68”, “72–73”, “76”, and “78” are given under the same numbers.