Hypogastrura aushensis Skarżyński & Babenko, 2010

Antipova, Maria & Babenko, Anatoly, 2024, New records of the genus Hypogastrura (Collembola: Hypogastruridae) from the Greater Caucasus, with the description of a new species from the monticola- group, Zootaxa 5437 (2), pp. 273-284 : 282

Hypogastrura aushensis Skarżyński & Babenko, 2010

Figs 17–21

Examined material: 7 females and 2 juv. on slides, North Caucasus, Kabardino-Balkaria, Mt. Elbrus, “Mir” Station [43.2894° N, 42.4608° E], 3500 m alt., 14.09.2020. G. Utvenko leg. ; 5 females and 1 male, same region, Irik River Valley [43.2968° N, 42.5906° E], alpine grassland, 3000 m alt., 24.09.1999. A. Babenko leg. The obtained COI gene sequences are available in the GenBank database under the following accession numbers: PP414778 and PP414779.

Remarks. The original description of this species of the crassaegranulata -group was based on material from the Western Caucasus (Kyshkager Mts. Ridge, Teberda Nature Reserve, Karachay-Cherkessia). A three-lobed apical vesicle on Ant. IV was considered as the main diagnostic feature of this species ( Skarżyński & Babenko 2010, p. 278). However, the new material from the Elbrus region showed this trait to be not too reliable, being variable (see Figs 17–20 ): in almost half of the mature specimens examined, as well as in all immatures, the subdivision of the apical vesicle is weak or almost invisible. However, at the population level, this feature appears to be quite reliable.

Individuals from the Elbrus region are characterized by the complete chaetotaxy of both thoracic ( Fig. 21 ) and abdominal terga (with p3 and p7 on Abd. IV and p2 on Abd. V always present). Although the asymmetric absence of some thoracic setae (m2, m2/3 or m4) is quite common, only two of 15 examined specimens appeared to be devoid of certain setae on both sides of the thoracic terga. As a result, the dorsal chaetotaxy in H. aushensis from the Elbrus region turns out to be completely identical to that in H. franconiana ( Stach, 1949) . These two species are obviously closely related and, apart from the shape of the apical vesicle on the antennae, differ only in the structure of the mucro: in H. aushensis , the lateral lamellae of the mucro are merged before its apex, forming a distinct subapical tooth, while in H. franconiana , they reach the tip, leaving the subapical tooth unpronounced.

The known range of Н. franconiana is rather wide and covers most of the Palaearctic with scarce records from the south of France to the mountains of Kazakhstan ( Stach 1949; Cassagnau 1959; Gisin 1960; Skarżyński 2006, 2006a; Skarżyński & Babenko 2010), while H. aushensis , at least for the time being, seems to be endemic to the Caucasus.

The status of the Caucasian individuals mentioned by Stach (1949) within the crassaegranulata complex (Skarżyński 2006, p. 35) is still open to question. According to Stach, these “two young individuals” were collected on “Dormagor-peak, 3600 m alt., 31.VII. 1936 ” by Dr. R. Wojtusiak, but we failed to locate such a name on any modern maps of the Caucasus. Based on the trip’s description ( Wojtusiak 1937), this ridge (not a peak!) is presently referred to as Shtulin Isthmus (Shtulinskaya peremychka). It links the Sugan Mt. Ridge with the Main (Watershed) Caucasian Ridge in the upper reaches of Cherek Balkarsky River. This area is located in the easternmost part of Kabardino-Balkaria at its border with North Ossetia – Alania. It is a little more than 80 air-km away from Mt. Elbrus. One of these specimens, kept in ISEAC, was studied by D. Skarżyński who wrote that it “has only weakly visible coarse skin granulation, thick ant. IV sensilla and fully complete chaetotaxy ” (Skarżyński 2006, p. 35). These observations are hardly too helpful as all these characters fit both species concerned. Nevertheless, the identity of Stach’s specimens with H. aushensis seems to be somewhat more probable simply because of the obvious presence of the latter species almost in the same part of the Central Caucasus. However, other options cannot be ruled out.

Figures

FIGURES 17–21. Hypogastrura aushensis: tip of Ant. IV (four different specimens from the Elbrus region); 21, chaetotaxy of thorax (lateral view) Scales: Figs 17–20, 0.01 mm; 21, 0.1 mm.