Myrmecofauna (Hymenoptera, Formicidae) of the yew-boxwood grove (Western Caucasus, Russia)

The data on the fauna and biotopic distribution of ants (Hymenoptera, Formicidae) in the yewboxwood grove of the Caucasian State Natural Biosphere Reserve are presented. A total of 27 ant species were identified, belonging to 17 genera of 4 subfamilies (Dolichoderinae, Ponerinae, Formicinae, and Myrmicinae). The genera – Lasius F. and Temnothorax Mayr are the richest and include 5 species each. For the yew-boxwood grove, all species of ants are presented for the first time.


Introduction
Yew-boxwood grove -Is a small area of mixed deciduous forests of the Black Sea coast of the Caucasus with an area of 300 hectares, which is located 20 km south of Sochi (Krasnodar Territory). This territory is part of the Caucasian State Natural Biosphere Reserve and is isolated from the main territory. The investigated areas are located on the right and left banks of the river Khosta on the spurs of Mount Bolshoiy Akhun. The altitude interval of the terrain ranges from 40 to 520 m above sea level. The climate of the region is warm and humid. The average annual air temperature is + 14.5°C, the average annual precipitation is 1350 mm. The soil cover of the yewboxwood grove is represented by humus-calcareous leached soils formed on Upper Cretaceous limestones with typical karst phenomena, an abundance of steep cliffs, sheer walls, and limestone slabs outcrops on the soil surface ( [1]). According to the floristic zoning of the Caucasus ( [2,3]), the territory of the yew-boxwood grove belongs to the Tuapse-Adler floristic region.
The ant fauna of the yew-boxwood grove has not been specially studied. The literature contains only fragmentary information about some species of ants from the vicinity of the city of Sochi and Khosta. So, M.D. Ruzsky ([4,5]) gives 10 species of ants, a little later V.A. Karavaiev in his works ( [6,7,8,9,10]) indicates the finding of 7 species, and K.V. Arnoldi gives ( [11]) one species -Ponera coarctata (Latreille, 1802). We could not find any other information concerning the ants fauna of the yew-boxwood grove in the literature, so the goal was set to study the species composition and biotopic distribution of ants in this area.

Materials and methods
The basis for writing this work was the material collected by us in 2018-2019 on the territory of a yewboxwood grove, as well as collection by pitfall traps -Y. Chumachenko and A. Bibin (2016-2017).
In total, more than 2500 specimens of ants were collected. Most of the collected material is stored in 96% ethanol. All material was identified by the first author (Z. Yusupov) and is kept in the collection preserved of the Tembotov Institute of Ecology of Mountain Territories of Russian Academy of Science.
The collection of the material was carried out according to standard methods: manual collection using an exhauster, the use of pitfall traps, and sifting.

Results and discussion
Currently, 27 species of ants belonging to 17 genera of 4 subfamilies (Dolichoderinae, Ponerinae, Formicinae, and Myrmicinae) have been reliably recorded for the yew-boxwood grove. The richest genus are Lasius F. (5 species) and Temnothorax Mayr (5 species). Some species from the genera -Lasius F., Myrmica Latr., and Tetramorium Mayr, require verification of their taxonomic status. According to our data, about 35 species of ants can be found on the territory of the yewboxwood grove. Below is an annotated list of registered ant species.
Family Remarks. Given the difficulty in identification ants of the caespitum-group, we designate this taxon here as close to T. caespitum.
In the zoogeographic aspect, the ant fauna of the yew-boxwood grove has a mixed character. As can be seen from Table 1, is dominated European-Caucasian (30.5%) and Mediterranean (26%) species, but also present European-West Siberian (13%), Trans-Palaearctic (4.3%), Balkan-Caucasian (4.3%) and East-Asian (4.3%) species. In addition, given that this region of the Greater Caucasus belongs to the Colchics floristic region, with original and distinctive flora and fauna, the Colchian species proper are also present among the ants -Nylanderia colchica and Temnothorax brauneri.
For a long time, the Black Sea coast of the Caucasus was an introduction place for many plant species, and most likely, along with the planting material, two invasive species were introduced there -Lasius neglectus and Nylanderia flavipes. The first species has a native range in the mountains of Central Asia ( [26]), but at the same time it was introduced in many regions of Europe, the Caucasus, Transcaucasia, Iran, and Asia Minor ( [23][24][25], [14][15][16]). The second species is native to East Asia (China, Korea and Japan) including for the Russian Far East (Kuril Islands) ( [30]). Currently, this species has been introduced to the United States, Iran, and also in some European countries ( [29]).
In relation to the humidity, mesoxerophiles (51.8%) and mesohygrophiles (40.7%) predominate, which is associated with the climatic conditions of the study area, where a humid climate prevails, but the amount of precipitation is unevenly distributed over the months, i.e. along with very rainy months, there are also present relatively dry periods. In addition, the region is also characterized by "physical dryness" associated with