On the ecology of bumble bees of the Talysh Region, Azerbaijan

Summary The Caucasian isthmus, which began to take shape in the tertiary period, is characterised by the presence of various plants and animals both of boreal and tropical origin. These characteristic species are mostly endemic. They are concentrated in the mountain systems of the Greater and Lesser Caucasus and alsoTalysh. The bumble bee fauna of Talysh contains 22 species belonging to two ecological groups : mesophile - Bombus lucorum L., B. zonatus apicalis SKOR., B. daghestanicus RAD., B. eriophorus caucasicus RAD. and xerophile species of the high mountains and steppes, most of which are endemic - B. argillaceus Scop., B. simulatilis RAD., B. armeniacus RAD., B. alboluteus PAL., B. vorticosus GERST., B. mlokosiewitzii RAD., B. incertus MOR., B. persicus RAD., B. melanurus LEP. SKOR., B. daghestanicus RAD., B. eriophorus caucasicus RAD. bzw. den xerophilen Arten des Hochgebirges und der Steppen, von denen die meisten en-demisch sind – B. argillaceus SCOP., B. simulatilis RAD., B. armeniacus RAD., B. alboluteus PAL., B. vorticosus GERST., B. mlokosiewitzii RAD., B. incertus MOR., B. persicus RAD. und B. melanurus LEP.

three parallel ridges, covered by humid forests of hyrcanian type, reaching up to 1000 m. They consist of relicts of the tertiary period such as Parrotia persica, Quercus castaniefolia, Albizzia julibrissin, Zelkowa carpinifolia, Pterocarya pterocarpa, Gleditschia caspica, Acer velutinum, Buxus hyrcaniana, Danae racemosa, Ruscus hyrcanianus, Ilex hyrcaniana, Laurocerasus officinalis. The second landscape dominating above 1500 m a. s. l., is a belt of dry steppes with prevalent Astragalus, Akantolimonus, Stachys, Salvia, Thymus, Onobrychis cornuta, Achillea, Euphorbia, Stipa, Eryngium, Scorzonera, Ferula, Prangos, Tanacetum. Small areas of subalpine vegetation also occur. Information for Talysh about distribution of bumble bees (Bombus spp.) in these different landscapes, their trophic relationships and other aspects of ecology is very scarce (Aliev 1980, 1984, Baker 1996, Skhirtladze 1979, whereas the composition of the fauna of 22 species seems quite clear (Aliev 1978). M a t e r i a l a n d m e t h o d s Material for the present paper was collected by the author, A. Bogachev, R. Effendi, P. Kasarjan and E. Selivanchik since 1929 in different landscapes and biotopes in Talysh. Specimens were collected using traditional methods such as sweep-netting and netting of individuals. Trophic relationships were established by the registration of plants on which each bumble bee was recorded feeding and the analysis of pollen of queens and workers. Specimens were determined using the binocular microscope MBS -1. The material is deposited in the Institute of Zoology, Azerbaijan Academy of Sciences.

Bombus mlokosiewitzi Radoszkowski, 1877
Material: Talysh, Tuli 16.07.1936, , leg. A. Bogachev. Distribution: Caucasian sub-endemic, mountain species. Distributed in Transcaucasia and northeastern Turkey (Skorikov 1938, Reinig 1974. Remarks: Occurs at edges of montane decidous forests, in glades of tall grass near the upper edges of the forest, and in subalpine meadows (Aliev 1984). In Talysh it is rare species, found in middle montane forests. Nesting above the ground. Food plants: Cirsium sp.

Bombus silvarum (Linnaeus, 1761)
Material: Talysh, Zuvand 14.06.1980, , leg. Effendi. Distribution: West Palaearctic species occcurring in meadows and steppes. Distributed in South, Central and partly in North Europe, and in Crimea, South Ural, and on islands in the Mediterranean Sea (Skorikov 1938, Panfilov 1957. Remarks: In Azerbaijan it is found in the Lesser Caucasus in montane meadows and glades in oak-ash forests with admixed hawthorn (Aliev 1984). In Talysh it is found in montane steppes. Nest above the ground. Food plants: Carduus sp.

Bombus simulatilis Radoszkowski, 1888
Material: Azerb. SSR, Lerik, Gilidara 27.07.1976, 2 , leg. H. Aliev. Distribution: Caucasian sub-endemic. Reported from Transcaucasia and north-eastern Turkey (Skorikov 1938, Reinig 1974, Aliev 1984. Remarks: Mainly in mountain steppes and meadows. In Azerbaijan it is found in the Lesser Caucasus in montane steppe meadows and in open oak-ash forests mixed with hawthorn and christs-thorn, as well as in subalpine meadows (Aliev 1984). In Talysh it is found in montane steppes. Nest above the ground. Food plants: Eryngium nigromontanum, Salvia sp., Teucrium parviflorum, Echinops sp., Carduus thoermeri. Skorikov, 1935 Material: Talysh, Zuvand 20.05.1980, 5 , leg. R. Effendi Distribution: Nominate subspecies Bombus zonatus zonatus Smith is found in the Balkan Peninsula, southern Moldova and Ukraine, in lower part of Don River, the Caucasus, north-east Turkey and northern Iran (Skorikov 1938). Bombus zonatus apicalis occurs throughout Transcaucasia. Remarks: In Azerbaijan occurs in the Lesser Caucasus, where it is found in foothill steppes, pine stands near lakes, montane decidous forests and gardens of the semi-desert area (Aliev 1984). In Talysh it is found in montane steppe meadows from 1600-2000 m a. s. l. Nesting above the ground.  (Panfilov 1956). Remarks: In Azerbaijan occurs in montane oak-ash forests, mountain meadows and gardens of foothill semi-desert belt of the Lesser Caucasus (Aliev 1980, Aliev 1984. In Talysh it is found in montane steppes and steppe meadows up to 2000 m. Nest above the ground.  (Skorikov 1938, Reinig 1974. Remarks: In Azerbaijan it is found in foothill steppes, low mountain oak-ash forests and montane steppes (Aliev 1984 (Panfilov 1957).

Remarks:
In Azerbaijan it is found in foothill steppes and gardens, low mountain open oak-ash forests, montane deforested areas, covered by meadow vegetation, and mountain steppes in The Lesser Caucasus (Aliev 1984 (Panfilov et al. 1961, Reinig 1974 (Skorikov 1923, Skorikov 1938. Remarks: Steppe species. In Azerbaijan occurs in mountain steppes of the Lesser Caucasus up to 3000 m. In Talysh it is found up to the height of 2400 m. in mountain steppes. Food plants: Scrophularia sp., Trifolium ambiguum.

Bombus pratorum (Linnaeus, 1761)
Material: Azerbaijan, Lerik 16.08.1984, , leg. H. Aliev. Distribution: Europe, Asia Minor, Central Asia, Caucasus (Skorikov 1938, Reinig 1967 . This is apparently due to the strong anthropogenic influence in that area, which results in a decrease of both species diversity and population density. The most important plants visited by bumble bees in these areas, growing mostly in glades and at the edges of forest, are several species of dutch clover (Trifolium), Rubus fruticosus, Albizia julibrissin, Ranunculus, Vicia, Zelkova, Gleditschia caspica, Diospyros kaki, Malus and Pyrus. In the area of dry steppes and steppe meadows with continental climate (with small areas of subalpine vegetation) from 1200 to 2400 m a. s. l., 18 bumble bee species are represented. The majority is endemic to the steppes and higher mountains: Bombus argillaceus, B. simulatilis, B. armeniacus, B. alboluteus, B. vorticosus, B. mlokosiewitzii, B. incertus, B. persicus, B. melanurus. Here bumble bees are trophically related to Astragalus, Acantholimon, Thymus, Eryngium, Cirsium, Salvia and Symphytum. In riverbeds and ravines, where vegetation is more mesophile, bumble bees forage on Chicorium, Mentha, and in the spring on orchard trees. In this area bumble bees nest primarily in the ground, under stones, where they use old burrows of rodents and also other appropriate hollows.