The study presents the results of ecological and faunistic research of communities of the wild bees (Hymenoptera, Apoidea) in the urban environment, on the example of Kyiv city. A retrospective analysis of bee communities in Kyiv revealed that 281 species from 42 genera belonging to 6 families were known in the period from 1900 to 1933. The main reason for changes in the species composition of wild bees is a significant reduction of green areas and habitats suitable for wild bees, as well as the transformation of vegetation and, consequently, the reduction of forage resources.
According to the results of current research, 246 species of wild bees from 42 genera belonging to 6 families have been recorded in the city. According to the frequency of occurrence in the general structure of wild bee communities, the absolutely constant species represented only 2% (Evylaeus politus , E. malachurus, Bombus terrestris, B. lucorum, B. lapidarius), the constant species represented 4 % (Сolletes cunicularius , Hylaeus communis, Andrena haemorrhoa, A. minutuloides, A. subopaca , A. flavipes , Heriades truncorum , Anthophora plumipes , Bombus hypnorum, B. pascuorum, the secondary - 19% (46 species) and accidental (75%, or 183 species) categories. The following types of urban environment are distinguished by the occurrence of species: little-altered areas (87 %), parks (48%), botanical garden (60%), and the Dnieper islands (54%). The change in species diversity occurs along the urbanization gradient. There is a gradual decrease in the occurrence of bee species starting with city parks. Thus, 19 species from 13 genera, 5 families (7%) were noted in the residential area, and 21 species from 9 genera and 5 families(8,5%) were found on the territory of railway constructions and adjacent zones. The representation of taxa is the lowest on the roadsides (12 species from 5 genera and 4 families, 5 %), where species of the family Mellittidae do not occur.
In the general ecological structure of wild bee communities of the city and selected types of urban environment, polylectic (47% of species and 80% of individuals), soil-nesting (58% and 75%, respectively) and social species (16% and 42%). Oligolectic bees were represented by a relatively smaller class: 31% of species and 20% of individuals. The kleptoparasites were represented by 22% of all species and 8% of all individuals, and bees that nest in hollows or plant substrate made up 20% of all species and 17% of individuals. In terms of the relative ratio of species belonging to different ecological groups, there was a statistically significant difference in structures of bee communities in different types of urban environment. The ecological communities of bees were most represented in the areas that belong to the “remnants of natural landscapes in the city”. In other types of environment, the ecological structure changed due to the reduction or complete disappearance of oligolectic species and kleptoparasites.
It is established that in the urban the city, wild bees visited more than 170 species of flowering plants from 45 families. As a result of the transformation of vegetation in the urban environment, ornamental plants, fruit trees, as well as ruderal and invasive species serve as an additional feeding resource for bees. The trophic relationships of wild bees have topical features, conditioned by the plant diversity and the proportion of available feeding plants. Among the studied areas, the topical simplification of trophic relationships occurred in the following order: M.M. Hryshko National Botanical Garden > little-altered natural areas> Dnieper islands> city parks> residential areas> railway structures and adjacent areas> roadsides.
The diversity of wild bees increased significantly with increasing diversity of plant communities. The social species were less responsive to plant diversity due to their biological characteristics and broad trophic relationships.
The greatest impact of urbanization was observed on the diversity of kleptoparasite species. It is proved that the diversity of wild bees primarily depended on the combined effect of the diversity of flowering plants and the index of urbanization.
It is established that 70.05% of wild bee species found on the territory of Kyiv, belong to the category “Least concern” according to the European Red List. “Data deficient” species made up 18.22%. The least represented categories were “Endangered” (Colletes nasutus), “Vulnerable” (Colletes fodiens), Systropha planidens, Bombus muscorum), and “Near threatened” (25 species). Four species are listed in the Red Book of Ukraine: Andrena chrysopus, Bombus argillaceus, B. muscorum, and Хylocopa valga.
