Green areas of the city (remnants of the natural landscape, parks, squares, etc.) are a refuge for most diverse organisms, include insects too. Such places provide them with fodder and nesting resources under certain conditions. However, as a result of the sanitary measures of a care, the simplification of the vegetation, etc., these places become unattractive to biota, which leads to the reduction of the most common urbotolerant species of insects. In order to preserve and maintain populations of some insect species, artificial nesting structures are installed in the most attractive and safe areas. We studied the trap nest (a set of reed tubes) for insects, which was located on the territory of the botanical garden NUBIP of Ukraine. As a result of the study of 50 separate nests, the species composition of individual groups of the wild bees and wasps inhabiting such nests was described. Measurements of individual nests (diameter and length of the reed tube) were made and it was found that the population of the insects, in particular Osmia bicornis (Linnaeus, 1758) (Apoidea, Megachilidae) and the wasps of the genus Trypoxylon Latreille, 1896 (Crabronidae) is almost 95 % with dominance of O. bicornis (78 %). It was determined that Osmia are not preferred to the nest with tubes of larger diameter or length, but the diameter and length of the reed tubes are positively correlated with the number of the bees larvae in the nest (the correlation coefficients are 0.44 and 0.48, p = 0.05, respectively). The wasps (Trypoxylon sp.) was preferred to the tubes with a diameter of mainly 0.5-0.7 cm (r = 0.56, p = 0.05). In addition, the composition of kleptoparasites, which lead to the death of the bee larvae, was studied. Thus, 20 % of Osmia nests were infected with flies Cacoxenus indagator Loew, 1858 (Diptera, Drosophilidae), and 10 % of the nests contained pollen mite Chaetodactylus osmiae (Dufour, 1839) (Arachnida, Sarcoptiformes).
Changes of avifauna in green areas of Almaty City in the beginning of 21st century
