Urban ornamental plants for sustenance of wild bees (Hymenoptera, Apoidea)

The aim of our study was to assess the attraction and value of flowering plants at green areas in support and sustenance of wild bees (Hymenoptera, Apoidea) populations in Kyiv. Study objects were the most common flowering ornamental plants of the city and the wild bees visiting their inflorescence during the vegetation season to collect pollen and feed on nectar. Study was conducted at 16 areas of observation and material collection, which include urban parks, M. M. Gryshko National Botanical Garden, green spaces of residential areas, roadsides, etc. Insects were collected following the standard method of catching individual specimens during spring and summer periods of 2012–2018. Based on the observations, we visualized trophic relations of bees with plants and calculated the biodiversity index of visiting insects for plants. Periodicity of florescence was analyzed using phenological data. Examination of urban green areas revealed ornamental plants that were the most attractive for bees, including more than 35 taxa of 20 families of trees, shrubs and grassy plants. Bees are superiorly attracted to plants of the genera Rudbeckia, Sedum, Gypsophila, Cerasus, Tagetes, Spiraea, Lonicera, Aesculus. There is a succession of plant flowering during spring-summer season, which must be considered while planting of greenery. Certain plant species attract insects at each period of inflorescence period, for example, Prunus, Rhododendron, Crataegus, Aesculus in spring, most of Asteraceae in summer. The diversity of blossoming plants is significantly lower to the end of summer and beginning of fall, coinciding with the decreasing flight activity of wild bees. Overall, the studied ornamental plants not only attract the most common species of wild bees, but also highly specific and rare species such as Bombus argillaceus and Xylocopa valga, protected by the Red Data Book of Ukraine. We found that blossoming green areas, made up by trees, shrubs and herbs ornamental plants, are important for feeding of many species of wild bees and sustaining their populations in urban conditions.