The Range of Forage Plants of the Bee Osmia cornuta (Latreille, 1805) (Hymenoptera, Megachilidae) in Donbass

The article presents the results of a long-term study of trophic relationships of the horned mason bee Osmia cornuta (Latreille, 1805) in Donbass. The list of forage plants of this bee in the study area includes at least 50 species from 23 families and 2 classes of angiosperms. Female bees were recorded collecting pollen on 25 plant species from 11 families. Microscopic examination of pollen samples confirmed that bees also collected pollen from the flowers of two anemophilous plant species: Quercus robur L. and Juglans regia L. The greatest share of forage plants (13 species) belongs to the family Rosaceae, and pollen collection on all these species was observed. The peak of nest-building activity in O. cornuta coincided with the blossoming of rosaceous fruit trees. It was shown that after artificially prolonged winter diapause, O. cornuta could successfully pollinate flowers of the alfalfa Medicago sativa L. Six plant species were recorded for the first time as forage plants for the horned mason bee: Cornus mas L., Magonia aquifolium (Pursh) Nutt., Chaenomeles superba (Frahm) Rehd., Nepeta transcaucasica Grossh., Lonicera altaica Pall., and L. edulis Turcz. ex Freyn.