Osmia cornuta (Hymenoptera, Megachilidae) as a pollinator of pear (Pyrus communis): fruit- and seed-set Bettina Maccagnani, Edith Ladurner, Fabrizio Santi and Giovanni BurgioApidologie, 34 3 (2003) 207-216DOI: https://doi.org/10.1051/apido:2003009