Osmia bicornis (Red mason bee)♀︎♂︎ Rododendron sp. Last update: 30 November 2019 garden resident Common Location Krimpen aan den IJssel, gardenObservations2019-IV-19 The Red mason bee (Osmia rufa / Osmia bicornis) uses the garden’s Rododendron intensively. The male for nectar… Red mason bee ♂︎ (Osmia bicornis / syn. Osmia rufa) …as well as the female for nectar and pollen. Red mason bee ♀︎ (Osmia bicornis / syn. Osmia rufa)