Osmia (Osmia) rufa | Red Mason Bee



Conservation status

Not evaluated - possible deliberate introduction (for use as a pollinator)

Species Biology


  • This species is now called Osmia bicornis
  • Large sized solitary species (10-14mm)
  • Chunky in appearance
  • Hairy bee, hairs on the abdomen are more ginger than those on the thorax, which are a mix of grey/ginger and black
  • Females have two small black horns projecting outwards from the face
  • Males are generally smaller and have white hair on the face


First recorded from Ireland in 2003. Known only from Belfast, Dublin and Cork cities. Likely to be a deliberate introduction

Flight period


Nesting biology

Cavity nesting

Flowers visited

Polylectic - Acer, Ilex, Carpinus, Echium, Symphtum, Brassica, Sinapis, Stellaria, Helianthemum, Hippocrepis, Onobrychis, Trifolium, Quercus, Lamium, Ajuga, Salvia, Papaver, Plantago, Ranunculus, Reseda, Prunus, Crataegus


World distribution(GBIF)

All of Europe and North Africa, inlcuding Denmark, southern Sweden, England, the Iberian peninsula, Sardinia and Corsica

Temporal change

Records submitted to Data Centre in 2021

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Conservation status: FitzPatrick Ú., Murray T.E., Byrne A., Paxton R.J., Brown M.J.F. (2006) Regional Red List of Irish Bees, Publ. Rep. to National Parks and Wildlife Service (Ireland) and Environment and Heritage Service (N. Ireland).

Flowers visited & World distribution: Westrich, P. (1989) Die Wildbienen Baden-Württembergs. Eugen Ulmer, Stuttgart, Germany.