Osmia

A genus of small but distinctive bees, which take their common name from the nesting habits of the commonest species, Osmia rufa which frequently excavates nest holes in mortar. Other species use a variety of natural crevices, including snail shells. The females carry pollen on brushes underneath the abdomen and visit a wide range of flowers. There are 11 species in the UK, including the two species previously placed in the genus Hoplitis.

Osmia rufa (=bicornis) - Familiar species often found nesting in masonry. Female has obvious 'horns' on head

Osmia spinulosa - note blue spotted eyes, also has orange scopae (obscured by pollen here)