Last May the female bee took over this old screw hole for a trellis and laid a series of eggs, each in its own compartment provisioned with pollen and nectar and walled off from the next by mud brought in from nearby.
The female has two horns on her face to help with moving the mud, hence the name Osmia bicornis (previously Osmia rufa).
This is the male, with longer antennae and a narrower waist, looking for a mate.
Not a great photo but here is the female bringing in a mouthful of mud to seal the hole.
and here is the hole as she left it.
This year I am hoping to tempt the solitary bees (including red mason bees in spring and leaf-cutter bees and others in summer) to take up residence in this purpose built solitary bee house.
This compartment contains a drilled out log (8mm holes) and raspberry canes.
This one contains a variety of plant stems and grass stems of different diameters.
This contains a small log and drilled out bamboo canes.
This one has a larger log with holes of various sizes and other plant stems.
On the side I have made a perspex-sided observation site with 8mm grooves where I hope to be able to photograph the bees.
This is a separate small bee house containing tubes of rolled up brown paper.
It will be interesting to see if the bees take to these houses. The red mason bees should emerge in the next few days. Last year they caught me by surprise but this year I am ready for them.