Bee species on -wooden- bee posts

[Africa]

We set up a bee post yesterday and just over 24 hours later we've seen male and female Osmia rufa inspecting holes. I predict lots of post watching - when not post reading - this season. Other than O. rufa, what other species should we expect to see? The post is on an ash branch, with drilled holes less than 10 mm diameter, south facing.

[eucera]

In Yorkshire you might be a little more limited than down in southern England.

However, Osmia caerulescens and O. leaiana are possibilities. You'd possibly get things like Chelostoma florisomne and maybe even C. campanularum if you are lucky. You may also find some crabronid wasps too, and possibly Eumenids as well.

Good observing!

[Africa]

Thanks Eucera, I'll keep my eyes open for these.