Yesterday it was a warm and sunny day; they were eagerly coming out. Last year I though that I only had Osmia cornifrons
at my bee houses but I may have been wrong. This newly emerged one doesn't seem to have horns.
Here is the video
. You can see them breaking the wall, hesitating, stepping outside, doing some stretching exercises and finally taking off. I hope that I have more chances to video this another day; today it is cold and rainy.
This is a view of their house
Another one emerging a few days later
Hymenoptera Anthophila Megachilidae Osmia representative