Lemon Yellow Face*

My image is of one of the tiniest bees I have ever photographed. It is on rough chervil. This plant is similar to cow parsley but it flowers later and doesn't grow as tall.

This is one of the yellow-faced Hylaeus bees but I'm afraid I don't know which species. Twelve of these are found in the UK. These bees collect pollen in their crops and regurgitate it into their nest cells. I've added another Hylaeus to extras. It's on hogweed. Some of these bees have white faces.

*Evidently these bees smell like lemons.