This small cuckoo wasp, Trichrysis cyanea [1, 2] is a regular visitor of the bee hotels in the garden. The species is clearly a minority around the other Cuckoo wasp species and often only one specimen at the time is present.



UPDATE 2022/vi/10
Since the previous observation more specimen visit the bee hotels every year and they can be found elsewhere in the garden as well.

Literature
1 Nederlands Soortenregister2 Paukkunen, J., Berg, A., Soon, V., Ødegaard, F., & Rosa, P., 2015. An illustrated key to the cuckoo wasps (Hymenoptera, Chrysididae) of the Nordic and Baltic countries, with description of a new species. ZooKeys, (548), 1.