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.

---

References

¹ Nederlands Soortenregister

² PAUKKUNEN, Juho, et al. An illustrated key to the cuckoo wasps (Hymenoptera, Chrysididae) of the Nordic and Baltic countries, with description of a new species. ZooKeys, 2015, 548: 1.