A male Stelis punctulatissima from the genus Stelis .
Presumably he was looking for a female here. He was hanging around a particular bamboostem in the bee hotel, but no female appeared.
The bees are cleptoparasites on a number of bees, among other the European wool carder bee (Anthidium manicatum) , which is also present in the garden en flies on the bee hotel. Up till now they’ve done that only to rest, I haven’t found a nest in the hotel yet.
References1 Nederlands Soortenregister
2 wildebijen.nl, "De Nederlandse bijen en hun relaties, overzicht van in Nederland en Vlaanderen voorkomende solitaire en sociale bijen (Apidea s.l.)"