This female Eustalomyia hilaris [1] inspected nest holes on the bee hotels. She is a parasite on among others diggerwasps. From that hostgroup at least Trypoxylon and Ectemnius nest in the nest blocks.

Literature
1 Nederlands SoortenregisterBee hotel
Eustalomyia hilaris♀︎
This female Eustalomyia hilaris [1] inspected nest holes on the bee hotels. She is a parasite on among others diggerwasps. From that hostgroup at least Trypoxylon and Ectemnius nest in the nest blocks.
Literature
1 Nederlands Soortenregister