Hey Paola,
I found the specimen in Hasselt - Diepenbeek. The coordinates are around: N50.934000, E5.411000
It flew in trough my open window and this is where I collected it. But in the grasslands around where I caught it I usually see a lot of Chrysididae as well, but never really managed to capture one on camera for an ID.
Kind regards,
Arne