Yes it is Hedychrum sp. (I would even say H. gerstaeckeri from the jizz and also because they like very much Achillea millefolium, but impossible to confirm by your pictures). Cheers
I have more photos so I can check them out. Which characteristics would be relevant for an identification of this cuckoo wasp? Maybe I have the right photos.
Hello Anja, I think from the coarse punctation on T3 and the mandibles, you might be right but maybe someone else could confirm you. I use to check the mesotibial groove as it is (I think) a more reliable feature. But it's tiny and of course, you need to catch the wasp and have a magnifying glass...
... I photographed this wasp in our garden in July. I assume it is Hedychrumgerstaeckeri. It has no prongs at the end of the tergite, the 3rd tergite with projecting angles. ...
Looks like a Hedychrum species. However, I am only a beginner with these, so you should wait for an expert opinion! I do not know which species, perhaps gerstaeckeri? Brian
:welcome: Nick! Well your ID is correct, I can't say anything else. Usually the smallest specimens belong to H. niemelai , but occasionally also gerstaeckeri males are small. The question on hairs is only for sex ID, if they are erected, then they are males (nobile, niemelai, gerstaeckeri ), if ...