@movq@www.uninformativ.de Oh, really!? You should come visit. :-)
As far as I know females are sitting in the shrubs and males fly around, but they’re not all that quick. They are slowly moving glowing dots that you can easily follow with your eyes. The bigger problem might be that they turn off and then on again. So, one could count duplicates. However, there’s typically a bit of distance between them (at least 30-50 cm I’d say, often more). Counting the same individual multiple times is not all that common (assuming that they don’t speed up when turned off). My counting was also conservative I believe.
Ah, Die Maus also covered them a few days ago: https://www.youtube.com/watch?v=OVGD5QEvtoc At the end, there’s a video were you can see the speeds a bit.