The behaviour first caught my attention - several of them were around, and all were doing a side-to-side wiggle as they worked their way along the reed leaves.
No interactions present.
Have you observed the "wiggling" behaviour? I wondered if it was to do with mating, or perhaps defensive (showing off the yellow flashes).
Lat/Lng: 52.4515, -0.1889
OS grid ref: TL231852