No interactions present.
It is possibly that this individual had emerged from the larval case you saw, but it had not only just emerged - this one will be 4 or 5 days old at least (the males are yellow when they emerge and take up to about 10 days before they become fully red.
Thank you, that is very useful information which I haven't seen elsewhere.
I can see several large larval cases at the base of plants in my pond currently, and will be waiting with interest to see what is flying!
Lat/Lng: 52.0, -1.5
OS grid ref: SP3937