This insect was startlingly un-affected by our 'fussing' round it to take the photos.
No interactions present.
David is quite correct to point out that there are two species of Emmelina, but since one of these (E. argoteles) has so far been found from only one wetland site in East Anglia I would say that this one is at least 99.9% likely to be Emmelina monodactyla! If E. argoteles starts being found in new places I'll have to change my opinion of course, but until then ...
Entomologist and biological recorder
Lat/Lng: 51.2, -2.4
OS grid ref: ST7747