Brachyptera risi - a sawfly, c 10mm (thnaks for the ID JS).
Lovely broods of Shoveler on The Shunan, a 9 and an 11, totally brilliant.
I'm a week out of date posting here, where are the flies and the beetles?
Here is a very tiny soldier beetle found in the previously mentioned bath tubs a week later, Rhagonycha limbata. I was chuffed to id this correctly and have now found a new key here https://drive.google.com/file/d/0B008cp9g-Pm8a3pET1BfejFERm8/view
This is a very common but nonetheless lovely thing easy to find at the moment.
Gastrophysa viridula (Green Dock Beetle, a Chrysomelid)
And as for the flies,
Argyra sp, male top female bottom (Dolichopidae)
Beris chalybata - a soldier fly (thanks to DD for these IDs)
Helophilus hybridus, more in my realm, a hoverfly
Quite a distinctive Empid, Empis stercorea