Small <1cm fly. Interesting colouration.
No interactions present.
A Tachinid fly fairly closely related to Phasia (=Alophora - old name) hemiptera, so the shape is similar. Also a parasite of shield bugs. This fly had a odd, restricted distribution on Britan, but now seems to be spreading slightly. For more info see http://tachinidae.org.uk/site/get-species.php?brcno=11402. Nice record, I will add it to the Recording Scheme Database.
Tachinid Recording Scheme
TRS Facebook Page
Lat/Lng: 51.408686180982, -0.08190929889679
OS grid ref: TQ334694