Wing length approximately 6mm
No interactions present.
David, I've looked hard at Maitland and Langmaid (I guess you have too) and the script for S gemmella seems to be the only one to fire, right down to the two bands on the palps. Clearly range isn't an issue either. B.
My friendly expert Rachel Terry has examined this specimen and agrees with this ID too.
Lat/Lng: 51.5, -0.4
OS grid ref: TQ1684