Overnight catch in a MBTV light trap. 1 of these caught.
No interactions present.
You might like to look at Grey Dagger Acronicta psi it may be another possibility as you can just make out some mottling. It flies between June & August. Though this image does look to be darker than what I would expect.
Lat/Lng: 51.2, -0.9
OS grid ref: SU8249