No interactions present.
Looks like spores eating away the fly, as in the photo, it's all over the fern to
It is the fungus Entomophthora which is very common as an insect (fatal) pathogen.
recording wildlife with The Recorder's Year on www.hbrg.org.uk/TRY.html.
Thanks M, very helpful
Lat/Lng: 51.81943, -1.38109
OS grid ref: SP427136