No interactions present.
Sylvicola ID inspired by Key at http://www.online-keys.net/infusions/keys/keys_view.php?key_no=1 and photos on-line eg those at http://www.pbase.com/tmurray74/gnats_anisopodidae. I think this was probably S fenestralis but the Key suggests other possible species from which it could only be separated by microscopic examination.
There are more nice photos on this French site: http://aramel.free.fr/INSECTES15'.shtml
Lat/Lng: 52.061168, 1.159024
OS grid ref: TM166450