About 15mm long.
No interactions present.
No problem with Nephrotoma.
To identify N. appendiculata, using Alan Stubb's test keys I have to answer Yes to:
1. Is the stigma pale? [I think we can agree it is].
2. Do the sides of the thorax have sharply-defined black markings?
3. On the side of the thorax, just in front of the haltere, is there an inverted black U-marking?
A supporting character is that A. appendiculata has a very broad dorsal black stripe down the abdomen.
Lat/Lng: 51.5, -1.8
OS grid ref: SU1987