It's not ringing any bells yet. Hopefully you kept it.
I see what you mean with C.plebejana although the basal patch does not extend to the costa the outer patches look ok. Hope you put it in the freezer Simon. They are in the county even though not shown in S&P.
I've just shown the image to John Langmaid, who says your identification is correct Simon. I won't say what he said about the image quality though...
Thanks Peter. I spent 30 minutes waiting for it to sit still, then it found the one bit of shadow.
Great to get a definite Crocidosema in 46. I IDed one at Arthur Chater's house about 10 years ago but as it was going to be new to the VC and wasn't a species we knew well it went down as a provisional. Arthur searched for larvae subsequently but we never proved the species' occurrence.