Posted by Tony Irwin on 07-10-2011 10:11
#4
Nelson published a paper which might help - Nelson, J.M. 1998 British dung-flies (Dipt., Scathophagidae) associated with stranded seaweed.
Entomologist's Monthly Magazine 134:77-84. In it he describes differences between
Scathophaga calida,
S. litorea and
Ceratinstoma ostiorum eggs, larvae and pupae.
Let me know if you would like a scanned copy.