No interactions present.
Not sure about the x90 - there are only 3 Sialis in UK. The early date of this one might suggest lutaria rather than the others, which tend to fly later, but you can really only do them confidently from genitalia.
recording wildlife with The Recorder's Year on www.hbrg.org.uk/TRY.html.
Of the three British Sialis, only S. lutaria usually breeds in still water, the others live in flowing streams and rivers.
And don't panic about the 'genitalia' feature: in male S.lutaria the diagnostic feature is a large projecting flap underneath the tip of the abdomen, easily visible with the naked eye in the field. Google 'Sialis lutaria genitalia' the there's a free download of the Freshwater Biological Association's handbook: see picture on p. 15.
If it helps at all there were many of these insects along the banks of a derelict stretch of canal.
Chris Brooks - www.dragonfly-images.co.uk
My Flickr site - www.flickr.com/photos/ceb1298
The common alderfly S. lutaria is often very abundant for a couple of weeks a year. I'd be very surprised if either of the other two species would breed in numbers in a derelict canal.
Lat/Lng: 51.2, -1.0
OS grid ref: SU7451