They are a few similar species which require microscopic exam to be specific it is likely S lutaria but could others requiring close inspection eg Sialis fuliginosa hence confidence limit
No interactions present.
It's best to leave the 'spp' (which is plural, anyway) off, as most sightings don't have it. Without it, other pics of Alderflies will appear.
My Flickr photos...
I think you will find that if the Observation is agreed with then the carousel Loads even with Spp in the context of the notes below of which ther abot 6-8 potential candidates with varing characteristics in that genus
"Abbreviated names Books and articles sometimes intentionally do not identify species fully and use the abbreviation "sp." in the singular or "spp." in the plural in place of the specific epithet: for example, Canis sp. This commonly occurs in the following types of situations:
The authors are confident that some individuals belong to a particular genus but are not sure to which exact species they belong. This is particularly common in paleontology.
The authors use "spp." as a short way of saying that something applies to many species within a genus, but do not wish to say that it applies to all species within that genus. If scientists mean that something applies to all species within a genus, they use the genus name without the specific epithet.
In books and articles, genus and species names are usually printed in italics. If using "sp." and "spp.", these should not be italicized.
The carousel in any case seems to load sp and spp in any case and probably the Genus as well in the context of the observation made if this notation is sufficiently used
Whats Happening with Nature ??? Visit the Nature Blog
Supporting FEET Conservation work & Biodiversity Recording
Your example of the Syrphus only works because more than one person has entered Syrphus spp as an ID!
You should use sp. for a sighting of one animal in a species, as in the picture you present of a Sialis. If there were more than one Sialis species in the picture, you would use spp..
Irrespective of that, if you left sp. or spp. off, and just had Sialis, you would find that there were lots of other pics of the same, whereas there are none, at the moment. I always think it is a good idea to use the simple form and so get the extra pictures, which helps people (me included!) to compare the sighting against other pics.
Keep smiling! ;)
Lat/Lng: 53.6, -1.8
OS grid ref: SE1322