Thanks very much for your quick and very informative reply. It caught my eye because of its size, although it could well have been 2cm not 2.5. I very much doubt I would have figured out its identity on my own! Your help is much appreciated.

A. grandis distribution is mostly western U.S. and Canada. One (undated) source says that there is only one record in Quebec. This would seem to favor the A. ladogensis ID, but I cannot see a way to make that determination from the photo.

It is highly unlikely that this is Arctopsyche. As you note, A. grandis is rare in the East, and of the two eastern species, only A. irrorata, confined to the southern highlands, has spotted (irrorate) wings. Most A. ladogensis adults have finished laying their eggs and expired by mid July. The next generation of larvae is pretty big by early September. This looks like any number of morosa group Hydropsyche that I have seen over the years. Arctopsyche also has a broader wing profile.

You are right, Thomas. I was misled by the size estimate (which appears to have missed the mark by a considerable margin) and should have taken a closer look at the photo.

to genus page.

Thanks again for your very informative comments. I don't have any other images so I guess that is as far as it can go! I greatly appreciate the time you put into looking at this.