Tiny Baetis mayflies are perhaps the most commonly encountered and imitated by anglers on all American trout streams due to their great abundance, widespread distribution, and trout-friendly emergence habits.
This specimen resembled several others of around the same size and perhaps the same species, which were pretty common in my February sample from the upper Yakima. Unfortunately, I misplaced the specimen before I could get it under a microscope for a definitive ID.
Dewalt on Jun 12, 2013June 12th, 2013, 2:05 pm EDT
Only Stenonema left in North America (after taxonomic revision) is S. femoratum. The underside of the abdomen has rows of roundish dark spots at the lateral margins. This one does not.
Entoman on Jun 12, 2013June 12th, 2013, 2:52 pm EDT
Hi Dewalt -
Welcome to the forum.
This specimen appears to have rounded gills as far as I can tell, and I'm sure Jason had it under a microscope for a better look than shows here. I wasn't aware that sternal maculation was diagnostic for this (now) monotypical genus. What is the source of your information?
"It's not that I find fishing so important, it's just that I find all other endeavors of Man equally unimportant... And not nearly as much fun!" Robert Traver, Anatomy of a Fisherman
Entoman on Jun 12, 2013June 12th, 2013, 3:21 pm EDT
I'm seeing lateral projections on 2 - 9 and rounded gills. I suggest we hold off on speculative posts that will fill this topic up with unnecessary clutter, at least until we hear more from Dewalt on his rationale. I'd sure like him to be able to address the central issue without having to scroll up the topic too far to find it.
"It's not that I find fishing so important, it's just that I find all other endeavors of Man equally unimportant... And not nearly as much fun!" Robert Traver, Anatomy of a Fisherman