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 one pretty clearly keys to Kogotus, but it also looks fairly different from specimens I caught in the same creek about a month later in the year. With only one species of the genus known in Washington, I'm not sure about the answer to this ID.
Rbpcaddis on Jul 13, 2007July 13th, 2007, 4:54 am EDT
Fishing last Sunday on a spring creek to be left nameless, my buddy and I came to a pool where the trout were slashing and leaping out of the water chasing something. Typical Caddis activity right? We saw no adults on the water. or escaping into the air. Any other bugs that the trout would be chasing like that. This was around 11am to 12:30 pm. We then encountered the same type of action later in the evening around 6 pm to dark. Would the be chasing tiny emerging midge pupa so aggressively/
Seriously, frantic feeding activity likely means the trout were chasing something reasonably elusive. It could have been insects making trial trips toward the surface film, but not actually yet ready to emerge. Some insects will do so for several days prior to emergence.