I carry with me many emerger patterns.
I think those flies look like sitting ducks to trout. They mimic vulnerable bugs that attempt to rise to the water’s surface. They’re high-percentage snacks.
Most of the takes I’ve had this summer have been on emergers: flies with shucks, materials suggesting air bubbles on their backs, and/or nascent wings. Fishing these flies with an induced take has been effective.
I have a long-time soft spot for the Serendipity. During an epic stay a few years ago on the Upper Madison, this fly accounted for more trout than any other.
The red fly is one of the classic Serendipities. I used elk hair, red thread, silver wire as ribbing, and crystal flash for legs. This one has bells and whistles, like a flashy sports car in Silicon Valley.
We’ll see which fly takes more fish.