If you fish the Farmington River, you are familiar with the winter/summer caddis (Dolophilodes distinctus) that hatch nearly all year long. There is a long history of regulars that used to dry fly fish the river almost daily as well. This particular hatch emerges with adult males that are winged, and females that are wingless that skitter across the water to the edge to find a mate. What they lack in size they must make up for in proliferation and taste as the trout never seem to pass these things up.
For the last 25 years I have spent many a day fishing this hatch and trying to refine a pattern that was easier to see and as effective if not more than the original foam emerger. What that fly made up for in its ability to fool fish it significantly lacked in visibility. You simply cannot see it well which detracted from my willingness to fish it as I grew older and my vision wasn't as good.
This pattern sits flush in the film, but the hi-viz parachute post rides high and really sticks out in the foam and film, and some days you can see the wakes of fish chase this one down. Dead drift or twitched this one is hard to beat and you might find that your local tailwater has these as well. On a wide gap Firehole 413 short shanked hook, I fish an 18 most of the time for reference.