1. Troutnut Forum
›
2. Fly Hatch Talk
›
3. Cinygma mayflies

I found a couple small (one or two dozen flies) clouds of these male spinners dancing low over the riffly parts of a pool in this fast river draining out of the Cascades.

This female spinner was collected with a male from the same swarm.

A couple days earlier I caught a male spinner of this species with some wing damage and missing tails, so I went back to the same pool try to get one more intact. This one has some leg damage, but between the two specimens you can get an idea what the whole insect looked like. There were small clouds of Cinygma dimicki spinners again over the same two small, specific locations in the pool, which is an interesting testament to how repeatably they choose their ideal mating habitat. I was able to capture this one and a female.