Mayfly Family Leptophlebiidae (Black Quills and Blue Quills)

I live in Arizona and I have a question...

Over the past several years I have witnessed a spectacular emergence of mayflies on a stream I frequent in the Mogollon Rim area of Arizona. The stream is a tributary to the Little Colorado River drainage.

The adults seem to emerge on exposed midstream rocks of along the shoreline. The duns can be very dense, sometimes every rock along shore has one drying its wings beforetaking flight They are a dark greyish brown bodied, dark grey winged adult, I have named them MOCHA DUNS for lack of knowledge of their true identity. Three tails on the adult as well. They are pretty big....a big size 14 to 16. I have captured several specimens as larvae that I believe are the same species as the ones I have observed as adults. The larvae have prominent gills. 3 long split tails, similar size and color, hign densities along shore and in the shallows, etc. I'm 90% sure that they are Leptophlebiidae. But I don't know the species, yet.

The trout don't seem to key in on the adults...since they emerge on land...but I have experienced some incredible fishing during very windy days while the hatch is on. The nymphs appear to have trouble holding on to the substrates they are trying to emerge on. I have witessed several swimming to a streamside cobble, grasping the rock for a moment, only to be swepped back into the water by small, lapping waves being caused by the wind. They try repeatedly but seem to get exhausted pretty quickly. They must be easy picking for fish cruising along the bank, as I have great success fishing imitations along the shore with short twitches. I have rarely seen duns on the surface of the stream, even on the windiest of days. They seem to emerge late morning to early afternoon.

CAN ANYBODY SUGGEST WHAT SPECIES THIS MAYBE. I don't have a scope or any literature anymore. I have experience with ID'ing but not lately

Any help would be appreciated by this inquisitive angler. Thanks


Jason Mszaros
The Drag Free School of Fly Fishing
928-273-9445

I can't remember where I read or heard these things (might have been on this site), but I want to make sure my vague recollections are not totally false. When Paraleptophlebia are mating, do they make exaggerated dives in clouds above the stream? If so, do they often end up in the water at these times or do they fall as spinners much later? Finally, when they emerge, do they do so at the stream bottom and then swim to the surface as duns?

Thanks for any help,
Shawn

This is one of the species that seem to be prevalent in our area of southwest NC. It emerges in March as I recall and again in October on certain streams. I would like to confirm that this next season.