Heptageniidae and Leptophlebiidae...

Leptophlebiidae (Mahogany)

Heptageniidae and Leptophlebiidae often share the same areas as the torrents, the former in the fastest stretches of the stream, the latter in the slowest stretches. Both hatch at the beginning of the season, but the phenomenon repeats until almost autumn. Fly-fishers know that during hatch the imitation par excellence is the surface nymph because the mature nymphs bring themselves to the surface and pass through, but carry out their metamorphosis anchored to stones or wood emerged from the shore. The Dun are caught sporadically, unlike the Spinner, another stage coveted by fish.

Vogel