This intriguing species has received a lot of attention in past angling books. Recent authors suspect that much of this credit was a case of mistaken identity, with Attenella attenuata receiving praise for the hatches of Drunella lata and Dannella simplex. Much of the credit was legitimate and accurate, but this species is no longer thought to be on par with its most popular cousins in Ephemerella and Drunella.
I have several specimens listed under this species, but I'm not positive the identification is correct.
Where & when
Time of year : June through mid-August
This species begins to emerge in Pennsylvania in early June, and good hatches last through early July in the Catskills. In the Upper Midwest it continues into August.
Time of day : Normally 9am to noon, but frequently in the evening during hot weather.
Habitat: Slow water
These mayflies emerge on the bottom of the stream and rise to the surface as fully formed duns. Trout relish the subsurface emergers and are sometimes selective to emergers only. Often they feed on the duns, too, which ride the water for an unusually long time to dry their wings.
Just like Drunella mayflies, Attenella attenuata duns rapidly change color after emerging. They start out bright green and fade into a dull medium olive color. Anglers should imitate the initial color.
These mayflies return as spinners within two days after emerging.
Their spinner falls can provide good action, especially since they're found at a time of year when little else is on the water. The specimens I photographed belong to a hatch whose spinners produced good dusk rises for me several times late one July.
This dun was badly damaged in transport and all its legs fell off, but I photographed it anyway because I wasn't sure I would fine more and it's an interesting species. Luckily I collected better specimens a few days later.