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Lateral view of a Male Baetis (Baetidae) (Blue-Winged Olive) Mayfly Dun from Mystery Creek #43 in New York
Blue-winged Olives

Tiny Baetis mayflies are perhaps the most commonly encountered and imitated by anglers on all American trout streams due to their great abundance, widespread distribution, and trout-friendly emergence habits.

27" brown trout, my largest ever. It was the sub-dominant fish in its pool. After this, I hooked the bigger one, but I couldn't land it.
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Miniature Blue-Winged Olives

This common name refers to only one genus. Click its scientific name to learn more.

Mayfly Genus Acentrella

These are often called Miniature Blue-Winged Olives.
The only Acentrella species commonly reported to be important to anglers is Acentrella turbida, though Acentrella insignificans is important in some western locales. See the species pages for distribution and timing details. This genus is one of two (including Heterocloeon) that can easily be distinguished from other Baetidae genera by the presence of a conical mesonotal projection. A. turbida lacks hindwings which is useful for distinguishing this species from all others in either genera. A. turbida was previously known by the names of its synonyms Pseudocloeon turbidum in the West and Pseudocloeon carolina in the East.
Female Acentrella (Baetidae) (Tiny Blue-Winged Olive) Mayfly Dun from unknown in Wisconsin
I've lost the date information for this specimen and taken a guess.
Dorsal view of a Male Acentrella insignificans (Baetidae) (Tiny Blue-Winged Olive) Mayfly Nymph from the Yakima River in Washington
Another nymph probably of the same species as this one emerged and was photographed as a dun and partly-molted spinner.

Miniature Blue-Winged Olives

Scientific Name
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