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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
Baetis

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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Tiny White-Winged Blacks

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

Mayfly Genus Tricorythodes

These are sometimes called Tiny White-Winged Blacks.
A cult following is something to which few insects can lay claim, but the tiny Tricorythodes mayflies certainly qualify. Their widespread, reliable, heavy hatches draw impressive rises of ultra-selective trout which demand the most of a technical dry-fly angler's skills.

It is surprising that such a great hatch took so long to come to the attention of fly fishermen. The Tricos were first introduced to anglers in a 1969 Outdoor Life article by Vincent Marinaro, who misidentified them as Caenis. By the early 1970s the identification had been corrected but Swisher and Richards still wrote in Selective Trout, "Few anglers are familiar with these extremely small but important mayflies." The next wave of publications boosted Tricorythodes to its current fame. I suspect their early dismissal was due in part to tackle limitations; anglers in the 1950s had no means to effectively tie and present size 22-28 flies.
Dorsal view of a Male Tricorythodes (Leptohyphidae) (Trico) Mayfly Dun from Mystery Creek #304 in Idaho
Lateral view of a Female Tricorythodes (Leptohyphidae) (Trico) Mayfly Spinner from the Bitterroot River in Montana
This female Trico was collected with an associated male and many others.
Tricorythodes (Leptohyphidae) (Trico) Mayfly Nymph from Willow Creek in Oregon

Tiny White-Winged Blacks

Scientific Name
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