Dark Gray-Winged Olive Duns

Mayflies

Caddisflies

Stoneflies

Scientific Name

Match	Scientific Name
	Baetis flavistriga

This common name refers to only one species.

Mayfly Species Baetis flavistriga

These are very rarely called Dark Gray-Winged Olive Duns.

This is one of the most widespread and abundant Baetis species, and it may produce fishable hatches under a variety of conditions.

This species is known in angling books by several old synonyms (Synonym: A former name of a taxon, usually a species. Entomologists frequently discover that two insects originally described as different species are one in the same, and they drop one of the names. The dropped name is said to be a synonym of the remaining name. These changes take a while to trickle into the common knowledge of anglers; for example, Baetis vagans is now a synonym of Baetis tricaudatus.), including Baetis quebecensus, Baetis levitans, Baetis cingulatus, and Baetis phoebus, in addition to the correct name.

Male Baetis flavistriga (BWO) Mayfly Nymph

View 8 PicturesThis nymph keys to Baetis assuming the villipore is present (hard to see in my photos or scope), and within that genus it tentatively keys to the flavistriga species complex, of which Baetis flavistriga itself is by far the most common in Washington state, so that's the most likely ID.

Collected July 6, 2020 from in
Added to Troutnut.com by on July 12, 2020

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Jargon Defined:

Nymph: The juvenile, underwater stages of mayflies, stoneflies, dragonflies, and damselflies and other aquatic insects whose juvenile stages are covered by hard exoskeletons. The word can also refer to the fishing flies which imitate these creatures, in which case it is used as a blanket term for flies imitating any underwater stage of an invertebrate (except for crayfish and leeches).

Synonyms: A former name of a taxon, usually a species. Entomologists frequently discover that two insects originally described as different species are one in the same, and they drop one of the names. The dropped name is said to be a synonym of the remaining name. These changes take a while to trickle into the common knowledge of anglers; for example, Baetis vagans is now a synonym of Baetis tricaudatus.