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Little Dark Hendricksons

Mayflies

Caddisflies

Stoneflies

Scientific Names

Match	Scientific Name
	Serratella levis
	Serratella micheneri
	Ephemerella needhami
	Serratella teresa
	Teloganopsis deficiens
	Ephemerella tibialis
	Serratella serrata

Like most common names, "Little Dark Hendrickson" can refer to more than one taxon. They're previewed below, along with 4 specimens. For more detail click through to the scientific names.

Mayfly Species Serratella levis

These are often called Little Dark Hendricksons.

Mayfly Species Serratella micheneri

These are often called Little Dark Hendricksons.

Mayfly Species Ephemerella needhami

These are often called Little Dark Hendricksons.

This small and slightly noteworthy mayfly appears during the finest hours of the year. Ernest Schwiebert describes an Ephemerella needhami day in Matching the Hatch:

"It was a wonderul morning, with a sky of indescribable blue and big, clean-looking cumulus clouds, and the water was sparkling and alive. You have seen the water with that lively look; you have also seen it dead and uninviting in a way that dampens the enthusiasm the moment you wade out into the current."

I have not fished a needhami emergence, but the exquisite nymphs show up often (though never abundantly) in my samples.

Ephemerella needhami (Little Dark Hendrickson) Mayfly Nymph

View 5 PicturesI took quite a few notes at the microscope when I collected this specimen. They're attached to the appropriate pictures.

I found this specimen in the same collection as a similar one. Since I only have strange views of this one, it's possible that they're actually the same specimen and I somehow confused my picture-ordering and got the impression that they're different nymphs.

Collected June 8, 2005 from in
Added to Troutnut.com by on May 26, 2006

Ephemerella needhami (Little Dark Hendrickson) Mayfly Dun

View 7 PicturesSee the comments for an interesting discussion of the identification of this dun.

Collected June 1, 2007 from in
Added to Troutnut.com by on June 4, 2007

See 7 more specimens...

Mayfly Species Serratella teresa

These are often called Little Dark Hendricksons.

Mayfly Species Teloganopsis deficiens

These are sometimes called Little Dark Hendricksons.

Anglers in western Wisconsin, where these little flies hatch in good numbers on summer rivers, have termed them "Darth Vaders" because of the very dark color of their wings.

Until recently, this species was known as Serratella deficiens.

Teloganopsis deficiens (Little Black Quill) Mayfly Nymph

View 6 PicturesThis nymph has tiny, barely detectable tubercles (

A few (not all) of the abdominal tubercles on this Ephemerella needhami nymph are circled. They are especially large in this species.

Tubercle: Various peculiar little bumps or projections on an insect. Their character is important for the identification of many kinds of insects, such as the nymphs of Ephemerellidae mayflies.) on its abdominal segments, and I could not find the maxillary palpi. I have tentatively guessed that it is Serratella deficiens.

Collected June 9, 2005 from in
Added to Troutnut.com by on May 26, 2006

Mayfly Species Ephemerella tibialis

These are sometimes called Little Dark Hendricksons.

Female Ephemerella tibialis (Small Western Dark Hendrickson) Mayfly Dun

View 1 Pictures

Collected September 7, 2007 from in
Added to Troutnut.com by on July 2, 2011

Mayfly Species Serratella serrata

These are very rarely called Little Dark Hendricksons.

This locally important species is rarely mentioned in fly fishing literature, and what little information is given is identical to that for Teloganopsis deficiens. Knopp and Cormier say both species can produce good hatches.

Jargon Defined:

Dun: Mayflies have two adult stages. They first emerge from the water as duns (scientifically known as the subimago stage). They then molt into the spinner (imago) stage, in which they mate and die. Sometimes the word "dun" is confusingly used to refer to a brownish gray color in fly tying materials.

Emergence: The transformation of a nymph or pupa into the adult winged stage of an insect. The term may refer to the emergence of an individual, or the daily or yearly event in which all individuals of a species emerge.

Nymphs: 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).

A few (not all) of the abdominal tubercles on this Ephemerella needhami nymph are circled. They are especially large in this species.

Tubercles: Various peculiar little bumps or projections on an insect. Their character is important for the identification of many kinds of insects, such as the nymphs of Ephemerellidae mayflies.

Useful References:

Knopp, Malcolm and Robert Cormier. 1997. Mayflies: An Angler's Study of Trout Water Ephemeroptera . The Lyons Press.

Schwiebert, Ernest G. 1955. Matching the Hatch. MacMillan Publishing Company.