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Identification needs

This page includes an automated list of specimens in need of more detailed identification. Because my academic specialty is salmonid behavior and I'm not an entomologist by training, I can only partially keep up with accurately identifying all the invertebrates I collect. I haven't had time to develop the at-a-glance familiarity experts have with many western species, and keying them out is often time-consuming or impossible from photographs, even with all the closeups I take. So I still rely on the generous volunteer help of more experienced entomologists to keep up with specific IDs. This page is intended to facilitate that help and prevent specimens from falling through the cracks.


If you can help with an improved ID on any of the specimens listed, please comment on the specimen page or shoot me an email at jason@troutnut.com with the specimen ID number (visible in its URL) and identification. If you can provide the rationale for the identification in a public comment, so others can learn more from it, that's ideal -- but feel free to just drop the name if you're busy and you're somebody I already know and trust to get it right.


Each list is prioritized with the specimens most recently added to the site appearing first, regardless of collection date.

Specimens unidentified to family

Mayflies unidentified to family

None. All caught up on these.

Caddisflies unidentified to family

Trichoptera (Caddisflies) Caddisfly AdultTrichoptera (Caddisflies) Insect Adult View 8 Pictures
Collected July 8, 2019 from the Ruby River in Montana
Added to Troutnut.com by Troutnut on July 18, 2019
Male Trichoptera (Caddisflies) Caddisfly AdultMale Trichoptera (Caddisflies) Insect Adult View 8 PicturesThis specimen was one of tens of thousands we saw on a July 1st evening on the Madison, beginning with big swarms around every vehicle and tree at the Eight Mile Ford access point and continuing all up and down the river bank. We somehow didn't catch any trout, perhaps because they were stuffed with pupae from when these things emerged. Or maybe we just weren't fishing well. Either way, this one represents a major hatch there.

I somehow forgot to photograph this important specimen against the hooks size chart, but fortunately I preserved a few. The body length is about 6 mm, and total length from head to wingtip is 9 mm.
Collected July 1, 2019 from the Madison River in Montana
Added to Troutnut.com by Troutnut on July 18, 2019
Trichoptera (Caddisflies) Caddisfly AdultTrichoptera (Caddisflies) Insect Adult View 6 Pictures
Collected June 30, 2019 from the Madison River in Montana
Added to Troutnut.com by Troutnut on July 17, 2019
Trichoptera (Caddisflies) Caddisfly AdultTrichoptera (Caddisflies) Insect Adult View 11 Pictures
Collected June 30, 2019 from the Madison River in Montana
Added to Troutnut.com by Troutnut on July 17, 2019

Stoneflies unidentified to family

None. All caught up on these.

Diptera (true flies) unidentified to family

None. All caught up on these.

Specimens unidentified to genus

Mayflies unidentified to genus

Female Baetidae (Blue-Winged Olives) Mayfly DunFemale Baetidae (Blue-Winged Olives) Mayfly Dun View 5 PicturesI captured this dun on the same night as a spinner which is probably of the same species.
Collected August 9, 2006 from the West Branch of Owego Creek in New York
Added to Troutnut.com by Troutnut on August 11, 2006
Female Baetidae (Blue-Winged Olives) Mayfly SpinnerFemale Baetidae (Blue-Winged Olives) Mayfly Spinner View 8 PicturesThis is one of the smallest mayflies I've ever collected, about 3mm long.
Collected August 9, 2006 from the West Branch of Owego Creek in New York
Added to Troutnut.com by Troutnut on August 11, 2006
Female Baetidae (Blue-Winged Olives) Mayfly SpinnerFemale Baetidae (Blue-Winged Olives) Mayfly Spinner View 12 PicturesThis species is probably in Centroptilum, Cloeon, or Procloeon. I captured this spinner on the same night as a dun which is probably of the same species.
Collected August 9, 2006 from the West Branch of Owego Creek in New York
Added to Troutnut.com by Troutnut on August 11, 2006
Female Heptageniidae (March Browns, Cahills, Quill Gordons) Mayfly DunFemale Heptageniidae (March Browns, Cahills, Quill Gordons) Mayfly Dun View 10 PicturesThis specimen is really strange, very different in form from any other mayfly I've seen. Unfortunately it was found alone crippled in an eddy and in pretty bad shape, and I couldn't find any others like it.
Collected June 28, 2005 from the Long Lake Branch of the White River in Wisconsin
Added to Troutnut.com by Troutnut on May 26, 2006
Male Baetidae (Blue-Winged Olives) Mayfly NymphMale Baetidae (Blue-Winged Olives) Mayfly Nymph View 10 PicturesThis male nymph is probably in its final instar (Instar: Many invertebrates molt through dozens of progressively larger and better-developed stages as they grow. Each of these stages is known as an instar. Hard-bodied nymphs typically molt through more instars than soft-bodied larvae.). The wing pads (
The wing pads on this final instar Baetidae mayfly nymph are extremely dark.
The wing pads on this final instar Baetidae mayfly nymph are extremely dark.
Wing pad: A protrusion from the thorax of an insect nymph which holds the developing wings. Black wing pads usually indicate that the nymph is nearly ready to emerge into an adult.
)
are extremely black and the large turbinate (
This male Baetidae dun has slightly turbinate eyes.
This male Baetidae dun has slightly turbinate eyes.
Turbinate: Shaped like a top or elevated on a stalk; usually refers to the eyes of some adult male Baetidae mayflies which are wider near the tip than at the base.
)
eyes are very apparent inside the nymph's head.
Collected June 9, 2005 from the Bois Brule River in Wisconsin
Added to Troutnut.com by Troutnut on May 26, 2006
Female Baetidae (Blue-Winged Olives) Mayfly DunFemale Baetidae (Blue-Winged Olives) Mayfly Dun View 4 PicturesThis specimen was collected on the same trip as a similar dun.
Collected May 28, 2005 from the Namekagon River in Wisconsin
Added to Troutnut.com by Troutnut on May 24, 2006
Female Baetidae (Blue-Winged Olives) Mayfly DunFemale Baetidae (Blue-Winged Olives) Mayfly Dun View 7 PicturesThis specimen was collected on the same trip as a similar dun.
Collected May 28, 2005 from the Namekagon River in Wisconsin
Added to Troutnut.com by Troutnut on May 24, 2006
Female Ephemerellidae (Hendricksons, Sulphurs, PMDs, BWOs) Mayfly SpinnerFemale Ephemerellidae (Hendricksons, Sulphurs, PMDs, BWOs) Mayfly Spinner View 6 PicturesI'm not sure of the species of this female spinner, and unfortunately I never found the associated males or duns to aid in identification. The egg-laying flight and fall of fairly large clouds of these females caused good rises of choosy trout for a week or so around early July on a large, cold spring creek in the northwoods. There is a distinctive stripe down the female's back, identical to that on this specimen collected a month later.
Collected July 1, 2005 from the Bois Brule River in Wisconsin
Added to Troutnut.com by Troutnut on April 22, 2006
Female Ephemerellidae (Hendricksons, Sulphurs, PMDs, BWOs) Mayfly DunFemale Ephemerellidae (Hendricksons, Sulphurs, PMDs, BWOs) Mayfly Dun View 5 PicturesI found this little dun floating down the water's surface stuck in her nymphal shuck (
Here's an underwater view of the pupal shucks of several already-emerged Brachycentrus numerosus caddisflies.
Here's an underwater view of the pupal shucks of several already-emerged Brachycentrus numerosus caddisflies.
Shuck: The shed exoskeleton left over when an insect molts into its next stage or instar. Most often it describes the last nymphal or pupal skin exited during emergence into a winged adult.
)
. Such stillborn (
This stillborn Ephemerella subvaria dun is trapped in its shuck.
This stillborn Ephemerella subvaria dun is trapped in its shuck.
Stillborn: In fly fishing, a stillborn insect is one which got stuck in its nymphal or pupal shuck during emergence and floats helplessly on the surface instead of flying away. It is a specific class of cripple, although it is sometimes used interchangeably with that term.
)
insects are sometiems targeted by the trout. I brought this one home to photograph since it's a species I don't have yet, but I haven't figured out which one.
Collected July 1, 2005 from the Bois Brule River in Wisconsin
Added to Troutnut.com by Troutnut on April 22, 2006
Female Ephemerellidae (Hendricksons, Sulphurs, PMDs, BWOs) Mayfly SpinnerFemale Ephemerellidae (Hendricksons, Sulphurs, PMDs, BWOs) Mayfly Spinner View 7 PicturesThis Ephemerellidae spinner was emerging unusually late, and on a warm stream. Since it's a female, identification is difficult. Her identical coloration suggests she's probably of the same species as this specimen collected on a cool trout stream almost a month earlier.
Collected July 28, 2005 from the West Fork of the Chippewa River in Wisconsin
Added to Troutnut.com by Troutnut on April 14, 2006

Caddisflies unidentified to genus

Leptoceridae Caddisfly AdultLeptoceridae  Caddisfly Adult View 7 Pictures
Collected June 30, 2019 from the Madison River in Montana
Added to Troutnut.com by Troutnut on July 17, 2019
Male Leptoceridae Caddisfly AdultMale Leptoceridae  Caddisfly Adult View 6 Pictures
Collected June 30, 2019 from the Madison River in Montana
Added to Troutnut.com by Troutnut on July 17, 2019
Male Leptoceridae Caddisfly AdultMale Leptoceridae  Caddisfly Adult View 12 Pictures
Collected June 29, 2019 from the Madison River in Montana
Added to Troutnut.com by Troutnut on July 17, 2019
Hydropsychidae Caddisfly AdultHydropsychidae  Caddisfly Adult View 2 PicturesThese specimens are either Cheumatopsyche or Hydropsyche. They escaped before I could catch them.I suspect, based on size, they are Hydropsyche, they are about 1/4 inch in length. Both H. occidentalis and H. californica are common in the Touchet River.
Collected July 27, 2011 from the Touchet River in Washington
Added to Troutnut.com by Bnewell on July 29, 2011
Hydropsychidae Caddisfly LarvaHydropsychidae  Caddisfly Larva View 5 PicturesThis is one of the most vividly green Hydropsychidae larvae I've caught.
Collected May 6, 2007 from Mongaup Creek in New York
Added to Troutnut.com by Troutnut on May 18, 2007
Hydropsychidae Caddisfly LarvaHydropsychidae  Caddisfly Larva View 2 Pictures
Collected March 13, 2005 from Cascadilla Creek in New York
Added to Troutnut.com by Troutnut on April 5, 2006
Philopotamidae Caddisfly LarvaPhilopotamidae  Caddisfly Larva View 2 Pictures
Collected March 13, 2005 from Cascadilla Creek in New York
Added to Troutnut.com by Troutnut on April 5, 2006

Stoneflies unidentified to genus

Perlidae (Golden Stones) Stonefly NymphPerlidae (Golden Stones) Stonefly Nymph View 2 PicturesThis is a nymph that has recently molted thus has not yet acquired its normal coloration.
Collected June 15, 2010 from the Flathead River-upper in Montana
Added to Troutnut.com by Bnewell on June 26, 2011
Chloroperlidae (Sallflies) Stonefly NymphChloroperlidae (Sallflies) Stonefly Nymph View 7 Pictures
Collected May 10, 2008 from the Chena River in Alaska
Added to Troutnut.com by Troutnut on April 20, 2011
Peltoperlidae (Roachflies) Stonefly AdultPeltoperlidae (Roachflies) Stonefly Adult View 5 PicturesThe adult stoneflies of this family look surprisingly normal given the strange shape of the nymphs.
Collected May 28, 2007 from Mystery Creek #42 in Pennsylvania
Added to Troutnut.com by Troutnut on June 4, 2007
Capniidae (Snowflies) Stonefly AdultCapniidae (Snowflies) Stonefly Adult View 3 PicturesThis drowned Capniidae adult showed up in my drift net sample while I was looking for nymphs. I took photos of the drowned adult in water like a nymph.
Collected March 29, 2005 from Salmon Creek in New York
Added to Troutnut.com by Troutnut on April 7, 2006

Specimens of select taxa unidentified to species

Ephemerella mayflies unidentified to species

Ephemerella (Hendricksons, Sulphurs, PMDs) Mayfly NymphEphemerella (Hendricksons, Sulphurs, PMDs) Mayfly Nymph View 2 PicturesEphemerella is a very common genus of mayfly in Montana but nymphs are difficult to identify to species.
Collected June 12, 2007 from Rock Creek in Montana
Added to Troutnut.com by Bnewell on June 26, 2011
Female Ephemerella (Hendricksons, Sulphurs, PMDs) Mayfly SpinnerFemale Ephemerella (Hendricksons, Sulphurs, PMDs) Mayfly Spinner View 8 PicturesI've seen Ephemerella invaria with green egg sacs and Ephemerella subvaria with yellow one. This one seems too large for dorothea. So what is it? I'm not sure.

Many females of this species were gathered in tight clouds to lay their eggs over the riffles in a mid-sized Pocono stream right at dusk. It would have been a fishable spinner fall if I'd stuck around to wait for them.
Collected May 28, 2007 from Mystery Creek #42 in Pennsylvania
Added to Troutnut.com by Troutnut on June 4, 2007
Ephemerella (Hendricksons, Sulphurs, PMDs) Mayfly NymphEphemerella (Hendricksons, Sulphurs, PMDs) Mayfly Nymph View 5 PicturesThe striking coloration of this Ephemerella nymph earned it a turn under the camera lens. It has a different look than others I've collected, but I still might tentatively guess it belongs to the widely variable (and ironically named) invaria species.
Collected April 14, 2007 from Cayuta Creek in New York
Added to Troutnut.com by Troutnut on April 22, 2007
Ephemerella (Hendricksons, Sulphurs, PMDs) Mayfly NymphEphemerella (Hendricksons, Sulphurs, PMDs) Mayfly Nymph View 2 PicturesI 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 the Namekagon River in Wisconsin
Added to Troutnut.com by Troutnut on May 26, 2006

Drunella mayflies unidentified to species

Male Drunella (Blue-Winged Olives) Mayfly DunMale Drunella (Blue-Winged Olives) Mayfly Dun View 3 Pictures
Collected July 7, 2019 from the Ruby River in Montana
Added to Troutnut.com by Troutnut on July 18, 2019

Paraleptophlebia mayflies unidentified to species

Female Paraleptophlebia (Blue Quills and Mahogany Duns) Mayfly DunFemale Paraleptophlebia (Blue Quills and Mahogany Duns) Mayfly Dun View 5 PicturesI hadn't seen an intact adult mayfly to catch all day, when suddenly I saw this Paraleptophlebia dun flying six inches in front of my face and nabbed it with my hand without even thinking. It has some sort of bright debris on it that probably comes from placing it in a transport container that hadn't been cleaned recently enough.
Collected July 28, 2019 from Mystery Creek #250 in Washington
Added to Troutnut.com by Troutnut on July 29, 2019
Female Paraleptophlebia (Blue Quills and Mahogany Duns) Mayfly SpinnerFemale Paraleptophlebia (Blue Quills and Mahogany Duns) Mayfly Spinner View 1 PicturesThis female is probably P. heteronea or P. memorialis since these are the two species collected during the last two weeks. It is interesting that the females are this very dark brown color while the males are lighter in color.
Collected June 29, 2011 from the Touchet River in Washington
Added to Troutnut.com by Bnewell on June 29, 2011
Female Paraleptophlebia (Blue Quills and Mahogany Duns) Mayfly AdultFemale Paraleptophlebia (Blue Quills and Mahogany Duns) Mayfly Adult View 1 PicturesThis female exhibits the dark chocolate color so common in this genus.
Collected June 5, 2011 from the Touchet River in Washington
Added to Troutnut.com by Bnewell on June 26, 2011
Male Paraleptophlebia (Blue Quills and Mahogany Duns) Mayfly SpinnerMale Paraleptophlebia (Blue Quills and Mahogany Duns) Mayfly Spinner View 1 PicturesNear P. memorialis.
Collected June 15, 2011 from the Touchet River in Washington
Added to Troutnut.com by Bnewell on June 26, 2011
Male Paraleptophlebia (Blue Quills and Mahogany Duns) Mayfly SpinnerMale Paraleptophlebia (Blue Quills and Mahogany Duns) Mayfly Spinner View 15 PicturesI wasn't actually fishing the river where I caught this one. I was just scouting, didn't like the look of the water, and as I was walking back to the car this little dun landed on my vest. Why can't they all be so easy to collect?
Collected September 8, 2006 from the East Branch of the Delaware River in New York
Added to Troutnut.com by Troutnut on October 4, 2006
Female Paraleptophlebia (Blue Quills and Mahogany Duns) Mayfly DunFemale Paraleptophlebia (Blue Quills and Mahogany Duns) Mayfly Dun View 4 PicturesI really hoped to catch some good blue quill specimens on this trip, but they are very fragile mayflies and this one was in the best condition of the few that I caught after I drove them home to my camera. It may not be pretty, but you get an idea of the size/shape/color anyway.
Collected April 19, 2006 from the Beaverkill River in New York
Added to Troutnut.com by Troutnut on April 21, 2006

Siphlonurus mayflies unidentified to species

Rhithrogena mayflies unidentified to species

Male Rhithrogena Mayfly SpinnerMale Rhithrogena  Mayfly Spinner View 14 Pictures
Collected July 8, 2019 from the Ruby River in Montana
Added to Troutnut.com by Troutnut on July 18, 2019
Female Rhithrogena Mayfly SpinnerFemale Rhithrogena  Mayfly Spinner View 3 Pictures
Collected July 2, 2019 from the Gallatin River in Montana
Added to Troutnut.com by Troutnut on July 18, 2019
Male Rhithrogena Mayfly SpinnerMale Rhithrogena  Mayfly Spinner View 11 PicturesThis male was collected at the same time as this female and is likely the same species.
Collected July 1, 2019 from the Madison River in Montana
Added to Troutnut.com by Troutnut on July 18, 2019
Female Rhithrogena Mayfly SpinnerFemale Rhithrogena  Mayfly Spinner View 5 PicturesThis one was collected at the same time as this male and is likely the same species.
Collected July 1, 2019 from the Madison River in Montana
Added to Troutnut.com by Troutnut on July 17, 2019
Female Rhithrogena Mayfly SpinnerFemale Rhithrogena  Mayfly Spinner View 1 Pictures
Collected July 9, 2011 from the Touchet River in Washington
Added to Troutnut.com by Bnewell on July 10, 2011
Rhithrogena Mayfly NymphRhithrogena  Mayfly Nymph View 1 Pictures
Collected May 12, 2005 from Hungry Horse Creek in Montana
Added to Troutnut.com by Bnewell on June 28, 2011
Rhithrogena Mayfly NymphRhithrogena  Mayfly Nymph View 1 PicturesBased on the lack of coloration and the two bars on the last tergite (
One tergite of this Isonychia bicolor mayfly spinner is highlighted in red.
One tergite of this Isonychia bicolor mayfly spinner is highlighted in red.
Tergite: The top (dorsal) part of a single segment on an insect's abdomen when it consists of a single chitinous plate (sclerite), or an individual sclerite if the segment has more than one.
)
this may be Rhithrogena virilis.
Collected May 12, 2005 from Hungry Horse Creek in Montana
Added to Troutnut.com by Bnewell on June 28, 2011
Male Rhithrogena Mayfly DunMale Rhithrogena  Mayfly Dun View 2 Pictures
Collected May 27, 2005 from the Vermillion River in Montana
Added to Troutnut.com by Bnewell on June 28, 2011
Rhithrogena Mayfly NymphRhithrogena  Mayfly Nymph View 1 PicturesNote the unusual red coloration of these Rhithrogena nymphs.
Collected July 17, 2008 from Rock Creek in Montana
Added to Troutnut.com by Bnewell on June 26, 2011
Rhithrogena Mayfly DunRhithrogena  Mayfly Dun View 1 Pictures
Collected March 27, 2010 from the Big Thompson River in Montana
Added to Troutnut.com by Bnewell on June 26, 2011
Female Rhithrogena Mayfly SpinnerFemale Rhithrogena  Mayfly Spinner View 9 PicturesI'm very tentatively (see the connected forum thread) sticking this mayfly in Rhithrogena for now.
Collected June 7, 2007 from the West Branch of the Delaware River in New York
Added to Troutnut.com by Troutnut on June 8, 2007

Cinygmula mayflies unidentified to species

Female Cinygmula (Dark Red Quills) Mayfly SpinnerFemale Cinygmula (Dark Red Quills) Mayfly Spinner View 7 PicturesThis female was collected from the same spinner cloud as this male.
Collected August 17, 2018 from Rock Creek in Montana
Added to Troutnut.com by Troutnut on June 13, 2019
Male Cinygmula (Dark Red Quills) Mayfly SpinnerMale Cinygmula (Dark Red Quills) Mayfly Spinner View 7 PicturesThis male was collected from the same cloud of spinners as this female and is probably the same species. I'm tentatively calling them both Cinygmula for now, but I'm really not sure about that ID yet.
Collected August 17, 2018 from Rock Creek in Montana
Added to Troutnut.com by Troutnut on June 13, 2019
Female Cinygmula (Dark Red Quills) Mayfly DunFemale Cinygmula (Dark Red Quills) Mayfly Dun View 6 PicturesThis one was collected in association with a male spinner probably of the same species.
Collected July 1, 2017 from the South Fork Stillaguamish River in Washington
Added to Troutnut.com by Troutnut on July 2, 2017
Male Cinygmula (Dark Red Quills) Mayfly SpinnerMale Cinygmula (Dark Red Quills) Mayfly Spinner View 11 PicturesI'm unsure of the ID on this one; keys put it closest to Cinygmula reticulata, but I'm very doubtful of the species and not positive on the genus. Epeorus is another possibility, but I don't know which species it would be.

This one was collected in association with a female dun probably of the same species.
Collected July 1, 2017 from the South Fork Stillaguamish River in Washington
Added to Troutnut.com by Troutnut on July 2, 2017
Cinygmula (Dark Red Quills) Mayfly NymphCinygmula (Dark Red Quills) Mayfly Nymph View 9 Pictures
Collected July 17, 2011 from the Gulkana River in Alaska
Added to Troutnut.com by Troutnut on July 20, 2011
Cinygmula (Dark Red Quills) Mayfly NymphCinygmula (Dark Red Quills) Mayfly Nymph View 8 PicturesThis nymph was one of many I collected with vivid white or semi-transparent markings on the front of the head, the sides of the pronotum (Pronotum: The top of the insect prothorax.), and the last abdominal segments.
Collected July 17, 2011 from the Gulkana River in Alaska
Added to Troutnut.com by Troutnut on July 20, 2011
Cinygmula (Dark Red Quills) Mayfly NymphCinygmula (Dark Red Quills) Mayfly Nymph View 7 PicturesThis very strange nymph appears to be undoubtedly Cinygmula, yet it lacks the telltale protruding mouthparts that usually make that genus so easy to identify.
Collected July 17, 2011 from the Gulkana River in Alaska
Added to Troutnut.com by Troutnut on July 20, 2011
Cinygmula (Dark Red Quills) Mayfly NymphCinygmula (Dark Red Quills) Mayfly Nymph View 3 Pictures
Collected May 10, 2008 from the Chena River in Alaska
Added to Troutnut.com by Troutnut on April 20, 2011
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