Blog & Latest Updates
Fly Fishing Articles
Insects by Common Name
> > The Yakima River
Landscape & scenery photos from the Yakima River
StateWashington
LocationYakima River
Date TakenJul 22, 2017
Date AddedJul 24, 2017
AuthorTroutnut
CameraCanon EOS 7D Mark II
Yakima River from WA highway 10 near Teanaway, with rafters floating down.
StateWashington
LocationYakima River
Date TakenJul 22, 2017
Date AddedJul 24, 2017
AuthorTroutnut
CameraCanon EOS 7D Mark II
StateWashington
LocationYakima River
Date TakenOct 1, 2017
Date AddedOct 1, 2017
AuthorTroutnut
CameraNIKON 1 AW1
20" rainbow caught swinging a sculpzilla through a deep riffle
StateWashington
LocationYakima River
Date TakenOct 1, 2017
Date AddedOct 1, 2017
AuthorTroutnut
CameraNIKON 1 AW1
StateWashington
LocationYakima River
Date TakenApr 9, 2021
Date AddedApr 11, 2021
AuthorTroutnut
CameraNIKON 1 AW1
Closeup insects from the Yakima River
Brachycentrus americanus (American Grannom) Caddisfly Larva
View 18 PicturesThis species of Brachycentrus was extremely common in mid-September kick net samples in the Yakima canyon.
View 18 PicturesThis species of Brachycentrus was extremely common in mid-September kick net samples in the Yakima canyon.Collected September 12, 2020 from the Yakima River in Washington
Added to Troutnut.com by Troutnut on September 19, 2020
Added to Troutnut.com by Troutnut on September 19, 2020
Male Onocosmoecus unicolor (Great Late-Summer Sedge) Caddisfly Adult
View 15 PicturesI first just assumed this was Dicosmoecus based on anglers' conventional wisdom since it's a large orange "October caddis," but Creno set me straight. I should have keyed it out. After another look under the microscope, it lacks an anepisternal wart on the mesopleuron (Mesopleuron: The side of the insect mesothorax, and the part to which the fore wings are attached in mayflies.), which rules out Dicosmoecus. The midtibiae have 2 apical (Apical: Close to the apex; tip or end.) spurs and 1 pre-apical (Apical: Close to the apex; tip or end.) spur, and from there the color pattern of the wing points to Onocosmoecus. The location then narrows the species to unicolor.
View 15 PicturesI first just assumed this was Dicosmoecus based on anglers' conventional wisdom since it's a large orange "October caddis," but Creno set me straight. I should have keyed it out. After another look under the microscope, it lacks an anepisternal wart on the mesopleuron (Mesopleuron: The side of the insect mesothorax, and the part to which the fore wings are attached in mayflies.), which rules out Dicosmoecus. The midtibiae have 2 apical (Apical: Close to the apex; tip or end.) spurs and 1 pre-apical (Apical: Close to the apex; tip or end.) spur, and from there the color pattern of the wing points to Onocosmoecus. The location then narrows the species to unicolor.Collected September 17, 2020 from the Yakima River in Washington
Added to Troutnut.com by Troutnut on September 19, 2020
Added to Troutnut.com by Troutnut on September 19, 2020
Heptagenia pulla (Golden Dun) Mayfly Nymph
View 11 PicturesThis specimen is interesting because Heptagenia pulla has not been reported from Washington or neighboring states (Saskatchewan is the closest), yet the distinctive key characteristics are clear.
It keys to the genus Heptagenia because the tarsal claw (Tarsal claw: The claws at the tip of the tarsus, on an insect's "foot.") has a single basal (Basal: close to the base; root or beginning) tooth, and the gills on segment 7 have fibrils.
For the species key:
1. The left mandible (Mandible: The paired jaws of an insect which are used for grabbing food, located immediately behind the labrum.) is planate (fairly straight-edged) whereas the right mandible (Mandible: The paired jaws of an insect which are used for grabbing food, located immediately behind the labrum.) is angulate (has one sharp turn on the edge).
2. The labrum (Labrum: The platelike structure forming the roof of the mouth of insects; the upper lip.) is much wider than long.
3. There's a thin light-colored streak lateral (Lateral: To the side.) to the eye on the head.
View 11 PicturesThis specimen is interesting because Heptagenia pulla has not been reported from Washington or neighboring states (Saskatchewan is the closest), yet the distinctive key characteristics are clear.It keys to the genus Heptagenia because the tarsal claw (Tarsal claw: The claws at the tip of the tarsus, on an insect's "foot.") has a single basal (Basal: close to the base; root or beginning) tooth, and the gills on segment 7 have fibrils.
For the species key:
1. The left mandible (Mandible: The paired jaws of an insect which are used for grabbing food, located immediately behind the labrum.) is planate (fairly straight-edged) whereas the right mandible (Mandible: The paired jaws of an insect which are used for grabbing food, located immediately behind the labrum.) is angulate (has one sharp turn on the edge).
2. The labrum (Labrum: The platelike structure forming the roof of the mouth of insects; the upper lip.) is much wider than long.
3. There's a thin light-colored streak lateral (Lateral: To the side.) to the eye on the head.
Collected April 9, 2021 from the Yakima River in Washington
Added to Troutnut.com by Troutnut on April 12, 2021
Added to Troutnut.com by Troutnut on April 12, 2021
Male Acentrella insignificans (Tiny Blue-Winged Olive) Mayfly Dun
View 11 PicturesThis specimen emerged indoors from nymphs I had collected, then partly molted into a spinner but got stuck along the way. I've included a couple pictures showing some of the spinner colors. It got a bit waterlogged after emerging, so the wings aren't in perfect shape, but it still represents one of two Baetids that were emerging and drawing trout to rise on the Yakima. Based on body size and shape, it is most likely the same species as this nymph.
View 11 PicturesThis specimen emerged indoors from nymphs I had collected, then partly molted into a spinner but got stuck along the way. I've included a couple pictures showing some of the spinner colors. It got a bit waterlogged after emerging, so the wings aren't in perfect shape, but it still represents one of two Baetids that were emerging and drawing trout to rise on the Yakima. Based on body size and shape, it is most likely the same species as this nymph.Collected September 12, 2020 from the Yakima River in Washington
Added to Troutnut.com by Troutnut on September 19, 2020
Added to Troutnut.com by Troutnut on September 19, 2020
Female Isoperla fusca (Yellow Sally) Stonefly Adult
View 13 PicturesThe family ID on this one was a little bit tricky. Just going by the size, shape, and color, it looks like Chloroperlidae. However, the second anal vein of the forewing is does not appear to be forked, and the apical (Apical: Close to the apex; tip or end.) maxillary palpal segment is close to the length of the penultimate segment, both of which rule out that family. The position of the cubitoanal crossvein (Crossvein: Short cross-wise veins in an insect wing which connect the long longitudinal (length-wise) veins.) relative to the anal cell in the forewing -- touching it in this case -- indicates Perlidae (and it really doesn't have the "look" of Perlidae at all), but other characteristics, such as the metathorastic sternacostal sutures and lack of gill remnants, point to Perlodidae. That's the right answer. Moving on to Perlodidae, the key characteristics in Merritt & Cummins lead straightforwarly to Isoperla, and the species key in Jewett 1959 (The Stoneflies of the Pacific Northwest) leads to Isoperla fusca.
There is one caveat: That source does suggest a May-July emergence, whereas this one was collected in mid-September.
View 13 PicturesThe family ID on this one was a little bit tricky. Just going by the size, shape, and color, it looks like Chloroperlidae. However, the second anal vein of the forewing is does not appear to be forked, and the apical (Apical: Close to the apex; tip or end.) maxillary palpal segment is close to the length of the penultimate segment, both of which rule out that family. The position of the cubitoanal crossvein (Crossvein: Short cross-wise veins in an insect wing which connect the long longitudinal (length-wise) veins.) relative to the anal cell in the forewing -- touching it in this case -- indicates Perlidae (and it really doesn't have the "look" of Perlidae at all), but other characteristics, such as the metathorastic sternacostal sutures and lack of gill remnants, point to Perlodidae. That's the right answer. Moving on to Perlodidae, the key characteristics in Merritt & Cummins lead straightforwarly to Isoperla, and the species key in Jewett 1959 (The Stoneflies of the Pacific Northwest) leads to Isoperla fusca. There is one caveat: That source does suggest a May-July emergence, whereas this one was collected in mid-September.
Collected September 17, 2020 from the Yakima River in Washington
Added to Troutnut.com by Troutnut on September 19, 2020
Added to Troutnut.com by Troutnut on September 19, 2020
Start a Discussion of the Yakima River:
Warning: Invalid argument supplied for foreach() in /home/jasonn5/func/commoncontent.fnc on line 182
Top 10 Fly Hatches
Top Gift Shop Designs
I outfish my daddy!
Electric blue Hendrickson dun.
I love buggers. Big, green, wooly ones.
I outfish my husband!
Be the trout. Eat mayflies.
Top Insect Specimens
Baetisca obesa Mayfly Nymph
Corydalus Hellgrammite Larva
Neophylax Caddisfly Adult
Rhyacophila fuscula Caddisfly Larva
Pteronarcys biloba Stonefly NymphMiscellaneous Sites
Troutnut.com is copyright © 2004-2022 Jason
Neuswanger (email Jason). See my FAQ for information about use of my images.
privacy policy
privacy policy