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Artistic view of a Male Pteronarcys californica (Pteronarcyidae) (Giant Salmonfly) Stonefly Adult from the Gallatin River in Montana
Salmonflies
Pteronarcys californica

The giant Salmonflies of the Western mountains are legendary for their proclivity to elicit consistent dry-fly action and ferocious strikes.

The Firehole River in Wyoming

Stream photos

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Female Skwala (Large Springfly) Stonefly AdultFemale Skwala (Large Springfly) Stonefly Adult
Lateral view of a Female Skwala (Perlodidae) (Large Springfly) Stonefly Adult from Mystery Creek #308 in Washington
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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.
Troutnut is a project started in 2003 by salmonid ecologist Jason "Troutnut" Neuswanger to help anglers and fly tyers unabashedly embrace the entomological side of the sport. Learn more about Troutnut or support the project for an enhanced experience here.

Baetis tricaudatus (Blue-Winged Olive) Mayfly Nymph Pictures

Baetis tricaudatus (Baetidae) (Blue-Winged Olive) Mayfly Nymph from the South Fork Snoqualmie River in Washington
Baetis tricaudatus (Baetidae) (Blue-Winged Olive) Mayfly Nymph from the South Fork Snoqualmie River in Washington
Baetis tricaudatus (Baetidae) (Blue-Winged Olive) Mayfly Nymph from the South Fork Snoqualmie River in Washington
Baetis tricaudatus (Baetidae) (Blue-Winged Olive) Mayfly Nymph from the South Fork Snoqualmie River in Washington
Ruler view of a Baetis tricaudatus (Baetidae) (Blue-Winged Olive) Mayfly Nymph from the South Fork Snoqualmie River in Washington The smallest ruler marks are 1 mm.
Ventral view of a Baetis tricaudatus (Baetidae) (Blue-Winged Olive) Mayfly Nymph from the South Fork Snoqualmie River in Washington
Dorsal view of a Baetis tricaudatus (Baetidae) (Blue-Winged Olive) Mayfly Nymph from the South Fork Snoqualmie River in Washington
There serrations of the gills that are supposed to characterize this species are maaaaybe visible on the sharpest edge of the gill in the middle, but I might just be imagining things. Crystal-clear images of the serrations are shown in a scientific paper using an electron microscope at about 2200x magnification, so I don't know if they're even visible under a dissecting microscope at all. Baetis tricaudatus (Baetidae) (Blue-Winged Olive) Mayfly Nymph from the South Fork Snoqualmie River in Washington
Baetis tricaudatus (Baetidae) (Blue-Winged Olive) Mayfly Nymph from the South Fork Snoqualmie River in Washington
Mouth parts, ventral view, with the labium removed Baetis tricaudatus (Baetidae) (Blue-Winged Olive) Mayfly Nymph from the South Fork Snoqualmie River in Washington
View of the labium removed from the rest of the head, since the shape of the labial palp is an important identifying characteristic Baetis tricaudatus (Baetidae) (Blue-Winged Olive) Mayfly Nymph from the South Fork Snoqualmie River in Washington
Baetis tricaudatus (Baetidae) (Blue-Winged Olive) Mayfly Nymph from the South Fork Snoqualmie River in Washington
I took this picture to capture the markings on the pronotum, after I had removed the head to dissect mouthparts. Baetis tricaudatus (Baetidae) (Blue-Winged Olive) Mayfly Nymph from the South Fork Snoqualmie River in Washington
There were some short, stout setae on the pedicels, a key characteristic, but I couldn't get a sharp enough photo for you to see them. Baetis tricaudatus (Baetidae) (Blue-Winged Olive) Mayfly Nymph from the South Fork Snoqualmie River in Washington

This mayfly was collected from the South Fork Snoqualmie River in Washington on May 14th, 2022 and added to Troutnut.com by Troutnut on May 16th, 2022.


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Baetis tricaudatus (Blue-Winged Olive) Mayfly Nymph Pictures

Taxonomy
  1. Kingdom Animalia (Animals)
  2. » Phylum Arthropoda (Arthropods)
  3. » Class Insecta (Insects)
  4. » Order Ephemeroptera (Mayflies)
  5. » Family Baetidae (Blue-Winged Olives)
  6. » Genus Baetis (Blue-Winged Olives)
  7. » Species tricaudatus (Blue-Winged Olives)
Collection details
Location: South Fork Snoqualmie River, Washington
Date: May 14th, 2022
Added to site: May 16th, 2022
Author: Troutnut
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