Lateral view of a Male Baetis (Baetidae) (Blue-Winged Olive) Mayfly Dun from Mystery Creek #43 in New York

Blue-winged Olives
Baetis

Tiny Baetis mayflies are perhaps the most commonly encountered and imitated by anglers on all American trout streams due to their great abundance, widespread distribution, and trout-friendly emergence habits.

The Middle Fork of the Koyukuk River in Alaska

Stream photos

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Glossosoma (Little Brown Short-horned Sedge) Caddisfly Larva Glossosoma (Little Brown Short-horned Sedge) Caddisfly Larva

Dorsal view of a Glossosoma (Glossosomatidae) (Little Brown Short-horned Sedge) Caddisfly Larva from the Yakima River in Washington

I caught this tiny larva without a case, but it seems to key pretty clearly to to Glossosomatidae. From there, the lack of sclerites on the mesonotum points to either Glossosoma or Anagapetus. Although it's difficult to see in a 2D image from the microscope, it's pretty clear in the live 3D view that the pronotum is only excised about 1/3 of its length to accommodate the forecoxa, not 2/3, which points to Glossosoma at Couplet 5 of the Key to Genera of Glossosomatidae Larvae.

11 Recently Added Photos

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.

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Updates from July 23, 2011

Closeup insects by Bnewell from the Touchet River in Washington

Female Epeorus (Little Maryatt) Mayfly Spinner

1 Picture

Female Epeorus (Heptageniidae) (Little Maryatt) Mayfly Spinner from the Touchet River in Washington

I associated this female with a male I collected one night later. For a great and informative discussion of all Epeorus species and other mayflies be sure and read, WESTERN MAYFLY HATCHES by R. Hafele and D. Hughes. They rate all of the western mayflies and they rate the hatch of this genus a 25 out of a possible 45 points based on several rating criterion. They provide insect photos, possible fly patterns and fly presentations. This is a great book.

Edit by Troutnut: Bob generally knows his IDs better than I do, but I think this one was misidentified as Epeorus longimanus. The darkened humeral crossvein is not supposed to be present in longimanus. I'm moving it up to Epeorus.

Collected July 23, 2011 from the Touchet River in Washington

Added by Bnewell on July 25, 2011

Collected July 23, 2011 from the Touchet River in Washington and added by Bnewell on July 25, 2011