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.

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Onocosmoecus (Great Late-Summer Sedge) Caddisfly Larva Onocosmoecus (Great Late-Summer Sedge) Caddisfly Larva

Lateral view of a Onocosmoecus (Limnephilidae) (Great Late-Summer Sedge) Caddisfly Larva from the Yakima River in Washington

This specimen keys pretty easily to Onocosmoecus, and it closely resembles a specimen from Alaska which caddis expert Dave Ruiter recognized as this genus. As with that specimen, the only species in the genus documented in this area is Onocosmoecus unicolor, but Dave suggested for that specimen that there might be multiple not-yet-distinguished species under the unicolor umbrella and it would be best to stick with the genus-level ID. I'm doing the same for this one.

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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.

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Lara Riffle Beetle Larva Pictures

Lara (Elmidae) Riffle Beetle Larva from the South Fork Snoqualmie River in Washington

Dorsal view of a Lara (Elmidae) Riffle Beetle Larva from the South Fork Snoqualmie River in Washington

This false-color image with contrast extremely boosted shows the structure of the gills that were sometimes retracted inside the abdomen.

Lara (Elmidae) Riffle Beetle Larva from the South Fork Snoqualmie River in Washington

Ventral view of a Lara (Elmidae) Riffle Beetle Larva from the South Fork Snoqualmie River in Washington

Ruler view of a Lara (Elmidae) Riffle Beetle Larva from the South Fork Snoqualmie River in Washington The smallest ruler marks are 1 mm.

This riffle beetle 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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