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

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.

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.
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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Stonefly Genus Sweltsa (Sallflies)

Only Sweltsa coloradensis has been specifically mentioned as a common species in my sources.

Where & when

In 140 records from GBIF, adults of this genus have mostly been collected during June (31%), July (31%), August (14%), May (11%), and April (11%).

In 70 records from GBIF, this genus has been collected at elevations ranging from 330 to 11201 ft, with an average (median) of 8999 ft.

Genus Range

Specimens of the Stonefly Genus Sweltsa

3 Female Adults
6 Adults
5 Nymphs

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Stonefly Genus Sweltsa (Sallflies)

Genus Range
Common Name
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