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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
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.

Dorsal view of a Holocentropus (Polycentropodidae) Caddisfly Larva from the Yakima River in Washington
This one seems to tentatively key to Holocentropus, although I can't make out the anal spines in Couplet 7 of the Key to Genera of Polycentropodidae Larvae nor the dark bands in Couplet 4 of the Key to Genera of Polycentropodidae Larvae, making me wonder if I went wrong somewhere in keying it out. I don't see where that could have happened, though. It might also be that it's a very immature larva and doesn't possess all the identifying characteristics in the key yet. If Holocentropus is correct, then Holocentropus flavus and Holocentropus interruptus are the two likely possibilities based on range, but I was not able to find a description of their larvae.
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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Green Rockworms

This common name refers to only one genus. Click its scientific name to learn more.

Caddisfly Genus Rhyacophila

These are sometimes called Green Rockworms.
The large free-living larvae of the Rhyacophila genus are among the best-known caddisflies, and for good reason, because their unique biology is both interesting to entomologists and compatible with trout fishing. There are over 100 species, and many of them can be important.
Lateral view of a Rhyacophila (Rhyacophilidae) (Green Sedge) Caddisfly Adult from Mystery Creek #199 in Washington
Dorsal view of a Rhyacophila fuscula (Rhyacophilidae) (Green Sedge) Caddisfly Larva from Mystery Creek #62 in New York
Rhyacophila (Rhyacophilidae) (Green Sedge) Caddisfly Pupa from the Long Lake Branch of the White River in Wisconsin
I collected this pupa and several like it from the same stream and on the same day as this larva. I suspect they're the same species. Every pupa I collected was in a brown casing like the one shown in one of the pictures below. I cut this pupa out of its case after a picture so you can see more details. It is close to but not fully developed.

Green Rockworms

Scientific Name
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