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.

I caught a nice brookie a few weeks earlier in this pool at the junction of a split channel in the stream. The huge fallen tree is great cover.

From the Mystery Creek # 23 in New York

Stream photos

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Neoleptophlebia Mayfly Nymph Neoleptophlebia Mayfly Nymph

Dorsal view of a Neoleptophlebia (Leptophlebiidae) Mayfly Nymph from the Yakima River in Washington

Some characteristics from the microscope images for the tentative species id: The postero-lateral projections are found only on segment 9, not segment 8. Based on the key in Jacobus et al. (2014), it appears to key to Neoleptophlebia adoptiva or Neoleptophlebia heteronea, same as this specimen with pretty different abdominal markings. However, distinguishing between those calls for comparing the lengths of the second and third segment of the labial palp, and this one (like the other one) only seems to have two segments. So I'm stuck on them both. It's likely that the fact that they're immature nymphs stymies identification in some important way.

10 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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Hydropsyche (Spotted Sedge) Caddisfly Adult Pictures

This species was really common along the Henry's Fork at the end of July. I photographed it along with a male that appears to be the same species, and another male of the same genus but a seemingly different, less common (on this day) species.

Lateral view of a Hydropsyche (Hydropsychidae) (Spotted Sedge) Caddisfly Adult from the Henry's Fork of the Snake River in Idaho

Hydropsyche (Hydropsychidae) (Spotted Sedge) Caddisfly Adult from the Henry's Fork of the Snake River in Idaho

Ventral view of a Hydropsyche (Hydropsychidae) (Spotted Sedge) Caddisfly Adult from the Henry's Fork of the Snake River in Idaho

Ruler view of a Hydropsyche (Hydropsychidae) (Spotted Sedge) Caddisfly Adult from the Henry's Fork of the Snake River in Idaho The smallest ruler marks are 1 mm.

This caddisfly was collected from the Henry's Fork of the Snake River in Idaho on July 31st, 2020 and added to Troutnut.com by Troutnut on August 17th, 2020.

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References

Jacobus, L. M., Wiersema, N.A., and Webb, J.M. 2014. Identification of Far Northern and Western North American Mayfly Larvae (Insecta: Ephemeroptera), North of Mexico; Version 2. Joint Aquatic Science meeting, Portland, OR. Unpublished workshop manual. 1-176.