Header image
Enter a name
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 Ephemerella mucronata (Ephemerellidae) Mayfly Nymph from the Yakima River in Washington
This is an interesting one. Following the keys in Merritt R.W., Cummins, K.W., and Berg, M.B. (2019) and Jacobus et al. (2014), it keys clearly to Ephemerella. Jacobus et al provide a key to species, but some of the characteristics are tricky to interpret without illustrations. If I didn't make any mistakes, this one keys to Ephemerella mucronata, which has not previously been reported any closer to here than Montana and Alberta. The main character seems to fit well: "Abdominal terga with prominent, paired, subparallel, spiculate ridges." Several illustrations or descriptions of this holarctic species from the US and Europe seem to match, including the body length, tarsal claws and denticles, labial palp, and gill shapes. These sources include including Richard Allen's original description of this species in North America under the now-defunct name E. moffatae in Allen RK (1977) and the figures in this description of the species in Italy.
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.
Troutnut is a project started in 2003 by salmonid ecologist Jason "Troutnut" Neuswanger to help anglers and fly tyers unabashedly embrace the entomological side of the sport. Learn more about Troutnut or support the project for an enhanced experience here.

By Troutnut on June 12th, 2022
I was traveling on the east side of the Cascades today, where all the rivers are ridiculously high from a combination of snowmelt and rain. It's dangerous to even get in the water. But I found a place to sample a few bugs in a small creek and added a couple stoneflies from my to-do list.

Closeup insects by Troutnut from Swauk Creek in Washington

Dorsal view of a Doroneuria baumanni (Perlidae) (Golden Stone) Stonefly Nymph from Swauk Creek in Washington
I'm not aware of any way to tell the two species of Doroneuria apart as nymphs, so this one is classified to species based on location alone. Doroneuria baumanni is found in the Cascades and in Washington, and the other species is not known here yet.
Dorsal view of a Alloperla (Chloroperlidae) (Sallfly) Stonefly Nymph from Swauk Creek in Washington
Ruler view of a Cinygmula (Heptageniidae) (Dark Red Quill) Mayfly Nymph from Swauk Creek in Washington The smallest ruler marks are 1 mm.
This one doesn't have the protruding mouthparts typical of Cinygmula, but I think it's just an oddball individual.

Quick Reply

Related Discussions

Topic
Replies
Last Reply
0
Mar 26, 2008
by Wbranch
12
Jul 31, 2007
by LittleJ
1
Apr 10, 2008
by LittleJ
Troutnut.com is copyright © 2004-2024 (email Jason). privacy policy