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.

Female Sweltsa fidelis (Sallfly) Stonefly Adult Pictures

In Baumann's Stoneflies of the Rocky Mountains, this specimen keys to Sweltsa fidelis, but the number of species in that key is fairly small and it might not be accurate.

Lateral view of a Female Sweltsa fidelis (Chloroperlidae) (Sallfly) Stonefly Adult from the Madison River in Montana
Female Sweltsa fidelis (Chloroperlidae) (Sallfly) Stonefly Adult from the Madison River in Montana
Ventral view of a Female Sweltsa fidelis (Chloroperlidae) (Sallfly) Stonefly Adult from the Madison River in Montana
Dorsal view of a Female Sweltsa fidelis (Chloroperlidae) (Sallfly) Stonefly Adult from the Madison River in Montana
Ruler view of a Female Sweltsa fidelis (Chloroperlidae) (Sallfly) Stonefly Adult from the Madison River in Montana The smallest ruler marks are 1 mm.

This stonefly was collected from the Madison River in Montana on June 30th, 2019 and added to Troutnut.com by Troutnut on July 17th, 2019.


Start a Discussion of Adult

References

Female Sweltsa fidelis (Sallfly) Stonefly Adult Pictures

Collection details
Location: Madison River, Montana
Date: June 30th, 2019
Added to site: July 17th, 2019
Author: Troutnut
Troutnut.com is copyright © 2004-2024 (email Jason). privacy policy