Header image
Enter a name
Lateral view of a Female Hexagenia limbata (Ephemeridae) (Hex) Mayfly Dun from the Namekagon River in Wisconsin
Hex Mayflies
Hexagenia limbata

The famous nocturnal Hex hatch of the Midwest (and a few other lucky locations) stirs to the surface mythically large brown trout that only touch streamers for the rest of the year.

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.

Midges

Midges are most popular with anglers who fish fertile, placid spring creeks and stillwaters. Their often tiny size frustrates anglers who encounter trout feeding selectively on their frequent hatches. Their many thousand species are impossible to sort out, but they all share similar stages and behavior as far as the angler is concerned.


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

True Fly Family Chironomidae

These are pretty much always called Midges.
Midges are the most important aquatic insects in some places, especially fertile spring creeks where they are extremely abundant and the current is so slow that it's efficient for trout to surface feed on very tiny insects.

Some midges are large, up to hook size 14, but the majority are size 22 or smaller. The number of genera and species is hopelessly huge for angler entomologists to ever learn, and the identifing characteristics often require slide-mounting tiny parts under high-powered microscopes. Even the most Latin-minded fisherman must slip back to the basics--size and color--to describe his local midge hatches.
Lateral view of a Stenochironomus poecilopterus (Chironomidae) Midge Adult from Mystery Creek #62 in New York
Dorsal view of a Chironomidae (Midge) True Fly Larva from unknown in Wisconsin
This large midge larva is about 3/4" long.
Lateral view of a Chironomidae (Midge) True Fly Pupa from the Gulkana River in Alaska

References

Midges

Scientific Name
Troutnut.com is copyright © 2004-2024 (email Jason). privacy policy