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.

Sunlight perfectly strikes the trees at a bend in the Foss River in the Washington Cascades.

From the Foss River in Washington

Stream photos

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Male Baetidae (Blue-Winged Olive) Mayfly Dun Male Baetidae (Blue-Winged Olive) Mayfly Dun

Lateral view of a Male Baetidae (Blue-Winged Olive) Mayfly Dun from Mystery Creek #308 in Washington

This dun emerged from a mature nymph on my desk. Unfortunately its wings didn't perfectly dry out.

7 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.

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.

Caddisfly Species Nyctiophylax affinis (Dinky Light Summer Sedges)

Where & when

Time of year : Early summer

Altitude: Lakes and streams

This widespread species is most common in the Midwest.

In 81 records from GBIF, adults of this species have mostly been collected during June (33%), July (26%), August (19%), May (14%), and September (7%).

In 39 records from GBIF, this species has been collected at elevations ranging from 328 to 7201 ft, with an average (median) of 2887 ft.

Species Range

source

Map of specific collection sites

Specimens of the Caddisfly Species Nyctiophylax affinis

1 Adult

Nyctiophylax affinis (Dinky Light Summer Sedge) Caddisfly Adult

12 Pictures

Nyctiophylax affinis (Polycentropodidae) (Dinky Light Summer Sedge) Caddisfly Adult from the Teal River in Wisconsin

This specimen is certainly Nyctiophylax and most likely Nyctiophylax affinis. I don't know my caddisfly parts well enough to definitively follow the Nyctiophylax key in Morse (1972), but that source states that affinis is the predominant Midwestern species, being widespread and common in the region where I found this one. The anatomy of this one seems to match those at least as well as the other two potential options based on range, Nyctiophylax uncus and Nyctiophylax banksi.

Collected June 7, 2021 from the Teal River in Wisconsin

Added by Troutnut on June 9, 2021

Collected June 7, 2021 from the Teal River in Wisconsin and added by Troutnut on June 9, 2021

Start a Discussion of Nyctiophylax affinis

References

LaFontaine, Gary. 1981. Caddisflies. The Lyons Press.
Morse, JC. 1972. The genus Nyctiophylax in North America. Journal of the Kansas Entomological Society 42(2): 172-181.