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.

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.

Mayfly Species Anafroptilum conturbatum (Tiny Sulphur Duns)

Where & when

Time of year : June to October

In 2 records from GBIF, adults of this species have been collected during July (50%) and May (50%).

In 2 records from GBIF, this species has been collected at elevations of 1450 and 6542 ft.

Species Range

Physical description

Most physical descriptions on Troutnut are direct or slightly edited quotes from the original scientific sources describing or updating the species, although there may be errors in copying them to this website. Such descriptions aren't always definitive, because species often turn out to be more variable than the original describers observed. In some cases, only a single specimen was described! However, they are useful starting points.

Male Spinner

Described in Needham et al (1935) as Centroptilum conturbatum
Body length: 5 mm
Wing length: 5 mm

Abdominal tergites 2-6 of male imago hyaline white; inner margin of second forceps joint distinctly tuberculate; distal joint unusually long.

Turbinate eyes dark blackish brown, in dried specimen. Head and thorax shiny black; pleural sutures brownish. Legs white. Wings hyaline, venation pale (see fig. 165). Abdominal segments 2-6, and part of 7, hyaline white, sometimes with faint dusky shading posteriorly on the middle tergites. Tergites 8-10, and often part of 7, chocolate brown. Sternites white; 2-6 hyaline, 7-9 opaque. Tails white. Second joint of forceps distinctly tuberculate on its inner margin; third joint strongly bowed; distal joint unusually long (see fig. 168). The plate between the bases of the forceps is conical on its posterior margin.

Specimens of the Mayfly Species Anafroptilum conturbatum

1 Nymph

Start a Discussion of Anafroptilum conturbatum

References

Mayfly Species Anafroptilum conturbatum (Tiny Sulphur Duns)

Taxonomy
Species Range
Common Name
Troutnut.com is copyright © 2004-2024 (email Jason). privacy policy