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.

Lateral view of a Psychodidae True Fly Larva from Mystery Creek #308 in Washington
This wild-looking little thing completely puzzled me. At first I was thinking beetle or month larva, until I got a look at the pictures on the computer screen. I made a couple of incorrect guesses before entomologist Greg Courtney pointed me in the right direction with Psychodidae. He suggested a possible genus of Thornburghiella, but could not rule out some other members of the tribe Pericomini.
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 Serratella frisoni

Where & when

In 4 records from GBIF, adults of this species have been collected during June (50%), May (25%), and April (25%).

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 Ephemerella frisoni
Body length: 5 mm
Wing length: 5 mm

A member of the serrata group (now a synonym of Serratella serrata); male imago distinguished by the pale whitish anterior abdominal segments. Nymph unknown.

Head and thorax deep blackish brown. Mesothorax broad; axillary cords barely extending beyond the tip of the scutellum; pleura with lighter brown tinges. Fore femora light sepia brown; tibiae and tarsi dull whitish; tibiae slightly shaded at base with sepia, and rather long, being about equal in length to the entire tarsus and more than twice the length of the femur. Middle and hind legs whitish; femora tinged with brown; tibiae about as long as the femora. Wings hyaline, all veins pale; a brown tinge at the extreme base. Abdominal segments 1-6, and the anterior half of segment 7, dull whitish, semi-hyaline; segments 8-10, and the posterior half of 7, pinkish brown, opaque; paler ventrally. On the anterior segments traces of a fine ruddy dorsal line are evident; also “lateral rows of small ruddy spots or streaks situated one on each segment in the central area” (McDunnough). Forceps pale with tinge of brown. Between the forceps at the base is a prominent tubercle, as the bicolor (now a synonym of Eurylopella bicolor) group; however, there are small lateral barbs apically on the penes. Tails white, unmarked.


Start a Discussion of Serratella frisoni

References

  • Needham, James G., Jay R. Traver, and Yin-Chi Hsu. 1935. The Biology of Mayflies. Comstock Publishing Company, Inc.

Mayfly Species Serratella frisoni

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