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 Kogotus (Perlodidae) Stonefly Nymph from Mystery Creek #199 in Washington
This one pretty clearly keys to Kogotus, but it also looks fairly different from specimens I caught in the same creek about a month later in the year. With only one species of the genus known in Washington, I'm not sure about the answer to this ID.
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 Drunella doddsii (Western Green Drakes)

This species together with the Drunella grandis sub-species make up the Western Green Drake hatch. Besides being smaller, the adults are difficult to tell apart from it's larger siblings; but D. doddsi nymphs have a few peculiar traits that set them apart. D. doddsi looks much thicker in the thorax, has a flat frontal head margin and a unique oval disk-like ring of hairs on its ventral surface. However, There are very few differences between the habits of these two species, and they are almost always discussed together in fly fishing books, so for many of the characteristics of doddsii, refer to the Drunella grandis page.

Where & when

Fred Arbona writes that doddsii is only found in "cold, fast-flowing sections of freestone rivers." This is the only important difference between it and Drunella grandis, which exists in a wide variety of habitats.
Species Range

Identification

To determine whether a specimen of Drunella belongs to Drunella doddsii, use the Key to Species of Drunella Nymphs.

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 doddsi
Body length: 13 mm
Wing length: 14 mm

A member of the fuscata group (now a synonym of Drunella walkeri); allied to E. fuscata in type of genitalia. Superficially very like E. grandis (now a synonym of Drunella grandis), but without the wide dark femoral bands, and with darker tarsi; genitalia distinct.

Head and thorax dark reddish brown; pleural sutures paler. Fore femur dark purplish brown; tibia slightly paler than femur; tarsus yellowish brown, paler at the tip. Middle and hind legs yellowish; femora shaded with brown, but without the prominent wide dark apical bands of grandis; the three basal tarsal joints shaded with purplish black. Wings hyaline; venation dark brown. Abdominal segments each with a broad median transverse band of dark brown, somewhat paler on the dorsal areas of the tergites; anterior and posterior margins widely pale. Pleural fold pale. All pale areas relatively wider than in grandis. Tails dark brown at the base, becoming pale at the tips. Second joint of the forceps strongly bowed, deeply constricted at the middle.

Nymph

Described in Needham et al (1935) as Ephemerella doddsi

Nymph (see fig. 50) without frontal horns, but with a broad frontal shelf, notched widely to receive the bases of the antennae (see fig. 151 f). No occipital nor thoracic tubercles. Anterior margin of the fore femur with spines or teeth; smaller spines on its posterior margin, and on both margins of the other femora as well. All femora somewhat flattened. Tibial ‘thumb’ about one-third as long as the tarsus; strong, rather sharp at the tip; directed outward. No dorsal abdominal spines. A broad ventral adhesive disc is present on the abdomen, extending from sternite 1 to 9; long hairs form its outer margin, short hairs occupy the inner space. General color yellowish to tan, with darker areas on eyes, wings, gills, bases of tarsi and tails; abdominal tergites shaded indefinitely with brown. Tails yellowish, darker at bases; tips light brown.

Specimens of the Mayfly Species Drunella doddsii

1 Male Dun
1 Female Dun
10 Nymphs

Start a Discussion of Drunella doddsii

References

Mayfly Species Drunella doddsii (Western Green Drakes)

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