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Western Green Drakes



Like most common names, "Western Green Drake" can refer to more than one taxon. They're previewed below, along with 11 specimens. For more detail click through to the scientific names.

Mayfly Species Drunella doddsii

These are pretty much always called 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 (Thorax: The thorax is the middle part of an insect's body, in between the abdomen and the head, and to which the legs and wings are attached.), has a flat frontal head margin and a unique oval disk-like ring of hairs on its ventral (Ventral: Toward or on the bottom.) 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.
Drunella doddsii (Western Green Drake) Mayfly NymphDrunella doddsii (Western Green Drake) Mayfly Nymph View 12 Pictures
Collected July 17, 2011 from in
Added to Troutnut.com by on July 20, 2011
Male Drunella doddsii (Western Green Drake) Mayfly DunMale Drunella doddsii (Western Green Drake) Mayfly Dun View 13 Pictures
Collected July 17, 2011 from in
Added to Troutnut.com by on July 20, 2011

Mayfly Species Drunella grandis

These are pretty much always called Western Green Drakes.
This species (or rather group of subspecies (Subspecies: Entomologists sometimes further divide a species into distinct groups called subspecies, which have two lower-case words on the end of their scientific name instead of one. The latter is the sub-species name. For example, Maccaffertium mexicanum mexicanum and Maccaffertium mexicanum integrum are two different subspecies of Maccaffertium mexicanum.)), together with Drunella doddsii, make up the famous Western Green Drake hatches. They are widespread throughout the vast Western region and can be abundant enough in many locations to provide world class angling.

It hasn't been all that many years since Western traditions and entomological "facts on the ground" began to influence the angler's lexicon heavily dominated by Eastern writers. Their initial reporting after visiting the region first popularized the phrase "Rocky Mountains answer to the popular Green Drakes of the East". This led to a false impression that lingers to this day. The reality is these giants of their family have abundant populations all over the West with no counterpart in the East, and the West does have abundant hatches of comparable Ephemeridae. The Western tradition of naming outsized Mayflies "Drakes" is the reason for what many consider a misnomer by giving it the same common name as the legendary Ephemerid of the East and surely contributed to confusion for anglers unconcerned with such subtleties.
Drunella grandis (Western Green Drake) Mayfly NymphDrunella grandis (Western Green Drake) Mayfly Nymph View 12 Pictures
Collected June 13, 2019 from in
Added to Troutnut.com by on June 14, 2019
Female Drunella grandis (Western Green Drake) Mayfly DunFemale Drunella grandis (Western Green Drake) Mayfly Dun View 6 PicturesI collected this specimen while away from all my good photography equipment except the camera and one of my macro lenses, so I made do. The lighting is from lamps in a hotel room, so it was hard to edit for really true colors, but I tried to get as close as possible. The body was 13 mm long, wing 19 mm long.
Collected July 14, 2017 from in
Added to Troutnut.com by on July 24, 2017
Drunella grandis (Western Green Drake) Mayfly AdultDrunella grandis (Western Green Drake) Mayfly Adult View 3 Pictures
Collected June 30, 2010 from in
Added to Troutnut.com by on June 29, 2011

Mayfly Species Drunella coloradensis

These are very rarely called Western Green Drakes.
This species is very similar to Drunella flavilinea. In areas where their ranges overlap, they can sometimes be found in the same streams. Allen and Edmunds (1962) say that Drunella coloradensis tends to favor colder water than Drunella flavilinea and that it may emerge as much as a month later.
Drunella coloradensis (Small Western Green Drake) Mayfly NymphDrunella coloradensis (Small Western Green Drake) Mayfly Nymph View 11 PicturesThis one nicely illustrates the variation in coloration within an single Ephemerellid species in a single stream, when compared to its lighter, banded counterpart.
Collected July 25, 2019 from in
Added to Troutnut.com by on July 26, 2019
Male Drunella coloradensis (Small Western Green Drake) Mayfly DunMale Drunella coloradensis (Small Western Green Drake) Mayfly Dun View 8 PicturesThe positive species ID on this dun comes from both the spinner that it (or possibly one other dun just like it) molted into and the overwhelming abundance of nymphs of this species in my kicknet samples from the same site.
Collected July 28, 2019 from in
Added to Troutnut.com by on July 30, 2019
Male Drunella coloradensis (Small Western Green Drake) Mayfly SpinnerMale Drunella coloradensis (Small Western Green Drake) Mayfly Spinner View 9 PicturesThis spinner molted from this dun, or possibly one other dun I had in the same container that looked just like it.
Collected July 28, 2019 from in
Added to Troutnut.com by on July 30, 2019

Mayfly Species Drunella flavilinea

These are very rarely called Western Green Drakes.
The Flavs pick up about a week after the closely related but larger Western Green Drakes (Drunella grandis and Drunella doddsii) finish hatching on most Western waters.

Their hatches may be complemented by simultaneous hatches of two less prolific species, Drunella coloradensis and Drunella spinifera.
Drunella flavilinea (Flav) Mayfly NymphDrunella flavilinea (Flav) Mayfly Nymph View 6 PicturesAlthough the identification is not certain because the nymph is not yet mature, the configuration of tubercles (
A few (not all) of the abdominal tubercles on this Ephemerella needhami nymph are circled.  They are especially large in this species.
A few (not all) of the abdominal tubercles on this Ephemerella needhami nymph are circled. They are especially large in this species.
Tubercle: Various peculiar little bumps or projections on an insect. Their character is important for the identification of many kinds of insects, such as the nymphs of Ephemerellidae mayflies.
)
on this one--particularly the forefemora--seems to best match Drunella flavilinea.
Collected July 2, 2019 from in
Added to Troutnut.com by on July 18, 2019
Female Drunella flavilinea (Flav) Mayfly DunFemale Drunella flavilinea (Flav) Mayfly Dun View 6 PicturesI can't be certain of the ID of this female dun, but I'm calling it Drunella flavilinea for three reasons: 1) the known abundance of "flavs" on the Henry's Fork, 2) clear differences in coloration from my confirmed specimens of Drunella coloradensis, which is the main lookalike, and 3) the habitat (a sizable river in a wide mountain valley, rather than a small, high-altitude stream) suggests it's not coloradensis.
Collected July 31, 2020 from in
Added to Troutnut.com by on August 16, 2020
Drunella flavilinea (Flav) Mayfly SpinnerDrunella flavilinea (Flav) Mayfly Spinner View 1 Pictures
Collected July 31, 2010 from in
Added to Troutnut.com by on June 29, 2011
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