Western Green Drakes
.............................Fly Fishing Yellowstone National Park

Western Green Drakes - (Drunella species)

The Western Green Drake common name is given to two different species of the
Drunella genus, the dodsi and the grandis. Both species are very similar. You could
determine the species from looking closely at the nymphs but not the duns. The
nymphs vary some but the duns vary little. It would take a microscope to determine the
species of the dun. Neither the duns or the nymphs varies enough that you need a
separate fly pattern or method of imitating them.
Trout can be taken on all stages of the Western Green Drakes life but the dun is
certainly the most popular stage to imitate. The large mayfly floats on the surface a few
seconds and brings about some very good action on the dry fly.
Most of the streams in Yellowstone National Park have these mayflies. The hatch times
vary greatly depending on the elevation of the stream and the surrounding mountains.
As a general rule, on the same stream, the
grandis species hatches first and the dodsi
species follows a few days later. This can vary from stream to stream. In other words,
dodsi species could hatch days before the grandis species hatches on a different
stream at a higher elevation. This is just for information. It should not make any
difference to you which species is hatching.

dodsi species also tends to be found in faster water than the grandis species.
Most anglers don't think of the Green Drake as being a Yellowstone National Park
hatch. So much publicity regarding this mayfly has been given to some of the nearby
streams that are outside of the park that the Green Drake hatches within the park seem
unimportant to many visiting anglers. It is certainly true that some nearby streams have
excellent Western Green Drake hatches but it is also a fact that several of the streams
within the park have excellent hatches. You can fish the hatches in the park for a much
longer period of time. Hatches take place in the Northeastern section of the park much
later than they do in the Northwestern section for example. In the forthcoming articles, I
will cover the fishing methods for these large mayflies.

Coming Up Next:
Western Green Drake - Nymphs

Copyright 2008 James