Insects and other foods the trout should be eating:
2. Blue-winged Ollives (Baetis brunnicolor) and Little BWOs
3. Blue Quills
4. Quill Gordons
5. Little Black Caddis (Brachycentrus)
6. Little Brown Stoneflies
7. Hendricksons & Red Quills
Most available/ Near hatching and/or other types of available food:
8. American March Browns
9. Sculpin, Minnows (Streamers)
"K.I.S.S. A Bug" Series - American March Brown - Part 1
The Two Faced Mayfly
The American March Brown managed to disguise itself as two different mayflies for years. Not
only did they fake us anglers, they also managed to fool the entomologist. This two faced mayfly
was both an American March Brown and a Gray Fox for many years. I have at least three dozen
books on mayflies that all have it wrong. There are still hatch charts that show the American
March Browns hatching up to a point and then the Gray Fox mayflies starting to hatch.
Up until just a few years ago, not only did anglers think it was two different mayflies, so did the
scientists. They thought the American March Brown was a species they named the Stenonema
vicarium and the Gray Fox (which really didn't even exist) was a different species they named the
Stenonema fuscum. Thanks to DNA testing, they recently discovered there are notable
differences in the American March Browns and the other mayflies they once lumped together in
the Stenonema group (genus). That discovery created the Maccaffertium vicarium, which is now
the correct scientific name for the American March Brown.
What does all of this name stuff have to do with the mayfly from a fly fishing standpoint?
As I see it, it's important from two different perspectives. One, is to advise you that the American
March Brown and the Gray Fox is the exact same mayfly.
Two, is to advise you there was a reason for the misidentification. The American March Browns
hatch over a long period of time. When they first start to hatch, they are large, averaging close to
a hook size 10. At the end of the long hatch period, they are smaller, averaging a hook size 12.
This doesn't seem like much difference, number wise, but if kelp in proper proportion, there's
quite a difference in the physical sizes of flies tied on a size 10 and a size 12 hook.
The first ones to hatch are also lighter shades of colors than the late season hatches. The late
season hatches that were thought to be the Gray Fox, are darker and smaller American March
The good news is that trout have yet to master DNA testing.
Why are they called "American" March Browns?
If the March Browns pulled off a criminal act, they could disguise themselves from the cops by
using a false name I. D.. They could claim their name was March Brown. They could claim they
were often called Western March Browns and they were not the American March Brown the cops
were looking for. .
This is just another of numerous problems created by the use of common names. There
are other mayflies that aren't even in the same group also called March Browns. They are the
Rithrogena genus of the Heptageniidae family. There's two species of these mayflies - the
Rithrogena morrisoni and the Rithrogena hageni.
The Western March Browns (usually just called March Browns) are a different mayfly from the
American March Browns, so be careful when purchasing March Brown flies.
Copyright 2012 James Marsh
But your Honor: I'm a Gray Fox. That
gal over there next to me is the real
American March Brown.
Thumbnails: Click to enlarge
Thumbnails: Click to enlarge
He is lying: He is an American March
Brown. He married my sister, your
honor. She would never marry a Gray