Troutnut.com Fly Fishing for Trout Home
User Password
or register.

American Brown Duns

Scientific Name
MatchScientific Name
*Maccaffertium vicarium

This common name refers to only one species.

Mayfly Species Maccaffertium vicarium

These are very rarely called American Brown Duns.
In the East and Midwest this is one of the most important hatches of the Spring. They are large flies which emerge sporadically, making for long days of good fishing.

This species contains the two classic Eastern hatches formerly known as Stenonema vicarium and Stenonema fuscom, the "March Brown" and "Gray Fox." Entomologists have discovered that these mayflies belong to the same species, but they still display differences in appearance which the trout notice easily. Anglers should be prepared to imitate both types.
Maccaffertium vicarium (March Brown) Mayfly NymphMaccaffertium vicarium (March Brown) Mayfly NymphView 5 Pictures
Region: Catskills
Collected Apr 19, 2006
Added Apr 21, 2006
Male Maccaffertium vicarium (March Brown) Mayfly DunMale Maccaffertium vicarium (March Brown) Mayfly DunView 10 PicturesI collected this mayfly on the same trip as a female of the same species. After these photos it molted into a spinner. This is the form of Maccaffertium vicarium which anglers call the "Gray Fox."
Region: Upper Midwest
Collected May 28, 2005
Added May 24, 2006
Female Maccaffertium vicarium (March Brown) Mayfly SpinnerFemale Maccaffertium vicarium (March Brown) Mayfly SpinnerView 7 PicturesI collected this mayfly on the same trip as a male of the same species. They are Maccaffertium vicarium mayflies of the type formerly known as Stenonema fuscom, the "Gray Fox."
Region: Upper Midwest
Collected May 28, 2005
Added May 24, 2006
Top 10 Hatches
Top 5 Products
Top 5 Specimens
Recent Updates
Last update July 19th, 2007.
Misc. Websites