Troutnut.com Fly Fishing for Trout Home
User Password
or register.
Scientific name search:

Mayfly Genus Maccaffertium (March Browns and Cahills)

Taxonomic Navigation -?-
» Genus Maccaffertium (March Browns and Cahills)
Species in MaccaffertiumNumber of SpecimensNumber of Pictures
Maccaffertium ithacaLight Cahill00
Maccaffertium luteum14
Maccaffertium mediopunctatumCream Cahill534
Maccaffertium mexicanumCream Cahill722
Maccaffertium modestumCream Cahill619
Maccaffertium pulchellumLight Cahill00
Maccaffertium terminatum525
Maccaffertium vicariumMarch Brown1156

9 species aren't included.
Common Name
MatchCommon Name
****March Browns and Cahills
Pictures Below ↓
Many of America's traditional flies, like the March Brown and the Light and Dark Cahills, originated in the Catskills to imitate the mayflies of this genus. Back then most they were in classified in Stenonema, the name by which many anglers still know them. Caucci and Nastasi wrote of them in Hatches II:

"There is a matrimony between Stenonema flies and Catskill rivers that is as synonymous as ham and eggs."

By far the most important species is Maccaffertium vicarium. Of the others, Maccaffertium ithaca is the most important, and Maccaffertium modestum and Maccaffertium pulchellum are also reported to produce localized fishable hatches. These lesser species amount to much of the sporadic Light Cahill hatching in evenings throughout the summer.

Anglers looking for information on the popular species Stenonema fuscom should know that it has been combined with Maccaffertium vicarium.  

Where & When


Regions: East, Midwest

This genus is only important in the East and Midwest. In the spring there are superhatches of Maccaffertium vicarium. The lesser species are primary players on the barren stage of summer evening mayfly hatches. Most of them emerge sporadically for months. Anglers know them as Light Cahills and Cream Cahills, and they reinforce the hatches of the closely related Light Cahill species Stenacron interpunctatum.

Hatching Behavior


The early-season species of Maccaffertium crawl to slow, shallow water before emerging. Apparently they lose their grip or otherwise end up in the drift during this movement, because they are common in the trout's diet in the weeks before they emerge. Common attractor (Attractor: Flies not designed to imitate any particular insect, but to incorporate characteristics attractive to trout. When trout aren't feeding selectively, attractors often outperform careful imitations as searching patterns because they are easier to see and incorporate more strike-triggering characteristics. They include legends like the Adams, Bivisible, and Royal Wulff.) nymphs like the Hare's Ear are good likenesses of this genus.

Most of them are good dry fly insects because they take a long time to emerge and ride the water for a while before getting airborne. They are generally sporadic emergers, but their high populations put at least a few of these insects on the water most nights of the spring and summer.

Nymph Biology


Maccaffertium mayfly nymphs are very adept clingers, but most species are at home in all stream habitats. They (and their close relatives in Stenonema and Stenacron) do not have the high oxygen requirements of the other genera in Heptageniidae.

Pictures of 59 Mayfly Specimens in the Genus Maccaffertium:

Specimen Page:1234...7
Maccaffertium mediopunctatum (Cream Cahill) Mayfly NymphMaccaffertium mediopunctatum (Cream Cahill) Mayfly Nymph View 9 PicturesThis specimen seems to be of the same species as a dun I photographed which emerged from another nymph in the same sample.
Collected May 29, 2007 from Paradise Creek in Pennsylvania
Added to Troutnut.com by Troutnut on June 4, 2007
Maccaffertium vicarium (March Brown) Mayfly NymphMaccaffertium vicarium (March Brown) Mayfly Nymph View 5 Pictures
Collected April 19, 2006 from the Beaverkill River in New York
Added to Troutnut.com by Troutnut on April 21, 2006
Female Maccaffertium mediopunctatum (Cream Cahill) Mayfly DunFemale Maccaffertium mediopunctatum (Cream Cahill) Mayfly Dun View 10 PicturesThis female looks very much like a male I collected a few hundred miles away a few days later, so I'm guessing it's the same species, which I believe is Maccaffertium mediopunctatum.
Collected May 23, 2007 from the Little Juniata River in Pennsylvania
Added to Troutnut.com by Troutnut on June 4, 2007
Specimen Page:1234...7

2 Streamside Picture of Maccaffertium Mayflies:

1 Underwater Picture of Maccaffertium Mayflies:

View Full SizeView Full Size and Comment (1.1X larger)
AddEmail
In this picture: Mayfly Genus Maccaffertium (March Browns and Cahills). From the Namekagon River in Wisconsin.


In this picture: Mayfly Genus Maccaffertium (March Browns and Cahills).
StateWisconsin
LocationNamekagon River
Date TakenApr 25, 2004
Date AddedJan 25, 2006
AuthorTroutnut
CameraOlympus C740UZ

Recent Discussions of Maccaffertium

2 tails or 3 1 Reply »
Posted by Snagy on Feb 5, 2010 in the species Maccaffertium vicarium
Last reply on Feb 6, 2010 by Taxon
I notice that while the dun, nymph, and spinner photos on the page are all listed as March Brown (maccaffertium vicarium). While the coloration patterns all seem to follow other March Browns I have seen, I notice that the winged flies pictures all have 2 tails, but the nymphs in the photos have 3. I was under the impression this species was a 2 tailed mayfly. Is the nymph mislabelled?
ReplyAnybody know more about Maccaffertium terminatum? 3 Replies »
Posted by Troutnut on Jun 8, 2007 in the species Maccaffertium terminatum
Last reply on Jun 11, 2007 by Konchu
I just wrote up what I found on the page for this species. I was mildly surprised to see so many of a species I've never seen mentioned in an angling context -- at least a few dozen throughout the evening. They piqued my curiosity.
Replydiff between march brown &gray fox 7 Replies »
Posted by Jrcald on Mar 12, 2007 in the species Maccaffertium vicarium
Last reply on Mar 13, 2007 by Troutnut
i know that gray foxs and march browns are classified in the same family but what are the differences ? what is the color differences are both bodies the same color tan ?
Reply
There is 1 more topic.

Your Thoughts On Maccaffertium:

You must log in at the top of the page to post. If you haven't registered yet, it's this easy:

Username:          Email:

Password:    Confirm Password:

I am at least 13 years old and agree to the rules.
Top 10 Fly Hatches
BaetidaeEphemerellidaeHexagenia limbataBaetisHeptageniidaeChironomidaeIsonychiaHydropsychidaeEphemerellaEphemerella subvaria
Top Gift Shop Designs
I outfish my daddy!Electric blue Hendrickson dun.I love buggers. Big, green, wooly ones.I outfish my husband!Be the trout.
Eat mayflies.
Top Insect Specimens
Rhyacophila fuscula Caddisfly LarvaEphemerella subvaria Mayfly DunHexagenia limbata Mayfly NymphCorydalus Hellgrammite LarvaEphemera guttulata Mayfly Dun
Miscellaneous Sites