Mayfly Genus Maccaffertium (March Browns and Cahills)
Taxonomic Navigation -?-
Kingdom Animalia (Animals)
» Phylum Arthropoda (Arthropods)
» Class Insecta (Insects)
» Order Ephemeroptera (Mayflies)
» Family Heptageniidae (March Browns, Cahills, Quill Gordons)
» Genus Maccaffertium (March Browns and Cahills)
9 species aren't included.
Common Name
| Match | Common Name |
 | March Browns and Cahills |
"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
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.57 Mayfly Specimens in the Genus Maccaffertium:
Maccaffertium terminatum Mayfly Spinner
View 11 PicturesI positively identified this specimen under a microscope with a good key. It was one of the more common species in a generally light mixed bag of mayflies over a big Catskill tailwater last night.
I swooped this one out of the air while it was mating with a female, so I can be certain about her ID as well.
View 11 PicturesI positively identified this specimen under a microscope with a good key. It was one of the more common species in a generally light mixed bag of mayflies over a big Catskill tailwater last night.I swooped this one out of the air while it was mating with a female, so I can be certain about her ID as well.
Region: Catskills
Collected Jun 7, 2007
Added Jun 8, 2007
Maccaffertium (March Browns and Cahills) Mayfly Adult
View 13 Pictures
View 13 PicturesRegion: Upper Midwest
Collected May 26, 2005
Added May 16, 2006
Maccaffertium vicarium (March Brown) Mayfly Dun
View 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."
View 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
2 Streamside Pictures of Maccaffertium Mayflies:
View Full Size
This Maccaffertium mayfly dun is well-camouflaged among the moss and cedar debris on a midstream log.
In this picture: Mayfly Genus Maccaffertium (March Browns and Cahills).
In this picture: Mayfly Genus Maccaffertium (March Browns and Cahills).
I photographed the underside of this March Brown dun right after it emerged so that I would have the exact color for an imitation.
In this picture: Mayfly Species Maccaffertium vicarium (March Brown).
In this picture: Mayfly Species Maccaffertium vicarium (March Brown).
Recent Discussions of Maccaffertium
2 tails or 3 4 Replies »
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
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