Genus: Maccaffertium
Species: Vicarium (I think)
Common Name: March Brown
Location: Berks County freestoner

Species is widespread in PA and one of our major hatches. It produces good nymphing ahead of and during the hatch, decent dry fly activity during the hatch, and monster but sometimes frustrating spinner falls. Time period is generally the month of May, early May in the more southern areas and getting later as you go north. Typical size is 10-14.

This guy was more like a 16, mid-June, and he wasn't an outlier, there was a fishable hatch going on. So that leads me to question the ID a bit, experts feel free to weigh in. But it was on a fairly cold, infertile mountain freestoner which could explain the late date and smaller size.

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Here's another picture of a March Brown, this one a poorer picture of a dead one in a cob web. Venango County freestoner. Size is closer to a 12.

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  March Brown2.jpg (50.82 KB)

Given that it is a spinner in your picture and you said it was from a mountain stream Ill have to say:

HEPTAGENIIDAE Stenonema nepotellum GREY FOX body-YELLOW wing-YELLOWISH CREAM,VIENED legs-CREAM VARRIANT DYED YELLOW size-14-18 mm. 6-8 EM 07/01/00 tails-2

Could be. FWIW, Stenonema nepotellum no longer exists. Reclassified as Maccaffertium mediopunctatum.

So if your right, I have the genus correct, but the species wrong, which is common with me. If so, the common name is Cream Cahill, not March Brown. Would help explain the timing and size. The brownish color threw me for a loop I guess, but individuals vary so much.

Still unsure, though. Just pretty sure on the Maccaffertium genus, which covers March Browns and a bunch of other species commonly called cahills (light cahills, cream cahills, etc.)

Mods, if the consensus turns out to be Maccaffertium mediopuncatum (Cream Cahill), feel free to change my first post and remove my 2nd one.

all of my data is older names, haven't had the chance to upgrade yet.over 50 years of data taken so far...I am still adding the caddis and stoneflys to it. this data was started by other people and given to me. printed out it fits a 7' by 6' wall.. with a few extras..It is detailed though and i only post parts of it..I even have the dubbing colors listed..

The second flysure doesn't look like a march brown to me, it looks like a coffin fly hand upside down in a spider web, it feet are pointing skyward.

It's a long dead MB in a cobweb. Coloration probably considerably different from a live bug, though, thanks to the length of time it had been dead.

Still torn on the original picture, but leaning more towards Sandfly's ID than my original one.

heres a pic of a MB spinner from penns creek 2 jams ago

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