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> > Maccaffertium vicarium... "March Brown" ...nymph

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BrookymanJanuary 30th, 2013, 1:14 am
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Posts: 797
I am going through some files. " March Brown"

A classic vicarium variant for my area. The [tergal] or top of abdomen marking are unique to most of my vicarium samples. Just goes to show how different they can appear

Mack.
Banned for threatening another user and then trying to circumvent a kinder "soft" ban with fake accounts
EntomanJanuary 30th, 2013, 4:48 am
Site Editor
Northern CA & ID

Posts: 2604
Very nice. You say this one is different from most of yours? Are the different ones you mentioned from the same stream? If so, post some pictures of your usuals for comparison. The reason I ask is because the different markings may be a gender character. Unless this is an earlier instar than I suspect, the spread, shape and size of the eyes makes me think this one is maybe female - which wouldn't make sense because if anything it should be the most common in your samples.

Those curly M shaped pale dorsal marks are fairly common, though maculation and marking differences outside those used in the keys seem to be highly variable with each ecosystem supporting different ones... Here's one that's similarly marked, but then again not.:) http://www.troutnut.com/fullsize/picture-im_regspec/842.

Anyway, I agree it's vicarium but I don't know about it being a variation as even by older standards the fully darkened posterior margins of the 9th sterna was a key character separating it from its synonymy, S. fuscum (Gray Fox).
"It's not that I find fishing so important, it's just that I find all other endeavors of Man equally unimportant... And not nearly as much fun!" Robert Traver, Anatomy of a Fisherman
BrookymanJanuary 30th, 2013, 6:05 pm
Banned
Posts: 797
Hey Kurt loaded another sample last 3 pictures.

Take a peek at the last 3 pictures that one has the very common marking. The ventral markings are more vibrant like. The arrows on the posterior bands that point forward are more advanced and the intensity of the maculation is very strong all the way towards the thorax. The dorsal side is also more typical of my vicarium. The dorsal median line that is very common is also more common for my vicarium. They were taken on the same day same riffle.

I also should have said maculation variation.

Mack.
Banned for threatening another user and then trying to circumvent a kinder "soft" ban with fake accounts
EntomanJanuary 30th, 2013, 8:38 pm
Site Editor
Northern CA & ID

Posts: 2604
Ah! Yes, I see what you're saying. The markings on the dorsum are even more different. Leg markings too! The latter specimen looks to be at a later instar so that is probably the reason. If these differences remain through the black wing stage, my next thought would be a gender difference, though the eyes look pretty similar to me. Perhaps the easiest way to tell the difference is the females will be substantially larger. However, if these specimens maintain these obvious differences throughout development, are determined to be the same sex, and are from the same stream, I would think these differences are enough to think in terms of the possibility of a different form.

I also should have said maculation variation.

Ha! And I thought you finally started off a thread using the latest nomenclature and would bring up the older synonymies as the discussion developed.:)
"It's not that I find fishing so important, it's just that I find all other endeavors of Man equally unimportant... And not nearly as much fun!" Robert Traver, Anatomy of a Fisherman
BrookymanJanuary 31st, 2013, 3:36 pm
Banned
Posts: 797
It is a funny looking one. One thing I can say is that very sample that has the typical 9th segment all blacked out they all key out the same in fine detail as vicarium. I think you nailed it. The instar state is the best answer that I think could apply to this situation. However the dorsal making are very unique verses the typical sample have the median dashes from the tenth forward.

Wait till you see my luteum larva it is very unique to most taxa illustrations and photographs. But it always keys out the same to luteum. However you brought some light to things in the other thread about go between samples. I can't help but wonder because all the samples that you and I are looking at all come from the same waterway and most often the same riffle. I say I wonder because all the farming and industry have left that area over the past 20 years. In the headwaters at site STENO-07 from the thread regarding collecting plan, I can and have drank that water right from the stream. 20 years ago you would have not even went in that water. It just makes a man wonder if that change from a destructive environment to being what it was 150 years ago if that has had a impact on all species. Remember that Heptagenia nymph that I load a while back that was right between 2 spies or so it appeared that also came from the same waterway. Also all my luteum's are coming from riffles and not open water as described in all past papers.


Mack.
Banned for threatening another user and then trying to circumvent a kinder "soft" ban with fake accounts

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