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Discussion Starter · #1 ·
Here's one for some of you more knowledgeable in the intimacies of entomology.
Fishing on the South Fork Snoqualmie last fall, i saw quite a few unidentified Mayfly Spinners (my identification skills are somewhat lacking, and i didn't have a camera at the time). They were about size 12, pretty standard mayfly shape and all, and it was sometime in the afternoon.
The interesting thing about these buggers was that their bodies were blood-red. I couldn't remember anything about a mayfly that naturally looks like this in any of my books. I did also notice, however, that there was a small stream or drainage ditch emptying into the South Fork nearby upstream which was the same red color. I suspect it was colored by a high iron content, but it wasn't the usual rusty-brown color that is pretty common.
I'm curious if anyone else has seen what i'm talking about.
The best theory i could come up with is that the mayfly nymphs in question lived in or just downstream from this drainage ditch, and accumulated a very high level of iron (or whatever)in their bodies, and in turn gave them this blood-bodied color.
Does anyone else know if this is actually possible, or is there some species of red mayfly i'm not aware of? Just thought i'd throw this out there in case we have any scientists in the group.:dunno
 

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I've seen a lot of PMD's that were rust- or burgundy- color, especially as a spinner (the rusty spinner is the fly that works for that), although I've never seen them in much volume on the Snoq and I've never seen one that is "blood-red." But, I suspect this is what you were seeing.

Circlespey
 

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You could try and find out by checking an entomology book or you could just sit down at the tying desk and start tying. Or you could head over to the flyshop and look for a duplicate to match.

If you are just wondering what species it is, you need to get an image of the bug. There are too many differences in species to try and identify it by only size and color.

The species you are referring to is very common in Washington. Probably an imago of the A.M.B.. The wing is the big identefier. Are there dark veins in a transparent wing or are the veins verigated or are the wings completely transparent? Is there a secondary wing? How many tails? How many segments? Are the eyes large or small and what color are they?

If you have answers to thers question, I have your species.
 

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Discussion Starter · #5 ·
yeah, good call troutman.
those are pretty much the most important features in identifying mayflies, and i didn't study it too hard at the time. color seems to be the least reliable feature, since there's so much variation within species. i'll be on the prowl this summer with a camera and a good ID book.
 

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I know exactly what you're talking about. After the caddis are done, you see a crapload of these every year. I've been told they're either Pale EVENING Duns, or Mahogany Duns.....who knows, just tie something to match em. :thumb
 
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Yeah.... and a March Brown is a Rhithrogena species, but there are others. I've seen the same spinner fall and was confused by the size of the spinners (pretty large, and dark) and the time of year (late summer, fall). I do recall their clear wings.
After much investigation, I surmised that these were probably of the Rhithrogena family but not a March Brown. There are other Rhithrogena that'll apparently hatch as late as the ones encountered on the South Fork (in higher-elevation mountain freestones and creeks). And I don't think the South Fork is high-enough elevation to put off March Browns from late-Feb - April to July through October.
Because of this mayfly, I always have some #12 and #14 H&L Variants which the fish seem to respond to very well - not just opportunistically but perhaps by recognition as well. It's a well-hackled, higher floating pattern (non-spinner specific features, but nice on the SF) but covers the size, shape and sillhoette well - heck, these are South Fork fish we're talking about... I know people who fish just one fly on that stream and catch puh-lenty o' those creek trout.
:beer2
 
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