Real Fly question

I've noticed, that many mayfly spinners ( I'm currently thinking PMD, but I
believe it applies to other species ) come in either a light olive, much
like the fully dried dun of the species, or various rusty shades.

Anybody know for sure, is this a boy/girl thing? the males one color the
females another? or what ? Just curious.

Last summer I rose a nice HFork trout on a #18 rusty spinner. Over eager,
I struck a tad too fast and just felt the fish a split second as I pulled it
away from the fish. I was amazed that he kept rising, but I could NOT get
him to take another rusty spinner and I got several floats that looked ok to
me. I switched to an light olive version, same size and pattern ....
'fish on,' first cast. I thought it was in interesting experience, thus I
share it G

No to all of your questions.
The long answer is: Mayflies are unique in that they have 4 stages in their
life cycle. Where most aquatic insetcs have only one stage after they
become an adult, or dry fly, mayflies have two. they start their adult
stage as a "dun" which is usually a drab color, and when they are ready to
breed, they cast off their skin and become lighter in color and sometimes
more brilliant. They become a "spinner" They are generally the same color
as the the dun but noticably different. After they breed, they die, and
fall onto the water. Then they are "spent flies".
If you have only noticed Rusty or olive spinners, it is because you have
not been observant when calibaetis, pale morining duns, pale eveneing dusn,
etc were in their spinner stage.

"jackk" wrote

If you have only noticed Rusty or olive spinners, it is because you have
not been observant when calibaetis, pale morining duns, pale eveneing
dusn,
etc were in their spinner stage.



OK, :-), let me try again

JUST the spinner stage of just Pale Morning Duns

I have seined specimens, on the water at the same time, that have the same
anatomical details that I believe are adequate to say they were all
Ephemerella, if not the same species. Add the fact that they appear to fall
from the same mating swarms, and I feel confident that are the same species.
These specimens were either a pale yellowish olive very similar to a fully
dried dun ( I'm sure you have observed that very fresh duns are very often a
brighter shade, until they dry ) or various ( implies several ) shades of a
rusty brown.

As my HFork story implied, these shades are different enough to apparently
be discerned by trout, and most experienced people I know, on western spring
creeks, carry both colors ... to fish PMD spinner falls.

Does anyone know what this color variation within species is linked to, if
anything known beyond 'variation' ? ... I have thought maybe it was sex, but
I haven't observed carefully enough to check out gonads.

Unable to live another second without an answer, I called Montana and spoke
to a 'known to be bugwise" person. I was told that the color is related to
how old the bug is AS a spinner. In other words, when a PMD dun molts into
a spinner it will be the olive cast, but it darkens fairly quickly, and gets
darker until it falls.

This seems to fit other 'facts" I have, such as it is my "impression" that
morning PMD spinner falls have a majority of olive colored spinners, while
the evening falls seem to have a much higher percentage of rusty ones.
This is just impression, thinking back on days I remember, I've never really
counted but I do usually glance at the water and start with the color that
seems to be most available.

--------------

There is nothing original here, but while I'm typing ( and I've been tying
these which is what got my poor old brain pointed this direction ) here is a
nice "Last Light Spinner"

hook ... 100 BL ... 16, 18 ( 18 mainly for where I fish )
thread 8/0 ... rust
Tail ... dun microfibits (sp) or some such .. a little long
body .. rusty turkey biot tied smooth ( house of Harrop has high quality
biots in great colors ... I 'think' Harry Mason sells them )
parachute post ... flourescent orange poly post ... trimmed a little shorter
than you want to G... it's an indicator, not a wing
lower wing ... half dozen fibers of sparkle organza tied spent, just behind
of post and trimmed to wing lenght on each side ( optional, but a nice
touch )
thorax .. fine dubbing, rust color
parachute hackle wing ... white, the barbs roughly the length of hook
shank , trim away the part that comes out over the head, so only barbs
coming out the sides are left
liquids ... head cement if you are so inclined and WaterShed, for sure

easy to see most of the time, compared to other spinner ties, and fish eat
it