"Willi" wrote

I'm definitely no entomologist but I think there are a number of
different mayflies that are lumped into what fishermen call "Baetis" -

for sure, and there are actually a lot of baetis species, too ... even for
the entomologists

some places the fishermen seem to use "baetis" others "BWO" and others
"olives" ... I think all those places and names account for a lot of
different bugs with very similar characteristics ........ I've given up on
sorting out the true entomology, although, by nature, I'd like to be able to





My favorite fly for the hatch is a CDC comparadun with either a quill or
thread body, 3 spread filarabits? for a tail and a lightly dubbed
thorax.



Neither of my two favorites was in my photo, I should have looked harder G
.... one is very similar to what you describe, but might be called a CDC
Sparkle Dun ...I sometimes use a quill body, sometimes just dubbing and
thread. The other is a knock down dun, really a thorax tie with the
wing on one side instead of the top ... lightly hackled, v-clipped on bottom
.. A PT nymph, floated, is another "first choice" and as you and others
on roff have pointed out a RS2 is hard to beat ... my variations include
sparse zelon or a doubled strand of crystal flash for the tails, not, to be
honest, because of effectiveness, but because I have a bitch of a time tying
and splitting two microbibits in these small sizes.

I agree size is far more important than color, and one reason, imho, the RS2
is so strong is it's extra sparseness

Thanks for all the other info, chasing Colorado Olives remains on my 'hope
to someday" list