Pale morning duns (PMD) are one of the prettiest little bugs that hatch in our local rivers.
We see adults in hues of pink through yellow, and the nymphs are typically rusty red in color.
I consider these bugs the “medium-sized” mayflies we encounter, compared to the blue-winged olives, in sizes 20 and 22, and our gorilla green drakes that are as large as size 10.
The PMDs we see are usually size 16 and 18, and tend to hatch midday.
All mayflies go through different stages in their life cycle, and the final stage of a PMD’s short-lived adult (dun) life is called the spinner phase.
After the aquatic transformation and emergence of the nymph (emerger) into an adult, they undergo yet another transformation outside of the water and become spinners.
Spinners are easily recognizable because of the extremely long tails they sport, and the graceful “dipping dance” they perform over the surface of the water.
Spinners are the egg layers for future generations of mayflies, and they always deposit their eggs slightly upstream from where they hatched out of the river.
If this didn’t happen — and this applies to most aquatic insects — these bugs would eventually wash down all the way to the oceans they feed.
Pretty smart, huh?
PMDs are now officially on the scene in the Roaring Fork and Fryingpan rivers, and we are seeing heavy numbers on the cloudy and warm days.
Our float guides have already seen a few “blanket hatches” on the Roaring Fork, and the hatch up the Fryingpan has just gotten kickstarted over the last few days.
If I had one PMD dry-fly pattern to fish with, it would be AK best’s melon quill in sizes 16 and 18, and for subsurface, Jeremy Stott’s mellow yellow takes the cake.
Everyone around here is obsessed with green drake mayflies, but pale morning duns are the loveliest in my book.
See you on the river, folks.
— This column is provided each week by Taylor Creek Fly Shops in Aspen and Basalt. Taylor Creek can be reached at (970) 927-4374 or taylorcreek.com.