Pale Morning Dun - The bug that keeps on giving

Pale Morning Duns They are that mayfly that we love to love, and there is a great reason for that.  They are prolific, widely distributed...

Pale Morning Duns
They are that mayfly that we love to love, and there is a great reason for that.  They are prolific, widely distributed, long-lasting and would easily be in the running for the most important food source for trout in North America.

This PMD is darker than many

Not to get too deep into the entomology of these bugs, but the term PMD (pale morning dun) is used as a blanket term to cover a bunch of distinct hatches.  The genus Ephemerella includes such popular mayflies as the Hendrickson, Red Quills, Sulphur Duns, Pale Evening Duns and of course, the Pale Morning Dun.

We know that anglers love to geek out on bugs, but we have to keep it simple, so we here in the Northwest, we refer to a smattering of summer mayflies as PMDs.  

While there are some subtle differences in these insects, they are all alike:  Trout can go crazy for them.  

Other similarities in the different species are that they are riffle-lovers.  Mayflies that hatch in riffles are the ones that draw the anglers to the water and the fish to the surface.  They can range from a #10 on the big side to a #22, but a nice, easy to see #16 is a really typical size.  They can range in color from a pale yellow to an olive to a mostly brown and maybe a little on the orange side of things.

Pink Cahills are in the same genus

They don't always hatch in the mornings either.  There is typically a nice hatch when the sun is off the water on our local favorite waters here.  Early and late are the times to fish.  However, there are plenty of rivers across the US where we should call these Pale Afternoon Duns, as the mid-day hatch is the main attraction.  The South Fork Snake is infamous for a mid-day mayfly hatch during  July and August.

This is my take on Mayflies:  As a rookie trout guide in the Rocky Mountains, the owner of the lodge personally trained all the new guides.  He had been guiding there for over 50 years, and forgot more about trout than most anglers will ever learn.  On day one, we see some mayflies hatching.  He asks me what bugs those are.  I wanted to impress, so I said "ephemerella, a pale morning dun". He scoffed, and then said "Boy, those are a #14 yellow".

A Sulphur Dun is closely related

The point of that is that there are a ton of great patterns that will work really well for our favorite summer mayfly, and not all of them say Pale Morning Dun in the name. Some may even have a different insect in it's name.  The Parachute Sulphur is an excellent PMD pattern, but many western anglers may shy away from it as Sulphur Duns are considered an east Coast hatch.

Our shop favorites include:
Pale Morning Dun
Sulphur Biot Dun
Callibaetis Quill Dun
Parachute PED
Red Quill

So don't be shy when selecting PMD flies.  Local variations on the insect can work across time zones, and by experimenting a little with fly selection,  you may just find the next hot new pattern for your home waters.