Phil’s Top 6 Patterns for Spring Mayfly Hatches

Geoff Grant of Orvis Adventures hooked this beautiful brown on a Parachute Adams last spring.

While I have yet to see my first trout rise of 2023, I know it will happen soon—the photo above was taken on May 1 last year—and I’ve seen plenty of photos from other parts of the country where mayflies are already popping. The next six weeks should feature the best dry-fly fishing of the year in Vermont, and I am ready to spend as much time on the water as I can.

I’m definitely one of those anglers who believes that presentation trumps imitation when it comes to fooling trout, so I do the vast majority of my fishing with a small number of flies. For mayfly season, I like patterns that are designed for different kinds of water, are visible even in failing daylight, and can be tied in a variety of colors. I almost always fish tandem rigs—dry-and-emerger or dry-and-spinner—to increase my chances of getting a strike and enhancing visibility. Here’s my basic selection, which covers almost any mayfly hatches I’ll encounter in the near future.

Parachute Adams (sizes 12-18)

No surprise here. The Parachute Adams works great as both an imitation of a mayfly dun and as an indicator pattern for the smaller fly tied behind it. At dusk, that bright white post can mean the difference between success and failure. In a pinch, you can even trim the hackle to make it look like a spinner.

Sparkle Dun (sizes 18-22)

I learned to love the Sparkle Dun when I guided at Hubbard’s Yellowstone Lodge in Montana in the mid 1990s. The fly sits low in the water, so it’s perfect for slow, flat stretches of river where the trout are extra wary. It’s my go-to for anything smaller than a size 18, and it works as an emerger in those tiny versions. Changing the colors of the body and tail allow you to imitate a wide variety of insects, and a wing tied in brightly colored deer hair can help with low-light visibility.

Light Cahill (sizes 12-18)

In the Northeast, there are a bunch of large, pale mayflies that hatch in spring and early summer, and the Light Cahill works for all of them. It’s also very buoyant when you apply floatant, so you can fish it in rough water without it sinking. I often use this as a searching pattern at dusk, when fish might also mistake it for a caddisfly or small moth.

CDC Mayfly Emerger (sizes 16 and 18)

For a general mayfly-emerger pattern, this one is tough to beat because it is just so buggy looking. I usually fish it on an 18-inch dropper line of 5X or 6X, with a Parachute Adams above it.

Bread Line Emerger (sizes 16 and 18)

For lighter mayfly species–light Cahills, sulfurs, and the like–I switch to a Bread Line, which offers good contrast between the body and the trailing shuck.

Rusty Spinner (sizes 12-18)

Evening spinner falls provide some of the best opportunities to catch big brown trout because the dying mayflies provide an easy meal and the low light makes the wary fish feel safe from predators. The Rusty Spinner covers most mayflies, and the key is to keep it right in the film, which makes it hard to see. Plus, takes can be extremely subtle. This is why a more visible top fly is often necessary.

Phil Monahan is Managing Editor of Brand Content for Orvis, and he’s been editing this blog since 2010.

3 thoughts on “Phil’s Top 6 Patterns for Spring Mayfly Hatches”

  1. Got my first trout of the season on a dry fly yesterday, April 26, 2023. It wasn’t on mayfly, but on a black Puterbaugh foam caddis #16. After observing what could have been two rises in fairly fast water, I changed from my leech and nymph to that dry caddis, followed by a green caddis pupa dropper. First cast resulted in a refusal. Wow, seeing those trout eyes right behind the fly always is exciting. He/she smashed it on the next cast. Great fight on a 4 wgt. Tried to get into the bankside boulders and brush, but I did land and release a fat 13+” rainbow. Not a giant, but a fun way to start the dry fly season.

    Have Fun!

    PeterG – Batavia, Illinois

  2. Hi I can see a very nice fishing congratulations for the great catch!!!!
    I was wandering if you happen selling fishing flies for fly fishing?

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