Dry FliesAutumn Dun Variant
The Autumn Dun Variant is a dry fly pattern designed by Cory Muench. This effective pattern works well in a variety of water conditions and is tied with traditional materials for a proven presentation.
Spring, Summer, Fall
Intermediate
Trout
Feb 2026
Overview
Cory Muench developed this pattern specifically for late-season mayfly hatches when darker insects dominate. The variant style features oversized hackle that creates a larger footprint on the water, helping it stay visible in autumn's lower light and choppier conditions. The color scheme matches the rusty browns and olives common in fall mayflies, making it a go-to choice from September through November.
Materials
Hook: Tiemco 102Y #15
Thread: Benecchi 12/0, grey
Tail: Grizzly barbs, dyed dun
Body: Pine squirrel underfur
Wing: CDC feathers, natural
Head: Pine squirrel underfur
Behavior & Presentation
Natural Behavior: Fall mayfly duns emerge in cooler temperatures, riding extended drifts as wings dry slowly in humid autumn air. Slower metabolism prolongs vulnerability.
Where Trout Eat It: Fish sip late-season duns drifting through runs, in tail-outs, and along seams during extended autumn emergence periods.
How to Fish It: Fish drag-free drifts through feeding lanes, focusing on visible rise forms. Extended drifts often trigger takes as fish inspect carefully.
Best Water: Work tail-outs with slow current, seams between flow speeds, runs with moderate depth, and riffle edges.
Strike Type: Expect deliberate rises or gentle sips as trout methodically feed on extended drifts.
Fishing Strategy
Rigging Suggestions: Use a 9-12 foot leader tapering to 5X tippet for delicate presentations. Apply floatant to the body and hackle.
Seasonal Timing: Most effective during peak feeding periods at dawn and dusk. Water temperatures between 45-65°F typically produce best results.
Pro Tips: Floats well with proper floatant application. The natural materials provide good visibility without spooking wary fish.
Entomology
Late-season mayfly duns emerge during cooler autumn temperatures and ride extended drifts while their wings slowly dry in the cool, humid air. The combination of slower metabolism in cold water and prolonged exposure time makes these fall emergers particularly vulnerable to methodical feeding by trout preparing for winter.
- Order
- Ephemeroptera
- Common Name
- Mayfly
- Organism Type
- insect
- Life Stage
- adult