Description
The Mayfly Dun: The Moment of Truth (The Crucial Stage)
The stage of the newly hatched adult Mayfly is called the Dun. This is arguably the most critical phase for the fly angler. Depending on surrounding circumstances such as temperature, wind, and weather, the time it takes before the Dun is able to fly away from the surface will vary.
These newly hatched Mayflies are often an easy and vulnerable target for the fish, and many will end up in Mr. Brown Trout’s stomach. When the hatching is frequent, many fish species might become selective and only feed on Duns.
Our Commitment: Perfect Imitation
Our commitment is to provide imitations of the real insect where the fly has the right shape, size, proportions, and colours, and, not least, leaves the correct print on the surface of the water.
This imitation of an adult mayfly in the Dun stage possesses all the right proportions and properties. It looks natural, feels natural, and fish will eat it.
Our Large-Winged Dun Imitation Features:
- Correct Surface Print: The imitation creates the precise silhouette on the water film that triggers the selective fish.
- Optimal Vulnerability: Designed to mimic the wing-drying, vulnerable Mayfly just before take-off.
- High Quality: Exact proportions and colours perfectly match the natural insect.
Recommendations for Best Results
We do recommend you to use a J:son Swivel for all your fly fishing. However, it is necessary to use a J:son Swivel whenever you are fishing a J:son fly in size 1 or 2 to ensure perfect presentation and minimize line twist.
The Spring & Autumn Staple – J:son Mayfly Dun 3 Olive Grey (Hook #18) The Olive Grey Dun in size #18 is a masterclass in precision, designed to match the globally prolific Baetis species (Blue Winged Olives). These small but vital insects dominate hatches during the cooler months of spring and autumn, often appearing in massive numbers on overcast or drizzly days.
Tied on a delicate size #18 hook, this imitation captures the exact silhouette and subtle olive-grey hue of the natural insect. Its realistic, air-filled wings and segmented foam body ensure a perfect water footprint, making it nearly indistinguishable from the real thing on a calm surface. When trout focus on small, dark-winged duns and refuse larger patterns, the Olive Grey Dun #18 is your most reliable solution for fooling selective fish in clear, slow-moving waters.