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 Golden Summer Match – J:son Mayfly Dun 3 Sulphur (Hook #18) When the summer warmth triggers the emergence of the bright, golden-yellow Sulphurs (Ephemerella spp.), trout can become notoriously single-minded. Our Sulphur Dun in size #18 is specifically designed to match these high-visibility hatches that define early summer fly fishing.
Tied on a precise size #18 hook, this imitation perfectly mirrors the vibrant yellow body and delicate wing profile of the natural Sulphur. The realistic foam body and air-trapping wings ensure it sits high in the surface film, exactly like a newly hatched dun drying its wings. In the clear water and bright light of June and July, the flawless silhouette and "Sulphur Yellow" hue of this Dun #18 provide the realism needed to fool even the most cautious trout during a heavy hatch.