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 Ultimate Micro-Imitation – J:son Mayfly Dun 5 Black (Hook #24) When the "Angler's Curse" is in full swing and the water surface is covered with thousands of tiny, dark specks, even a size #22 can be too large. The J:son Black Dun #24 is specifically engineered for these extreme situations. It is the ultimate imitation of the smallest Caenis species and other micro-mayflies that hatch in staggering numbers during warm, windless summer evenings.
Despite its incredibly small size, this fly maintains the anatomical precision that J:son is famous for. The dark foam body offers surprising buoyancy for a size #24 hook, and the delicate wing silhouette provides the exact visual trigger required to fool large, selective trout feeding on micro-insects. When fish are rising in a rhythmic, "sipping" motion to insects you can barely see, the Black #24 is often the only way to turn a frustrating evening into a legendary session.