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 Micro-Hatch Specialist – J:son Mayfly Dun 4 Cinnamon Brown (Hook #22) The Cinnamon Brown Dun in size #22 is a crucial pattern for any angler facing selective fish during the late summer and autumn months. As the season progresses, mayfly generations often decrease in size, and these tiny, cinnamon-colored duns (often from the Baetidae family) become the primary target for trout and grayling.
Tied on a fine size #22 hook, this fly offers the perfect combination of a delicate cinnamon-brown profile and J:son’s famous durability. The realistic foam body ensures that even this tiny fly floats high, while the wing silhouette mimics a small dun ready to leave the surface. This is an essential "low-water" fly for calm rivers and glassy lake surfaces where trout have plenty of time to inspect your offering.