J:son Mayfly Dun 2 Vanilla Cream #12

The Mayfly Dun: The Moment of Truth

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. When the hatching is frequent, many fish species become selective and only feed on Duns. To succeed, your fly needs the right shape, size, proportions, colors, and, not least, the correct footprint on the water.

J:son Mayfly Dun 2 Vanilla Cream (#12)

The Pale Summer Specialist – Ephemera Danica & Vulgata Expert The J:son Mayfly Dun 2 Vanilla Cream in size #12 is a precision-engineered 20 mm dry fly. This specific color profile is the gold standard for imitating the large, pale mayflies that define the peak of the fishing season. It is the ultimate choice for matching the European Green Drake (Ephemera danica) and the Lakeshore Mayfly (Ephemera vulgata) during their most active hatching periods.

Why this fly delivers:

• Correct Surface Print: The combination of an extended foam body and precisely shaped upright wings creates the perfect "sail" silhouette. This specific footprint on the water film is the primary trigger for large, selective trout.

• Optimal Vulnerability: This imitation is designed to sit in the surface film exactly like a natural dun struggling to dry its wings. This "vulnerable" posture makes it an irresistible, high-protein meal.

• Unsinkable Foam Technology: Utilizing J:son’s proprietary foam-body technology, this fly offers incredible buoyancy. It rides high and stable, requiring minimal maintenance even after multiple catches.

• Anatomical Accuracy: From the realistic, air-trapping wings to the delicate tail filaments, every proportion is modeled after the real insect to pass the "inspection test" in slow, clear water.

Pro Tip: For a J:son flu 1-2 fly with its large wing surface, it is highly recommended to use a J:son Swivel. The wings can act as a small propeller during casting, which often leads to leader twist. A swivel ensures a natural presentation and keeps your line in perfect condition for the moment a trophy fish rises.