Sulphur Dun - Dun

Often time there is some confuion regarding the Sulphur Dun and the Eastern Pale Evening Dun as they are very simnilar in appearance. However, the Sulphur dun is a true sulphur color while the Eastern Pale Evening dun is more tan in color. The Sulphurs will hatch about two weeks later than the pale Evening Duns.

The sulphur dun mayfly hatch usually takes place in the late afternoon, usually when the water and air temperatures are relatively warm. This hatch can often last up to two hours on a sunny day, and even longer when it's cloudy.

Due to the warm temperatures at the time of the sulphur dun hatch, the adult mayflies can dry their wings quickly. This means they only ride on the surface of the stream a short time before flying away. The hatch occurs in slow moving or almost still water, never in swift water.

Just prior to the hatch, the sulphur dun nymphs move to the nearest slow moving water from the moderately flowing water they live in. Ideal places to fish in streams with pocket water is the calm water pockets and the shallow portions of the pools. The reason for this is that the sulphur dun's wings occasionally do not dry adequately prior to the insect's being caught in the faster moving water. Most of the time, however, the duns are able to dry their wings in the slow moving water and fly away.

As always, our Perffect Fly sulphur dun fly pattern is designed to be the most imitative pattern around.

As a side note, the South Holston River tailrace is known throughout the southeast for its sulphur dun hatch.