F-Dun CDC Dark Olive - Dry Fly

Dry fly - F-Dun CDC Dark Olive - Dark Olive Mayfly

The F-Dun CDC Dark Olive is a slim-profile dry fly designed to imitate a dark olive mayfly at the subimago stage. Its dark olive body, clearly segmented with reddish-brown ribbing, is paired with a generous CDC wing in natural gray-brown tones.

The tying remains slender despite the prominent wing. The long amber-brown tail, dark thorax and hackle fibers set around the front of the body give the fly a detailed, lifelike silhouette. The different shades of brown, olive and gray also help avoid an overly uniform look on the water.

Which mayfly does it imitate?

The F-Dun CDC Dark Olive mainly represents dark olive mayflies at the subimago stage, when the insect has just emerged from its nymphal shuck and drifts briefly on the surface before taking off.

Its coloration can match various Baetis species, including Baetis rhodani, depending on the size and shade of the insects present. As always with olives, color can vary greatly according to the river, season and light conditions: observing the insects on the water remains the best guide.

Key strengths

• Slim silhouette: a slender body that stays close to the natural proportions of a small mayfly.
• Segmented dark olive body: the reddish-brown ribbing clearly defines the different abdomen segments.
• CDC wing: its soft fibers add lightness and movement while creating a clearly identifiable wing.
• Detailed tying: the fine tail, dark thorax and hackle fibers enhance the silhouette without making the fly overly bulky.

Fishing advice

Use it when you see dark olive mayflies or steady rises to small flies drifting on the surface. It is especially useful on glides, margins and moderate currents where fish have enough time to inspect the imitation.

Present it with as natural a drag-free drift as possible, avoiding drag. For selective fish, a fine tippet and a discreet approach will help you make the most of its relatively light, detailed tying.

Technical specifications

La Fine Mouche's take: a very attractive dark mayfly imitation, with a particularly well-defined body and a CDC wing that keeps a natural look. We especially like the contrast between the dark olive body, the reddish-brown ribbing and the lighter wing fibers, which add plenty of depth to the tying without weighing it down.