CDC Biot Comparadun   -   Originator : Shane Stalcup (U.S.A.)    |   Size: 16 & 12    

The CDC Biot Dun has a reputation for fooling discerning fish, and is arguably the most effective small mayfly imitation around. It makes for the most delicate of presentations and is surprisingly visible on the water. Because the body sits within the surface film it also works when fish are taking emergers. The Wildflies version is constructed using an alternative winging procedure to produce a more buoyant fly with a comparadun wing.

The size 16 version imitates the duns of Deleatidium mayflies while the size 12, with its flash of yellow, represents those of the spiny gilled mayfly Coloburiscus humeralis.   

Fishing tip:  Treat the tail, abdomen and thorax with paste floatant, ensuring that you don't get any on the CDC (protect the wing between the thumb and forefinger of the opposite hand when applying). The drawback of CDC dry flies is that having caught a fish they need to be dried completely before they can be fished again. Simply rinse off the fish slime, remove excess water with a couple of false casts and dry on your vest while fishing another.   

Coloburiscus Dun