There is a tendency among some fly fishers to view caddis flies as a less complex insect when compared to mayflies. To a certain extent, this is a valid perception but there are times when a caddis hatch can yield difficulties requiring an imitation that does not conform to a common image associated with the stage that can cause trout to feed from the surface. I find this to be particularly true during a heavy emergence when trout have the opportunity to select only those individual insects that are least likely to escape quickly from the water.
In the U.S.A., it was probably the late Gary LaFontaine who introduced caddis patterns that target the brief but often attractive transition from caddis pupa to winged adult. Putting my own touch on LaFontaine’s concept, was mostly a matter of exchanging CDC for the synthetic yarn used in the original, but the Bubble Back Caddis possesses a couple of other distinctive features as well.
While fished mainly as a dry fly, the CDC Bubble Back Caddis is tied without wings or hackle. This pattern draws its name from the bubble effect created by cupping the CDC feathers over the abdomen in a manner that provides remarkable flotation with little else to support the fly. Like most other emerging patterns, this fly rides fairly low in the film and should be fished either dead-drift or twitched gently with the rod tip.
Olive, Tan, Gray, and Black are the colors I find most useful on the waters of the Yellowstone region, although the color chart for caddis does not end there. Adding a selection of Bubble Back Caddis to your fly fishing boxes can provide a back-up plan for those times when trout seem unusually resistant to a more common representation of this important insect.
CDC Bubble Back Caddis
Hook: TMC 206 BL size 12-20
Shuck: Sparse tuft of dubbing over three Wood Duck fibers
Abdomen: Paired CDC Feathers looped over dubbed body to create a humped effect.
Legs: Partridge fibers tied as a collar.
Thorax: Dubbing to match natural
Rene’ Harrop with a fine Yellowstone rainbow trout – on the CDC bubble back caddis.