Published Mar 1. 2023 - 1 year ago
Updated or edited Mar 4. 2023

The Day Drifter caddis: A More Lifelike Peeping Caddis Fly Featuring a Caddis Worm That's Got Legs


Image: Comparison of the Day Drifter Caddis (left) with the natural Brachycentrus occidentalis


A video describing the backstory of the fly and how to tie it is posted at:



Most rivers in the Western USA have a Brachycentrus (occidentalis) hatch starting in later April that peaks in May called the Mother's Day hatch. This hatch is increasingly important for daytime fly fishers in that Brachycentrus is now recognized as a cased caddis that drifts during the daylight hours and not just at sunrise & sunset.

A Brachycentrus larva looks like a worm with six joined legs. The caddis worm color varies from chartreuse & pastel shades of green that lighten all the way to a cream color in some individuals. Brachycentrus uses the locally available sodden plant debris that are assembled into a stick-built chimney-like case. The debris is held together by a silk-like material the caddis itself excretes. The color of cases on the Upper Arkansas River where I fish are very dark brown to almost black. In the video, Brachycentrus cases from other rivers are seen as banded tan & brown stick-built chimney-like tubes.

Not widely utilized is the fact that the worm is not fixed in its case & can extract itself out of its case if needed. The often brightly colored larva has been observed sliding in and out its case, so that as it drifts it can signal a flashing color to the trout. The larva also holds its legs well out from its body as it forages for food. It is these natural extensions of the worm body and legs out of the case that the Day Drifter caddis mimics.

The peeking caddis pattern was developed by George Anderson circa 1970s to imitate the Brachycentrus of the Mother's Day Caddis hatch on the Yellowstone River ( ). Reportedly, Anderson thought the key to a successful cased caddis pattern was it had to convince trout that the case contained a living caddis worm. To represent the worm Anderson tied in a greenish dubbing band just ahead of the brownish case. Hence the name “Peeking Caddis” is used for a fly tied wholly on the hook shank. The style of this fly tied with a caddis worm extending out over the hook bend is called the “Peeping Caddis.”


Hook: I like to use 2x wide gap hooks with a 1 cm shank length--like the Firehole 633 or Tiemco 206 size 12-14 to imitate fully mature cased caddis. Smaller hook sizes imitate less mature larva.

Thread: SemperFli brand nano-silk brown 30 denier.

Ribbing: UTC Ultrawire amber color in small (0.1- 0.15mm) size. If a darker case is desired, use black wire.

Caddis Worm: Take an old chartreuse, green, or cream, colored fly line and, using pliers, strip off about five mm of the fly line’s PVC coating to expose the Dacron core. Use a bodkin to tease apart the fibers of the exposed Dacron core. Color the exposed fibers and cut butt end of the PVC fly line dark brown using a permanent marker. Finish the caddis worm by using scissors to cut the middle fibers out to make two groups of about 3 legs each. Cut off the fly line at an angle about 1 cm from the legs and tie that angled piece in on the top of the hook shank so that it projects out like a tail about 4-8mm from the hook bend: how far out is a tyers choice. It seems to me that trout can respond well to an absurd-looking worm hanging way out there.

Weighting: Optional--no bead or lead wire at all in the lightweight version--use instead a long taper cut piece of fly line to form the underbody for the case. For the heavy version place a 2-2.5 mm black bead just behind hook eye. I prefer not to use a bead at all as it really looks out of place at the small end of the case. To compensate, I add quite a bit of weight under the case by lashing three short pieces of 0.015-to-0.020-inch (0.4-0.5mm) lead wire on top of the shank and over the lashed in piece of fly line. These three pieces, along with the underlying hook shank to form a square cross section that if done right form a taper down to the hook eye. The weight on top of the shank acts to invert the fly so that the hook point drifts up & reduces fouling. The lead pieces are stopped well short of the hook eye and staggered as to where they are tied off at-- so that the micro-fritz body can be tapered down towards the hook eye.

Case: The stick-like debris that Brachycentrus uses for its case are usually shades of tan, brown, dark brown & on up to brownish black. Use a color of SemperFli micro-fritz to match the natural in your river. For the U. Arkansas River where I fish, I use the dark mocha brown fritz. After the weight is lashed in, cut and tie in a 3-inch piece of micro-fritz at the hook bend. Wind the micro-fritz over the caddis worn then side by side on down the taper to the hook eye. Spiral the ribbing wire forward over the micro-fritz body. Whip Finish.


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