Hook Curved-shank scud/emerger hook (TMC 2487-type), 16-22 (16 is as big as you'd want)
Thread Black 70 denier
Materials
Craft foam, 2mm Black craft foam mm (strip slightly wider than thick (body))
Para post wing material (optional) White poly yarn (1 strand (indicator))
Rabbit dubbing Black dubbing (thin 1.5 in noodle (head))
Dry-fly hackle Brown hackle (1 small feather)
Head cement Clear head cement (one drop)
How to tie it
Start the black thread on the front third of the shank; snip a point on the end of a 2mm black foam strip and catch it in there with a couple of securing wraps so it can't spin, then bury the tie-in.
Push the foam up out of the way and take the thread in touching turns well around the bend. The body extends until it's almost level with the hook point.
Tie the foam down at the rear: one medium wrap, then tight turns. This sets the back of the body.
Spiral the thread back up over the foam in two or three tight bands, compressing the underbody into small segments to thin it.
Fold the foam strip over the top toward the eye, pull it fairly snug (this is a low caddis, not a humped beetle), and lock it at the front with tight turns; snip the tag as close as possible and bind it flat with as few wraps as you can.
Optional indicator: slip a strand of white para post under the thread, pull both ends up, and wrap the thread back over it to the body.
Tie in a small brown dry-fly hackle by a stripped stem, concave side toward the hook.
Dub a small head of black rabbit, a thin noodle about an inch and a half long.
Wind about four turns of the hackle over the dubbed head; tie off with two wraps, trim, and ramp a small thread head.
Whip finish, trim the indicator post shorter than the hackle tips, and add a drop of head cement.