Body Black stretch vinyl (Stretch Flex/Midge Flex/Scud Back) (1 strip)
Rib Fine silver or red wire (1 length)
Thorax Black thread or fine dubbing (as needed)
How to tie it
Slide a white bead to the hook eye. The white bead imitates the white gill tuft of the chironomid and helps sink the fly. Start thread behind the bead.
Run thread down the curved shank to the bend and tie in the wire rib, then tie in a strip of black stretch vinyl by one end.
Build a slim, smooth thread underbody forward to just behind the bead.
Spiral-wrap the stretch vinyl forward in overlapping turns to form a slightly tapered, segmented body, and tie off behind the bead.
Counter-wrap the wire rib forward in 5-6 evenly spaced open turns for segmentation and to give a gas-bubble sheen, then tie off.
Build a small thread or dubbed thorax right behind the bead, whip finish and coat the body (not the bead) with head cement or UV resin for durability and translucency.
The slim profile and shiny rib mimic the gas trapped under the pupal shuck.