Well, I know it doesn’t make perfect sense. But, it was the first thing that came to mind and then I dissected the realities of the underwire showing. Let’s forget that part.

underwire swittersbHere the flash bounces off the bead head, the hook’s bend and the wire ribbing around the pupa’s abdomen…hence the ‘underwire’ reference. Wire ribbing is used to do a couple of things: secure materials to the hook and make them more durable; add some weight; add segmentation and sometimes provide a degree of flash with the right lighting situation.

The light’s glint off the bead head, the sparkle dubbing in the thorax, the movement of a Starling hackle fiber in the wing or perhaps that segmented wire wrapping might trigger a follow and take.