This pattern was developed to imitate a hatching caddis pupa, which it does with remarkable effectiveness. During a hatch, an unweighted fly can be fished in the surface film or, with split shot, deeper in the water column. Were this just a hatch-matching fly, though, it probably wouldn't make my list. But the Sparkle Pupa is a highly productive, all-purpose prospecting pattern. Even if I haven't seen a caddis for weeks, I'll comb the riffles with this fly-right along the bottom-and rarely be disappointed. The shimmer and sparkle of the Antron bubble seems to be the secret, and this fly often turns the trick when more subtle or subdued patterns draw a blank.