This pattern was developed by Ralph Cutter, local guide out of Nevada City, CA. A simple fly to tie, Ralph attributes it's success to the translucent Krystal Chenille that emits a perfect glow and the hackle which gives a halo sillouette to the fly appearance from under the water. But readily admits that "any old beetle pattern probably works just as well".
Fish this pattern where snails are abundant, especially in alkaline lakes, like Lake Davis. Look for snails in the foam lines or shorelines of the lakes. Use a floating line with a greased leader within 2 inches of the fly.
Cast the fly and let it drift naturally. In addition, you can utilize a slow strip or hand twist retrieve. Using an intermediate line and an ungreased leader, the snail will sink and this can be a good thing. Doug Oulette, a fishing guide out of Reno, will let the snail sink a couple of feet and raise the rod tip while pulling back on the line with his stripping hand with one long pull. This brings the snail pattern to surface quickly. He noticed that snails will often rise to the surface quickly with an attached air bubble. Then, he lets the snail sink slowly since snails will often lose their air bubble and sink. He found that 90% of the takes were on the descent. The Sparkle Snail was discussed by Gary Borger in 2011 using weight to submerge the fly. There is also a reference to Donovan Lynch of the Cowichan Fly Fishers in Vancouver Island designing the pattern. The pattern is quite popular throughout British Columbia. Weight was added both by a wire ribbing and leadfree wire. Peacock Herl is often used for the body, 6-7 strands of Peacock are necessary to build up the bulk. The ribbing is important when using the Peacock herl to reinforce the body. The pattern is very similar to Ralph Cutters Floating Snail but it has an Aft hackle as well as the heavier weight. Take a look at the Sheep Creek Special, that was derived from a Fore and Aft pattern as well, in which the late Jon Baiocchi tied his version of a snail pattern as well using Krystal Chenille.