My history with the emerald caddis pupa is explained in a 01/01/2012 post, so I will not repeat it here. In short I began using it with success in Pennsylvania, and its effectiveness translated to Colorado and western rivers. Besides being an effective imitation of various caddis species, I suggest that the emerald color is a significant triggering characteristic that attracts fish during times of the year when a specific matching caddis species is not present in significant quantities.
The style of fly is copied from Gary LaFontaine’s emergent caddis pupa, which is described in Caddisflies. As Gary prepared to write his book, he performed dives in Montana rivers so he could observe the behavior of caddis as they emerged and moved through their life cycle. He was dissatisfied with the many patterns in existence at that time, and he sought improvements. During his dives he identified a significant triggering characteristic and then searched through many materials until he found a solution. He discovered that caddis pupa surrounded themselves with a bright air bubble as they swam from the stream bottom to the surface to quickly pop free and emerge into the adult stage. He was certain that imitating this glittering air bubble would lead to a caddis wet fly imitation with improved effectiveness.
After much trial and error he stumbled on to a material called antron yarn. This fabric was used in the manufacture of carpeting, and during his experiments, he noticed that it created the illusion of an air bubble similar to natural emerging caddis. With this discovery he designed caddis subsurface patterns that used antron yarn which also was known as sparkle yarn. The critical element of the LaFontaine caddis pupa is the sheath that surrounds the abdomen, and this body component is comprised of antron yarn tied in at the bend and then folded forward to create a shroud above and below the body. Since LaFontaine’s ground breaking book, many tiers have created alternative flies and a vast number of variations, but the original design continues to catch fish and has served me well over many years. I plan to continue fishing with a proven winner that is fairly simple and straightforward to produce.
For some reason I did not seem to fish caddis pupa as frequently in 2015 as in previous seasons, and consequently I counted twenty-five in my boat box and bins. Since I established a target beginning inventory of thirty, I only needed to tie five to reach my goal. I cranked these out yesterday, and I am prepared for caddis situations in 2016. One reason for less caddis pupa usage was fewer trips to the Arkansas River during the early part of April. I also suspect that I defaulted to the ultra zug bug in many situations where I may have previously resorted to an emergent caddis pupa.