In late winter each year the Orvis and Dan Bailey catalogs arrive in the mail. They both have gorgeous full color pages of pictures of flies of all descriptions. I carefully scan all the creations designed to fool our piscatorial friends.
On the pages of the Orvis catalog I found photos of bead head caddie pupa and larva flies. Being especially fond of caddie ties, my initial response was, "who dreamed up that dumb idea?" Upon arriving in southwestern Montana for some early spring nymphing for trout, I discovered the "hot" new fly was that dumb bead head caddie larva. Skeptically tying up a few, I conducted my own on-stream experiment. To my surprise and pleasure, the bead heads do indeed work very effectively. In fact they consistently out-performed my standard wet caddie ties.
Being somewhat adventurous, I decided to see what effect a brass bead head would have on my other favorite wet flies: leeches, wooly buggers and serendipities. Again, very positive results.
Why do bead headed flies attract trout? I don't know, but I have an educated guess. In recent years, flies tied with various types of glitter and flash materials have become very popular. Apparently the trout have approved, as well. I think the bead heads are just another form of flash. The subtle glint under water gets the attention of the fish. In the case of caddie pupa, there possibly is a specific reason the bead heads work. Fly tiers have attempted for decades to imitate that "spot of light" given off by emerging caddie pupa. Perhaps the reflective quality of the beads imitate the "spot of light" better than most other tying materials.
Some purists will sniff that the bead heads are not really imitative flies, but only attractors. Probably so, but since most flies are also attractors I gladly accept any new effective fly tying idea. No complicated tying techniques are required. Simply slip a brass bead over the hook point and onto the shank. It will seat securely against the eye of the hook as the regular fly body is tied on behind it.
I use four sizes of brass beads: 3/32 for the heads of small nymphs, such as serendipities; 4/32 for size 10 and 12 caddie larva and pupa; size 5/32 for leech ties and 3/16 for wooly buggers. The brass beads are available from craft and hobby stores. Presumably, fly shops will add them to their supplies. Silver beads will probably be available also.
I normally do not weight my nymph flies, preferring to add any needed weight to the leader. The beads add just enough weight for proper dead drifting the flies in moderate flows. In heavy water, additional lead may be needed on the leader. The slight weight on the head of leeches and wooly buggers allows an up and down undulating action on the retrieve.
I doff my fishing hat to the tier "who dreamed up that dumb idea." I fully expect additional bead head flies to be commercially available in the future. It may not be the ultimate development in fly tying evolution, but it is a simple, creative idea. Some of us need all the help we can get.