Most fly fishermen agree that the use of bead head flies originated in Europe in the early 1980′s. Several innovative tyers added beads to the heads of their flies for extra flash and to give their nymphs extra weight to sink them deep in swift currents. These flies were so successful that word of their effectiveness spread like wildfire and within a very short time fly tyers world wide began modifying existing patterns and designing new ones utilizing beads. Bead head flies became popular in the U.S. for many reasons:
In heavily fished waters the extra weight of the bead head will sink a small fly deeper than it could have been fished previously. As a result, nymph fisherman started using smaller and smaller flies and began catching more fish than before.
The added flash from the bead often attracts trout, especially those that have been stocked in public water.
The extra weight of the bead reduces the need for split shot on the leader: thus it is easier to cast with fewer tangles.
Many bead head flies are very simple in design so they are fast and inexpensive to tie.
The advent of tungsten beads made it possible for fly fishers to sink even tiny flies down deep.