The killer bees scheme is a fear based scheme which is not used a lot anymore. Like all fear based schemes, they loose their impact after a while since humans become numb for a specific fear after a while. They even get num for all fears after a long time and the level of scares have to be constantly increased, usually going all the way to war. Fears can best be used in a combinational style, like aids therapy. The combined effect can be more powerful than the independent fears.