Technical Abstract: A summary is presented of 30 years of extensive research on semiochemicals as they affect the boll weevil, Anthonomus grandis Boheman, in cotton. Traps and the pheromone, grandlure, in particular have greatly extended our knowledge of the behavior of this leader of economically important field crop insects and will be one of the key factors in eliminating this insect from the United States in the 21st century.