Looplure,cis-7-dodecenyl acetate, is the sex pheromone ofTrichoplusia ni, (Hübner) and hexalure,cis-7-hexadecenyl acetate, is an attractant for males ofPectinophora gossypiella(Saunders). Quantitative field experiments were conducted to evaluate looplure, hexalure, and 9 related compounds, as agents for the disruption of sex pheromone communication inT. niandP. gossypiella. Communication in each species was disrupted to a small degree by a number of the related compounds. However, looplure and hexalure were most active forT. niandP. gossypiella, respectively. Thus, the related compounds appear to have little potential for behavioral control of these 2 species.