Suppression of mating by beet armyworm (Noctuidae: Lepidoptera) in cotton with pheromone

Two cotton fields of 14.1 and 15 ha, respectively, received a single treatment of Yoto-con-S(R) twist-tie rope dispensers containing a 70:30 blend of (Z,E)-9,12-tetradecadien-1-ol acetate and (Z)-9-tetradecen-1-ol acetate, two components of the sex pheromone of the female beet armyworm, Spodoptera exigua (Hubner). The rope dispensers, each containing 160 mg of total pheromone blend, were applied at the rate of 1,000 units/ha when the cotton was in the 8-10 leaf stage. The pheromone treatments suppressed trap captures of male beet armyworm moths and mating by sentinel female moths for >100 d. On average, fewer beet armyworm egg masses (57%) and larvae (95%) were recorded in the pheromone-treated fields compared with the control field. These results suggest that pheromone can be used to protect cotton from a strong flying insect like beet armyworm, even in relatively small fields.