Submitted to: Journal of Agricultural and Urban Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/3/1996
Publication Date: N/A
Interpretive Summary: Since 1977, the beet armyworm has become a chronic and often very serious pest of cotton and other crops throughout the southern U.S. In 1995, the beet armyworm was credited with causing almost $150 million dollars in losses to cotton producers in the Rio Grande Valley of Texas. Scientists at the Insect Attractants, Behavior, and Basic Biology Research Laboratory, Gainesville, Florida, are developing biological methods to mitigate problems with secondary pests such as the beet armyworm using mating disruption technology combined with other tactics. In 1994, two cotton fields, each ca. 35 acres, were treated with beet armyworm sex pheromone. The pheromone treatment completely suppressed mating for >100 days and significantly reduced larval infestations on cotton. Although the pheromone-treated fields were separated from the control field, the distances were minimal. The results demonstrate that mating disruption, a nontoxic and environmentally benign technology, can be used to protect cotton from a strong flyer like the beet armyworm, even in relatively small fields with little isolation. Mating disruption technology can be integrated into IPM programs using a variety of unobtrusive tactics including conservation and management of natural enemies and the use of biological pesticides such as Bacillus thuringensis to manage beet armyworm in cotton and other crops.
Technical Abstract: Two cotton fields of 14.1 and 15 ha, respectively, received a single treatment of Shin-Etsu 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 (BAW), Spodoptera exigua (Hubner). The rope dispensers, each containing 160 mg of total pheromone blend, were applied at the rate of 1,000 units per ha when the cotton was in the 8-leaf stage. The pheromone treatments completely suppressed trap captures of male BAW moths and mating by sentinel female moths for >100 days. BAW egg masses and larvae also were significantly reduced in the pheromone-treated fields compared to the control field. Although the pheromone-treated fields were separated from the control area, the distances were minimal (0.2 and 4 km, respectively). These results demonstrate pheromone can be used to protect cotton from a strong flying insect like the BAW, even in relatively small fields.