Submitted to: Journal of Applied Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 6, 2005
Publication Date: January 1, 2006
Citation: Dickens, J.C. 2006. Sexual response to plant volatiles moderates aggregation pheromone in colorado potato beetle.. Journal of Applied Entomology. 130(1):26-31. Interpretive Summary: The Colorado potato beetle (CPB) is a serious pest of potato and related crops such as eggplant and tomato. Alternative methods for management of CPB are desperately needed as it has evolved resistance to over 25 pesticides and other control measures. Attractants offer an alternative to pesticides and could be used to disrupt mate finding or host utilization, to survey populations for timing of insecticide applications, or to enhance the activity and specificity of a pesticide. Combinations of host plant volatiles attractive to CPB and a male-produced aggregation pheromone have been identified and are available for use. I report that the combination of the pheromone + plant attractant is preferred by both sexes over the pheromone or plant attractant alone. Male CPB orient to plant attractants in laboratory studies while females show no preference; the presence of these plant attractants determines responses of male and female beetles to the aggregation pheromone. Based on these results, combinations of pheromone + plant volatiles may be the most efficacious for survey and management of CPB in the field. These results will be useful to ecologists, and chemists, and to applied entomologists seeking new strategies to control CPB using attractants.
Technical Abstract: Orientation of the Colorado potato beetle, Leptinotarsa decemlineata, to a male-produced aggregation pheromone, (S)-CPB I, a three component plant attractant blend comprised of (Z)-3-hexenyl acetate + (+)-linalool + methyl salicylate, and potato volatiles nonanal and 2-phenylethanol active in coupled gas chromatography/electroantennogram experiments, were tested. Both the three component plant attractant blend and 2-phenylethanol were attractive to adult beetles. While male beetles oriented preferentially to both plant attractants versus a control, females showed little preference. Combining the plant attractants with the pheromone resulted in sexually-dimorphic responses similar to those seen with either plant attractant alone. Nonanal abolished the sexually-dimorphic response to the pheromone + 2-phenylethanol blend. In both laboratory bioassays and field experiments, a combination of the pheromone + the three-component plant attractant were preferred over the plant attractant alone. Thus, it seems likely that combinations of pheromone + plant volatiles may be the most efficacious for field use.