Both male and female-produced pheromones influence Colorado potato movement in the field

Authors: Haber, Ariela; Weber, Donald

Submitted to: Pest Management Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/22/2021
Publication Date: 12/12/2021
Citation: Haber, A.I., Weber, D.C. 2021. Both male and female-produced pheromones influence Colorado potato movement in the field. Pest Management Science. https://doi.org/10.1002/ps.6739.
DOI: https://doi.org/10.1002/ps.6739

Interpretive Summary: Colorado potato beetle (CPB) is a key pest of potato in the Northern Hemisphere, infamous for its evolution of resistance to pesticides with many modes of action. Detailed knowledge of the pheromones of this pest could serve to monitor its populations as well as to manipulate the beetles' behavior as a component of potato integrated pest management. But knowledge of CPB pheromones is incomplete. In this study, we evaluated the response of male and female beetles to caged "bait plants" with groups of male-only and female-only adult beetles, larvae, and uninfested plants in the field in Maryland, USA. Male bait plants attracted both female and male adults, as expected based on the known male-produced aggregation pheromone. We discovered that female bait plants attract male beetles just as strongly, and that this effect increases with number of females on bait plants. Results demonstrate that CPB females produce a sex pheromone that attracts males from a distance. The findings indicate the importance of both female- and male-produced pheromones in the behavior of CPB in the field, and the potential for their use as management tools for this key pest. Results should be of interest to pheromone and potato researchers and pest managers.

Technical Abstract: Colorado potato beetle (Leptinotarsa decemlineata; Coleoptera: Chrysomelidae) is a widespread key pest of potatoes and other nightshade crops of the temperate northern hemisphere. Its evolution of multiple pesticide resistance is a continuing threat if chemical control is relied upon for pest management. An integrated approach including semiochemicals and other non-pesticidal tactics is essential to sustainable management. In addition to the known volatile aggregation pheromone produced by male adult beetles that is attractive to both females and males, there is also a yet-unidentified female-produced sex pheromone. Using caged "bait plants" in the field in Maryland, USA, we tested the attraction of male and female beetles to groups of male-only, female-only, larvae, and uninfested bait plants. Results of five field experiments demonstrate that the female-produced sex pheromone is as attractive to male beetles as is the male-produced aggregation pheromone, yet it is not at all attractive to females. To our knowledge this is the first demonstrated instance of a beetle species using bidirectional communication between males and females. Use of semiochemicals for monitoring and management of Colorado potato beetle should consider male-, female-, and plant-produced volatiles as important tools for pest manipulation in potato IPM.