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

Colorado potato beetle [Leptinotarsa decemlineata (Say); Coleoptera: Chrysomelidae] is a widespread key pest of potatoes and other solanaceous 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 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 attractive to male beetles, whereas the male-produced pheromone is attractive to both females and males. Male attraction increased with higher densities of females on bait plants, but female attraction did not change with female density on bait plants.

This is the first study to demonstrate male attraction to the female sex pheromone in the field, and to our knowledge, the first to demonstrate 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-, as well as plant-produced volatiles as important tools for pest manipulation in potato integrated pest management. Published 2021. This article is a U.S. Government work and is in the public domain in the USA.