Toxicity and Repellency of the Volatile Oils from Aloysia polystachya Against Rhipibruchus picturatus (Coleoptera: Bruchinae)

Abstract

The seed beetle Rhipibruchus picturatus (Coleoptera: Bruchinae) causes substantial losses during the storage of seedpods from Prosopis alba Griseb., Fabaceae. The use of volatile oils is a key strategy to develop new pest control management programs because they are efficient, less toxic, and less persistent in the environment than synthetic pesticides. In this sense, the volatile oils from leaves of Aloysia polystachya (Griseb.) Moldenke, Verbenaceae, were studied in the present work. Carvone and limonene were their main constituents. The volatile oil, carvone, and limonene exhibited potent insecticidal activity against R. picturatus. Additionally, the pure compounds and the volatile oils produced repellent behavior in insects and inhibited acetylcholinesterase in vitro assays. The data obtained demonstrate the potential of volatile oils from A. polystachya for the future development of new storage pest control strategies.