Electrophysiological and laboratory behavioral responses of a leaf beetle pest of elm, Ambrostoma quadriimpressum, to selected plant volatiles and essential oils

Abstract

The leaf beetle Ambrostoma quadriimpressum Motschulsky (Coleoptera: Chrysomelidae) is distributed in China, Siberia, and elsewhere in northeastern Asia. This pest feeds only on buds and leaves of elm trees (Ulmaceae) and inhibits elm trees sprouting, increasing the risk of damage and destruction by other pests. We investigated selected plant compounds that could be used for the development of semiochemical‐based push‐pull methods for the control of this elm pest. Electroantennogram (EAG), Y‐tube olfactometer, and wind tunnel bioassays were conducted to test the electrophysiological and behavioral response of A. quadriimpressum to nine individual volatiles and five essential oils. Individual volatiles and essential oils were selected based on their activity against insects in previous studies. The individual volatiles and essential oils were dissolved in dichloromethane and adsorbed by filter paper. Using a pipette, odor stimuli were delivered as 0.5‐s puffs of air into a continuously humidified air stream in the odor delivery tube at 400 ml per min. Ambrostoma quadriimpressum adults display strong EAG responses to l mol l−1 isoeugenol, (1R)‐(+)‐α‐pinene, 1% pepper oil (derived from the pericarp of Piper chinense Miq.), and peppermint oil [derived from the aerial parts of Mentha haplocalyx (Briq.)] compared to the control. In behavioral assays conducted using a Y‐tube olfactometer and a wind tunnel, adult beetles were attracted by (1R)‐(+)‐α‐pinene but repelled by 0.1% pepper oil. The results provide a basis for the development of a ‘push‐pull’ strategy to manage A. quadriimpressum.