Effects of plant volatiles on electrophysiological and behavioral responses of Cryptorrhynchus lapathi

Electroantennogram (EAG), Y-tube olfactometer, and wind tunnel bioassays were conducted to test the electrophysiological and behavioral responses of Cryptorrhynchus lapathi L. (Coleoptera: Curculionidae) to six individual volatiles and seven essential oils (compounded volatiles). The aim of this study was to select effective plant compounds that can be used in the development of semiochemical-based push-pull methods for the control of this harmful insect. Male and female C. lapathi displayed strong EAG responses to linoleic acid, alpha-pinene, (Z)-3-hexen-1-ol, geraniol, turpentine oil, and salicylaldehyde. Y-tube olfactometer assays indicated that salicylaldehyde and alpha-pinene elicited strong repellent effects on female C. lapathi. Linoleic acid and (Z)-3-hexen-1-ol showed greater luring effects on male and female C. lapathi compared with the control. Turpentine oil was stronger repellent, and geraniol showed stronger luring effects on male C. lapathi than the control. Wind tunnel assays with both male and female C. lapathi indicated that salicylaldehyde, alpha-pinene, and turpentine oil elicited repellent effects compared with the control. Linoleic acid, (Z)-3-hexen-1-ol, and geraniol were stronger lures of both male and female C. lapathi than the control. These results provide a basis for the further development of C. lapathi luring and repellent agents.