Cinnamyl alcohol: An attractant of the flower thrips Frankliniella intonsa

Flower-inhabiting thrips find hosts using olfactory and visual cues. In this study, we report the identification of a plant-produced attractant of the flower thrips Frankliniella intonsa (Trybom), an important agricultural pest worldwide. GC–MS analysis of solid-phase microextraction samples from blueberry flowers, Vaccinium corymbosum L., that mediate the attraction of adult F. intonsa revealed that the major component was cinnamyl alcohol, followed by cinnamyl acetate, cinnamaldehyde, germacrene D, β-bourbonene, β-caryophyllene, and benzyl benzoate. The biological activity of the floral compounds was investigated using commercial cinnamaldehyde, cinnamyl alcohol, β-caryophyllene, cinnamyl acetate, and benzyl benzoate in hot pepper (Capsicum annuum L.) fields. Significantly more F. intonsa males and females were caught in red delta traps with cinnamyl alcohol than in all other traps. Cinnamaldehyde and cinnamyl acetate attracted adult F. intonsa but were not as attractive as cinnamyl alcohol. β-Caryophyllene and benzyl benzoate were not attractive. Furthermore, the addition of four minor components to cinnamyl alcohol did not result in increased trap catches relative to cinnamyl alcohol alone, indicating that cinnamyl alcohol is responsible for attracting adult F. intonsa toward blueberry flowers. Therefore, this phenylpropanoid could be used as an effective lure for monitoring and controlling F. intonsa.