title: Habituation inFrankliniella occidentalisto deterrent plant compounds and their blends.
abstract: Feeding and oviposition deterrence of three secondary plant compounds and their 1:1 blends to adult femaleFrankliniella occidentalisPergande (Thysanoptera: Thripidae) and the potential for habituation of the thrips to the pure compounds and the 1:1 blends at various concentrations were investigated. In choice assays, we tested dose-dependent feeding and oviposition deterrence of the two fatty acid derivatives methyl jasmonate andcis-jasmone, the phenylpropanoid allylanisole, and their blends when directly applied to bean leaf discs. The concentration required to reduce the feeding damage by 50% relative to the control treatment (FDC50) was lowest forcis-jasmone and highest for allylanisole. The feeding deterrent effect of both jasmonates was increased when blended with allylanisole. Feeding deterrence and oviposition deterrence were strongly correlated. In no-choice assays conducted over four consecutive days, we discovered that dilutions at low concentrations (FDC15) applied to bean leaves resulted in habituation to the deterrents, whereas no habituation occurred at higher concentrations (FDC50). We observed a tendency that the 1:1 blends reduce the probability that thrips habituate to the deterrent compounds. Our results may be useful in the development of integrated crop protection strategies with the implementation of allelochemicals as pest behaviour-modifying agents.
authors.affiliation: Division of Crop Protection Department of Crop Sciences University of Natural Resources and Life Sciences (BOKU) Peter-Jordan-Straße 82 1190 Vienna Austria.
authors.forename: Barbara
authors.initials: B
authors.lastname: Egger
authors.affiliation: Institute of Applied Statistics and Computing (IASC) Department of Landscape, Spatial and Infrastructure Sciences University of Natural Resources and Life Sciences (BOKU) Peter-Jordan-Straße 82 1190 Vienna Austria.
authors.forename: Bernhard
authors.initials: B
authors.lastname: Spangl
authors.affiliation: Division of Crop Protection Department of Crop Sciences University of Natural Resources and Life Sciences (BOKU) Peter-Jordan-Straße 82 1190 Vienna Austria.
authors.forename: Elisabeth Helene
authors.initials: EH
authors.lastname: Koschier
keywords: Thripidae; Thysanoptera; Western flower thrips; allylanisole; cis‐jasmone; feeding deterrence; methyl jasmonate; secondary plant compound